X. OPERATIONS UPON THE LACHRYMAL APPARATUS
Operations upon the lachrymal apparatus are divided into--
I. Operations upon the lachrymal canals. II. Operations upon the lachrymal gland.
The majority of operations are undertaken for the relief of obstruction to some portion of the canal which leads from the conjunctival sac to the nose, obstruction to which causes an overflow of tears (epiphora)--a condition which must be distinguished from hypersecretion (lachrymation).
The obstruction may occur in any part of the canal, that is to say, in the puncta, canaliculi, lachrymal sac or duct; and it is most important to determine the cause and position of the obstruction in every case before undertaking an operation for its relief. Hence it need hardly be said that the nose should be carefully examined in every case unless the cause is obvious. The operations are divided into two classes:--
1. Those which are undertaken for the relief of the obstruction.
2. Those which are undertaken for the obliteration of the canals.
Except under exceptional circumstances, the latter operations are only undertaken when a cure cannot be brought about by the former.
The presence of a septic focus, such as a distended lachrymal sac, apart from the irritation and increased lachrymal secretion caused thereby, is a source of grave danger to the eye if not relieved, as it is a frequent cause of serpiginous corneal ulceration.
OPERATIONS FOR THE RELIEF OF LACHRYMAL OBSTRUCTION
DILATATION OF THE CANALICULUS
=Indications.= (i) Contraction of the puncta following marginal blepharitis, especially when associated with ectropion.
(ii) Preparatory to syringing or probing.
(iii) To dilate a stricture of the canaliculus.
=Instruments.= Nettleship’s canaliculus dilator (Fig. 163).
=Operation.= The operation is performed under adrenalin and cocaine, a little solid cocaine being rubbed in over the canaliculus.
The lid is slightly everted and put on the stretch by pulling it downwards and outwards with the thumb. The depression caused by the punctum is seen on the top of a small elevation. The point of the dilator is entered vertically into the punctum and then turned parallel with the lid margin and passed onwards with a steady pressure. At the same time it should be rotated between the finger and thumb, until the inner bony wall of the lachrymal sac is felt. The only difficulty which may be experienced is in entering the dilator into the punctum, owing to the small size of the latter. For this reason the fine point of Nettleship’s dilator is more suitable than the form modified by Lang. Even Nettleship’s dilator is too large in a few cases, and here a large sharp-pointed pin is sometimes of use in defining the punctum before using Nettleship’s dilator.
SLITTING THE CANALICULUS
=Indications.= To enlarge the punctum and direct the entrance to the canaliculus inwards. This is especially desirable before ectropion operations and for the removal of concretions (leptothrix) from the duct. In former days the canaliculus used to be slit with the idea of passing very large probes down the lachrymal duct; this has now been abandoned, since slitting the canaliculus throughout its whole length, as is required for this treatment, does away with the capillary attraction.
=Instruments.= Dilator, canaliculus knife (Fig. 164), straight iris forceps, sharp-pointed scissors.
=Operation.= It is usually performed on the lower canaliculus. The eye is cocainized as in the previous operation and the patient is made to look up.
First step. The canaliculus is first dilated. The knife is inserted for a short distance with the handle parallel to the lid margin. The lower lid being held on the stretch by the thumb, the handle of the knife is raised towards the brow, thus dividing the canaliculus. The blade of the knife should be directed upwards and slightly backwards.
Second step. As the lips of the wound are liable to reunite, it is better to remove the posterior lip of the groove. This is performed by seizing the latter with forceps and dividing it with scissors. The entrance to the canaliculus should be kept open by means of the dilator passed twice a week for a month.
SYRINGING THE LACHRYMAL DUCT
=Indications.= (i) To test whether the lachrymal canals are patent.
(ii) By constantly cleansing the sac and washing away all purulent discharge the mucous membrane may regain a more healthy condition, and so an obstruction due to an alteration in the mucous lining may be relieved. In cases with a purulent discharge a small quantity of protargol (10% solution) may be left in the sac after syringing.
(iii) The injection of adrenalin and cocaine into the sac before its excision.
=Operation.= The eye is cocainized and the patient made to look up. The punctum is everted by pulling down the lower lid. The canaliculus is then dilated. The nozzle of the lachrymal syringe (Fig. 165) should be passed until it is felt to impinge on the bony outer wall of the sac. Withdraw the syringe slightly and apply gentle pressure to the piston. The fluid will either regurgitate through the upper canaliculus or, if the duct be patent, pass down into the nose and so into the throat.
=Complications.= If too forcible syringing be used extravasation of the fluid may take place. This is accompanied by pain and swelling in the lachrymal region. It usually subsides under hot fomentations, but suppuration and even cellulitis of the orbit have been known to occur.
PROBING THE LACHRYMAL DUCT
=Indications.= (i) In cases of congenital lachrymal obstruction due to débris blocking the duct.
(ii) When syringing has failed to bring about a cure, a probe may be passed once or twice to see if dilatation causes any improvement. It is especially useful in children.
(iii) As a preliminary to the insertion of styles.
Various forms of probes are employed, those of Bowman being in general use. Too fine a probe should not be used, otherwise a false passage is liable to be made.
=Operation.= This is performed under adrenalin and cocaine, which should be injected into the lachrymal sac.
The lower punctum is dilated and the probe passed parallel to the lid margin until it is felt to impinge upon the lachrymal bone. Keeping the point applied to the bone, the handle of the probe is rotated upwards through rather more than a quarter of a circle and passed by a gentle pressure downwards and slightly outwards into the duct, keeping the point of the probe close to the bone the whole way. The direction of the probe after entering the duct should be downwards, outwards, and backwards in the direction of the first molar tooth on the same side. The backward direction of the duct is much more marked in young children than in adults.
=Complications.= A false passage may be made into the antrum of Highmore. If such an accident should occur, no further attempt should be made to pass a probe for a few days until the wound has healed.
THE INSERTION OF STYLES
A few surgeons still insert styles into the lachrymal duct with the idea of continuous dilatation. The hollow styles used by Bickerton are the ones most frequently employed.
=Instruments= for dilating, slitting the canaliculus, probing, and styles. Also Stilling’s knife.
=Operation.= A general anæsthetic is desirable.
First step. The canaliculus is dilated and slit up, the posterior lip being removed (see p. 29).
Second step. The duct is dilated by probing (vide supra) or enlarged by passing Stilling’s knife down it.
Third step. A style is passed down the dilated duct. The lower end of the style should rest upon the floor of the nose, otherwise there is a tendency for the style to slip into the duct and disappear. Care should be taken that the upper end does not rub on the globe. Styles should generally be left in position from three to six months. A style should at first be made of lead wire and moulded until a suitable pattern is obtained, from which a hollow gold style can be made subsequently.
=Complications.= 1. Dacrocystitis may follow the insertion of a style, which should then be removed until the inflammation has subsided.
2. The style may slip down the duct. If this should occur an attempt should be made to grasp it through the slit canaliculus. The lower end may present in the nose and the style can then be withdrawn with forceps. Occasionally styles lodge in the antrum of Highmore, in which case they must be removed after localization by the X-rays through an opening from the mouth above the canine tooth.
OPERATIONS FOR THE OBLITERATION OF THE CANALS
When syringing and probing have failed to relieve the lachrymal obstruction, one of the following operations for the obliteration of the lachrymal passages may be employed.
OBLITERATION OF THE CANALICULI
=Indications.= In cases of lachrymal obstruction in which an immediate operation upon the globe is required.
=Operation.= Under cocaine. Fine sutures armed with a small curved needle are passed beneath both the upper and lower can[al]iculus and tied so as to include them in the ligature. Permanent obliteration may be caused by the destruction of the lining membrane with the actual cautery.
EXCISION OF THE LACHRYMAL SAC
=Indications.= (i) For mucocele in cases of lachrymal obstruction which have failed to yield to other treatment.
(ii) In all cases of tuberculous disease of the sac.
(iii) For a recurrent lachrymal abscess after subsidence of the acute inflammation.
(iv) For hypopyon ulcer associated with lachrymal obstruction.
(v) Before operation on the globe in cases of lachrymal obstruction.
(vi) For lachrymal fistula.
=Instruments.= Small scalpel, forceps, Muller’s speculum (Fig. 166), Axenfeld’s retractor (Fig. 167), straight scissors, horsehair sutures.
=Operation.= Hæmorrhage is the most troublesome part of this operation; it is best controlled by injecting adrenalin (made from the dried gland, ʒj, and ℥j of water) and cocaine, 10%, into the sac a quarter of an hour before operating. Swabs on the end of a glass rod dipped in adrenalin and cocaine may also be used during the operation. A general anæsthetic is desirable, but many surgeons perform the operation under local anæsthesia, produced by injecting 5% cocaine with 1 in 1,000 adrenalin into the tissue surrounding the sac; but the latter plan has the disadvantage that the mixture may cause severe toxic effects, and the patient usually experiences some pain while the upper portion of the incision is being made and the lower end of the sac is being divided.
First step. The internal tarsal ligament is first defined by putting the lids on the stretch. An incision should be made, 15 millimetres in length (5 millimetres of which should fall above the tarsal ligament), backwards and inwards directly over the lachrymal sac. Muller’s retractor is then inserted to retract the wound laterally, the hooks being made to engage the margins of the incision by means of forceps. The superficial fascia and the fibres of the orbicularis muscle are then divided. The internal tarsal ligament in the upper part of the wound, together with the glistening deep fascia, is exposed and divided carefully so as not to injure the lachrymal sac, which is found directly beneath it (Fig. 168).
Second step. With scissors the sac-wall is then separated from the deep fascia which encloses it, first externally and then internally, the canaliculi being divided. Axenfeld’s retractor is then inserted in the longitudinal axis of the wound (Fig. 167). The middle of the sac is grasped with forceps and pulled forward, and the top of the sac is defined and detached. This is frequently difficult owing to the troublesome hæmorrhage which often occurs. The sac is pulled well forward, and the posterior wall is separated, the neck of the sac being divided as far down the duct as possible by means of scissors. A large probe is passed down the duct into the nose. Some surgeons remove the periosteum of the lachrymal bone as well as the sac, which is unnecessary. The wound is closed by three sutures, the middle one including the divided ends of the internal tarsal ligament. A firm dressing should be applied so as to keep the walls of the cavity in contact. In tuberculous cases it is desirable to curette the lower end of the duct after removal of the sac. The stitches are removed on the seventh day.
=Complications.= These may be immediate or remote.
=Immediate.= 1. Inability to find the sac. This may happen to a beginner, and is generally due to the fact that the dissection is carried too much inwards towards the nose. It should not occur if the guides to the sac carefully borne in mind, namely, the internal tarsal ligament and, on the inner side, the lachrymal crest, which can easily be felt with the finger or forceps in the wound.
2. Opening the conjunctival sac. This may take place when dividing the canaliculi. It is more likely to occur if the deep fascia has been imperfectly divided before carrying out the dissection to the inner side. As a rule the opening heals readily.
3. Opening of the orbit, due to the division of the fascia attached to the posterior lip of the lachrymal groove. It is recognized by the fact that orbital fat presents in the wound, and for this reason it makes the operation more difficult. It is most likely to happen when the lower end of the sac is being divided. It lays the orbit open to the possibility of septic infection. The internal rectus has been divided, no doubt due to the fact that the fascia, which passes from the outer surface of this muscle, is attached to the posterior lip of the lachrymal groove, and the muscle has been thereby pulled up into the wound; with ordinary caution such an accident is impossible.
4. Injuries to the cornea. Corneal abrasions by the clumsy insertion of retractors may lead to severe corneal ulceration.
=Remote.= 1. Epiphora. Normally the lachrymal secretion is largely removed from the conjunctival sac by a process of evaporation. It is only when the hypersecretion of tears takes place that the lachrymal apparatus is called much into use. As a rule, patients who have had the lachrymal sac excised do not complain of epiphora, except in a cold wind. Occasionally this epiphora may be so troublesome that removal of the palpebral portion of the lachrymal gland is desirable for its relief. There is no fear of the conjunctival sac becoming dry after this operation, since there are numerous accessory lachrymal glands (glands of Waldeyer and Krause) opening on to the superior fornix.
2. A sinus. The wound may break down and a sinus may form at the site of the incision. These cases are nearly always of tuberculous origin and not infrequently have underlying bone trouble. They can usually be made to heal by the use of iodoform and scraping.
3. Recurrence of the mucocele or lachrymal abscess. Occasionally the mucocele may re-form, or an abscess result after removal of the sac. This is due either to a piece of sac-wall being left behind, or to the relining of the cavity with epithelium from the cut end of the duct. It is particularly liable to occur in cases of a tuberculous nature. Firm pressure with the dressings after the operation is the best method of preventing the cavity relining with epithelium. If the condition has arisen, the pseudo-sac should be excised.
OPENING A LACHRYMAL ABSCESS
=Indications.= Lachrymal abscess is due to an inflammation around the sac-wall through which infection of the cellular tissue has taken place. The abscess should not be opened until pus is present, as even considerable swelling and œdema will often subside without suppuration; this is usually about the end of the third day. Further, if the opening be made too soon, the inflammation takes considerably longer to subside.
=Instruments.= Beer’s knife, forceps, and probe.
=Operation.= Usually performed under gas. An incision is made over the lachrymal sac and is carried downwards and inwards to the bone by a single puncture of the knife. The pus is evacuated, and the cavity stuffed with gauze, which should be changed daily for the first three days. Hot fomentations should be applied. As soon as the swelling has subsided, the lachrymal obstruction should be treated by one of the methods previously described.
OPERATIONS UPON THE LACHRYMAL GLAND
REMOVAL OF THE PALPEBRAL PORTION
=Indications.= For obstinate epiphora after removal of the lachrymal sac.
=Instruments.= Fixation forceps (two pairs), two sharp hooks, strabismus scissors, suture.
=Operation.= Usually performed under adrenalin and cocaine.
First step. The upper lid is doubly everted. The eversion is best carried out by holding the singly everted lid between forceps and then re-everting it; the forceps are then given to an assistant to hold. With a syringe a few drops of 5% cocaine are injected through the conjunctiva into the area to be operated upon.
Second step. The gland is seen beneath the conjunctiva at the outer part of the upper fornix, seized with forceps, and drawn forwards. A horizontal incision is made with scissors through the conjunctiva, which is dissected backwards. The edges of the wound are then held apart by means of sharp hooks (Fig. 170).
Third step. The gland, which is seen as a nodule, is drawn forward with forceps. By means of the scissors the gland is separated from its attachments along its whole length, starting on the inner side, the wound being subsequently closed with a few points of catgut suture.
REMOVAL OF THE ORBITAL PORTION
=Indications.= It is usually undertaken for tumours (endotheliomata, &c.) and retention cysts.
=Instruments.= Knife, artery and dissecting forceps, retractors, ligatures.
=Operation.= Performed under a general anæsthetic.
First step. An incision, three inches long, is made through the skin immediately below the outer third of the orbital margin. The underlying orbicularis palpebrarum is divided, and the orbital fascia covering the gland is defined and incised.
Second step. The gland is first separated from the periosteum of the depression in the bone in which it lies, and is drawn forward and carefully dissected out from the lid. The wound is then closed with sutures.
=An abscess in the lachrymal gland= should be opened by an incision similar to, but not so long as that in the above operation.
OPERATIONS UPON THE ORBIT
EXPLORATION OF THE ORBIT (KRÖNLEIN’S METHOD)
In this operation the bony outer wall of the orbit is divided above and below, and turned outwards so as to expose the orbital contents without interfering with the globe; the bony wall, being kept attached to the overlying tissue, can be replaced subsequently without fear of necrosis.
=Indications.= The operation is performed in cases of a suspected tumour of the orbit, which, if small and non-malignant, can be removed, the eye being left in situ. If doubt exists as to the nature of the tumour a piece can be removed and examined microscopically, either at the time of the operation or later. It is especially suitable for tumours of the optic nerve and for orbital cysts behind the globe.
=Instruments.= Scalpel, dissecting forceps, artery forceps, scissors, periosteum detacher, chisel and hammer, or preferably, a motor rotary saw, and retractors.
=Operation.= Performed under a general anæsthetic.
First step. A slightly curved incision with the convexity forwards is made so as to expose the outer margin of the orbit and carried down to the bone. The periosteum is separated from the inner surface of the outer wall of the orbit by means of a periosteum detacher and divided horizontally, the finger is inserted, and the orbit explored. If a small tumour or cyst be found it can sometimes be shelled out through this incision without enlarging the wound further.
Second step. The eye and orbital contents are carefully protected with a large flat retractor. The bone is first divided above, by means of either a chisel or a saw. The upper incision should pass through the base of the external angular process of the frontal bone, and run backwards and slightly downwards to the posterior end of the spheno-maxillary fissure. The lower incision should run directly backwards from the lower orbital margin into the spheno-maxillary fissure. The triangular wedge of bone attached by its outer surface to the soft tissues in the temporal fossa is then forced outwards. In doing this care must be taken not to fracture the orbital wall anteriorly, otherwise the space to work in will be much reduced.
Third step. Consists in the removal of the tumour. Care must be taken to displace the external rectus to one side so as to avoid injury to it as much as possible. If the case should be one of an optic nerve tumour, for which the operation is most frequently performed, the optic nerve is divided close behind the globe. The tumour is freed from the surrounding ciliary nerves and the ophthalmic artery and brought up into the wound as much as possible. The optic nerve is then divided at the apex of the orbit and the tumour removed. The wound in the periosteum of the outer wall of the orbit is closed with a catgut suture, the bone, together with the soft parts, replaced in position and the skin wound closed by sutures. A drainage tube should be inserted for at least twenty-four hours.
=Complications.= 1. Proptosis. The operation is liable to be followed by great proptosis as the result of hæmorrhage into the orbit. If the optic nerve has been removed, the globe may be dislocated forwards between the lids and come in contact with the dressings.
2. Corneal ulceration. As the cornea is frequently anæsthetic from division of the ciliary nerves, ulceration is very liable to follow. It is, therefore, desirable in many cases to stitch the lids together after closing the skin wound.
3. Defective outward movement in the globe is of frequent occurrence, owing either to injury of the external rectus or the sixth nerve, or to involvement of them in the scar tissue. Stitching the periosteum together obviates the latter to a certain extent.
4. As the wound cicatrizes a certain amount of enophthalmos is very liable to result.
EVISCERATION OF THE ORBIT
=Indications.= This operation is usually performed for some form of new growth originating either in the eye or the orbit.
=Operation.= This may be modified (1) according to the position of the growth. In severe cases of rodent ulcer and sarcomatous growths, which involve the lids, it is desirable that the lids should be removed with the tumour; but in cases of tumour of the optic nerve, or disease situated far back in the orbit, and not involving the lids or conjunctiva, these structures may be retained, since a much better socket is thus obtained. (2) The nature of the growth. In simple tumours, such as nævi and some cases of arterio-venous aneurism which have failed to yield to other treatment, the incomplete method, in which the lids are retained, is all that is necessary, but in malignant cases they should be removed.
The Complete Method. An incision down to the bone is first made, completely encircling the orbital margin and including any growth that may be involving the skin. The periosteum is then separated completely, as near to the optic foramen as possible. Care must be taken in dealing with the periosteum over the lachrymal bone, as the bone is liable to be fractured and an opening made into the nose if undue force be used. The apex of the cone formed by the periosteum is divided, as far back as possible, with curved scissors, and the whole orbital contents are removed. The wound is packed with gauze, and skin-grafting is subsequently performed when the bone has become covered with granulations; this usually occurs about the end of the second week.
The Incomplete Method. The globe is first enucleated and the outer canthus divided. The lids are well retracted and an incision is carried down to the bone along the orbital margins. The periosteum is then stripped up from the walls of the orbit and the apex of the cone divided as far back as possible, as in the previous operation. The conjunctiva and outer canthus are then united with sutures. As a rule, skin-grafting is not necessary after this operation.
OPENING AN ORBITAL ABSCESS
Orbital abscesses should be incised where they point. In the upper lid care should be taken not to divide the levator palpebræ muscle; the incision should be placed well to one side. In making an incision over the inner side of the orbit care should be taken not to detach the pulley of the superior oblique. The cause of the abscess should be ascertained if possible. Suppuration in the ethmoidal sinuses coming through from the nose is the commonest cause, and should be treated appropriately (see Section V).
SECTION III
OPERATIONS UPON THE EAR
BY HUNTER F. TOD, M.A., M.D. (Cantab.), F.R.C.S. (Eng.) Aural Surgeon to the London Hospital
Chapter I
EXAMINATION OF THE EAR: GENERAL CONSIDERATIONS WITH REGARD TO OPERATIONS
In order to perform successfully the various operations upon the ear, it is essential that the surgeon should be familiar with the technique of its examination, which, for the sake of convenience, will first be briefly described.
EXAMINATION OF THE EAR
For this purpose it is necessary to make use of certain instruments in order to obtain a clear view of the deeper parts of the auditory canal and tympanic membrane. Most important amongst these are the following:--
=Mirror.= A head-mirror, such as the ordinary laryngological mirror with a focus of eight inches, is to be preferred to the hand-mirror, as it leaves both hands free for manipulation.
