An outline of inflammation and its effects being first principles of surgery

Introduction

The first principles of Surgery with which the student should make himself familiar are those relating to inflammation and its effects. An intimate acquaintance with this subject is of as great importance to the practical surgeon as that of fever to the practical physician. Independent of any interest attached to the investigation of its phenomena, the researches of modern pathologists have shown that disordered vascular action forms the ground- work of many diseases, and, at some period or other, accompanies almost all. Diseases may be of themselves purely inflammatory ; or in¬ flammation may be united with them, or supervene during any part of their course. Many cases which formerly went under the very convenient title of nervous , as, for example, amaurosis , are now known to be in general the result of inflammation or its effects ; and hence, an opposite and more successful line of treatment has been adopted. So readily is this species of morbid action kindled up, and so widely diffused is the structure in which it has its seat — wherever, indeed, vascularity can be detected — that we need not wonder at its so frequent occurrence. The time is probably not far distant when the nature of disease will be better understood; and when inflammation will be allowed to hold a more prominent share in its constitution than is even yet assigned to it.

By the surgeon, inflammation may be considered under two points of view — either as a morbid process, requiring its approach to be carefully watched and every means adopted to keep it in sub¬ jection ; or, as an act of restoration on the part of nature to repair injuries or get rid of foreign bodies introduced within the system. This apparent discrepancy, with respect to the ultimate effects pro¬ duced by inflammation, gave rise to a discussion amongst some of the older writers, as to whether it should be viewed as a salutary or destructive process. The question may be readily and satisfac¬ torily answered. When inflammation takes place in any of the great cavities of the body, from the application of cold to the surface,

IV

INTRODUCTION.

it may, if unchecked, either lead to the loss of life or so impair the structure of organs as to render them ever afterwards incapable of performing their proper functions; hence it is assuredly a morbid action intended to answer no good end, and causes the most serious and fatal consequences. On the other hand, how highly useful, nay, indispensably necessary, is inflammation? Without it, the progress of mortification could never be arrested and the dead parts cast off* from the living; the mouth of a bleeding artery could not be permanently closed; no collection of purulent matter or foreign body travel to the nearest outlet and be discharged; no chasm made by ulceration filled up; no breach of surface repaired; no wound healed; and hence, no operation attempted. We may go a step farther, and state that, besides the salutary effects thus naturally obtained, inflammation is frequently induced by the surgeon where he wishes to obliterate some cavity or canal, as in the radical cure of hydrocele or in the treatment of a sinuous ulcer. Suited for the purposes now mentioned, inflammation must always be of a limited and peculiar character ; when too sluggish, it requires to be urged on; when too violent, it must be repressed. We are, therefore, taught that inflammation is the most fatal of all diseases; and, in fact, with a few exceptions, all diseases threatening speedy destruc¬ tion to life spring from it; while, again, it is the only way by which lost parts can be restored, or the effects of injuries repaired. Without it, in short, the business of the surgeon would, in many cases, be at an end.

In calling the student’s attention to this subject, we have never deemed it necessary to make any apology for the length of time occupied in its discussion, as we consider that on this knowledge depends, in a great measure, the success of his future labours. We have no hesitation in stating, from our own individual experience, that one of the greatest errors committed in the first acquirement of a surgical education is the hurrying over doctrines which appear dry and uninteresting, and passing on to the consideration of inju¬ ries and operations, without stopping to contemplate what it is that renders the former so dangerous or leads so often to the necessity for the latter. In this way, the separate parts of surgery are eagerly sought after, while its fundamental principles are neglected; to use a metaphor, the branches are cultivated while the parent trunk, around which they entwine, lies forgotten. But let the student turn in what direction he pleases, inflammation continually crosses his path; it presents itself wherever he goes; its effects are revealed to him in every new state which comes under his notice; it is to

INTRODUCTION.