=Sources of illumination.= Although the light reflected from the sky on a bright cloudless day is excellent, it can seldom be made use of, and so for practical purposes the source of light is usually artificial. It is wiser always to use the same kind of light--for instance, electric--as in this way a more accurate comparison can be made of the various pathological conditions seen on examination. In the consulting room, the lamp recommended by Dr. Greville Macdonald, furnished either with a thirty-two candle-power frosted burner or with a Nernst light, is most suitable. As a portable lamp, it is useful to have an electric bull’s-eye lamp, run off from a dry-celled battery: it can be held in the position of the ordinary lamp, the light being reflected into the ear by means of the head mirror. The ordinary surgical head-lamp, although not well adapted for inspection of the deeper parts of the auditory canal, is eminently suited for obtaining good illumination during the performance of the mastoid operations; or in its stead a head-mirror with lamp attached may be used, as recommended by Clar (Fig. 171).
=Aural specula.= Of the various aural specula employed, Gruber’s is very good (Fig. 172). A special speculum in which a portion has been removed from the narrow end is sometimes useful in order to facilitate operative procedures within the external meatus.
=Forceps.= The best are angular spring forceps with bulbous points (Fig. 173).
=Position of the patient.= The patient should sit upright in a chair with the side to be examined turned towards the surgeon. To prevent movement, the head should be supported by an assistant or by a head-rest fixed to the back of the chair. The lamp is placed a little behind and to the left of the patient’s head, on a level with the head of the examiner.
=Technique of examination.= To convert the external meatus into a straight canal, the auricle has to be pulled backwards and downwards in an infant, backwards in a child, and backwards and upwards in an adult. The speculum should be warmed and inserted gently into the meatus by the thumb and index-finger of the left hand, whilst the pinna is held between and pulled back by the second and third fingers (Fig. 174). This leaves the right hand free for manipulation. The largest possible speculum should be used, in order to give the maximum amount of room and illumination. It should only be introduced into the meatus as far as the adaptable cartilaginous portion permits--about half an inch in the adult--and not forced into the bony portion. The utmost gentleness is essential in order to obtain the confidence of the patient; this is absolutely necessary for the performance of the various small operations upon the auditory canal and tympanic cavity under local anæsthesia.
=Method of cleansing the ear.= Except when the auditory canal is completely blocked by inspissated pus, cerumen, or epithelial débris, it is sufficient to mop out the ear with small pledgets of cotton-wool. To prevent injury to the walls of the meatus and to the tympanic membrane, the pledget is held between the blades of the forceps in such a fashion that it partially projects beyond its points (Fig. 175). The forceps is passed through the lumen of the speculum along the auditory canal and then quickly withdrawn. This is repeated with fresh pledgets until the meatus is cleansed. If there is much purulent discharge, only a brief moment may be given (after the withdrawal of the forceps) in which to inspect the deeper parts. Such a view, however, should always be obtained in order to form an accurate diagnosis. If this method fails to cleanse the ear, syringing becomes necessary.
=Technique of syringing.= The patient should be sitting down, as syringing may cause giddiness. The fluid should be aseptic, and at a temperature of 100° F. The patient’s head is inclined to the affected side, and the auricle is pulled upwards or backwards. The syringe is inserted a short distance within the meatus, and applied to the upper posterior wall so that the stream of lotion flows along the roof of the canal to the drum, and returns along the floor, thus washing out the contents. The best syringe is one with a metal plunger, as it can be easily sterilized. After syringing, the auditory canal should be dried and again inspected. If the inspissated pus or epithelial débris cannot be removed by simple syringing, an ear-bath of warm hydrogen peroxide (10 vols. %) should be given, and the ear again syringed after ten minutes.
=Syringing out of the attic.= In certain cases of chronic attic suppuration, it is advisable to syringe out the attic. For this a special syringe is necessary. It consists of a fine canula whose point is turned up almost at right angles to its shaft (known as Hartmann’s canula), to which is fitted a piece of india-rubber tubing and a ball syringe. Milligan’s modification of this instrument is now generally used, as it permits of the canula being held in the hand, and instead of having a ball syringe, is connected by rubber tubing to a small irrigator (Fig. 176).
The patient sits upright in a chair in the ordinary position for examination of the ear; a speculum is inserted into the meatus, and held in position with the left hand; the canula, together with the ball syringe (if Hartmann’s is used), is held in the right hand. Under good illumination the canula is passed inwards along the auditory canal, and its point inserted through the perforation. By gently pressing on the syringe, the fluid is forced into the attic, which is thus washed out.
With Milligan’s instrument, the irrigator is fixed about two feet above the level of the ear. While the canula is being inserted, the escape of lotion is prevented by compressing the tube against the shaft of the instrument by means of the thumb. After the canula has been inserted into the opening, relaxation of this pressure permits of flow of the lotion. Milligan’s method is better than Hartmann’s, as the surgeon has more control over the instrument. Pain due to the introduction of the canula may be greatly minimized by previously inserting within the margins of the perforation either a pledget of cotton-wool soaked in a saturated solution of cocaine, or a crystal of cocaine.
After the cavity has been thoroughly washed out, the auditory canal is carefully dried as a final step, gentle inflation by Politzer’s method may be performed in order to expel any fluid still remaining within the attic.
GENERAL CONSIDERATIONS WITH REGARD TO OPERATIONS
In this connexion two points must be borne in mind: (1) The surgeon must have a good view of the part operated upon. For this reason when operating upon the auditory canal, the tympanic membrane, and tympanic cavity, he will usually require to work by reflected light.
(2) There must be no movement of the patient’s head during the operation. If the operation is performed under a local anæsthetic, it is therefore very important that the patient’s head should be kept fixed by means of an assistant.
=Preliminary surgical toilet.= If there be no existing suppuration, the ear should be cleansed, some twelve hours before the operation, by first giving an ear-bath of hydrogen peroxide lotion. This is done by making the patient incline the head to the opposite side so that the affected ear is uppermost. The warm solution is then poured into the meatus. After ten minutes the ear is syringed out with a 1 in 5,000 aqueous solution of biniodide of mercury, and a strip of sterilized gauze is then inserted into the auditory canal. The auricle and surrounding parts should also be surgically cleansed, and afterwards protected by a simple aseptic compress. If, as in furunculosis of the external meatus, syringing or cleansing of the ear is very painful, drops of a 10% solution of carbolic acid in glycerine may be instilled frequently into the meatus instead. If there is an existing otorrhœa, it is obviously impossible to render the field of operation absolutely aseptic. The ear, however, should be cleansed, but the auditory canal should not be plugged with gauze. The existence of a purulent discharge is no excuse for lack of cleanliness. Failure of such precautions may lead to disaster; for example, to perichondritis of the auricle as a sequel of the mastoid operation.
Before the actual operation takes place, if necessary after the anæsthetic has been given, the ear and surrounding parts should again be carefully cleansed, and the auditory canal syringed out with biniodide of mercury solution.
In intrameatal operations the head should be wrapped in a sterilized towel, and a square of sterilized lint, having an aperture in the centre so as to expose only the auricle and meatus, should be placed over the side of the head and face. In operations on the mastoid process, and in those involving a post-auricular incision, the head should also be shaved for at least two or three inches beyond the region of the ear.
=Anæsthesia.= Both local and general anæsthesia are used. Unless contra-indicated for some special reason, and unless the operation is a very trivial one, it is wiser to give a general anæsthetic. Of these, chloroform is the most suitable in adults and infants, and the A. C. E. mixture in children. Ether, although it may be safer, is frequently a source of annoyance to the operator, as it tends to increase the hæmorrhage.
In order to produce local anæsthesia two methods may be employed: (1) The instillation of fluids into the meatus; (2) subcutaneous injection of fluids beneath the lining membrane of the meatus and into the surrounding parts of the auricle.
The solution usually employed is a sterilized aqueous solution of cocaine hydrochloride in varying strengths up to 20%, to which may be added equal parts of 1 in 1,000 adrenalin chloride solution; the latter not only increases its analgesic properties, but also acts as a powerful hæmostatic.
Instillation. As the auditory canal and the tympanic membrane are lined with epithelium which is very resistant to the absorption of fluids, complete anæsthesia is almost impossible to obtain. This method, therefore, is practically limited to such trivial operations as the curetting away or snaring off of granulations or polypi from the external or middle ear. To render anæsthesia more complete, the affected part may be finally rubbed over with a crystal of solid cocaine hydrochloride just before the operation--is begun. On the other hand, if the raw surface is large--for example, the wound left after a recently performed complete mastoid operation--the cocaine employed should not be stronger than a 5% solution in order to minimize the risk of poisoning. Gray of Glasgow has suggested, as a more penetrating anodyne solution, a mixture consisting of a 10% solution of cocaine hydrochloride in equal parts of aniline oil and absolute alcohol, a solution which he especially advocates in order to produce anæsthesia of the tympanic membrane before doing paracentesis.
Subcutaneous injection. This is a modification of Schleich’s method, and was first introduced by Neumann of Vienna. It consists in injecting a very weak solution of cocaine and adrenalin chloride subcutaneously beneath the periosteum lining the auditory canal. By this method even the complete mastoid operation has been performed, and in certain clinics it is used continually in the minor operations of paracentesis of the tympanic membrane, division of intratympanic adhesions, extraction of polypi, and ossiculectomy. A solution of beta-eucaine or novocaine may be used in preference to cocaine, as being less dangerous. According to Neumann, three solutions are necessary: (a) a 1 in 2,000 solution of adrenalin chloride containing a 1% solution of beta-eucaine; (b) a 1 in 3,000 solution of adrenalin chloride containing a 1% solution of cocaine; (c) a 20% solution of cocaine.
The syringe for injecting the solution has a capacity of I cubic centimetre, and for convenience its needle is fixed at an obtuse angle to the body of the syringe (Fig. 177). The technique of the injection depends on whether the operation is to be limited to the auditory canal and tympanic cavity, or is to involve the mastoid process.
If the complete mastoid operation is going to be performed, the needle of the syringe, now filled with the eucaine solution, is thrust through the skin about the middle point of the mastoid process, and a few drops of the solution are injected. The needle is then forced upwards towards the temporal ridge, at the same time being thrust in deeply until it touches the bone, so that a syringeful of the solution is injected beneath the periosteum. The needle is then withdrawn and reinserted at the same point, but in a backward direction, the solution being injected along the posterior portion of the mastoid process; in a similar manner the solution is injected downwards towards the tip of the mastoid. The ear being now pulled well forward, the needle is made to pierce the fold between the auricle and the mastoid process, just above the posterior ligament, and is pushed inwards between the anterior border of the mastoid process and the cartilage of the meatus, and a further syringeful of the solution is injected. A large speculum is now inserted into the ear, so that by pressing it against the wall of the meatus the skin, at the termination of the cartilaginous portion, is made to project in folds. The needle of the syringe, filled with cocaine solution, is pushed into this fold, and a few drops of the solution injected. By degrees the needle is still further pushed inwards, keeping it in close contact with the bony wall so that the fluid is injected beneath the periosteum. If the injection has been successful, a white bulging of the superior wall of the auditory canal will be noticed. To render anæsthesia complete, further injections may be made into the inferior and anterior walls of the auditory canal. Finally, a pledget of cotton-wool soaked in a 20% solution of cocaine is pushed into the tympanic cavity.
In the case of simple opening of the mastoid, subcutaneous injections into the auditory canal are not necessary. On the other hand, if the operation is limited to the auditory canal and tympanic cavity, the injections into the mastoid process are not required, but a primary injection of a small quantity of eucaine solution into the auriculo-mastoid fold considerably diminishes the pain produced during the act of injection into the auditory canal. Fifteen minutes should be allowed to elapse before the operation is begun. The anæsthesia lasts about half an hour.
Difficulties. It is by no means easy to inject fluid beneath the periosteum of the auditory canal, owing to its close adherence to the bone. The needle by mistake may repierce the skin at a point farther in, so that the fluid, instead of being injected beneath the periosteum, is injected into the auditory canal itself. In these cases anæsthesia will not be obtained, and the operator may possibly blame the principle of subcutaneous injection, rather than his own faulty technique.
In favour of subcutaneous injection it is urged that most of the minor operations within the tympanic cavity, including ossiculectomy, may be performed with the patient sitting up in the chair in the consulting room, and further, that the patient can afterwards go home; that the operation is rendered more easy owing to there being practically no bleeding; and that in the case of the more severe operations, such as opening of the mastoid antrum, the surgeon, in a case of emergency, may make use of this method if he cannot possibly obtain the services of an anæsthetist.
Against subcutaneous injection is the pain of the injection, which may be so great that the patient will not submit to it, and in consequence the proposed operation may have to be postponed.
In the case of the mastoid operation, it is difficult to believe that local anæsthesia, however efficient, will be looked upon with favour either by the surgeon or by the patient, except when a general anæsthetic is absolutely contra-indicated. The discomfort produced by retraction of the parts, the jarring caused by chiselling, and the consciousness of what is taking place, are far more unpleasant and more of a shock to the patient, than a general anæsthetic carefully given. Further, it is not always possible to foretell the extent of the operation, and if repeated injections become necessary, there is danger of eucaine or cocaine poisoning being produced.
=Position of the patient and the surgeon=
1. In the minor operations the patient may be operated on whilst in the sitting posture, whether a local anæsthetic or a general one of gas and oxygen is employed. The relative positions of the patient and the surgeon are then the same as for the ordinary routine examination of the ear. Special care, however, should be taken that the patient’s head is supported by the anæsthetist or assistant in order to prevent involuntary movements.
2. If the patient is operated on in the recumbent position, the head may rest comfortably on an ordinary pillow, but if chiselling is going to take place, the best support is a loosely filled sand-bag. The head should be turned towards the opposite side so that the affected ear is uppermost, and the surgeon stands at the side to be operated on. The lamp, the source of reflected light, should be held about six inches above the patient’s shoulder on the opposite side.
II. OPERATIONS UPON THE EXTERNAL AUDITORY CANAL
OPERATIONS FOR FURUNCULOSIS
The operative treatment consists in incising the furuncles and, if necessary, curetting out their contents.
=Indications.= (1) If, in spite of palliative treatment for two days, the pain be so intense as to prevent sleep, and be accompanied by pyrexia.
(2) If there be accompanying œdema of the auricle and surrounding parts.
(3) If the furuncles occur during the course of a middle-ear suppuration, and occlusion of the external meatus prevents free drainage of the purulent secretion.
When possible, it is always preferable to operate under a general anæsthetic, such as gas and oxygen. If, however, the patient objects to a general anæsthetic, it should be explained that, in spite of the application of anodynes, the operation, although of momentary duration, will be excessively painful.
=Operation.= After the ear has been thoroughly cleansed, a large aural speculum is inserted within the meatus and the auditory canal dried with pledgets of cotton-wool.
The instrument usually used for this operation is a small and narrow sharp-pointed knife known as Hartmann’s furunculotome (Fig. 178, C). Equally suitable, however, is a fine bistoury; or, if necessary, a small tenotome or the ordinary paracentesis knife.
The surgeon holds the speculum in position within the meatus with the left hand, and with the right inserts the knife through the lumen of the speculum along the meatus until its point passes the innermost limit of the furuncle. It is then quickly withdrawn, at the same time incising the furuncle freely down to its base. Another method is to transfix the furuncle by passing the knife through its base and making it cut outwards through the skin. In a similar manner any other furuncles that may be present are incised or transfixed.
If the inflammatory process, instead of being localized as a furuncle, extends to the subcutaneous tissues, and especially if it is accompanied by much pain, pyrexia, and occlusion of the external meatus, linear scarification may become necessary.
After incision, the contents of the furuncle are rapidly scooped out with the curette (Fig. 178, A). Slight hæmorrhage may occur, but can be arrested at once by plugging the meatus for a minute with a strip of sterilized gauze. The auditory canal is finally syringed out with a warm aqueous 1 in 5,000 solution of biniodide of mercury and firmly plugged with gauze soaked in a 10% solution of carbolic acid in glycerine; a hot fomentation being afterwards applied to the side of the head.
If the operation has been performed under a local anæsthetic (and this should only be done if a solitary furuncle is present), the pain is usually too great to permit of firm packing of the auditory canal. This after-packing, however, should be carried out, if possible, for the following reasons: firstly, it presses out the contents of the furuncle; secondly, it prevents auto-infection from one hair follicle to another; and thirdly, it tends to dilate the auditory canal.
=After-treatment.= If the furuncles have occurred during the course of a middle-ear suppuration, the gauze plugging must be removed within a few hours after the operation. The ear is then syringed out once or twice daily with a warm solution of lysol or carbolic acid, a small wick of gauze soaked in a 10% solution of carbolic acid in glycerine being afterwards inserted along the meatus.
If there be no accompanying middle-ear suppuration, the packing should not be removed for at least twenty-four hours. The pain produced by the first dressing may be severe, but can be usually avoided by first soaking the gauze with 5% solution of cocaine for a few minutes before removal and then gently withdrawing it whilst the ear is being syringed with a warm aseptic lotion. For the next two or three days it is sufficient to insert a drain of gauze soaked in a 1 in 3,000 alcoholic solution of perchloride of mercury.
=Results.= Although cure may be expected, it is not uncommon for further furuncles to occur in crops at repeated intervals. This is due to auto-infection of the hair follicles, which to a large extent may be prevented by painting the surface of the auditory canal daily, for at least two or three weeks, with an oil containing a drachm of nitrate of mercury to the ounce.
In the case of diffuse inflammation, although relapses are uncommon, superficial necrosis of a portion of the bony meatus may afterwards occur as a result of involvement of its periosteal lining. If this takes place, stenosis of the auditory canal may afterwards occur from subsequent cicatrization.
=Dangers.= With ordinary precautions no accident should occur, but the following may be mentioned: (1) if the furuncles are deeply placed, the tympanic membrane may be incised inadvertently, and a middle-ear suppuration may result; (2) a too violent incision may cut through the meatal cartilage posteriorly, and, as a result of septic infection, may give rise to perichondritis of the auricle. This, fortunately, is rare.
REMOVAL OF EXOSTOSES FROM THE EXTERNAL MEATUS
=Indications.= The indications vary, depending on whether there is a coexisting middle-ear suppuration or not.
=If there be no middle-ear suppuration.= Operation is not urgent, but is justifiable under the following conditions:--
(i) When one ear only is affected. (a) If there be complete deafness due to obstruction of the auditory canal. The question of operation, however, should be decided by the patient, because it may be postponed indefinitely so long as no symptoms occur.
(b) If there be recurring attacks of discomfort or of pain in the ear as a result of eczema, of otitis externa, or of actual pressure of the growth itself. The patient may desire operation to obtain permanent relief.
(c) If there be deafness of the opposite side from other causes, and the presence of the exostoses is causing deafness of the functionally good ear.
(ii) When both ears are affected. In addition to the indications already given, operation is advisable on the worse side if there be almost complete obstruction on both sides, accompanied by recurrent attacks of deafness, owing to the narrowed passage of the auditory canal becoming repeatedly blocked from accumulation of cerumen or epithelial débris.
Operation is contra-indicated if previous examination indicates that the deafness is due to a chronic middle-ear catarrh or internal-ear disease, as in these cases restoration of hearing, which is the primary object of the operation, will be impossible.
=If middle-ear suppuration be present= operation is generally advisable.
(i) In acute middle-ear suppuration operation is urgent if there are signs of retention of pus, provided it is impossible to dilate the lumen of the auditory canal. Before resorting to operation an attempt should always first be made to obtain free drainage, as the obstruction may be due merely to inflammatory swelling of the tissues lining the auditory canal. With cessation of the acute inflammation, this swelling may subside and the lumen of the auditory canal again become patent; and if recovery with healing of the tympanic membrane takes place the hearing may again become normal, rendering the operation no longer necessary.
(ii) In chronic middle-ear suppuration operation is always indicated if there are symptoms of retention of pus. It is also advisable as a prophylactic measure, although not urgent, even although no acute symptoms are present.
=Operation.= =When there is no middle-ear suppuration.=
The operation may be performed either (a) through the external meatus or (b) by reflecting the auricle forward by a post-auricular incision.
=Through the external meatus.= This method is only indicated if the exostosis is situated at the entrance of the meatus and is pedunculated.
A general anæsthetic is given, the patient being in the recumbent position. The surgeon works by reflected light. After the ear has been thoroughly cleansed a large-sized aural speculum is inserted into the meatus and the outlines of the exostosis are defined with a probe. A small gouge or chisel is used. It is inserted into the meatus in such a fashion that its point presses between the pedicle of the exostosis and the wall of the bony meatus. With successive sharp taps of the mallet, the gouge is made to cut through the pedicle, care being taken that the instrument is not driven in too deeply, on to the tympanic membrane.
The growth, which can now be felt to be movable within the meatus, can usually be removed by grasping it between the blades of forceps, or can be expelled by syringing the ear. After its removal the auditory canal should be plugged for a few minutes with a solution of cocaine and adrenalin chloride. This checks all hæmorrhage, and at the same time enables the surgeon to get a good view of the deeper parts to see if further growths are situated more deeply within the meatus. Such growths, provided they are pedunculated and do not abut on the tympanic membrane, can sometimes also be removed by the same method; much depends on their shape and situation. If sessile or too deeply placed, the operation may have to be completed by reflecting forward the auricle. Before terminating the operation a clear view of the tympanic membrane should always be obtained.
The meatus is finally syringed out with a 1 in 5,000 aqueous solution of biniodide of mercury and dried, a strip of sterilized gauze being inserted into the auditory canal. A simple dressing is then applied to the side of the head.
Other methods of operation through the external meatus.
(a) Perforation of the exostosis, or enlargement of the small passage existing between multiple exostoses, by means of the burr.
Although successful results have been recorded, this method is not advised, as cicatricial tissue almost invariably causes closure of the opening made. To keep the opening patent it is necessary to insert a small lead or silver canula, frequently a source of great discomfort.