V prevent its inroad and subdue it when it has appeared, that he ob¬ serves the experienced surgeon manifesting such anxiety; and it is the great agent against which he is admonished he has to contend in the ordinary routine of daily practice. We cannot afford space to enter into minute particulars; but let him select any subject which is considered to belong to this branch of his profession; let him turn to wounds and their consequences; diseases or injuries of the coats of the vessels; those of the bones or joints; of the uri¬ nary organs; the organs of sense; the head, chest, or abdomen >' or any of the various operations required, and we think a little reflection will teach him the intimate connection between all these and inflammation — the necessity, therefore, for the minute and careful study of the latter — and the impossibility of making any permanent and valuable progress without such fundamental in¬ struction. Wherever, indeed, we have found this rule reversed, there crude and ignorant notions were sure to prevail.

Were we to descend from what experience has taught us and be required to bring forward authority in vindication of the position we have taken up, we would gladly appeal to one of the greatest names left us on earth; nor, under the present circumstances, could we stimulate the student to industry, should we be stepping far out of our path in bringing before him a few of the most remarkable features in the history of John Hunter. Here he is furnished with an instance of an individual, born in an obscure parish, receiving scarcely the rude outlines of a common education, and bred at first as a carpenter, who, by self-tuition, perseverance, and unwearied application, gradually rose in life till he assumed the most con¬ spicuous place in the metropolis of his country. We might, there¬ fore, dwell on his professional industry to illustrate what ours should be, or hold up his limited means and humble origin as an example for all to persevere. To his unceasing labours, Hunter was mainly indebted for the distinction he acquired ; and, with the exception of a few hours allowed for repose, his indefatigable mind seems to have been ever at work. He has done, in many respects, for our profession, what Newton did for natural science. He was constantly bent on its improvement; and, in every department to which he turned his attention, we discover the traces of his masterly hand. The great monument of his industry, and that which will hand down his fame to all future ages, has fortunately been pre¬ served; nor was it a mind of any ordinary description which thus ventured to shadow forth in one vast series the universe of life. The conception, it has been said, was worthy of Milton ; the labour

VI

INTRODUCTION.

could have been achieved by few men except Hunter. Volumes have been written on his genius; orations have been spoken in his praise; but one glance round the gallery of his Museum is worth them all. Where we asked for Hunter’s epitaph, we would lead the enquirer into this noble edifice and say —

Such men as Hunter appear only once during the existence of a world; and it is no easy task for posterity to speak concerning them as they deserve. The former reflection is startling but correct. Thus, while Newton, Locke, Bacon, Shakspeare, Scott, and many others, are infinitely removed from the rest of mankind, Hunter stands alone in our profession. When we think of all that he has accomplished, we are almost tempted to regard him as supernatural. His life resembles the transit of a comet, which bewilders while it excites admiration ; which dazzles with excess of brilliancy, and then for ever disappears. How humble do any of the men of the present day appear when placed by the side of Hunter. In his immense career, every thing bore reference to one great idea — the discovery and elucidation of nature’s laws. From the course of investigation which he pursued, he stepped at once out of the night of darkness into the full sunshine of knowledge. The difficulties he had to contend with, only add an intenser lustre to the glory he has ac¬ quired; and any imperfections we now perceive in his writings are as the shadows of a great landscape, rendering its prominent objects more distinct. By his own exertions alone, he liberated many parts of surgery from the impurities by which they were disfigured. On the lofty elevation reared by his own labours, he stood pre-emi¬ nent ; and his history records all that gives life a value, and refines and ennobles the species. The peculiar character which distin¬ guishes any past generation must always be interesting to that which follows, and may afford matter for much useful discourse ; but the peculiar character of man, and of the mind of man — for ever active, yet for ever varying — is a theme of more permanent utility and sublimer interest. Here our brief sketch must close. Earthly fame is too often like a withered leaf, at one time tossed by the winds, at another, trodden under foot of men; but the grave of Hunter will be for ever clad with the verdure of immortality.