(b) If the exostosis has a very fine pedicle, it may be possible to nip through its base with a pair of forceps, but it is not so sure a method as the employment of a gouge and mallet.
(c) Such methods as attempts to destroy the growth by means of the galvano-cautery or by the pressure of laminaria tents should be avoided; they are useless and unsurgical.
=By reflecting the auricle forward.= This is indicated if the exostoses are multiple, have a broad base, and are deeply situated.
The position of the patient, and the anæsthetic, are the same as in the previous operation. Reflected light may not be necessary.
The ear and the surrounding parts are carefully cleansed and the head is shaved for a short distance over and beyond the mastoid process. A curved incision is made close behind the auricle (Fig. 226), beginning at the upper level of its attachment and extending downwards along the retro-auricular fold. The incision goes down to the bone. The auricle is reflected forward and the soft tissues are separated from the bone until Henle’s spine and the posterior upper margin of the auditory canal are brought into view. Any bleeding, chiefly from branches of the posterior auricular artery, is at once arrested by pressure forceps, ligatures being afterwards applied. The assistant’s duty is to hold the auricle well forward and at the same time to keep the wound dry by swabbing.
The fibrous portion of the canal is carefully separated from the bony portion with the periosteal elevator, the growth, if possible, being exposed without tearing through the thin layer of skin which covers it.
The method of procedure now depends on the character and number of the exostoses present.
(a) If situated superficially, they are removed by chiselling through their base with a gouge. They should be thoroughly removed, if necessary cutting through the normal bone well behind their base.
(b) If deeply placed, they are more easily removed by first chiselling away a part of the upper posterior wall of the external meatus. This is done in the same manner as in the early stage of the complete mastoid operation (see p. 397). If possible the antrum should not be exposed, and care should be taken not to cut too deeply for fear of injuring the tympanic membrane.
(c) If the exostoses spring from the anterior wall, it is necessary to make a T-shaped incision through the posterior membranous portion of the auditory canal in order to bring them into view clearly. This is done with a tenotomy knife, the flaps being held apart by means of forceps. The growths can now be removed by means of the gouge and mallet.
(d) If the obstruction is due to multiple small exostoses forming an annular stricture within the bony canal, it is better to separate the membranous portion completely from the bony meatus. In doing so the skin over the exostoses tears through, so that the membranous portion can be reflected outwards as a finger-like process. To give greater room for the operation, the auricle and fibrous portion are pulled well forward by means of a loop of gauze passed through the lumen of the cartilaginous meatus.
If necessary, reflected light should now be used. To reach the exostoses it may be necessary, as in the previous case, to remove part of the posterior bony wall. With the gouge and mallet the exostoses are carefully chiselled away. They frequently abut on the tympanic membrane, so that their removal without injuring it may be well-nigh impossible. It is of the utmost importance that the field of operation should be kept dry, if necessary by repeatedly mopping out the canal with pledgets of cotton-wool soaked in adrenalin solution. The chief difficulty is to determine the situation of the tympanic membrane. A fine probe is used to discover any existing chink between the growths; this will be a guide to show the direction in which to work. As soon as a small passage has been made, sufficient to allow of a view of the deeper-lying parts, the ear should be syringed out and dried, and a thorough inspection made. The tympanic membrane can usually be seen as a greyish-blue membrane; at other times it can be recognized by touching it with a probe. After making certain of the position of the membrane, the rest of the operation is easy. A small seeker (Fig. 219), such as is used in the mastoid operation, is passed through the opening already made, and with it the deeper limits of the exostoses can be felt. The opening is gradually enlarged by removing the growths piecemeal with the chisel or gouge.
Although the burr is contra-indicated when operating through the external meatus, it is frequently of great service in these cases in rendering the walls of the canal smooth. The disadvantages of using a burr are, that it is less easy to control (unless the surgeon has had considerable experience in using it), and that it destroys all the epithelial lining of the auditory canal with which it comes in contact. It should, therefore, only be used in those cases in which there is a complete ring of exostoses, but should be avoided if the exostoses are limited and if it is still possible to leave untouched a portion of the epithelial lining of the auditory canal.
When the surgeon considers he has successfully removed the obstruction, he should verify this fact by syringing out and drying the ear, and again obtaining a clear view of the tympanic membrane.
The fibrous portion is now replaced by inserting a finger into the cartilaginous meatus and pressing it back into the bony canal, the auricle being meanwhile pulled back into its normal position. The edges of the posterior wound are sutured together and the auditory canal is gently packed with gauze which should be inserted right down to the tympanic membrane. It is not necessary to make special meatal skin flaps, as careful packing of the auditory canal should be sufficient to keep the parts in apposition.
=When middle-ear suppuration is present.= In acute middle-ear suppuration the chief difficulty is to decide what operation to perform. As operation is only indicated if there is retention of pus, it is wiser to open the mastoid antrum; the exostosis, if superficial and pedunculated, can also be removed at the same time. If, however, the obstruction is due to multiple and deeply placed exostoses, this part of the operation should be deferred to a later date, that is, after the acute symptoms have subsided.
In chronic middle-ear suppuration the only operation to be recommended is the complete mastoid operation (see p. 392).
=After-treatment.= The after-treatment is practically the same whatever operation has been performed. The first dressing need not be done until the third day. The gauze plugging is then withdrawn and the auditory canal is syringed out and dried. If only a single exostosis has been removed the wound surface is small, and it is usually sufficient to puff in some boracic powder and again insert a piece of gauze. This may be repeated every second day, healing usually taking place within two or three weeks. In the case of deeply situated multiple exostoses, especially if removed from the anterior wall, considerable swelling of the soft parts lining the auditory canal may occur as a result of the manipulations. In such cases, after syringing out any existing blood-clots, some cocaine and adrenalin solution should be instilled into the meatus. An aural speculum is then gradually worked into the auditory canal, which is gently mopped out with small pledgets of cotton-wool, and the deeper parts are carefully inspected. Sometimes the torn ends of the fibrous portion, instead of covering the bony walls, are found to project into the auditory canal and to cause considerable narrowing of its lumen. By careful manipulations with the probe or by stroking the edges with tiny pledgets of cotton-wool, these rough surfaces may be smoothed down. It is very important, in the early days of the after-treatment, to prevent any narrowing at the site of the operation. This is one of the chief causes of subsequent failure. The gauze should always be reinserted right down to the tympanic membrane, and if there is not much secretion it should be packed firmly against the posterior and outer portion of the canal in order to prevent subsequent stenosis from the tendency of the cartilage to prolapse forward owing to the soft parts having been separated from the bony canal at the time of the operation.
The wound behind the ear heals very quickly and the stitches can generally be removed on the third or fourth day. Subsequent treatment consists in preventing the formation of granulations over the wound area. This is best accomplished by keeping the auditory canal aseptic and dry. If granulations occur they should be touched from time to time with a saturated solution of trichloracetic acid. If healing has not taken place within two weeks, it will frequently be advantageous to discontinue the gauze packing and, in its stead, to instil drops of pure rectified spirit.
If a middle-ear catarrh with secretion of fluid occurs, owing to the tympanic membrane having been injured, it may be impossible to continue the gauze packing. In these cases only a fine drain of gauze should be inserted into the meatus, the dressing being changed as frequently as may be necessary.
Provided asepsis is maintained, the middle-ear inflammation usually subsides rapidly with healing of the membrane. After healing has taken place, inflation of the middle ear is recommended twice a week, for two or three weeks, in order to aid recovery and to prevent adhesions forming within the tympanic cavity.
=Dangers.= 1. If the exostoses be deeply situated, the tympanic membrane may be injured.
2. If much of the anterior wall of the auditory canal be removed, the temporo-maxillary joint may be opened.
3. It is possible that the tympanic membrane may not be recognized, and, by working too deeply, the labyrinth or the facial nerve may be injured.
=Prognosis.= Provided no accident has occurred during the operation, a successful result should be obtained. Stenosis, however, may occur from cicatricial contraction if the operation has been incompletely performed.
REMOVAL OF FOREIGN BODIES
Before considering the question of removal of foreign bodies, the following points cannot be emphasized too forcibly:--(1) No attempt should be made to remove a foreign body until it is certain that one really exists. (2) Provided there is no middle-ear suppuration, a foreign body left in the ear will very rarely cause any immediate harm. (3) The most serious complications are due almost invariably to ill-advised haphazard attempts to remove the foreign body; as a rule from working blindly in the dark without making use of reflected light.
If a foreign body be suspected, the surgeon should first carefully examine the auditory canal in order to determine its character and position and the condition of its walls. On this will depend the treatment to be employed.
If the object be a living insect it should be killed at once by the instillation of warm oil, rectified spirit, or chloroform. This will cause immediate relief of the intense pain and tinnitus which may have been set up by its movements against the sensitive tympanic membrane.
The methods employed for the removal of a foreign body are syringing, extraction by instruments through the external meatus, and removal by operation by making a post-auricular incision and reflecting forward the auricle.
=By syringing.= In the vast majority of cases syringing is successful, and therefore should always be tried except under the following conditions:--(a) If the foreign body be of such a nature that it may be driven inwards; for example, a percussion cap for a toy pistol, lying with its concavity outwards.
(b) If there be much inflammation and swelling of the walls of the external meatus, unfortunately frequently due to previous unsuccessful attempts at extraction by instruments. In such cases forcible syringing may cause considerable pain, and in addition immediate removal of the foreign body may be impossible owing to the temporary occlusion of the meatus.
Unless urgent symptoms of retention of pus behind the foreign body are present, it is wiser to wait for a few days until the inflammation has subsided, in order that the canal may become more patent and permit of a more favourable opportunity for removal of the foreign body. The auditory canal, in the meanwhile, may be mopped out two or three times a day with pledgets of cotton-wool, and a 1 in 5,000 alcoholic solution of biniodide of mercury afterwards instilled into the ear.
The method of syringing has already been described (see p. 308). The syringe should be a large one with its tip protected by some india-rubber tubing. The point is inserted within the meatus up against the foreign body and the stream of lotion is directed towards any chink which may exist between it and the auditory canal. It may be necessary to use many syringefuls with considerable force before the foreign body can be expelled, but the syringing should be stopped if pain or giddiness are caused.
If the foreign body cannot be removed at the first attempt, drops of rectified spirit may be instilled into the ear several times a day, provided there are no urgent symptoms. This will tend to diminish any swelling of the soft tissues of the external meatus and of the foreign body if it is a vegetable substance. The ear should again be syringed after two or three days. In many cases this will now be successful; if not, the foreign body may be moved gently with a probe (using a speculum and reflected light), great care being taken not to push it further into the auditory canal, and another attempt may be made to remove it by prolonged syringing. If this fails it may be left in situ for a still longer period, provided there are still no symptoms requiring its immediate removal. In some cases, instead of the instillation of alcohol, a 5% solution of carbolic acid in glycerine or olive oil proves more effectual.
In the case of a hard substance, repeated attempts may be made to dislodge it before resorting to further measures; but in the case of a soft vegetable substance like a pea, it must not be forgotten that moisture tends to make it swell and perhaps will necessitate almost immediate extraction by instruments.
Extraction by instruments.
=Indications.= (i) If inspection shows that the foreign body can at once be removed by a suitable instrument: for example, a percussion cap the edge of which may be grasped by a pair of forceps (Figs. 179 and 193); or a small boot button whose shank, if it faces outwards, may be caught by a small hook.
(ii) If repeated attempts have failed to remove the foreign body by syringing.
(iii) If previous attempts by others have failed, and the foreign body has been pushed in beyond the isthmus, and cannot be removed after prolonged syringing.
(iv) If syringing produces violent giddiness, showing the probable presence of a perforation of the tympanic membrane.
(v) If there be symptoms of acute inflammation of the middle ear or of pus being pent up behind the foreign body.
=Operation.= An anæsthetic may not be necessary in adults if the foreign body is not too deeply placed within the ear, if its removal appears to be a simple matter, and if the patient is of a placid temperament. Otherwise, unless contra-indicated for some special reason, a general anæsthetic should always be given in children, and it is also preferable in adults for the following reasons:--(1) Inability to remove the foreign body after repeated attempts by syringing usually means that its extraction by instruments will be a somewhat difficult matter. (2) The risk of injury to the meatal walls or tympanic membrane from involuntary movements of the patient during the operation is far greater than the risk of the anæsthetic. (3) If the foreign body cannot be removed through the meatus by means of instruments, the post-meatal operation is indicated. This, if necessary, can be done at once if the patient is under a general anæsthetic.
If no anæsthetic is given the patient may sit up in a chair; otherwise, the recumbent position is advised.
It is usually necessary to use an aural speculum, but if the foreign body be situated near the entrance of the meatus a sufficient view may be obtained by pulling the tragus forward and the auricle backward. Good illumination is essential.
(i) If the body be a soft substance, such as a pea, the core of an onion, or a fragment of wood, it is best removed by fixing into it some form of sharp hook (Fig. 178, D). These hooks vary in shape. They may be curved, or shaped like a crochet-hook, or have the sharp point placed at right angles to the shaft of the instrument.
In the case of a round substance like a pea, especially if it is tightly impacted within the meatus, its removal is sometimes facilitated by first slicing it into pieces by means of a small bistoury.
As a rule, the foreign body is impacted at the junction of the cartilaginous and bony portion of the auditory canal; sometimes, however, it is more deeply situated within the osseous meatus, usually the result of previous attempts to extract it.
In the former case, the instrument is passed along the upper posterior wall of the canal between it and the foreign body, the point of the hook being kept upwards or downwards so as not to project into the auditory canal. The instrument is first passed well beyond the foreign body, and then the shaft is twisted round so that the hook projects into the auditory canal. With a quick movement it is drawn outwards a short distance so that the point of the hook pierces the impacted substance. Gentle traction is now used and in the majority of cases the foreign body can be extracted.
If this fails, a slightly curved fenestrated scoop (Fig. 180) or curette should be passed, if possible, between the foreign body and the anterior wall of the auditory canal. The hook already fixed into the foreign body prevents it from being driven further within the meatus, whilst the scoop, if it can be got beyond the foreign body, can usually lever it out.
If the foreign body has been pushed in beyond the isthmus and lies deeply within the osseous canal, it is better to pass the hook along the anterior inferior wall of the meatus, because owing to the inclination of the tympanic membrane its anterior inferior margin is much more deeply placed than its upper posterior part.
(ii) In the case of a hard substance, such as a piece of stone, coal, or a bead, blunt hooks may be used instead of sharp ones. They should be passed into the meatus beyond the foreign body in the manner already described.
(iii) In other cases, depending on its shape and position, the foreign body is better removed by means of a snare, the loop of which is manipulated round it and then drawn tight in the same manner as in the extraction of a polypus.
The chief points to observe in these manipulations are (a) not to push the foreign body farther in and (b) not to injure the walls of the meatus or the tympanic membrane.
=Other methods of extraction= are--(1) Drilling through the foreign body, if it is a hard substance, and then inserting a fine hook into the opening so made. (2) The agglutinative method, which consists in dipping a small paint-brush into a concentrated solution of seccotine or glue and then inserting it into the meatus until it comes in contact with the foreign body. The brush is left in this position for several hours in the hope that it may become adherent to the foreign body; if so, on withdrawing the brush from the ear, the foreign body should be extracted with it. This method can only be used provided the ear is kept dry.
These procedures, although said to be successful in a few cases, are not recommended.
=After-treatment.= If the tympanic membrane and auditory canal have not been injured, it is sufficient to dry the meatus and puff in a little boracic powder. If there be abrasions of the canal, a small strip of gauze should be inserted and changed as frequently as it becomes moist with secretion, the meatus, if necessary, being also syringed out with an aseptic lotion. If there be acute inflammation of the walls of the canal, accompanied by much swelling and purulent discharge, drops of glycerine of carbolic (1 in 10) may be instilled frequently. After the inflammation has subsided, an alcoholic solution of 1 in 3,000 biniodide of mercury may be employed. If the tympanic membrane has been injured, either from the presence of the foreign body itself or from the attempts at extracting it, the treatment is similar to that for an ordinary middle-ear suppuration.
=Removal by operation.= This may be done in the following ways:--
=By means of a post-aural incision.=
=Indications.= (i) If prolonged attempts to remove the foreign body by instruments have failed. This operation becomes imperative if there are signs of retention of pus within the middle ear.
(ii) If the foreign body has been pushed into the tympanic cavity and cannot be removed otherwise. In such cases, if the perforation is large and the foreign body is small, an attempt may first be made to dislodge the substance by injecting fluid into the middle ear through the Eustachian tube by means of the catheter and syringe (see p. 372). This method, however, is rarely successful.
=Operation.= The procedure is the same as for the removal of exostoses (see p. 318). After separating the fibrous from the bony portion of the canal, an incision is made through it and the cut edges are held aside with forceps. Usually the foreign body can now be seen lying within the canal. It is best removed by passing a small fenestrated curette beyond it and levering it out. In some cases one of the hooks already mentioned will be found to be more suitable. Forceps should not be used, as they may inadvertently push the foreign body farther in. If the foreign body be very deeply placed, removal of the upper posterior portion of the bony meatus may be necessary. The subsequent steps of the operation and its after-treatment are similar to that already described in the case of an exostosis.
=By means of an operation upon the mastoid.=
=Indications.= (i) If the above measures fail to remove the foreign body.
(ii) If there be symptoms of inflammation of the mastoid process, or of internal-ear or of intracranial suppuration.
(iii) If there be facial nerve paralysis the result of pressure from the foreign body.
=Operation.= The operation performed depends on the condition found. Simple opening of the mastoid antrum may be sufficient in a case of recent middle-ear suppuration, although it is usually necessary also to remove a considerable portion of the posterior wall of the auditory canal before the foreign body can be extracted. If these measures fail, an attempt may be made to dislodge the foreign body by forcibly syringing through the aditus, or by the insertion of a probe through it, into the tympanic cavity. If this likewise ends in failure, it will then be necessary to perform the complete operation. These cases fortunately are rare.
If it be certain that chronic middle-ear suppuration already exists, the complete mastoid operation is indicated.
If it becomes necessary to operate on the mastoid process, owing to other means having failed to dislodge the foreign body, it is wiser, as a rule, to perform the complete operation at once, because, under these circumstances, irreparable destruction must have taken place within the tympanic cavity.
The technique of these operations and their after-treatment are described in the chapter on operations upon the mastoid process (see p. 390).
OPERATIONS FOR STENOSIS OF THE EXTERNAL MEATUS
Stenosis, or stricture of the auditory canal, is practically always the result of traumatism or inflammatory conditions; it is only very rarely congenital.
=Indications.= (i) If there be deafness of the other ear, and the functionally good ear periodically becomes deaf from obstruction of the narrow passage by cerumen or epithelial débris, and the patient is weary of conservative treatment.
(ii) If there be recurrent attacks of otitis externa.
(iii) If there be retention of pus, the result of inflammation of the external or middle ear, which is not relieved by conservative treatment.
The operation is contra-indicated if there is accompanying deafness, due to chronic middle-ear or to internal-ear disease, provided there is no suppuration within the external or middle ear.
=Operation.= The method of operation depends on whether the stricture is membranous, fibrous, or bony in consistence, or whether it is limited or is causing a general narrowing of the auditory canal. It may take one of the following forms:--
Dilatation. This method is not very satisfactory, and is limited to recent cases of membranous or fibrous stricture of the annular variety. After cleansing the meatus, a small laminaria tent is inserted through the stricture, and if the pain is not too severe it is left in situ for at least twenty-four hours and then withdrawn. The ear is again carefully cleansed, and if possible a larger laminaria tent is substituted. This procedure is repeated until the maximum amount of dilatation has been obtained.
Incision of the stricture. This also is limited to membranous or to fibrous strictures of the annular variety.
The operation, if necessary, may be performed under a local anæsthetic, produced by subcutaneous injections, although usually a general anæsthetic is preferable.
The ear and surrounding parts are surgically cleansed by the ordinary methods. The surgeon works by reflected light. The patient may be in either the sitting or the recumbent position, depending on whether a local or general anæsthetic is given. In the latter case the auditory canal should be filled with cocaine and adrenalin solution before the anæsthetic is administered in order to diminish bleeding as far as possible.
The ear having been dried, a conveniently large aural speculum is inserted, and with a tenotome or a furunculotome radiating incisions are made through the stricture. One of the small flaps thus made is grasped with a fine pair of tenaculum forceps, and the surgeon cuts through its base, keeping the knife as close as possible to the wall of the auditory canal. Each flap is treated in a similar fashion. Instead of making radiating incisions, the tissue forming the obstruction may be transfixed through its base, the knife being made to cut in a circular fashion right round the auditory canal, keeping as close as possible to its wall.
On completion of the operation, a piece of india-rubber tubing, of as large a size as possible, is inserted into the dilated canal. It should only be removed for the purpose of cleansing and should be at once reinserted. A silver canula, if necessary, can afterwards replace the india-rubber tubing. This canula may have to be worn for months.
This operation is often most unsatisfactory, as the stricture, instead of being annular as first supposed, may be found, on operation, to extend a considerable distance along the auditory canal and, in addition, to be partially due to a general thickening of the underlying bone.
Excision of the stricture. The auricle is reflected forward and the preliminary steps of the operation are performed as already described for removal of a deep-seated exostosis (see p. 319). The surgeon makes a transverse incision with a knife through the fibrous portion of the auditory canal, just external to the stricture, and carries it right round the meatus, thus separating the outer portion of the membranous from the bony canal. The fibrous portion is now pulled outwards by means of a retractor, and the thickened tissue, forming the stricture, is peeled off from the surrounding bony meatus with a small periosteal elevator and so removed. If the stenosis is partially due to thickening of the walls of the canal itself, it may also be necessary to chisel away a considerable portion of its upper posterior part. After completion of the operation a clear view of the tympanic membrane should be obtained.
In this operation a considerable portion of the bony canal is denuded of its epithelial lining membrane, so that there is a special tendency to the re-formation of cicatricial tissue. To prevent this taking place two methods may be employed:--(1) If much of the upper posterior wall of the bony meatus be removed, a post-meatal flap should be made and kept in position by means of a catgut suture carried through the skin behind the auricle. The formation of such a flap is described as a step in the complete mastoid operation (see p. 401).
(2) If no bone be removed, the membranous portion is replaced in situ, the posterior auricular wound closed, and as large an india-rubber tube as possible is inserted into the meatus. A week or ten days later, as soon as granulations begin to form, skin-grafting may be undertaken (see p. 410).
If grafting be not successful, the india-rubber tube or silver canula must be kept constantly within the meatus (only being removed for cleansing purposes) until healing takes place.
The complete mastoid operation is indicated in the case of stenosis occurring in chronic middle-ear suppuration if symptoms of retention of pus occur.
In acute middle-ear suppuration, however, every attempt should be made to avoid operation, as the lumen of the auditory canal may again become patent after the acute inflammation has subsided.
OPERATIONS FOR ATRESIA
Atresia of the external meatus may be either congenital or acquired.
=Indications.= (i) In congenital cases operation is only justifiable if the atresia is due to a membranous web situated in the outer part of the auditory canal and if, as a result of tuning-fork tests and of inflation through the Eustachian tube, it is fairly certain that the middle ear is normal.
Operation is contra-indicated in cases of bony atresia. Although attempts have been made to make an artificial canal in order to restore the hearing power, a successful result has not yet been obtained. Apart from the difficulty of retaining the patency of any canal so made, the accompanying malformation of the middle ear renders a successful result impossible (Paper by author, Journal of Laryngology, &c., March, 1901). Although the tympanic membrane is said to have been exposed by operation in a few cases, experience has shown that the supposed tympanic membrane was really the capsule of the temporo-maxillary joint.
(ii) In acquired cases operation is indicated if the other ear is deaf; if the site of the occlusion of the auditory canal is in its outer part and is due to membranous or fibrous tissue, and if there is no previous history of middle-ear disease, and if the labyrinth is still intact.
Operation is not advised if the other ear is normal, unless the patient particularly desires it.
Operation is contra-indicated if there is internal-ear deafness on the affected side and if the other ear is normal; or if there is a definite history of the closure of the auditory canal having been the result of a previous middle-ear suppuration. In the latter case the destructive changes within the tympanic cavity will be so marked that the chances of improving the hearing will be very slight in spite of the most successful operation.
=Operation.= If the obstruction be due to a fibrous band, an attempt may be made to remove it by excising it by the intrameatal method. In other cases the post-auricular method is necessary.
The chief point to remember is to make a large opening. For this reason the post-auricular method is to be preferred, as a considerable portion of the upper posterior wall can be removed and a large meatal flap fashioned (see p. 401).
=Results.= If the stricture or point of occlusion of the auditory canal is limited and composed of membranous and fibrous tissues, a good result can be usually obtained, and there is no reason why complete recovery of hearing should not take place if the labyrinth and tympanic cavity are normal.
Unfortunately, as in all cases of stricture, there is a tendency for it to recur.
OPERATIONS FOR AURAL POLYPUS
In this section only the aural polypi which project from the tympanic cavity into the external auditory meatus will be considered; whereas the treatment of granulations, and with them the minute polypi which are still limited to the tympanic cavity, will be discussed in the chapter on operations within the middle ear.
=Indications.= An aural polypus should always be removed because, apart from the fact that it is a symptom of underlying disease, it may obstruct free drainage of the purulent discharge, and therefore become a source of danger.
=Operation.= The simplest and the best method is removal by the snare.
In the case of small and soft polypi, the polypus is removed by traction--formerly called =avulsion=--after the snare has been tightened round its pedicle; with a large, tough, fibrous polypus considerable force may be required to tear through its pedicle. This procedure in the case of polypi arising from the region of the tegmen tympani has been known to give rise to fatal meningitis. In such cases the pedicle of the polypus should be cleanly cut through by the snare--so-called =excision=.
As aural polypi are always associated with suppuration, it is especially necessary that the ear should be thoroughly cleansed before operation.
A local anæsthetic (see p. 310) is sufficient in the case of smaller polypi, but if the polypus be large and tough, it is wiser to give a general anæsthetic, such as gas and oxygen. Or a 3% solution of cocaine may be injected into the growth, which, according to Frey of Vienna, renders removal absolutely painless; this, however, has not always been my experience.
The size of the polypus and the origin of its pedicle should be determined before operating, if necessary by using a probe (Fig. 181); also it must be diagnosed from a bulging congested tympanic membrane, or from the inner surface of the tympanic cavity, which may be exposed to view owing to complete destruction of the membrane having already occurred.
A Wilde’s snare is generally used. It is a fine angular snare fitted with soft copper wire. The loop of the snare should be bent downwards and forwards and should be of such a size as to just surround the growth. The snare is held between the thumb and the first and second finger of the right hand (Fig. 182). Under good illumination, and using the speculum and reflected light if necessary, the shaft of the snare is passed along the upper portion of the auditory canal until the edge of the polypus is reached. The loop is made to encircle the polypus (Fig. 183), the snare is gradually pushed inwards with a gentle sinuous movement until it reaches the point of attachment of the growth. The loop is then tightened until it firmly grasps the neck of the polypus (Fig. 184). The friable tissue is torn through by gentle traction and the polypus is withdrawn in the snare. Care must be taken not to injure the tympanic membrane through which the polypus may be projecting; it is for this reason that the loop is bent at an angle to the shaft of the snare so that it may lie parallel to the tympanic membrane whilst in the act of grasping the polypus. If the polypus be very small its pedicle may be clearly defined before operation, and the snare passed round it directly (Fig. 185).
If the polypus be very large and tough, the snare is made to cut clean through its pedicle as near to its attachment as possible, instead of employing traction. The snare is then withdrawn, the polypus being afterwards grasped and removed by means of forceps. In this latter case it may be necessary to use a stronger snare fitted with piano steel wire instead of the ordinary copper wire. On removal of the polypus there may be considerable hæmorrhage. After it has ceased the ear is syringed out and dried. The auditory canal is then inspected, and if it is found that the growth has not been removed completely, this can be done now by reapplication of the snare.
After final cleansing of the meatus, a strip of gauze is inserted, and the ear protected with a pad of cotton-wool and a bandage.
=After-treatment.= The dressing should be removed within twenty-four hours, and the ear cleansed by syringing. After mopping it dry drops of rectified spirits should be instilled.
On removal of the first dressing, any polypoid tissue which remains may be cauterized under cocaine anæsthesia by the actual cautery, or by a bead of chromic or trichloracetic acid (see p. 348).
Further treatment consists in keeping the ear clean and dry. For the first few days it should be syringed daily, dried, and spirit drops instilled. As the secretion becomes less the syringing should be diminished. If the perforation be large, instead of instilling drops, some finely powdered boric acid may be puffed in.
=Other methods of removal.= These are not recommended, but merely mentioned for the sake of completeness.
By forceps. The rough and ready method of extracting a polypus forcibly from the ear by means of forceps, although practised formerly, has now been discarded as being unsurgical and dangerous.
Ligation. The operation consisted in passing a snare over the polypus and grasping it tightly as near to its base as possible. The snare was then twisted round its axis in order to tighten the loop further and so obliterate the blood-supply of the growth, the wire of the snare being afterwards cut through with pliers and the snare withdrawn. After a few days the polypus became gangrenous from want of blood-supply, and separated from its deep attachments.
Curetting. This method, which should only be made use of in the case of small multiple polypi within the tympanic cavity, will be considered when discussing the treatment of granulations within the middle ear (see p. 398).
=Dangers.= Hæmorrhage is seldom profuse, but if it is, it can always be arrested by packing the meatus with cocaine and adrenalin solution.
The chief dangers are injury to the contents of the tympanic cavity, such as dislocation or removal of the ossicles; or subsequent meningitis. These mishaps are usually the result of forcible extraction, or of blindly curetting the ear after this has been done. Meningitis, however, has been known to occur, in spite of every precaution being taken, if, owing to caries of the tegmen tympani, the polypus has its origin from the dura mater of the middle fossa.
=Prognosis.= If the polypus be single and of recent origin, the result probably of acute inflammation of the middle ear, its removal may cause complete recovery and cessation of the middle-ear suppuration.
In the case, however, of multiple polypi associated with chronic middle-ear suppuration and usually signifying underlying bone disease, recurrences may be frequent and further operations may become necessary.
It may here be emphasized that a polypus in itself is not a disease, but merely a symptom of disease.
After removal of a large polypus, the patient should always be kept under observation for a day or two in case of symptoms of acute inflammation of the mastoid process arising and necessitating further operation.
Chapter III
OPERATIONS UPON THE TYMPANIC MEMBRANE AND WITHIN THE TYMPANIC CAVITY
SURGICAL ANATOMY OF THE TYMPANUM
=The tympanic membrane.= The chief points to notice when operating on the tympanic membrane are its inclination and its relation to the inner wall of the tympanic cavity.
The normal membrane is inclined obliquely downwards and forwards so that it forms an obtuse angle of 140 degrees with the roof and an acute angle of 27 degrees with the floor of the external meatus. In infants the inclination is even greater.
Its relation to the tympanic cavity varies in its different parts. It lies nearest to the inner wall in the region of the umbo, being only 2 millimetres distant from the promontory, and is furthest from it in the posterior quadrant.
Running backwards, just below the posterior fold, is the chorda tympani nerve, which may be cut through in the act of paracentesis and in division of the posterior fold.
=The tympanic cavity.= For the purpose of description the portion of the tympanic cavity above the level of the tympanic membrane is known as the attic or epitympanic cavity; whilst the part below its level is called the cellar or hypotympanic cavity (Fig. 186).
The =attic= contains the head of the malleus and the body and short process of the incus, and communicates posteriorly with the antrum by a variable sized opening--the aditus. Its roof, the tegmen tympani, a plate of bone frequently of extreme thinness, separates the cavity of the middle ear from the middle fossa of the cranium. The facial canal extends backwards along the inner and upper border of the tympanic cavity, passing above the vestibule and the fenestra ovalis to curve downwards posteriorly beneath the external semicircular canal, which at this point forms the inner and inferior boundary of the aditus.
The =ossicles= form a movable chain fixed at three points: namely, the attachment of the handle of the malleus to the tympanic membrane; the posterior ligament of the incus, a feeble structure, binding its short process to the entrance of the antrum; and the strong annular ligament connecting the footplate of the stapes to the margins of the fenestra ovalis.
In addition, the anterior, external, and superior ligaments of the malleus also tend to keep it in position and limit its movements.
The tensor tympani muscle, extending from the processus cochleariformis, crosses the tympanic cavity to be inserted into the inner margin of the neck of the malleus; and the stapedius muscle emerging from the apex of the eminentia pyramidalis is inserted into the head of the stapes.
These ligaments and muscles partially divide the cavity into smaller compartments, such as the outer attic and Prussak’s space, so that in some cases inflammation may be limited to only a part of the tympanic cavity; a fact to be remembered in considering the question of operative procedures.
OPERATIONS UPON THE TYMPANIC MEMBRANE
PARACENTESIS
=Indications.= The chief object of paracentesis (myringotomy or simple incision) is to permit of escape of fluid from the tympanic cavity.
(i) In acute inflammation of the middle ear, if the acute symptoms continue in spite of palliative treatment, and the following conditions are present:--(a) An increasing congestion and bulging of the tympanic membrane, especially if accompanied by earache and pyrexia. (b) The obvious presence of pus within the tympanic cavity, shown by a circumscribed, angry red or yellow protuberance on the tympanic membrane. (c) Accompanying cerebral symptoms, such as drowsiness, vomiting, vertigo, and convulsions. (d) Tenderness over the mastoid process. (e) Paroxysms of pain acute enough to prevent sleep.
Paracentesis should be done early in infants and in specific fevers. In the former case even a slight middle-ear inflammation may give rise to all the cardinal symptoms of meningitis, which frequently subside rapidly as the result of simple paracentesis; in the latter, there may be rapid destruction of the drum, which a timely incision may possibly prevent.
(ii) In middle-ear catarrh with exudation. Paracentesis is justifiable in order to remove the secretion, if the hearing does not improve after a month’s treatment, owing to the existence of exudation within the tympanic cavity.
(iii) As a preliminary to intratympanic operations.
=Operation.= The auricle and surrounding parts are surgically cleansed (see p. 309), the preliminary toilet, if possible, being carried out at least half an hour before the operation is performed.
Although apparently a trivial matter, it is of the utmost importance to render the auditory canal as aseptic as possible in order to prevent secondary infection of the tympanic cavity from without.
It is wiser to give a general anæsthetic, such as gas and oxygen, as the pain of the operation may be intense. If this is refused, local anæsthesia by Gray’s solution (see p. 310) or by a subcutaneous injection of cocaine and adrenalin may be employed. In infants an anæsthetic is not necessary.
The patient may be sitting up or lying down. If a general anæsthetic has not been given, the patient’s head must be held firmly by an assistant in order to prevent sudden movement. The surgeon works by reflected light in order to obtain a clear view of the tympanic membrane.
The point of election for the incision is through the posterior part of the membrane, excepting when it is obvious from the bulging and appearance of the membrane that the incision must be made in the anterior inferior quadrant.
The incision is made by means of a paracentesis knife, which is shaped like a tiny bistoury set at an angle to its handle (Fig. 187). The double-edged spear-shaped knife is now seldom used, as with it there is a tendency to puncture rather than to incise the membrane.
The tympanic membrane is pierced by the paracentesis knife at its inferior posterior margin. With a quick movement the drum is incised freely, the incision being carried in an upward direction midway between the malleus and the circumference of the membrane posteriorly, until it reaches Shrapnell’s membrane (Fig. 188). In making this incision the inclination of the membrane must not be forgotten. Owing to its lower margin being more deeply placed than the upper, there is a tendency for those who have not had much practice in doing a paracentesis to begin their incision too high up, as they fail to realize the greater depth of the canal at this point. The soft tissues of the upper posterior wall of the external meatus close to the membrane, if much congested, may be incised also in the act of withdrawing the knife. In doing this the chorda tympani nerve may perhaps also be cut, resulting in loss of taste on the affected side for a time; this is a matter of no importance. As a result of this free incision, drainage is given to the contents of the tympanic cavity, attic, and antrum.
In order to prevent rapid closure of the perforation and to give better drainage, some authorities advise making a flap-shaped incision. To do this, the membrane is incised upwards, nearly to its upper border; the knife is then carried backwards and downwards before it is withdrawn from the wound.
Occasionally the acute inflammation is limited to the attic, Shrapnell’s membrane appearing deeply congested and bulging outwards so as to cover the processus brevis, whilst the rest of the membrane may be only slightly injected. In such cases it is sufficient to incise the bulging area, beginning the incision just above the region of the processus brevis and carrying it horizontally backwards to its posterior extremity (Fig. 189).
=After-treatment.= In acute middle-ear inflammation, after the first rush of blood and discharge has been mopped away, a small drain of sterilized gauze should be inserted into the auditory canal and the ear protected with a pad of sterilized gauze. The dressing and gauze drain should be changed as often as may be necessary, depending on the amount of discharge. The ear should not be syringed out unless the discharge becomes very profuse and thick.
In acute middle-ear catarrh with exudation, a Siegle’s speculum (Fig. 194) should be inserted into the meatus after free incision of the membrane, and as much fluid as possible extracted by suction. In addition, gentle inflation by means of Politzer’s method will help to expel from the middle ear the fluid, which should then be mopped out of the external meatus. This should be repeated daily.
=Difficulties and dangers.= The usual fault is to mistake the congested posterior wall of the external meatus for the membrane.
If the patient is not under an anæsthetic, the incision may be made too timidly, the membrane being only scratched. The pain thus inflicted will cause the patient to jerk away the head and probably prevent the membrane from being incised freely. The incision, therefore, must be made in a bold and rapid manner. It is better to make the incision too free than too small.
Care must be taken not to plunge in the knife too deeply for fear of wounding the mucous membrane of the inner wall of the tympanic cavity. This may result in adhesions between it and the membrane.
Further, cases have been recorded in which a too violent incision has injured or dislodged the ossicles, or in which severe hæmorrhage has occurred, presumably from puncturing the bulb of the jugular vein, which was projecting abnormally through the floor of the tympanic cavity.
The two chief causes of failure are insufficient drainage from too small an incision, which may necessitate a further operation, and secondary infection from without.
=Results.= In the majority of cases, provided free drainage is established, the discharge ceases and healing of the membrane takes place from within a day or two to four weeks, depending on the character of the case. If the symptoms continue it may become necessary to perform the mastoid operation (see p. 373).
ARTIFICIAL PERFORATION OF THE TYMPANIC MEMBRANE
The object of the operation is to equalize the pressure within the tympanic cavity and external meatus so as to enable vibrations of sound to be transmitted more readily by the membrane and chain of ossicles to the inner ear.
=Indications.= (i) In the case of an extremely calcified membrane which apparently cannot vibrate.
(ii) To relieve tinnitus or vertigo which appears to be due to an alteration of tension within the tympanic cavity, the result of an impermeable stricture of the Eustachian tube.
(iii) As a means of diagnosis. If the hearing be improved or the subjective symptoms relieved as a result of the artificial opening, then, if the perforation closes (as it probably will do), the surgeon is in a position to suggest some more radical measure, such as ossiculectomy (see p. 351).
=Operation.= Two methods are employed: (i) The knife; (ii) The galvano-cautery. The perforation should be made in the postero-inferior quadrant.
In favour of the galvano-cautery is the fact that the perforation does not tend to close so rapidly. On the other hand, considerable damage may be done unless it is applied with extreme care. For this reason it is wiser to operate under a general anæsthetic, such as gas and oxygen.
If the paracentesis knife be used it is not sufficient to make a simple incision; a small triangular flap must be excised. The operation should be performed under good illumination. The paracentesis knife is inserted boldly through the membrane a little behind and above the umbo. The membrane is incised in an upward and slightly backward direction towards its margin; then downwards parallel to its posterior border; then horizontally forward, meeting the original point of the incision. The excised portion of the membrane is removed by seizing it with a fine pair of crocodile forceps, or by means of a fine snare, if it has not been completely detached.
The galvano-cautery is applied cold; when it is in contact with the drum, the circuit is closed so that the point of the cautery becomes red-hot. After the membrane has been burnt through it is withdrawn rapidly so as not to scorch the surrounding tissues. In using the cautery care must be taken to push it only just through the membrane for fear of injuring the inner wall of the tympanic cavity.
=After-treatment.= The after-treatment consists in protecting the ear by a strip of gauze, which is changed as often as may be necessary.
DIVISION OF THE ANTERIOR LIGAMENT
=Indication.= It is advised by Politzer in those cases of marked retraction of the drum in which inflation causes an immediate improvement in hearing, which, however, only lasts a short time. In several cases Politzer found the cause of this to be due to tension of the anterior ligament causing retraction of the malleus.
=Operation.= The anterior fold is divided with the paracentesis knife just in front of the processus brevis of the malleus. The knife is then introduced 2 millimetres inwards through the incision and made to cut in an upward direction as far as Shrapnell’s membrane (Fig. 190, C). This should divide the ligament.
If the operation be successful, improvement in hearing and also diminution of the subjective noises should take place.
DIVISION OF THE POSTERIOR FOLD
=Indication.= The same as for the anterior ligament. Owing to the increased tension of the upper posterior quadrant of the tympanic membrane, it is assumed that the movements of the malleus are diminished, and with this the hearing power. Seeing, however, that the prominence of the posterior fold is due to the projection outwards of the processus brevis as a result of the handle of the malleus having become indrawn with the membrane, it is difficult to understand how its division can possibly be a means of restoring the retracted membrane to its normal condition.
On the few occasions on which I have performed this operation, no improvement has followed. Others, however, maintain that it may do good in certain cases. This, perhaps, may be possible if it is combined with other intratympanic operations, such as division of the anterior ligament or of the tensor tympani muscle.
=Operation.= The paracentesis knife is inserted through the most prominent part of the fold and is made to cut through it from above downwards (Fig. 190, B). If this is successful, gaping of the cut edges takes place and the membrane assumes a less retracted position, and increased hearing and diminution of the subjective symptoms should occur on inflation and rarefying of air within the external ear.
INTRATYMPANIC OPERATIONS
=General considerations with regard to intratympanic operations and their results.= The chief difficulty, from a clinical point of view, is to determine beforehand the exact pathological changes which already exist within the tympanic cavity. For this reason the indications given with regard to operation are of necessity somewhat empirical. For example, retraction of the tympanic membrane may be due to closure of the Eustachian tube; to adhesions between it and the promontory; to contraction of the tensor tympani, of the anterior ligament, or of the posterior fold. An operation to remove only one of these causes may, therefore, be insufficient; the difficulty is to know what to do. Even if further operations are performed, the result may be negative owing to adhesions having taken place already between the ossicles themselves, or from binding down of the incudo-stapedial joint or of the stapes to the inner wall of the tympanic cavity. And apart from this, even if temporary benefit is obtained, the final result may be worse than that which existed before operation owing to the natural tendency for adhesions to re-form.