The importance which Mr. Hunter attached to the study of inflammation may be gathered from the eagerness with which he pursued the investigation of its phenomena. What skill he pos¬ sessed in surgery is mainly to be attributed to his accurate know-

INTRODUCTION.

vii

ledge of anatomy, and the profound views he entertained of disease. His treatise on “Blood and Inflammation” is invaluable, and will always be a lasting mark of his genius and reputation. In it he brought to light much that was unknown or misunderstood, and he stripped other parts of the absurd explanations with which they were encumbered. As in all his other works, we find him taking the deepest and most original views of morbid action, founded on the closest observation and experiment; for, without these, Mr. Hunter was, fortunately, not much addicted to theory. The most interesting chapter is that on “ The Adhesive Inflammation,” and which contains all that is known on this subject in the present day. Next we might reckon that on ulceration and the different kinds of absorption which go on in the healthy and morbid states of the body; but it is needless to make selections from a work replete with interest, and which should be carefully and frequently read by every candidate for surgical fame.

Since Mr. Hunter’s time, many valuable observations have been made on inflammation, especially on the nature of the morbid action itself; nor, even now, does it appear a little singular that this great man should have contented himself with reasoning on the state of the vessels rather than attempting to ascertain by experi¬ ment their actual condition. On this head, we are deeply indebted to the early investigations of Drs. Philip, Thomson, and Hastings, and, more recently, to the philosophical and accurate researches of Cendrin and Kaltenbrunner. Nevertheless, much difference of opinion still exists, and much therefore remains to be accomplished. The more immediate phenomena of inflammation are so intimately connected with the structure and functions of the minute vessels, that it is impossible to understand the one without a constant reference to the other; and before the student looks narrowly into this part of the subject, we would recommend him to have his mind rightly informed respecting the capillary circulation. Were the physical and physiological properties of the arterial system better known, we should have much less difficulty in answering the question, “what is the condition of the vessels during inflamma¬ tion?” and to this want of knowledge do we attribute all the errors which have been committed, and all the useless discussions which have arisen. The investigation might, in truth be so far defined, as an examination into the difference between the healthy and morbid states of the capillary branches; and hence the necessity of having a just conception of the one before we pretend to judge of the other. In order that we might not be misunderstood on this intricate

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INTRODUCTION.

question, we have taken the liberty of making a few preliminary remarks on the nature of the vessels by which the first part of the circulation is carried on. In the brief outline there given, we have only alluded to those points which are essentially connected with the phenomena of inflammation; and, we may farther add, that the statements contained in that and the succeeding section are derived either from our own or the experiments of others.

In the following pages, it has been our aim to render a simple statement of known or acknowledged facts: they may, therefore, contain nothing new or very striking. We have likewise, as far as possible, endeavoured to avoid controversy, except where such was absolutely demanded; and then we have generally assigned what appeared to us the strongest reasons for believing in the particular view set forth. To prevent unnecessary reference to authorities, it will be seen that we have consulted the writings of Mr. Hunter and Burns, Drs. Philip, Thomson and Hastings, and Gendrin and Kaltenbrunner. There are others of minor importance to which we may also have occasionally referred. In conclusion, our object in publishing this work has been, first, to enable us to abridge the early part of our lectures, and allow longer time for the discussion of other important subjects ; and, secondly to furnish the surgical student with an outline of inflammation and its effects brought down to (he present period.

FIRST PRINCIPLES OF SURGERY.

Section I. Of The Arterial System

The arterial system is made up of a series of cylindrical tubes, through which the blood is transmitted to all parts of the body. Each artery divides into two or more smaller branches, which again subdivide into others; so that the vessels, as they recede from the heart, diminish in size but increase in number. The arteries thus constitute so many descending cylinders, having- an arborescent or conical form, with the apex towards the heart. The sum of the areas of the branches into which any vessel divides is always greater than the trunk from which the branches proceed. On this subject, no accurate calculation has been made; but, according to Haller, it may be stated nearly as one to one and a half. The ultimate terminations of arteries are so minute as to escape detection with the naked eye. They have, accordingly, received the name of capillary — a phrase in daily use, yet one to which no accurate definition has been affixed. The same general observations apply to the distribution of the veins, although these are more numerous and larger than the arteries. It) estimating the size of the veins, we, of course, begin by tracing them from their origin in invisible, vessels, to their union or termination in the larger trunks ; hence we state, that the sum of the areas of the small veins exceeds that of the superior or inferior cava. These points are of great importance to remember, when attempting to estimate the velocity of the blood’s motion in the different series of vessels; as, according to the ordinary laws of fluids, it must be slower in the capillary arteries and veins than in the larger trunks of either system.