The prognosis is better in the case of post-suppurative conditions than in the non-suppurative ones.
Improvement by operation may be hoped for if a temporary increase in the hearing power, with diminution of the subjective symptoms, is obtained as a result of inflation; especially in those cases in which the malleus is only locally adherent to the promontory.
Generally speaking, however, these operations are not recommended, owing to the impossibility of being able to give a good prognosis, and therefore they can only be considered as experimental.
These operations are contra-indicated--(1) If there be internal-ear deafness.
(2) If the stapes (as shown by tuning-fork tests and Gellé’s test) be ankylosed within the fenestra ovalis, especially in the case of otosclerosis.
(3) If the membrane be completely adherent to the inner wall at its upper posterior quadrant, especially if this is of long standing, as the stapes will almost certainly also be fixed by adhesions.
DIVISION OF INTRATYMPANIC ADHESIONS
The position and extent of the intratympanic adhesions vary exceedingly, and may be the result either of middle-ear catarrh or suppuration. The following conditions may be found:--
(i) Adhesion of the handle of the malleus to the promontory, the rest of the tympanic membrane being movable.
(ii) Adhesions between other parts of the tympanic membrane and the inner wall of the tympanic cavity, either by bridles or bands of fibrous tissue, or by the membrane itself being adherent over a large area.
(iii) Adhesion of the edge of a perforation to the inner wall.
(iv) Adhesions surrounding the articulation between the incus and stapes, and the stapes itself.
=Indications.= Operation is justifiable in the case of adhesion of the malleus to the promontory if the rest of the membrane is freely movable; if the membrane bulges outwards and there is temporary improvement in hearing on inflation; and if examination shows that the labyrinth is intact. This operation is all the more indicated if there is marked deafness on both sides: it should then be attempted on the worse side. If, however, the intratympanic adhesions are extensive, it is very doubtful whether an attempt to separate the free part of the membrane from the part adherent to the inner wall is worthy of consideration.
It must also be remembered that adhesions in the region of the stapes cannot be seen, unless a large perforation of the membrane already exists. Operation is then only justifiable as a last resource if there is extreme deafness accompanied by distressing subjective symptoms.
=Operation.= Unless the patient is very sensitive or nervous, local anæsthesia is sufficient. It is more convenient for the patient to be sitting up in a chair than to be in the recumbent position. The surgeon works by reflected light. Before the operation is begun, the ear must be surgically cleansed and carefully dried.
(i) Adhesion of the handle of the malleus to the promontory. With a paracentesis knife the membrane is incised round the handle of the malleus (Fig. 191). A small sickle-shaped knife, fixed at right angles to its shaft, is then inserted through the incision (in front of or behind the malleus as may be most convenient to the operator) and is made to cut through the adhesions between the malleus and the promontory (Fig. 192). In order to make sure that this has been accomplished, a small ring-knife, such as is used in the operation of ossiculectomy, is passed round the tip of the malleus, between it and the inner wall of the promontory, and slight traction is then exerted in order to pull the handle of the malleus outwards from the inner wall.
Provided asepsis has been maintained, this small operation seldom gives rise to any inflammatory reaction. The after-treatment consists in inserting a strip of gauze into the auditory canal; if it becomes moist with secretion, it should be changed.
Many methods have been devised to prevent recurrence of adhesions, but few are successful. Amongst these are daily inflation of the ear by means of Politzer’s method or the catheter; the injection of oil into the middle ear; and the insertion of small pieces of celluloid between the malleus and inner wall of the promontory according to the method of Gomperz. Another method is to resect the handle of the malleus (Fig. 195). After being freed from the promontory as above described, the manubrium is cut through with a pair of fine scissors (Fig. 174) just below the processus brevis, and the lower fragment is removed by means of Sexton’s forceps (Fig. 193).
(ii) Adhesion between the membrane and the inner wall of the tympanic cavity. Siegle’s speculum should be used to determine the position and extent of the adhesions (Fig. 194).
There are two methods of operation:--
(a) In the case of bands forming a bridle between the tympanic membrane and inner wall, an attempt may be made to cut through them. This is done by incising the membrane with a paracentesis knife in front of or behind the adherent portion, and then inserting through this incision the sickle-shaped knife. By rotating it upwards or downwards, as the case may be, the bands forming the adhesions are cut through. If this has been successfully performed, and if the retraction of the membrane was solely due to these bands, the tympanic membrane will be found to be freely movable on diminishing the pressure of air within the external meatus by means of Siegle’s speculum.
(b) If the adhesions be extensive, the only method affording a chance of success is to separate the free portion of the tympanic membrane from the part adherent to the inner wall, leaving the latter in situ. To do this the membrane is incised with a paracentesis knife just beyond the margin of the adherent portion, the incision being carried right round the affected part. A tiny spatula, bent at right angles to its shaft, is then inserted through the incision and passed round beneath the movable portion of the membrane so as to free it completely (Fig. 192).
(iii) Adhesion of the edge of a perforation to the inner wall. If the middle-ear suppuration has only recently ceased, it may be sufficient to divide the adhesion with a small knife curved on the flat and afterwards force the tympanic membrane outwards by means of inflation through the Eustachian tube, and by rarefaction of the air within the external meatus. In the majority of cases, however, it is necessary to excise the adhesion, especially in the more chronic conditions. This is done by cutting through the movable part of the membrane just beyond the adherent portion (vide supra).
(iv) Adhesions surrounding the articulation between the incus and stapes, and the stapes itself. These adhesions can only be observed if a large perforation involves the upper posterior quadrant. Even then it may be anatomically impossible to see the stapes. The operation should only be performed if definite bands of adhesions can be seen. Sometimes, although rarely, it happens that such adhesions are present. If the incudo-stapedial joint be fixed to the inner wall of the tympanic cavity, the adhesions are separated from it by passing the knife between the joint and the inner wall. In order to cut through adhesions surrounding the base of the stapes, a small horizontal incision should be made along its upper margin, and also along the lower, if this is in view. This operation, however, is seldom of any value.
TENOTOMY OF THE TENSOR TYMPANI
=Indication.= The chief indication for this operation is marked retraction of the tympanic membrane, in a case of middle-ear deafness, in which there are no adhesions between the membrane and the inner wall of the middle ear, and in which it is assumed that the retraction is due to shortening of the tensor tympani muscle.
=Operation.= The first step of the operation is to incise the tympanic membrane with a paracentesis knife in a vertical direction just behind the margin of the malleus. At the same time the posterior fold can be cut through, if required, by continuing the incision upwards. Through the incision thus made Schwartze’s tenotomy knife (a very fine blunt-pointed instrument curved on the flat (Fig. 196)) is inserted, its point being directed upwards. The knife is pushed upwards until its shaft is on a level with the processus brevis. The handle is then rotated in a forward direction so that the sharp edge of the knife, which is kept close to the posterior border of the neck of the malleus, makes a circular movement forwards and downwards and thus cuts through the tendon of the muscle. If the knife has been too deeply inserted, the attempt to rotate the shaft forwards will be resisted by the projecting processus cochleariformis. To overcome this difficulty the shaft of the instrument is rotated backwards so as to raise the point of the tenotomy knife and thus free it; the instrument is then withdrawn slightly and the shaft again rotated forwards. The division of the tendon can be distinctly felt, and may be accompanied by a slight crackling noise; after this has been effected, the knife is rotated backwards and withdrawn through the incision in the tympanic membrane.
=After-treatment.= There is usually a slight effusion of blood within the tympanic cavity, but no special treatment is required beyond keeping the ear aseptic. Absorption takes place rapidly.
The result of the operation is disappointing. There is seldom any improvement with regard to hearing; a few cases, however, have been reported in which the attacks of vertigo have diminished in intensity.
TENOTOMY OF THE STAPEDIUS
=Indications.= They are limited.
(i) As the result of middle-ear suppuration the malleus and incus may become exfoliated. The theory has been advanced that the unopposed action of the stapedius muscle prevents free movement of the stapes in these cases, and for this reason tenotomy of its tendon is advocated.
This operation, however, should only be performed provided that the edge of the membrane is not adherent to the inner wall of the tympanic cavity, and there is no internal-ear deafness.
(ii) The operation is also performed as a preliminary measure to removal of the stapes (see p. 361).
=Operation.= The operation is simple, as the head of the stapes and the tendon of the stapedius muscle are usually within view in consequence of the destruction of the tympanic membrane. The ear is cleansed and dried, and the part rendered insensitive by the previous application of a pledget of cotton-wool soaked in cocaine solution. The tiny tendon is severed with a snick of the paracentesis knife, cutting through it from above downwards under good illumination.
=Results.= These vary; usually there is no improvement, but sometimes marked increase of hearing occurs. As the operation can do no harm and can be done without any inconvenience to the patient, it may be attempted subject to the restrictions given above.
REMOVAL OF GRANULATIONS FROM THE TYMPANIC CAVITY
=Indications.= Granulations should always be removed if conservative treatment fails.
=Operations.= (a) Cauterizing; (b) Curetting. The former method is employed when the granulations are very small and localized; the latter when they are multiple and larger.
=Cauterization.= The tympanic cavity is cleansed and rendered anæsthetic (see p. 310). The auditory canal and tympanic cavity are then carefully dried. This is of importance in order to prevent scalding of the surrounding tissues during the act of cauterization. The ordinary electric cautery is used; only a weak current is necessary as the point of the cautery, of necessity, is very small. Under good illumination, the cautery is inserted cold along the auditory canal until it just touches the granulation. The circuit is then closed, and on the point of the cautery becoming white-hot, it is pressed against the granulation and then rapidly withdrawn from the ear. The current should not be shut off until the cautery is withdrawn, otherwise it will adhere, on cooling, to the tissues with which it is in contact, and on withdrawal will cause bleeding.
Instead of the electric cautery, the granulations may be touched with a bead of chromic acid fused on to a probe, or with a saturated solution of trichloracetic acid. The galvano-cautery has the greatest effect. Chromic acid has the disadvantage that unless it is very accurately applied it tends to affect a larger area than was possibly intended. Trichloracetic acid, although more localized in effect, is not so potent.
After-treatment consists in blowing in a slight amount of boric acid powder and keeping the ear dry.
=Curetting.= This is performed by means of small ring-knives (Fig. 178) or sharp spoons. They vary in size, and are either straight or bent in different directions to the shaft of the instrument. The instrument selected depends on the position and size of the granulation.
To minimize the hæmorrhage, adrenalin may be added to the cocaine solution. The curette is made to encircle the granulation and cuts through its attachment with a firm movement, limited to the area of the granulation. Curetting should not be done in a haphazard fashion, but deliberately under good illumination. If bleeding occurs it must be arrested before further curetting takes place.
After-treatment. The ear is syringed out to remove any fragments of granulation tissue or blood-clot. It is then dried and a strip of sterilized gauze inserted. After twenty-four hours this is removed and drops of rectified spirits, if necessary containing ten grains of boric acid or a drachm of the perchloride of mercury lotion to the ounce, may be instilled into the ear three or four times a day.
=Dangers.= With due care none should occur. The following mishaps, however, have occurred from too violent curetting: (1) Injury or displacement of the ossicles; (2) internal-ear suppuration from dislodging of the stapes or injury to the promontory; (3) facial paralysis; (4) meningitis from injury to the tegmen tympani; (5) acute inflammation of the mastoid process.
=Results.= Provided that the granulations are localized and due to inflammation of the mucous membrane, a good result may be anticipated. If, however, there be underlying bone disease of the tympanic walls, or if the mastoid process be already affected, recurrences are usual, and further operative treatment may become necessary.
OPERATIONS UPON THE OSSICLES
DIRECT MOBILIZATION OF THE OSSICLES
The object of the operation is to improve the hearing by breaking down the fibrous adhesions with the tympanic cavity, which diminish the mobility of the ossicles.
=Direct massage of the malleus.= =Indications.= (i) As a therapeutic measure. If the malleus be adherent to the promontory and there is no improvement on inflation, but perhaps slight improvement as a result of pneumatic massage.
(ii) As a means of diagnosis. If temporary improvement takes place it may be assumed that the stapes is not absolutely fixed, and that the deafness is partly due to adhesions preventing movements of the ossicles, a condition which may point to the advisability of performing ossiculectomy in suitable cases.
=Operation.= The ear is rendered insensitive by means of cocaine or Gray’s solution (see p. 310).
The manipulation is carried out with a Lucae’s probe (Fig. 197). Within its handle is a spring to render its movements resilient; and at its tip is a cuplike depression to embrace the point of the processus brevis of the malleus. The tip of the probe may be covered by a fine layer of cotton-wool or india-rubber.
The probe is inserted, under good illumination, into the auditory meatus and is applied to the processus brevis of the malleus. The vibrations are given by the rapid movements of the hand from the wrist, the arm being kept fixed. This procedure, which may be painful, should not last longer than one minute. Frequently there is considerable reaction, shown by congestion about the processus brevis and Shrapnell’s membrane. It is therefore wiser not to repeat the procedure at shorter intervals than one week.
=Results.= It is difficult to foretell what the result will be, as it is chiefly dependent on the extent of the adhesions already existing within the tympanic cavity and on the mobility of the stapes within the fenestra ovalis. If the latter is already fixed, then improvement is impossible. If, however, the adhesions are limited, a better result may be obtained by this method than by pneumo-massage and inflation. The surgeon must be guided by the extent and duration of the improvement as to how long to continue the treatment. Unfortunately, relapses are not uncommon, though temporary benefit may be obtained.
=Massage of the stapes.= This is only done as a last resource in the hope of obtaining some improvement in hearing.
=Indications.= (i) In cases in which mobilization of the malleus has caused no improvement, and it is hoped, from the history of the case, that this is due to fibrous adhesions fixing the stapes within the fenestra ovalis. This condition must be carefully distinguished from otosclerosis or bony ankylosis of the stapes, in which latter conditions any such procedure is absolutely contra-indicated.
(ii) Direct mobilization may be undertaken as a preliminary step previous to removal of the stapes itself. If the stapes is movable and slight improvement occurs, then its removal may be justifiable under certain conditions. If, however, the stapes is fixed and no improvement occurs, then its removal will be attended with such difficulty as to almost negative this being attempted.
=Operation.= If a perforation of the upper posterior quadrant be present, a small pledget of cotton-wool soaked in a 20% solution of cocaine is brought into contact with the inner wall of the tympanic cavity. After a few minutes Lucae’s probe is placed in position against the head of the stapes and the vibratory movements are carried out. If no perforation of the drum exists, then it is first necessary to excise a flap in the upper posterior quadrant of the membrane.
=Difficulties.= The chief difficulty is anatomical. Projection forward of the upper posterior part of the tympanic ring or a deeply placed niche of the fenestra ovalis may prevent a view of the stapes.
If the membrane has to be incised, the slight amount of bleeding may also prevent a good view being obtained.
There is no actual danger in the operation, but if the stapes is fixed or if much force is used, it is by no means difficult to fracture the crura of the stapes.
REMOVAL OF THE OSSICLES
Except under the most rare conditions only the malleus and incus are removed; the stapes, if possible, being left undisturbed.
These operations will therefore be considered separately.
=Removal of the malleus and incus.= This operation was first proposed by Schwartze in 1873, and later by Kessel, Ludewig, Sexton, and Zeroni.
=Indications.= The indications for operation may be considered with regard to (1) chronic middle-ear suppuration and (2) non-suppurative middle-ear disease, whether the result of a previous middle-ear suppuration or of a chronic middle-ear catarrh.
In chronic middle-ear suppuration, the chief object of the operation is to ensure drainage and if possible to remove the cause of the suppuration; in non-suppurative conditions, to improve the hearing.
It may here be mentioned that the position of the perforation in the attic region is frequently of importance when considering the question of treatment. If situated in front of the malleus, the disease is probably limited to the outer attic region and malleus; if just behind the malleus, then probably both the malleus and incus are affected; but if the perforation extends farther back, involving the upper posterior quadrant of the drum, especially its bony margin, it suggests disease not only of the ossicles together with the walls of the aditus and antrum, but perhaps also of the mastoid process (Fig. 198).
(i) In chronic middle-ear suppuration. Before operation is considered, it is presumed that conservative measures, such as syringing, instillation of astringent and antiseptic drops, and washing out of the attic by means of Hartmann’s canula with various solutions, have been given a thorough trial and failed.
(a) If the suppuration be limited to the attic region (although the main portion of the tympanic membrane is intact), provided there is marked deafness and there are symptoms of lack of free drainage indicated by recurrent attacks of headache, a feeling of heaviness or giddiness, or pain radiating up the head on the affected side.
(b) If there be caries of the malleus and incus, and the outer attic wall, with recurrence of granulations after repeated removal, especially if accompanied by cholesteatomatous formation, provided there is no evidence of disease of the mastoid process itself.
(c) Although the general symptoms and the condition found on examination justify the complete mastoid operation, yet if the patient refuses to have this operation performed, the simpler operation of ossiculectomy may be undertaken if desired. This will permit of free drainage and diminish the risk of future intracranial complications. It should, however, be clearly explained to the patient that no guarantee can be given with regard to effecting a permanent cure as a result of this operation.
(ii) In non-suppurative conditions.
(a) If there be marked middle-ear deafness, the result of adhesions, and the malleus is fixed to the promontory. Operation is justifiable if it is found that after each inflation of the middle ear, improvement of hearing is obtained which, however, is not permanent but only temporary.
(b) If, as the result of artificial perforation, made under the conditions already laid down, improvement takes place temporarily, but a relapse occurs from closure of the perforation (see p. 340).
(c) If tinnitus and attacks of vertigo, due to marked retraction of the membrane, are temporarily relieved by inflation. In this case operation should only be carried out as a last resource after all other measures have failed to cure and if the symptoms are very severe and distressing.
(d) If there be marked middle-ear deafness with extensive adhesions on both sides and evidence points to the stapes being freely movable. The operation is justifiable, as an experiment, on the worse side.
=Operation.= The only operation to be considered is the intrameatal one. Stacke originally suggested a post-auricular incision, and reflecting the auricle forward, and, after removing the ossicle, to remove also the outer attic-wall by means of the chisel. This method, however, has now been given up as being too radical, but will be mentioned later on in connexion with the mastoid operation (see p. 397).
Unless contra-indicated, a general anæsthetic should be given, as it is not always possible to foretell whether the operation will be difficult or easy. In addition it may be necessary to curette out granulations and also to remove the outer wall of the attic. Unless the patient is very insensitive, this is almost impossible under local anæsthesia (see p. 311).
Before the anæsthetic is given, the ear should be filled with a 5% solution of cocaine containing a 1 in 2,000 solution of adrenalin chloride in order to diminish the bleeding during the operation.
The field of operation is isolated from the surrounding parts by covering the head with a sterilized towel having an opening cut in it just sufficient to expose the auricle and meatus.
The following are the steps of the operation: (1) freeing the malleus from its attachments to the tympanic membrane, and from the inner wall of the middle ear, if adherent to it; (2) cutting through the tendon of the tensor tympani muscle; (3) removal of the malleus; (4) removal of the incus; (5) removal of the outer wall of the attic; (6) curetting out of granulations, if present. The method of operation varies slightly according to the condition found.
=Removal of the malleus.= In post-suppurative and non-suppurative conditions the chief cause of failure is the recurrence of adhesions, so for this reason it is wisest to remove the membrane as completely as possible.
With a paracentesis knife, the membrane is incised below and behind the malleus. The incision is then carried upwards along its posterior border to the posterior fold, then round the complete margin of the tympanic membrane and along the anterior fold and border of the malleus, so as to meet the original point of the incision. The knife is then reinserted just in front of the processus brevis and cuts through the anterior ligament in an upward direction; in a similar fashion the posterior fold is also cut through (Fig. 190).
The next step is tenotomy of the tensor tympani muscle (see p. 345).
The malleus thus freed can easily be removed by seizing its handle with a pair of Sexton’s (Fig. 193) or crocodile forceps (Fig. 179). In removing the malleus it is necessary to remember that its head is situated within the attic and therefore cannot be pulled out directly, but must first be drawn downwards until it is seen within the tympanic cavity. If this precaution be not taken, the neck of the malleus may be broken, leaving the head behind. If this takes place its extraction may be a matter of difficulty.
Instead of using Sexton’s forceps, the malleus may be removed by means of Wilde’s snare. This is the method advocated by Schwartze. After cutting through the tensor tympani muscle, the loop of the snare is threaded over the head of the malleus and guided upwards until it embraces its neck. The loop is then drawn tight so as to hold the malleus firmly in its grasp. The ossicle is extracted by first pulling it downwards (Fig. 199), so as to dislodge it from the attic, and then outwards (Fig. 200).
Another method of extracting the malleus, and in my opinion the one to be preferred, is by Delstanche’s ring-knife (Fig. 201). This instrument differs from the ordinary ring-knife in that the upper border of its anterior part is especially sharpened so as to form a fine cutting surface. After the malleus has been freed from the membrane by means of the paracentesis knife, Delstanche’s ring-knife is made to encircle its handle. It is then pushed gradually upwards, keeping as close to the posterior border of the malleus as possible, until it cuts through the attachment of the tensor tympani. In doing this the instrument will embrace the neck of the malleus (Fig. 202). This permits of sufficient leverage to extract the malleus by gentle traction in a downward and outward direction without danger of fracturing its shaft. If much resistance be felt, probably the tensor tympani muscle has not been cut through, and another attempt should be made to do this before trying further extraction. The advantage of this instrument is, that once the knife has encircled the malleus it should be possible not only to cut through the tensor tympani, but to extract the bone itself without the use of any other instrument. If Schwartze’s tenotomy knife be used, two tenotomy knives are required, one for the right and one for the left ear. Delstanche’s ring-knife is equally good for either ear.