When an artery of the middle size, as the popliteal, is examined, it is found to consist of three distinct tunics, to each of which con¬ siderable interest is attached, because on them depend the physical and physiological properties of the vessel. The first or outermost coat, named also the cellular or elastic, is made up of dense white fibres, closely compacted together. It is susceptible of great dis¬ tension, as evinced in cases of aneurism — highly elastic, especially in the longitudinal direction, as proved by cutting an artery across;

1 1 — e mgn I and of such firm structure, that a ligature drawn tightly around fails to divide it. It varies much in thickness in different arteries, and even in different branches of the same artery ; circumstances which have not been sufficiently acknowledged. Thus it is more abundant in the aorta and large vessels, where elasticity is required ; while it seems wanting in the arteries of the brain. It is connected to the common sheath which envelopes arteries by means of fine cellular tissue, which is of great utility in checking hemorrhage when the vessels are cut across ; and into the cells of which is secreted a serous fluid in the young, and an oily-looking substance in the adult subject.

On dissecting off the outer tunic, we arrive at a number of fibres, placed obliquely round the artery, constituting segments of circles so united as to form rings, having a yellowish hue in the larger, and a reddish colour in the smaller vessels, and divisible, in the former, into several layers. These constitute the middle or fibrous tunic; or, as it has been named by some, the muscular or proper membrane of arteries. It is distinguished from the outer¬ most coat by its fibrous appearance, by the difference in its distri¬ bution throughout the vessels, and by its physical and organic pro¬ perties. The fibres are flattened, dense, elastic, and easily divided by the pressure of a ligature. They are much more apparent in the small than in the large vessels ; and, therefore, proportionally thicker in the former than in the latter, being opposed in this respect to the external tunic ; they cannot, however, be traced in arteries less than a line in diameter, and seem to be also wanting in those of the brain. The identity of the fibres of the middle tunic with those of muscle, has, for many years, been a subject of keen dispute. After a repetition of some of the experiments, and a careful consideration of the arguments on both sides, we have been forced to the conclusion, that the arterial fibre has nothing in common with that of muscle. We will only allude, at present, to a few of their physical differences. In the first place, it has been sufficiently proved that the structure of artery contains no fibrin, a substance which enters so abundantly into the formation of muscle. Beclard, indeed, has stated, in his treatise on general anatomy, that he discovered fibrin in the composition of artery ; but he hesitates to consider it as proper muscular or fibrinous tissue. Berzelius and Dr. Young have denied the existence of fibrin in the arterial tunics; and we are not aware that the result of their analysis has been contradicted by any succeeding chemist. Other striking proofs of the difference in the composition of artery and muscle are afforded by the application of alcohol, diluted acids, or hot fluids, not corrosive in their nature. All these agents shrivel and harden the arterial tissue — a phenomenon depending on the more complete coagulation of one of its chemical principles (albumen); while they exert no change on the muscular substance. The fibres of muscle are also much looser in structure than those of artery ; neither do they possess the elasticity so conspicuously

THE ARTERIAL SYSTEM.

seen in the latter. The effects of compression are widely different. When muscular fibres are surrounded with a tight ligature, they undergo a sort of strangulation ; when the experiment is repeated on those of arteries, they are divided or cut. For these and other reasons, we dissent from the doctrine of the arterial and muscular fibres being one and the same ; a doctrine which has been too readily, and without due precaution, admitted.