=Extraction of the incus.= Although it is frequently stated that extraction of the incus is more difficult than that of the malleus, in reality it is the easier part of the operation as, unlike the malleus, it has no firm attachments.
After removal of the malleus all hæmorrhage must be arrested and a view obtained of the inner wall of the tympanic cavity. If it be possible to see the long process of the incus and its articulation with the head of the stapes, the articulation should be cut through with a small sickle-shaped knife. The knife is inserted just in front of the long process of the incus and, keeping close to it posteriorly, is made to cut downwards and backwards, thus separating its connexion with the stapes. Frequently the long process cannot be seen, or it may indeed have already disappeared as a result of caries. Theoretically this delicate manœuvre is performed in order to prevent injury or dislodgment of the stapes during the act of removal of the incus. From a practical point of view, however, it does not appear to make any difference whether the incudo-stapedial articulation is cut through or not.
A variety of instruments have been described for the purpose of removal of the incus. Ludewig’s incus hook (named after Ludewig, who was one of the first to draw attention to this operation) is still recommended by many as being the best. It consists of a solid curved hook, having a length of 5 millimetres and a width of 2 millimetres, bent at right angles to its shaft (Fig. 203). A pair of these are necessary, one for each ear; also several sets of different sizes may be required owing to the variation in depth, height, and roof of the attic region. I, however, prefer Zeroni’s (Fig. 204). This hook, instead of being solid, consists of a steel eyelet having a backward curve similar to that of Ludewig’s.
The technique is the same whichever pattern is employed. The instrument is inserted in such a fashion that the hook is directed upwards, having its concavity backwards. It is passed into the attic at the point previously occupied by the head of the malleus. The shaft of the instrument is then rotated backwards so that the hook passes over the body of the incus (Fig. 205). As the rotatory action is continued downwards and finally forwards, the incus is dislodged from its position and forced into the tympanic cavity. It can now be seized by a pair of Sexton’s or crocodile forceps and removed. If it falls into the floor of the tympanum, it can usually be dislodged by syringing, or else by means of a small hook passed in circular fashion along the floor of the cavity.
=Removal of the outer wall of the attic.= In the majority of cases of chronic middle-ear suppuration, it is advisable to remove the outer wall of the attic in addition to performing the simple operation of ossiculectomy. If granulations be present they should first be removed, in order to give a clear view of the inner wall of the tympanic cavity, which can usually be obtained, owing to the fact that a large perforation of the membrane is probably present. The malleus and incus are then removed.
To remove the outer wall of the attic a small but strong pair of punch-forceps is required (Fig. 206). The instrument is directed along the roof of the auditory canal, its cutting edge held upwards and the blades kept slightly open, until the outer blade is felt to pass over the outer wall of the attic. The handle is then depressed so that the end of the forceps is forced upwards and embraces the outer wall between its points (Fig. 207). This is confirmed by attempting to withdraw the forceps, which the outer bony wall of the attic will now prevent. The position of the forceps being assured, its blades are brought together by pressure on the handle, and in this manner a small portion of the bone is punched out. In this way the outer wall of the attic is gradually cut away in small fragments. Sometimes this is extremely easy, owing to the auditory canal being large and the outer wall of the attic being thin and easily cut through. In other cases, owing to the thickness of the bony walls or to the narrowness of the canal, it is extremely difficult. If the outer wall of the attic has been completely removed, a fine probe, whose point is bent upwards, can be inserted into the attic and then withdrawn without encountering any obstruction, owing to the roof of the attic and outer wall of the auditory canal being now continuous. In some cases this part of the operation may not be necessary, as the outer wall of the attic may have already disappeared as a result of the caries.
Into the larger opening thus made, small curettes are passed upwards and backwards and any granulations in the region of the aditus and entrance to the antrum are curetted away. Finally the cavity is thoroughly swabbed out with the pledgets of cotton-wool soaked in a 1 in 2,000 alcoholic solution of biniodide of mercury. The cavity is then dried and a small drain of sterilized gauze inserted within the auditory canal, the ear being afterwards covered with a pad of gauze kept in position by a bandage.
=After-treatment.= In cases of non-suppuration there is rarely any pain, and if asepsis has been maintained, there is seldom much discharge beyond slight sanious oozing. Unless there is considerable discomfort the dressing need not be changed for two or three days. If possible the ear should not be syringed, but merely mopped out with pledgets of cotton-wool moistened with boric lotion and then dried, the gauze drain being afterwards inserted. This process may be repeated daily until healing is complete.
In middle-ear suppuration there may be considerable pain, owing to the forcible bruising of the tissues of the inner part of the auditory canal during the act of removal of the outer wall of the attic. Sometimes, indeed, there is much swelling of the lining membrane of the canal, with the occurrence of furuncles as the result of septic infection.
If there be no pain, the after-treatment is the same as above described, excepting that it may be necessary to syringe out the ear at each dressing owing to the discharge. If there be much pain, with swelling of the canal, the gauze drain should be removed and a 10% solution of carbolic acid in glycerine frequently instilled into the meatus. Subsequently drops of rectified spirit may be substituted.
=Difficulties.= 1. If the auditory canal be very small there may not be sufficient room to insert the instruments through the speculum. In such cases, if there be no middle-ear suppuration, it is wiser to leave the condition alone. If, however, suppuration exists, either the conservative treatment must be continued or the complete mastoid operation recommended.
2. Hæmorrhage, especially on curetting away the granulations, may be sufficient to prevent a view of the deeper parts. It can, however, usually be arrested quickly by plugging the auditory canal with gauze soaked in adrenalin and cocaine solution. Even if the surgeon has to wait a few moments, this must be done, as it is very necessary to obtain a clear view of the field of operation.
3. Extensive adhesions between the membrane and inner wall may render it difficult to separate the shaft of the malleus without fracturing its neck.
4. In old-standing cases in which there is a large perforation of the membrane, the malleus may be so retracted as not only to be difficult to see but difficult to seize. In this particular case, division of the tensor tympani with Schwartze’s tenotome and then extraction of the malleus by means of Sexton’s forceps is a better procedure than trying to encircle its shaft with Delstanche’s ring-knife.
5. Removal of the incus by the ordinary instruments may be rendered impossible owing to the narrowness of the attic posteriorly from chronic thickening of its walls. In these cases a seeker, such as Schwartze uses in the mastoid operation (Fig. 219), may be employed with advantage. It is passed over the incus in the same manner as an incus hook.
=Accidents.= 1. Fracture of the handle of the malleus. This is the result of too forcible extraction. If a Delstanche’s ring-knife has been used, this may be due to the tensor tympani not having been cut through; this should now be done. The head of the malleus is then removed either by means of a small hook or some form of curette bent at right angles to its shaft, depending on what is most suitable for the case in question.
2. Failure to extract the incus. In the course of a chronic middle-ear suppuration, the incus may become exfoliated or gradually disappear as the result of caries. It does not therefore always follow that inability to extract the incus means that the surgeon has failed in his manipulations, although frequently this is the case, the instruments failing to extract the incus, or perhaps dislodging it into the mastoid antrum, a fact which is difficult to determine and may only be discovered if the subsequent performance of the complete mastoid operation becomes necessary.
3. Facial paralysis. This accident is usually due to the incus hook not being inserted high enough up, so that, instead of entering the attic, it presses on the inner upper border of the tympanic cavity, and on being rotated in a backward and downward direction, it follows the line of the facial canal (Fig. 208). If much force be employed the frail wall of the facial canal will be fractured or pressed in on the underlying facial nerve. It is very rarely, however, that the nerve is completely crushed or torn through, and therefore recovery almost invariably takes place.
The facial nerve may also be injured whilst curetting away granulations in the upper posterior part of the tympanic cavity.
4. Injury to or removal of the stapes. This very rarely occurs during the act of removal of the incus, but is generally the result of too violent curetting. If only the crura be broken off, it does not matter; but if the stapes itself be dislodged from the fenestra ovalis, the subsequent symptoms may be attacks of vertigo, nausea, and vomiting. As a rule these symptoms subside. If, however, the internal ear becomes infected (although judging from literature and my own experience this is of very rare occurrence), complete deafness or even meningitis may occur as the result of labyrinthine inflammation or suppuration.
=Results.= (a) With regard to arrest of the disease. If the disease be limited to the ossicles themselves and to the anterior and outer part of the attic, a favourable prognosis may be given. Complete cessation of the discharge and scarring over of the affected part may take place within a month, or after a much longer period.
If, however, the disease be more extensive and involves the walls of the attic posteriorly and the region of the aditus, as shown by the presence of a fistula or granulations, the prognosis is uncertain and continuance of the discharge and recurrence of the granulations may eventually necessitate the complete mastoid operation.
(b) With regard to hearing. In the case of chronic attic suppuration the hearing power may be increased to a distance of 12 feet off for conversation, provided the internal ear is not affected and the stapes is not fixed within the fenestra ovalis; occasionally the result is much better. On the other hand, the hearing power may be made worse.
In post-suppurative conditions, the prognosis is not so favourable, as frequently the stapes is already bound down by adhesions; this is the more probable in the case of chronic middle-ear catarrh. In both these conditions the operation should never be performed without first explaining to the patient that it is practically experimental. The chief cause of failure is the recurrence of adhesions, which even the most complete and careful operation cannot always prevent.
=Removal of the stapes.= This operation is still in its infancy and it is, as yet, impossible to express an opinion with regard to its success or failure, and therefore the indications laid down are only tentative.
The objects of the operation are: (1) to improve the hearing in cases of deafness presumably due to fixation of the stapes within the fenestra ovalis, and (2) to relieve symptoms of tinnitus and vertigo due to the same cause.
Before this operation is advised careful examination must be made in order to determine whether the labyrinth is intact, especially if the operation is undertaken with the view of improving the hearing.
=Indications.= (i) If there be ankylosis of the stapes on both sides, accompanied by marked deafness and distressing subjective symptoms, operation is justifiable on the worse side.
(ii) In a one-sided affection provided the subjective symptoms of noises and giddiness are so oppressive as to render the patient’s life unbearable. The operation, of course, must not be attempted unless every other form of treatment has failed.
=Operation.= The operation may be performed either through the meatus, or by reflecting forward the auricle by means of the post-aural incision, and chiselling away the upper posterior part of the bony meatus in the manner suggested by Stacke (see p. 397).
The choice of the operation depends principally on the existing anatomical and pathological conditions.
If the meatus be very narrow the intrameatal method may fail to bring the stapes into view. If, on the other hand, the meatus be wide and there be a large perforation, the result of previous middle-ear suppuration, the incudo-stapedial joint or the head of the stapes itself may be actually within the field of operation.
The intrameatal method. The patient should be fully anæsthetized and the operation performed under good illumination. A portion of the tympanic membrane in its upper posterior quadrant is excised in order to bring into view the incudo-stapedial joint. The incision is begun just behind the handle of the malleus and is carried upwards and backwards in a circular fashion through the tympanic membrane along the posterior fold, and then downwards for a little distance along its margin. The flap so made either falls downwards, or can be pressed downwards so as to expose to view the inner wall of the tympanic cavity. With a small knife, curved on the flat, the incudo-stapedial joint is cut through. With a fine hook the long leg of the incus is dislocated forwards or backwards from the stapes. The head of the stapes will now be seen, with the tendon of the stapedius muscle running horizontally backwards. With a paracentesis knife, the tendon is cut through close to its attachment to the stapes.
A fine, blunt-pointed hook is now inserted between the crura of the stapes. If the stapes be not firmly ankylosed it can usually be removed by slight traction. If, however, it be firmly fixed, its crura will probably be broken. To determine whether the stapes is ankylosed or not, direct pressure of the probe on the head of the stapes may be necessary. If the head of the stapes cannot be seen, it is advisable, as suggested by Dench of America, to punch out part of the upper posterior margin of the attic-wall with the attic forceps (see p. 357).
The post-aural method. The preliminary steps of the operation are the same as have been already described for removal of an exostosis (see p. 318).
After separating and reflecting forward the membranous from the bony portion, the upper posterior part of the tympanic ring is chiselled away until a view of the stapes can be obtained. The incus is then disarticulated from the stapes.
If the stapes be ankylosed by fibrous adhesions to the margins of the fenestra ovalis, an attempt may be made to free it by cutting through the adhesions with a fine bistoury. If this be impossible, a sharp hook may be fixed into the margin of the plate of the stapes in the hope of forcibly extracting it. Some authorities advise chiselling away of the margins of the fenestra ovalis. If an opening can be made into the vestibule by this means, it is hoped that the resulting scar tissue will form a membrane more resilient than the ankylosed stapes, and, in this way, permit vibrations of sound to enter the labyrinth. This operation, however, necessitates the complete mastoid operation in order to freely expose the region of the fenestra ovalis.
=After-treatment.= It is sufficient to protect the ear with a small gauze drain. Occasionally there may be considerable vomiting and vertigo as an immediate result of the operation; this usually passes off within two or three days. Meanwhile the patient should be kept in a recumbent position and, if necessary, given small subcutaneous injections of morphine.
=Difficulties.= The chief difficulty is to obtain a good view; even if this be obtained it is difficult to extract the stapes without fracture of its crura.
=Dangers.= As a result of opening up the labyrinth, one would expect considerable risk of infecting the internal ear. Judging from recorded cases, this, however, seldom occurs.
=Results.= The chief advocate of the removal of the stapes is Jack of Boston (Boston Med. and Surg. Journ., January, 1895), who again in 1902 (Archives of Otology, vol. xxxi, p. 407) stated: (1) that removal of the stapes did not destroy the hearing but sometimes improved it; (2) that the operation upon cases of moderate deafness might give brilliant results but was also attended with some risk to the hearing; (3) that the operation on the profoundly deaf was not advisable, as usually the stapes could not be removed owing to surrounding adhesions, and even if it were, no improvement was likely to occur owing to the sound-perceiving apparatus having probably already undergone irremediable changes.
Blake (Archives of Otology, vol. xxii), on the other hand, states emphatically that stapedectomy is harmful rather than beneficial.
The question, therefore, of removal of the stapes from the point of view of hearing is purely experimental. If there be bony ankylosis, it will be found impossible to remove the bone, and an attempt to do so will result in fracture of its crura. If, on the other hand, it be not ankylosed but movable, probably massage or, in cases of perforation of the tympanic membrane, direct mobilization of the bone will give results as good as those following stapedectomy.
The most favourable results are to be expected in those cases in which the operation is performed to relieve symptoms the result of previous middle-ear suppuration. In otosclerosis no benefit is ever obtained, and therefore the operation is absolutely contra-indicated.
On the other hand, there is ample evidence that the hearing power, in spite of removal of the stapes, may be retained. As an example may be quoted a case in which the stapes was removed accidentally in curetting out the ear after the removal of the malleus and incus, and in which I afterwards performed the complete mastoid operation owing to the continuance of the middle-ear suppuration. In spite of this, whispering could be heard at a distance of 20 feet (Journal of Laryngology, &c., vol. xxii, p. 33).
IV. OPERATIONS UPON THE EUSTACHIAN TUBE
Under this heading may be considered manipulations requiring special technical knowledge and skill: (1) Catheterization; (2) passing of bougies; and (3) washing out the tympanic cavity through the Eustachian tube.
CATHETERIZATION OF THE EUSTACHIAN TUBE.
=Indications.= (i) As a means of diagnosis in order to determine (a) the amount and character of the obstruction within the Eustachian tube; (b) the condition of the mucous membrane and whether any exudation is present within the middle ear.
(ii) For the purpose of treatment. (a) In order to instil medicated drops or vapours into the Eustachian tube and tympanic cavity; (b) as a preliminary measure to the passage of bougies into the Eustachian tube or to washing out the tympanic cavity through the Eustachian tube.
(iii) Catheterization is preferable to Politzer’s method if only one ear is affected. Politzer’s method, on the other hand, is preferable to catheterization (a) in small children; (b) in the case of slight middle-ear catarrh if both ears are affected; (c) if the passing of the catheter is very difficult and causes pain owing to nasal obstruction; (d) in nervous individuals who object to the catheter; (e) if the sudden inflation by means of Politzer’s method is more effectual than by catheterization.
Points to notice before inflation. 1. Care must be taken that the lumen of the catheter is not obstructed, and that the compressed air bag and auscultation tube are also in working order.
2. The nose must be cleansed of all secretion; if filled with crusts or in a septic condition, inflation must be avoided.
3. The patient should be sitting. Sometimes on inflation of the ear, especially for the first time, an attack of giddiness or faintness may occur.
4. The nose should always be examined to see that the passage is free. If it be obstructed catheterization may be impossible, or some special manipulation will be required in order to pass the catheter through the nose.
5. In order to prevent muscular contraction of the palatal muscles, which may grip the end of the catheter and so prevent its entrance into the orifice of the Eustachian tube, the patient should be told to breathe quietly and keep the eyes open.
A short silver or plated catheter is usually used. It is 5 inches in length and curved at its extremity. To indicate the position of the point of the catheter in the post-nasal space, a ring is attached to its outer and wider extremity corresponding with the concavity of the curvature of its beak (Fig. 209). The size of the catheter varies in diameter from Nos. 1 to 4 English size, that is, the same scale as used for urethral catheters. The source of compressed air used for the inflation is usually a Politzer bag having an india-rubber tube attached. At its end is a vulcanite pointed nozzle which accurately fits into the wider extremity of the catheter.
=Technique.= The patient is seated facing the surgeon, the head being supported by a prop or by an assistant. If the patient be at all sensitive, it is wiser to spray a very small quantity of a 2 or 5% solution of cocaine or eucaine into the nose, or, better still, to pass gently a probe tipped with a small pledget of cotton-wool soaked in the cocaine solution along the inferior meatus. This will effectively anæsthetize the region of the pharyngeal orifice of the Eustachian tube, which is the most sensitive part.
The surgeon stands in front of the patient. The larger extremity of the catheter is held lightly between the thumb and first finger of the right hand, its beak being turned downwards, whilst the tip of the nose is tilted up by the thumb of the left hand (Fig. 210). In introducing the catheter into the nostril, the right hand is kept low down so that the stem of the catheter is almost in a vertical position. In this way the tip passes over the floor of the vestibule. As the catheter is gently pushed through the nose the right hand is raised so that the instrument assumes the horizontal position and passes backwards between the septum and the inferior turbinal, its beak being kept in close contact with the floor of the nose (Fig. 211). As the beak of the catheter enters the post-nasal space, it will be felt to glide over the soft palate.
With regard to the best method of introducing the beak of the catheter into the orifice of the Eustachian tube, opinions vary. Of the many methods advised only two will be given.
The first is more suitable to those who have not had much experience in using a catheter; the second is the one naturally adopted by an expert.
The first method. The catheter is pushed backwards until it is felt to impinge against the posterior wall of the naso-pharynx. The beak, which at this stage is directed downwards, is next rotated a quarter of a circle inwards so that it points horizontally towards the opposite side; the position is shown by the ring at its outer extremity (Fig. 212). The catheter is now gently withdrawn until the beak is felt to catch against the posterior edge of the vomer. During these procedures the stem of the catheter should rest on the floor of the nasal cavity. The manipulations are carried out with the right hand whilst the outer extremity of the catheter is kept fixed in position by means of the thumb and finger of the left hand.
The catheter is next pushed a short distance backwards to free it from the soft palate and rotated downwards, and finally round in an outward direction until the ring points to the outer canthus of the eye on the side to be catheterized (Fig. 213).
The point of the instrument should now engage the Eustachian tube; if, however, inflation shows this not to be the case the probability is that the catheter has been pushed too far backwards and rests on its posterior lip. This can be remedied by drawing it a little further outwards.
The second method. The catheter, with its beak turned downwards, is passed gently and rapidly along the inferior meatus of the nasal cavity, and at the same time rotated slightly outwards against the inferior turbinal bone. Whilst the catheter is within the nose, this outward rotation is prevented by the narrowness of the inferior meatus, but as soon as the beak of the catheter has passed behind the level of the inferior turbinal into the free post-nasal space, it will revolve outwards and upwards and in so doing will enter the Eustachian tube, which lies just behind and above the posterior end of the inferior turbinal bone.
Provided there be no abnormal obstruction within the nose, this method is an exceedingly simple one. With the practised hand the manipulation can be carried out so smoothly and quickly that the catheter will be in position before the patient has had time to realize the fact.
=Difficulties.= 1. Irritability of the mucous membrane. The passing of the catheter through the nose may set up a violent spasm of sneezing or coughing. When the beak has entered the post-nasal space, the irritation may cause such intense contraction of the palatal muscles that the point of the catheter may become fixed and its movement rendered impossible. If this takes place, the catheter should be withdrawn and the part anæsthetized by means of cocaine and eucaine solution, which is best applied locally on a pledget of wool at the end of a probe.
2. Partial nasal obstruction. On inspecting the nose the obstruction is usually found to be due to a deviated septum or spur, or to adhesions situated at its anterior part. Sometimes a passage can be effected by simply diminishing the curve of the catheter. At other times the obstruction can be overcome by introducing the catheter with its stem held upwards and outwards, so that on entering the nose the beak dips in beneath the anterior end of the inferior turbinal. As the catheter is pushed gently inwards its outer extremity is brought round with a circular movement so that it gradually assumes the horizontal position. No force must be used. As the catheter is pushed farther in, it may rotate to a varying degree according to the formation of the nasal cavity. Sometimes, indeed, the catheter may make a complete rotation during its passage through the nose. At other times, after the obstruction is passed, the catheter is best pushed through the nose with the beak pointing directly upwards. The great point is gentleness; the catheter should be allowed to take whatever position suits it best, but after the beak has entered the post-nasal space the stem should lie horizontally along the floor of the nose and its beak should point downwards.
3. Complete nasal obstruction. If the obstruction be one-sided, then the catheter must be introduced into the nasal space through the opposite side.
This is performed in the ordinary manner, except that the catheter must be longer and possess a larger curvature. On reaching the post-nasal space, its beak is turned round so as to point towards the outer canthus of the eye on the affected side. It may be necessary to alter the curve more than once in order to get the point of the catheter to exactly engage into the orifice of the Eustachian tube.
If both sides be completely obstructed, the only method to adopt is catheterization from the mouth. The ordinary catheter is used. It is passed into the mouth, its beak being directed upwards, until it reaches the posterior wall of the pharynx. The catheter is then pushed directly upwards until its stem impinges against the soft palate. The beak is then turned outwards until it lies almost horizontally. In this position it should enter Rosenmüller’s fossa. The catheter is now withdrawn a little and should be felt to pass over a slight obstruction--the posterior lip of the Eustachian orifice. By gently pressing the beak slightly outwards, it should engage within the entrance of the Eustachian canal.
4. Obstruction within the post-nasal space. A common error in introducing the catheter is to push it too far backwards, so that on rotation of the beak outwards it passes behind the Eustachian tube and lies in Rosenmüller’s fossa. In this position the sounds referred to the examiner’s ear through the auscultation tube during the act of inflation differ from the normal sounds in that they are soft and distant. In a case of doubt inflation should again be practised with the catheter in varying positions. If the catheter be in the correct position, the patient should be able to talk without discomfort, and there should be no tendency to retching or coughing. If, however, the beak lies in Rosenmüller’s fossa, considerable irritation is caused, and on inflation the patient feels the air in the throat and not in the ear.
Catheterization may be rendered difficult by the presence of a large pad of adenoids or of a tumour; or inflation of air into the Eustachian tube may be quite impossible owing to the occlusion of its pharyngeal orifice, the result of scarring.
=Mishaps.= 1. Rupture of the tympanic membrane. With a normal membrane this is difficult to produce, in spite of even forcible inflation. Such an accident usually occurs at the site of some previous scar or atrophic patch in the membrane. If it occurs, there may be a temporary feeling of giddiness, noises, and pain in the ear. Inflation, of course, should be stopped at once and the ear protected for a day or two by plugging the meatus with a piece of cotton-wool.
2. Severe epistaxis. This is usually the result of trying to force the catheter through an obstructed nose, but it may also take place, though rarely, when manipulations have been carried out in a gentle fashion.
3. Syncope. This is fortunately of rare occurrence and usually only happens on the first occasion that the catheter is passed. For this reason the patient should always be in a sitting posture, and on the slightest appearance of pallor or faintness the catheter should be withdrawn. The attack invariably passes off, but for the moment it is very unpleasant.
4. Surgical emphysema. If the point of the catheter lacerates the mucous membrane, the air may be forced into the submucous tissue. This mishap, however, rarely occurs as the result of simple catheterization, but is more likely to follow forcible attempts to pass a bougie into the Eustachian tube.
PASSING OF THE EUSTACHIAN BOUGIE
=Indications.= This may be done for the following reasons:--
(i) As a means of diagnosis, to demonstrate the existence and position of a stricture.
(ii) To dilate a stricture.
(iii) As a therapeutic measure, to treat the mucous membrane of the Eustachian tube by means of a medicated bougie.
Bougies are made of various materials, but for ordinary purposes the gum-elastic is the best. They are about 7 inches in length with a slightly bulbous point.
In the adult the length of the Eustachian tube is approximately 1-1/2 inches, of which 1 inch forms the cartilaginous and 1/2 inch the osseous portion. The narrowest part of its lumen is known as the isthmus, and is situated at the junction of its cartilaginous and bony portion. On passing the bougie through the catheter into the Eustachian tube, it is essential to know how far its point is projecting beyond the point of the catheter. For this purpose the bougie may be marked at its outer extremity. Five inches from the point of the bougie, that is, the same length as the catheter, is a black band a centimetre in length; a centimetre farther up is another black band; and again after an intervening space of a centimetre is a third black band (Fig. 214).
=Technique.= The catheter is introduced in the ordinary way, and its position within the entrance of the Eustachian orifice is verified by means of inflation. It is kept fixed with the left hand, and the bougie is pushed into the catheter until the beginning of the first mark on the former just reaches the outer extremity of the latter; the tip of the bougie will now be flush with the point of the catheter. If there be no pain and no resistance, the bougie is very gently pushed on until the beginning of its second black band just enters the catheter. Its point will now project 2 centimetres within the Eustachian tube; that is, to about the region of the isthmus. If the bougie has been successfully introduced into the Eustachian tube, the patient generally states that the instrument is felt within the ear itself. No force should be used for fear of making a false passage, and with gentle manipulation it is very rare for actual pain to occur. On reaching the isthmus resistance may be met with, but by the exercise of slight pressure the bougie can usually be made to pass through it; if there be much resistance the bougie should be withdrawn and a finer one substituted. After passing through the isthmus, the bougie may be pushed in another centimetre, but no further, in case it may actually enter and injure the contents of the tympanic cavity.
After the tip of the bougie has passed through the isthmus the surgeon will hear its movements through the auscultation tube as a rub or crackling sound. It is left in position for five or ten minutes and then withdrawn. The ear should then be gently inflated, when the air entry into the tympanic cavity will probably be found to be much more free.
As the passage of the bougie causes a certain amount of reaction, it should not be passed oftener than once a week. Although no force should ever be employed, the largest possible bougie should be passed at each successive sitting until complete dilatation has been obtained.
=Difficulties.= 1. If the catheter be not in position, the bougie may pass behind the tip of the Eustachian orifice and enter Rosenmüller’s fossa. This can usually be felt by the patient as a pricking sensation in the throat, and may produce retching and coughing.
2. A stricture of the Eustachian tube may be so great as to prevent entrance of the bougie.
=Dangers.= (a) Surgical emphysema. If the mucous membrane be lacerated by the bougie, air may be forced into the subcutaneous tissues on inflation, after its withdrawal. In some cases the surgical emphysema is so considerable as to involve the side of the neck and face, and indeed has been known to necessitate the performance of laryngotomy.
The best treatment is to make the patient suck ice and to forbid all attempts at blowing the nose and coughing. Sometimes it is also necessary to scarify the pharynx and soft palate with a small bistoury. Recovery may be hastened by gentle massage of the neck and face. Inflation should not be attempted again for at least a week.
(b) The bougie may be pushed in too far and cause injury to the contents of the tympanic cavity.
(c) The tip of the bougie may break off whilst in the Eustachian tube. With a gum-elastic bougie this is very rare, but it is more likely to occur if the brittle celluloid bougies are used. To prevent this unfortunate disaster the bougie should be carefully examined before passing it, to see that it is not cracked nor broken. If such an accident does happen it is wiser to do nothing, because as a rule the fragment is afterwards expelled spontaneously.
=Results.= If the obstruction be fairly recent and limited to the pharyngeal end of the Eustachian tube, excellent results may be obtained by using either the simple bougie or the catgut variety moistened with a 5% solution of silver nitrate.
Owing to the general thickening of the tube, there is a marked tendency for further stricture to take place in the more chronic cases, even if a temporary improvement is obtained, and for this reason the use of the bougie is seldom to be recommended.
WASHING OUT THE TYMPANIC CAVITY THROUGH THE EUSTACHIAN TUBE
=Indications.= (i) In chronic middle-ear suppuration in which the perforation is situated in the anterior inferior quadrant and the continuance of the otorrhœa is apparently due to the secretion not being able to drain from the tympanic cavity. This method may be employed to effect drainage and in order to cleanse the tympanic cavity thoroughly before the instillation of medicated drops. In these cases the floor of the tympanic cavity is usually at a considerable depth beneath the lower limit of the membrane (Fig. 186).
(ii) In order to remove a small foreign body lying on the floor of the tympanic cavity which cannot be expelled by syringing. The operation is only tentative and is seldom successful.
=Contra-indications.= (i) If there be acute middle-ear suppuration; (ii) if the perforation be very small, as there will be a considerable risk of the fluid being driven into the mastoid antrum and further infecting it.
=Technique.= A catheter of wide calibre is passed in the ordinary manner. Inflation is practised to see if it is in the right position. The left hand fixes the outer extremity of the catheter at its entrance within the nose and keeps it in position. The patient inclines the head over to the affected side and holds a receiver beneath the ear. A small brass syringe whose nozzle accurately fits the outer extremity of the catheter is used. Slight force may be required during the act of syringing, but must not be sufficient to cause pain within the ear. A certain amount of fluid always escapes into the throat although the catheter is in its right position, and this may set up an attack of retching and coughing. To avoid this the patient should incline his head slightly forward as well as to the affected side and breathe gently with the mouth open. If the manipulation be successful the fluid will trickle out of the external meatus.
A foreign body is rarely expelled by this method, as the force of fluid syringed into the Eustachian tube is seldom sufficient, and it is not wise to use too great pressure. In order to expel all the fluid from the tympanic cavity, the ear is afterwards inflated by Politzer’s method, and at the same time the fluid is mopped out of the ear by means of pledgets of cotton-wool.
=Results.= If the continuance of the middle-ear suppuration has been chiefly due to the retention of the purulent secretion in the lower part of the tympanic cavity, this method of treatment is frequently most satisfactory. In other cases no benefit is obtained owing to the suppuration being due to other causes.
=Dangers.= The chief danger is the infection of the mastoid cells.
Chapter V
OPERATIONS UPON THE MASTOID PROCESS: WILDE’S INCISION AND SCHWARTZE’S OPERATION
With few exceptions the conditions requiring operative procedures on the mastoid process are the result of some suppurative lesion which has originated within the tympanic cavity.
The object of such operations is to arrest or eradicate the disease which, by further extension through the bony walls of the temporal bone, might eventually cause death by giving rise to some suppurative intracranial complication.
For their successful performance a knowledge of the anatomical relationships of the mastoid process is essential. It is sufficient here to remind the reader of the main surgical points in this connexion (Fig. 215).
SURGICAL ANATOMY OF THE MASTOID AREA
=The mastoid antrum.= At birth the mastoid antrum is almost fully developed. In infancy it is situated superficially and at a much higher level in relation to the auditory canal than in the adult. In the infant, also, the petro-squamous and the squamo-mastoid suture are still patent. As the mastoid cells develop, the antrum gradually becomes more deeply placed, so that in the adult it is from half to three-quarters of an inch from the surface.
Its roof, the tegmen tympani, is continuous with that of the attic. Anteriorly it is separated from the external auditory meatus by the posterior wall of the auditory canal, whose innermost margin forms the outer wall of the aditus. On its inner wall lie the semicircular canals, whilst posteriorly the lateral sinus is separated from it by an intervening layer of mastoid cells or compact bone. Between the semicircular canals and the lateral sinus is a small area composed of a thin layer of bone, separating the antrum from the posterior fossa of the cranial cavity.
=The mastoid process.= In the infant this is undeveloped and is merely represented by a small bony protuberance. By the fourth year it has practically reached the adult type.
Anatomically the mastoid process can be subdivided into three chief types: (1) the pneumatic, in which the cells are few and large; (2) the diploic, containing numerous small cells; and (3) the compact, in which the bone is extremely dense. Mixed types are frequently found, the cortex, as a rule, being more dense than the deeper portion. Occasionally it is uniformly sclerosed, almost of the consistence of ivory, but in these cases the condition is usually pathological, the result of chronic inflammation of the mastoid process.
The mastoid cells converge towards the antrum and may be divided into two groups: (1) those extending vertically downwards to the tip of the mastoid process; and (2) those lying between the antrum and the sigmoid process of the lateral sinus. In addition to these two groups, it must not be forgotten that cells may extend in other directions; for instance, (a) anteriorly, along the root of the zygoma; (b) posteriorly, communicating with the cells of the occipital bone; (c) inferiorly, between the floor of the tympanic cavity and the jugular fossa; (d) internally, spreading inwards towards the apex of the petrous bone and surrounding the labyrinth; or (e) enveloping the orifice of the Eustachian tube.
The facial nerve, after dipping beneath the external semicircular canal, passes vertically downwards through the mastoid process to emerge at the stylo-mastoid foramen. Entering this foramen and running along the canal are the stylo-mastoid branches of the posterior auricular artery. These vessels, if cut through by the chisel, may bleed in a marked manner, thus drawing the attention of the operator to the fact that he is in close proximity to the facial canal and nerve.
=Surface anatomy.= Although it is impossible to foretell with certainty before operation what the anatomical structure of the mastoid process may be, yet some information may be gathered from the formation of the skull.
In the dolichocephalic type, the mastoid process is broad and frequently contains large cells, especially at its tip and round the lateral sinus, which is usually deeply placed. In the brachycephalic type, on the other hand, there is a greater tendency for the mastoid process to be narrow and to consist of dense bone, for the middle fossa to extend low down and to overlap the outer wall of the antrum, and for the lateral sinus to project forward and superficially, even to within 2 or 3 millimetres of the posterior border of the external meatus.
The posterior root of the zygoma may be considered approximately the line of demarcation between the roof of the antrum and mastoid process, and the floor of the middle fossa of the skull. This, however, is only a rough guide, as in some cases, especially of the brachycephalic type, the middle fossa may dip below this point. If this ridge is not well marked, then Reid’s base-line must be taken as the guide.
Just behind the auditory meatus, at its upper posterior margin, is the spine of Henle, which forms the anterior boundary of the suprameatal triangle. Macewen, who first described this triangle, gave it as a guide for the exposure of the antrum. Experience, however, has shown that no reliance can be placed on this as a landmark, as, if the bone is chiselled through at this point, it is by no means uncommon to expose the dura mater of the middle fossa. A point 10 millimetres (two-fifths of an inch) behind the spine of Henle corresponds to the anterior border of the sigmoid sinus. Behind the suprameatal triangle and beneath the zygomatic ridge is the body of the mastoid process, which has a smooth surface and is perforated by small foramina through which pass tiny vessels.
The antrum, in the adult, is situated at a slightly higher level than the tympanic membrane, its floor roughly corresponding with a line drawn horizontally backwards through the middle of the posterior wall of the bony meatus.
HISTORY OF THE MASTOID OPERATION
Although opening of the mastoid process as an operative measure dates back to the eighteenth century, yet Schwartze, in 1873, was the first to establish the operation as a practical procedure.
Schwartze’s operation consisted in the simple opening of the antrum and mastoid cells, leaving the middle ear untouched. This procedure was carried out no matter whether the disease was recent or long standing. It soon became recognized, however, that this operation did not effect a cure in all cases, more especially in those in which the disease involved the walls of the tympanic cavity.
Küster, in 1889, suggested removal of the posterior wall of the external auditory meatus, and about the same time von Bergmann advocated removal of the outer attic-wall. The Küster-Bergmann operation, first practised by Zaufal, may therefore be considered to be the origin of the complete mastoid operation.
Stacke’s name is frequently though wrongly mentioned in association with the complete operation, which is sometimes termed the Schwartze-Stacke operation. Stacke’s operation was devised with a view to removal of the ossicles and outer wall of the attic in those cases in which the bone disease was limited to these regions. This operation, however, is occasionally of service in the performance of the complete mastoid operation (see p. 397).
Thus the year 1889 may be considered as the starting-point of the complete mastoid operation. Since that date many modifications have been introduced, the majority of which are not worthy of reference.
After the technique of the operation had been developed and practised for some time, more careful attention was directed to the after-treatment. In the earlier days of the radical operation it was the rule to leave the wound open and to plug it with gauze, or to insert a drainage tube which was carried through the membranous portion of the external meatus.
The next step was the making of post-meatal skin flaps, with closure of the posterior incision and packing of the wound through the auditory canal; and the names most prominently associated with this are Panse, Körner, and Stacke.
Still more recently, in order to shorten the after-treatment, the wound cavity has been skin-grafted by the method first suggested by Siebenmann and afterwards amplified by Charles Ballance.
The operations which will be considered are:--
1. Wilde’s incision.
2. Opening of the mastoid process and antrum.
3. The complete or radical mastoid operation.
Although definite indications for the above operations will be given, it must be remembered that in many cases the extent of the operation will depend very largely on the pathological condition found during the course of the operation itself, as frequently the clinical symptoms are not sufficient to determine beforehand what operation is indicated.
In comparing the simple opening of the mastoid cells and antrum with that of the complete or radical operation, the fundamental difference is that in the former the tympanic cavity and its contents are not interfered with, whereas in the complete operation the middle ear, antrum, and mastoid cells are converted into one large cavity. In consequence, complete recovery of hearing may take place in the former case; in the latter, however, this is not possible.
Although these operations, especially in the more acute conditions, are performed from the point of view of saving the life of the patient, due regard must also be given to the preservation or restoration of the hearing power, if this indeed is possible. If the hearing power be very poor, that is, if conversation cannot be heard more than 12 feet off, and especially if the deafness be partially due to changes having already taken place within the labyrinth, then the complete operation is to be preferred if it be doubtful whether Schwartze’s operation will be sufficient to eradicate the disease. If, on the other hand, the hearing power of the affected ear be fairly good, and with this there is deafness of the opposite side, then, unless it is absolutely essential that the complete operation should be performed, an attempt should be made to effect a cure by the simpler operation, provided it is first explained to the patient that it may perhaps be necessary to perform the complete operation afterwards.
WILDE’S INCISION
In cases of acute inflammation of the mastoid process or of a subperiosteal abscess lying over it, Wilde made a post-aural incision, incising the tissues down to the bone. The indications for doing this are now considered to be very few, but it must be remembered that in Wilde’s day the mastoid operation had not been developed.
=Indications.= (i) In infants it is sometimes justifiable, as the pus may have escaped to the surface of the mastoid process either through the squamo-mastoid suture or along the posterior wall of the auditory canal, between the periosteum and bone, without there being any actual disease of the bone.
(ii) As a temporary measure, to permit of drainage of a subperiosteal abscess, if the operation on the mastoid process cannot be performed for twenty-four hours or more.
(iii) In acute middle-ear suppuration a free incision down to the bone may relieve the pain if there are symptoms of periostitis of the mastoid process; it is, however, rarely necessary.
=Contra-indications.= In older children and adults (with the above exceptions) this operation is not sufficient, as the periostitis or subperiosteal abscess over the mastoid process is secondary to underlying bone disease which can only be eradicated by an operation on the mastoid process itself. Although healing may apparently take place, fistulæ or other evidences of mastoid disease almost invariably occur afterwards.
=Operation.= In an infant a general anæsthetic is not necessary, but in an adult gas anæsthesia is advisable. The mastoid region is surgically cleansed; the auricle is pulled forward and a free incision is carried down to the bone, in a curved direction downwards over the mastoid process. Originally Wilde made a vertical incision; but it is better, if possible, that the incision should be the same as would be made in performing the mastoid operation, which indeed will probably have to be carried out afterwards. After the hæmorrhage has ceased and the purulent contents of the abscess, if present, have drained away, fomentations should be applied and changed frequently during the first twenty-four hours. After this a simple dry dressing is sufficient.
=Results.= Except in the case of tiny infants, this procedure is seldom successful in curing the condition, and must be considered as only a temporary measure.
SCHWARTZE’S OPERATION
(Opening of the mastoid process and antrum)
=Indications.= (a) In acute middle-ear suppuration. (i) If, in spite of free drainage, earache, pyrexia, and tenderness over the body of the mastoid do not abate within three days. This is all the more urgent if the condition is the result of scarlet fever or influenza, as in these cases the disease may spread with extreme rapidity.
(ii) If there be an obvious abscess over the mastoid process; except in infants, in whom Wilde’s incision may be attempted as a tentative measure, although it is not recommended.
(iii) If there be symptoms of meningeal irritation.
(iv) If a profuse otorrhœa has continued for over four weeks and is accompanied by sagging downwards of the upper posterior wall of the external meatus, a definite sign that the antrum is involved.
(v) If a profuse otorrhœa has continued for over eight weeks, with no sign of abatement, even although the temperature may be normal and although there may be no symptoms of inflammation of the mastoid process. The continuance of the otorrhœa is presumably due to accumulation of pus in a large antral cavity. The object of the operation is to permit of free drainage and to prevent involvement of the mastoid process itself. The question of operation, however, must be considered very carefully. There is no doubt that in many cases conservative measures may effect a cure even although the suppuration has already existed for many months.
(b) In chronic middle-ear suppuration. Although the complete mastoid operation is usually indicated, yet the simple opening of the mastoid antrum may be advised under the following conditions, provided there are no symptoms of inflammation of the mastoid process nor signs of disease of the bony walls of the tympanic cavity:--
(i) If the perforation, however large, be surrounded by a rim of tympanic membrane (showing that there is no disease of its bony margins), and if the malleus be not adherent to the inner wall of the tympanic cavity.
(ii) If the hearing be good, that is, if speech is heard farther off than 12 feet, especially if the other ear (from whatever cause) be quite deaf.
Politzer, among others, still maintains that there is frequently no communication between the affected mastoid cells and the antrum if the mastoid abscess is the result of acute middle-ear suppuration. For this reason he considers that the antral cavity should only be opened if there be definite evidence of bone disease between the abscess cavity and the antrum, or if symptoms of extra-dural abscess or some intracranial complication be present. It is, however, difficult to believe that some communication, however microscopic, does not always exist between the antrum and the mastoid cells, seeing that the latter originally developed as outgrowths from the antrum itself, and must have become infected by direct extension from it. At the same time there is no doubt that complete recovery takes place in a certain number of cases in which the antrum has not been opened.
In my opinion, however, it is always wiser in such cases to open the antrum. Politzer considers that if this be done, healing does not take place so rapidly as in those cases in which the antrum has not been opened. On the other hand, if the antrum be not opened, the main object of the operation, that is, free drainage of the contents of the aural cavity, is not attained.
=Operation.= Preparation of the patient. The head should be shaved for a space of 2 inches around the mastoid region, twenty-four hours before the operation if possible. In women the hair in front of the ear, instead of being shaved off, should be combed forward and plastered down with carbolic soap. By doing this the hair can be arranged so as to cover the bald area during convalescence, a matter of great satisfaction to the patient.
The area of the operation and surrounding parts should be thoroughly washed with ethereal soap solution and afterwards protected with a compress of 1 in 2,000 solution of biniodide of mercury. After the patient has been anæsthetized, the cleansing process should be repeated, and the auditory canal syringed out with the lotion. The head is then covered with a sterilized towel drawn tightly over the ear and scalp, a portion of the towel being afterwards cut away so as to expose only the field of operation. The patient should be in the recumbent position, the head resting on some hard substance, such as a partially-filled sand-bag, and turned over to the opposite side, so that the affected ear is uppermost.
In addition to the ordinary instruments, those specially required for this operation are a well-balanced mallet and several gouges and chisels of varying size, one or two sharp spoons, a seeker, and a malleable blunt-pointed silver probe. They should be sterilized in the ordinary manner.
The incision. The surgeon stands at the side to be operated upon, facing the patient’s head. The auricle is pulled forward. An incision is made through the skin, beginning just above the pinna, and is carried downwards in a curved direction towards the tip of the mastoid process, lying about half an inch behind the insertion of the auricle (Fig. 216). Before making the incision, the tip of the mastoid process should be determined. Care must be taken not to let the knife slip at the end of the incision and so incise the neck tissues. The line of incision should correspond to what will afterwards be the middle of the wound cavity in the bone. If the incision be made too far forwards or too far backwards, one of the edges of the skin incision may afterwards tend to overlap the opening in the bone and in this way hinder the dressing and perhaps lead to the formation of a sinus. If there be much thickening of the soft tissues and periosteum, it may be necessary to make the incision longer than usual in order to expose the field of operation sufficiently.
In the upper angle of the incision the temporal fascia and the underlying temporal muscle will be exposed. Except in very muscular subjects, in whom the muscle comes low down into the wound and has to be cut through, it is better to push the lower border of the muscle upwards by means of a periosteal elevator. The incision is now carried right down to the bone throughout its length.
If there be an abscess over the mastoid process, its purulent contents should be allowed to drain away, the abscess cavity being then irrigated with a weak solution of biniodide of mercury (see p. 389).
Exposure of the field of operation. The periosteum and overlying soft tissues are then reflected forwards and backwards with a rugine, until the following points are brought into view: namely, the upper posterior margin of the bony meatus (taking care not to separate the fibrous from the bony portion of the meatus) and Henle’s spine in front, the zygomatic ridge above, and the fibres of the sterno-mastoid muscle below (Fig. 217). The tip of the mastoid process should just be seen. To do this it may be necessary to cut away some of the fibres of the sterno-mastoid muscle.
If the surgeon has two assistants, the duty of one of them is to hold apart the edges of the wound by means of retractors, whilst the other is employed in keeping the wound dry. If there be only one assistant, the edges of the wound may be held apart by metal retractors.
Careful examination of the field of operation should now be made. There may be no external signs of disease. As a rule, however, as a result of the inflammatory process having already extended to the surface, the periosteum is found to be much thickened, with extreme vascularity of the underlying bone, or there may be a subperiosteal mastoid abscess of varying size.
Excepting in infants, in whom pus may escape through the squamo-mastoid suture, a subperiosteal abscess is always secondary to a fistula in the bone, which is usually situated over the body of the mastoid process just behind the suprameatal triangle. It may, however, occupy some other position.
In the case of Bezold’s mastoid abscess (see p. 389), although no fistula may be seen on the surface of the bone, pus may be found to well up from beneath the mastoid process on cutting through the fibres of the sterno-mastoid muscle. In other cases there may be actual necrosis of the bone, as a rule involving the lower margin of the squamous portion of the temporal bone (see p. 390).
The method of opening the antrum in a straightforward case will first be described.
Opening the antrum. The approximate surface marking of the antrum is the suprameatal triangle and the region just behind it, which, however, as has been mentioned, is an uncertain guide. It is wiser, therefore, in all cases of operation on the mastoid process to assume that the case is one in which the lateral sinus extends far forward and is superficial, and that the middle intracranial fossa is low lying.
The area of bone to be removed depends on the age of the patient; in the adult it is about half an inch square, having as its boundaries the zygomatic ridge above and Henle’s spine in front.
The bone should be removed by short decided taps of the mallet on the gouge or chisel, held in contact with the bone in a sloping direction (Fig. 217). This precaution is specially indicated whilst in the act of removing the bone from above downwards and from behind forwards, in order to prevent injury to the middle fossa, which may be low lying, or the lateral sinus, which may project abnormally far forward (Fig. 218).
To permit of better control over the instrument, the hand holding it may rest lightly against the patient’s head, which is now covered with a sterilized towel. This control should always be sufficient to prevent the chisel or gouge being driven unexpectedly too far inwards, an accident which may easily happen if, by chance, there is a sudden diminished resistance to the stroke owing to unexpected softening of the bone or the inadvertent exposure of the dura mater. It is this accidental slipping of the instrument which is often responsible for injury to the lateral sinus or the facial nerve. With regard to choice of instruments, I prefer the gouge, as it is safer than the chisel, owing to it having rounded edges.
On removal of the superficial part of the cortex, the mastoid process may be found to be sclerosed, or to consist of small or large cells filled with granulations or purulent secretion.
(a) If the bone be sclerosed. The operation may be extremely difficult, as the antrum is frequently of small size and very deeply placed. As the tympanic cavity must not be interfered with, it is not permissible to insert the seeker along the auditory canal into the attic in order to determine the position of the aditus. The only guides, therefore, are the anatomical landmarks.
The best method is to chisel away the bone close to and parallel to the upper posterior margin of the external meatus. In chiselling along the upper wall of the opening, the gouge, instead of being directed downwards, as was the case in removal of the outer portion of the cortex, is now directed inwards and at the same time slightly upwards and forwards. In enlarging the lower part of the opening, the bone is chiselled away obliquely inwards and upwards. The strokes of the gouge are made alternately from above and below, so that gradually a funnel-shaped opening is formed, having its point directed towards the aditus.
Anteriorly, the bone is removed as close to the posterior wall of the auditory canal as possible, including the suprameatal spine. Above, the line of chiselling must not extend beyond the zygomatic ridge, whilst below sufficient bone should be removed towards the tip of the mastoid process to permit of inspection of the deeper parts of the wound.
From time to time the operator makes use of the seeker (Fig. 219). This is a blunt-pointed probe whose tip is bent at right angles to its shaft. With it any opening is probed carefully to see whether it is merely a mastoid cell, or dura mater covering the outer wall of the lateral sinus, or the middle cranial fossa, or if indeed it is the antrum itself. The chief mistake is to work too low down. If the antrum be small it may be missed, and the bone may be chiselled away too deeply in endeavouring to discover it and the facial nerve or the external semicircular canal injured. It is wiser, therefore, to work high even if the dura mater of the middle fossa is exposed by doing so. This should not lead to any harmful result provided the dura mater is not injured.
As soon as the antrum is reached, pus will be seen to ooze through the opening made, especially if it is under tension. The probe or seeker can now be passed into a cavity of varying size. The antrum is recognized by its smooth surface, which has quite a different appearance to that of the mastoid cells.
(b) If the mastoid be not sclerosed. The pathological condition found on removal of the superficial cortical layer depends on the anatomical structure and on the extent and virulence of the inflammatory process. Only a few cells may be involved, or on the other hand the whole mastoid process, if it be of the pneumatic type, may be converted into a mere shell of bone, forming a large cavity filled with masses of septic granulation tissue, carious bone, and pus. Sometimes, indeed, owing to the tegmen tympani or bony wall of the sigmoid sinus being already destroyed, the dura mater above or the lateral sinus posteriorly may be found already exposed within the cavity. If this is the case the pus may pulsate if present in large quantity. Any patches of soft carious bone or granulation tissue should be removed with the curette.
If the disease be limited to a few superficial mastoid cells, it is sufficient, according to those who do not always explore the antrum, to expose and curette the cavity freely and to do nothing further. This, however, should only be done if the bone surrounding the abscess cavity is hard and apparently normal, and if there is no tract of granulations leading from it in any direction. If an opening be found leading directly into the antrum, it should be enlarged with the curette or gouge. The extent of the antrum is next defined with the seeker, any overlapping ledges of bone being removed by the gouge until the whole of its inner surface is exposed.
The region of the aditus is now inspected under good illumination, using a head-light if necessary. It is recognized as a small opening at the anterior inner part of the antrum, on the floor of which may be seen the posterior border of the external semicircular canal, standing out as a whitish rounded eminence. Bone may be removed from its upper inner margins, but the lower portion should not be interfered with for fear of injuring or displacing the incus. To confirm the opening into the aditus, a blunt-pointed curved probe may be passed for a short distance through the aditus into the attic (Fig. 220).
With the curette all granulations should be removed.
Treatment of the mastoid process. The question now arises as to how much bone to remove. This depends on the condition found; the chief point is to make certain of removing all the infected cells.
In the case of marked sclerosis, the opening need not be large because, if the bone between the cortex and the antrum be solid, it is hardly probable that infection can spread through it to any outlying cells in the tip of the mastoid or elsewhere.
In the diploic and pneumatic varieties, the seeker must be used constantly in order to discover any outlying cells, which are then opened freely. If this be done systematically, infected cells may be found some distance away from the antrum itself, although an area of apparently healthy bone lies between them and the antrum. It must not be forgotten that cells may extend posteriorly as far as the occipital bone, or anteriorly along the zygomatic process, or even into the upper posterior part of the auditory canal itself (see p. 374). If such infected cells be not discovered, healing will be prevented.
However small or large the opening may be, all rough corners must be removed, so that at the end of the operation a smooth funnel-shaped cavity exists. To obtain this a burr may be used, worked either by the electric motor or, if a portable one, by an assistant. The burrs are of various sizes and of the cross-cut variety recommended by Ballance. Some operators perform the operation by burring throughout. Personally, during the earlier stages of the operation, I prefer to use the gouge and mallet. If the operator has not had much experience in the use of the burr there is always a slight risk, if it be not kept sufficiently under control, and especially if too great pressure be used, of it being driven through the dura mater above or into the lateral sinus posteriorly, or of it injuring the contents of the tympanic cavity. As a means of finishing the operation no instrument could be better. In private practice, however, few surgeons keep one. For this reason it is advisable to become accustomed to the chisel and gouge.
Removal of part of the posterior wall of the auditory canal. This may be necessary if the anterior wall of the antrum and mastoid process be affected. The fibrous portion of the auditory canal is partially separated from the bony portion and held forward by means of a retractor. The upper posterior portion of the bony meatus can now be removed either by means of punch-forceps or by the chisel, to what extent does not matter so long as its innermost portion, ‘the bridge,’ is not interfered with, that is, so long as the tympanic cavity and aditus are not encroached upon.
Exposure of the dura mater and lateral sinus. This may have already occurred before the operation, as a result of extension of the bone disease, or it may be necessary to do so during the course of the operation. Owing to the fact that an extra-dural abscess is a frequent complication of acute inflammation of the mastoid process, Victor Horsley and Körner advocate the exposure of the dura mater and the lateral sinus in every case, especially if a tract of carious bone leads in their direction. No harm is done in exposing these structures, and it precludes missing an extra-dural abscess.
It is better to expose the dura mater than to leave it covered with infected bone and septic granulations.
Final step of the operation. In order to make certain that a free opening exists between the antrum and the tympanic cavity, some warm boric lotion should be syringed through the opening of the aditus. A small syringe is used, having a fine piece of india-rubber tubing fixed on to its point. The end of the tubing is pushed into the entrance of the aditus. The fluid is then syringed through and should emerge from the external meatus. This is also beneficial in order to cleanse the tympanic cavity of its purulent secretion. To expel all the fluid from the middle ear the syringe is emptied and the piston withdrawn to its full extent. Its point is again placed within the entrance of the aditus and the piston pressed home, so that air is forced through and so drives out any remaining fluid from the tympanic cavity into the external meatus, which in its turn should be carefully dried. If there be no perforation, or if it be very small, the membrane should be freely incised before fluid is syringed through the aditus.
Immediate treatment of the wound cavity. The wound cavity is lightly packed with sterilized ribbon gauze, half an inch in width. Care must be taken to introduce the gauze right down to the aditus and to pack the cavity evenly.
The wound should be left open for a few days until the acute inflammation of the soft tissues has subsided, after which the upper and lower angles of the wound can be partially closed by sutures. A strip of gauze is also inserted into the auditory canal and a light dressing of plain sterilized gauze and a pad of cotton-wool covers the ear and surrounding parts. The bandage should be passed round the head and not beneath the chin, as the latter method is often a source of great discomfort to the patient during the stage of vomiting following the anæsthetic.
Blake of America has suggested that the wound should be allowed to fill with blood-clot on the supposition that the subsequent organization of the clot will result in a rapid closure of the wound. This method cannot be considered seriously owing to the impossibility of keeping the wound sterile.
=After-treatment.= There is seldom any shock, but there may be considerable pain during the next twenty-four hours.
If there has been no subperiosteal abscess, the dressing need not be removed for forty-eight hours. If an abscess has been present the dry dressing should be removed after twenty-four hours, and if there is much œdema and inflammation of the surrounding region, a compress of wet boric lint, kept in position by a few turns of a bandage, should be substituted, and changed every four hours.
Drainage tubes should be shortened and removed as soon as possible. The gauze within the wound cavity should be changed every second day, or daily if there be much secretion. If there be much discharge and the condition be very septic, an ear-bath of hydrogen peroxide may be given at each dressing and the cavity syringed out with a weak solution of biniodide of mercury; otherwise it is sufficient to use boric acid lotion.
If the operation has been successful, the purulent discharge from the tympanic cavity rapidly diminishes, frequently ceasing before the third day. The auditory canal is then firmly packed with gauze, especially in its outer part, in order to prevent stenosis of its lumen, which is liable to occur if the posterior fibrous portion of the canal has been separated from the bony meatus during the operation. Granulations very quickly block the aditus and so separate the antrum and mastoid cavity from the tympanic cavity. The wound can now be treated as an ordinary deep surgical wound, care being taken that it is packed from the bottom at each dressing.
If all the diseased bone has been removed, smooth healthy granulations will cover the wound. The continuance of pus from any spot, or the local growth of exuberant granulations, suggest the presence of an infected cell or a fragment of carious bone. Under cocaine anæsthesia, the part should be inspected carefully, and, if necessary, curetted freely. In other cases the local application of chromic or trichloracetic acid is sufficient.
After the second week the wound becomes shallower, actual healing of the wound depending on the size of the cavity.
Unless a very large amount of bone had to be removed, the resulting deformity is not great and usually only consists of slight sinking in of the skin. In some cases the final result is only a fine scar, which can generally be concealed by the hair.
The difficulties and dangers of the operation are considered in the next chapter (see p. 412).
=Results.= 1. If the operation has been successful (and this is usually the case), pyrexia and pain rapidly disappear, the patient experiencing remarkable relief from the head symptoms, so that within twenty-four hours he feels almost well. Healing of the wound is usually complete within six weeks, and before this date the hearing power will probably have been restored to normal.
2. The operation may not have been successful and the following unfavourable symptoms may occur:--
(a) The pyrexia may continue irregularly for a few days. If there be no other symptoms, this is probably due to septic absorption from the wound and need not cause very great alarm. If accompanied by pain, it may either mean that all the infected mastoid cells have not been opened, or suggest the onset of osteomyelitis of the temporal bone. If, in addition, such symptoms as rigors, delirium, optic neuritis, headaches, or vomiting occur, they indicate some intracranial complication.
In cases of doubt it is wiser to explore the wound under a general anæsthetic and then to determine what operation will be necessary.
(b) The general condition of the patient may be excellent, but otorrhœa or a fistula over the mastoid process may persist. Continuance of otorrhœa, in spite of healing of the wound posteriorly, means that although the disease involving the mastoid process has been eradicated, yet the walls of the tympanic cavity are themselves involved. This will probably necessitate the subsequent performance of the complete mastoid operation.
On the other hand, the suppuration may cease from the middle ear with complete recovery of hearing, and yet a fistula of the mastoid may remain. This means that all the diseased bone has not been removed. This should now be done.
TREATMENT OF SPECIAL CONDITIONS
=In an infant.= In an infant under two years of age the incision should be somewhat higher than usual. In making it, too much pressure should not be used, as the bone is frequently thin at this age, and if carious it may be so soft that the knife may possibly enter the intracranial cavity. In exposing the area of operation, it must be remembered that the posterior root of the zygoma and the antrum lie at a much higher level than in the adult. The opening into the antrum, therefore, is made almost above rather than behind the margin of the auditory canal. In these cases a fistula is usually present, and the bone is so soft that it can generally be removed by means of a sharp spoon or curette. At the same time, however, the aditus should be exposed and the opening made funnel-shaped in order to allow of proper dressing.
=Subperiosteal abscess.= The treatment depends on the extent of the abscess. If it be small, the lining membrane may be dissected away, the wound being afterwards treated in the ordinary manner. If the abscess cavity extends upwards towards the parietal region, or forwards along the temporal fossa, then drainage tubes should be inserted, their ends being brought out into the mastoid wound. It is rarely necessary to make counter-incisions. The completion of the operation is seldom difficult, as the fistula actually leads into the antrum. If the fistula be a large one and the bone is carious a sharp spoon may be used; otherwise a gouge is necessary.
=Bezold’s mastoid abscess.= If the lower portion of the mastoid process be composed of large cells, the abscess within the mastoid may break through the bone at its inner surface in the region of the digastric fossa. In consequence of this the pus may infiltrate the neck tissues beneath the fascia of the sterno-mastoid muscle and form a large abscess recognized clinically as a hard and painful swelling situated below the mastoid process instead of over it. This condition was first described by Bezold.
After exposing the antrum in the ordinary way, the tip of the mastoid process is opened freely. It is usually found to contain large cells filled with pus. Any granulation tissue is curetted away and the cavity dried. The inner surface of the bone is then inspected carefully in order to find the opening, which usually leads into the digastric fossa. The margins of the fistula should be curetted freely and the opening enlarged, if necessary. If the deep-lying cervical abscess be large, the finger may be passed into the abscess cavity behind the mastoid process, between it and the cut fibres of the sterno-mastoid muscle. In this way the limits of the cavity can be made out, and any septa forming pockets within it can be broken down. A counter-incision should be made through the tissues of the neck at the lower limit of the abscess. The opening should be sufficiently large to permit the insertion of a large drainage tube into the cavity. If the abscess be small it may not be necessary to make a counter-opening, but merely to insert a drainage tube into it, passing it from above downwards along the passage made by the finger.
=Necrosis.= In children necrosis of the temporal bone is not uncommon, especially if the middle-ear suppuration occurs in the course of a specific fever or is the result of tuberculous infection.
The part usually affected is the lower margin of the squamous portion of the temporal bone and the tympanic ring. Sometimes, however, the necrosis is very extensive, involving a large area of the petrous bone, including the labyrinth. These cases are always grave, and if a fatal result occurs it is usually in consequence of meningitis.
In adults necrosis is rare excepting as a localized patch usually situated superficially in the cortex of the mastoid process. Partial necrosis of the labyrinth, more especially of the vestibule and the portions of the semicircular canals, is also met with occasionally. When the necrosed area is superficial, such as the squamous portion of the temporal bone or the cortex of the mastoid process, it should be removed. If, however, it be situated more deeply, forcible removal should not be attempted until the sequestrum becomes loose, the wound cavity being meanwhile kept as aseptic as possible.
=Osteomyelitis.= In children, as the result of acute inflammation of the mastoid process, the bone may be found riddled with small points of pus, sometimes termed osteomyelitis. As a result of free opening of the mastoid cavity recovery, as a rule, takes place in the ordinary manner.
Distinct from this is another condition in which thrombosis of the diploic veins occurs. It is, fortunately, a rare complication of mastoid disease. It may occur before operation or be the result of infection of the bone as a result of operation. The infection tends to spread in every direction, more especially upwards along the parietal region and towards the occiput. With this, localized areas of necrosis or abscesses may occur, giving rise to painful swellings on the head, and usually are accompanied by cellulitis of the scalp, pyrexia, and intense headaches.
The only chance of recovery is to expose the affected area freely, and thoroughly remove all the diseased bone. To do this it may be necessary to lay bare the dura mater over a considerable area. If, however, the disease be not quickly eradicated, death will eventually occur as a result of extension of the septic infection to the larger veins, or from some other intracranial complication.