The third or internal coat of arteries is their lining membrane, thin, smooth, and transparent. ; and unlike either of the others, by extending uniformly throughout the whole system. It is readily divided by the ligature, neither admitting of extension, or possess¬ ing elasticity; and, although apparently weak, is yet strong enough to resist dilatation from the impetus of the blood after the outer tunics have been dissected off. In properties, it resembles the serous membranes; being moistened by a watery fluid in health, and throwing out adhesive lymph when attacked by inflammation. The arterial system thus made up, is admirably adapted for con¬ veying the blood to the most distant parts of the body. The strength of the different branches may be conceived from the expe¬ riment of Dr. Hales, in which a force equal to a column of water one hundred and ninety feet high was required for bursting the carotid of a dog. Under this pressure, the vessel did not previously dilate, but burst at once; and from which it may be inferred, that dilatation of the coats of arteries, as in aneurism, can only be effected gradually and by length of time.

The arterial tissue is highly organised, being supplied with blood-vessels, nerves, and absorbents The nutritious arteries, the vasa vasorum, as they are named, are remarkable for coming from a neighbouring branch, and not from the trunk itself which they supply ; they anastomose very sparingly with those either above or below, and can be traced only to the fibrous tunic, although the effects of disease show the lining membrane to be also copiously supplied. The nerves are principally derived from the ganglions of the great sympathetic, and partly also from the cerebro-spinal system ; they can only be distinctly traced on the larger branches, and seem to be lost in the second tunic. It is important to recollect the origin and distribution of the nerves, as we will have occasion to refer to them hereafter. Lymphatics cannot be demonstrated either by injection or the microscope ; but their presence is proved from the ulcerations seen in the inner coats of arteries, and from the manner in which a ligature is detached.

Before speaking of the physiological properties of the arteries, let us briefly allude to what is known respecting their terminations. When an artery, according to Haller, is traced to its final division, it will be found to end — either in a red vein or veins — in an excreting duct, as in any of the glandular organs — in an exhalant, as on the skin or a serous membrane — in very minute vessels, as lymphatics — or in a colourless vessel, arteria non rubra , through which red blood does not circulate in the healthy state. The

mgn 1*

Morgan’s principles of surgery.

ultimate distribution of arteries is discovered by injecting the vessels with quicksilver in the dead body, or by examining them with the microscope in the living ; and both of these inform us that arteries terminate in red veins. But although either method affords the only proof on which we can depend, certain changes going forward in the living body tend to support the opinion that arteries have other terminations. Thus the phenomena of secretion and nutri¬ tion prove the distribution of arteries to exbalant surfaces and secreting organs ; but whether, as Haller has supposed, the vessels thus ramifying become at once continuous with the secreting duct of a gland, or form the exhalant tube in the surface of a membrane; or whether, as stated by Mascagni, the arteries have lateral pores through which the secreted or exhalant fluid passes directly from the blood— we are, in the mean time, perfectly unable to determine. In like manner, from injections having in some instances been transmitted from arteries into lymphatics, Magendie has espoused the doctrine first promulgated by Bartholine, that there is a direct communication between these two sets of vessels ; but the proof of this is not yet complete. Again, the termination of arteries in vessels capable of only transmitting the colourless portion of the blood, rests on such evidence as to make it no longer a matter of uncertainty. When the course of the blood, in the transparent parts of an animal, is watched with the microscope, the vessels through which it passes are seen to become gradually smaller, till at length we can only detect a single globule within their canal. Our means will not permit us to carry the examination farther; but the inference is fair, that there are vessels still more minute which we cannot perceive, and through which the colourless por¬ tion of the blood is moving. Nay, we are perfectly assured that many textures are nourished by transparent vessels alone, for the phenomena of acute inflammation and mechanical irritation have shown that such textures may be suddenly distended with red blood ; and thus the vascularity of parts, which are colourless in the natural state, is rendered apparent by disease. Setting aside, therefore, part of the hypothetical description given by Haller (for he himself allows, that where direct investigation failed, he had recourse to the uncertain evidence of analogy), we may admit without much fear of future contradiction, that arteries, when traced to their ultimate terminations, either become continuous with a red vein or veins, or pass into colourless vessels, or ramify in secreting organs or textures in a way at present unknown to us.

Pounded partly on this view of the minute arteries conveying red or pale blood, Bichat has described the capillary system under three different heads; in organs in which it contains blood, as muscles ; in organs in which it contains blood and other fluids, as bone; and in parts in which it contains no blood, as in ligament or tendon. Such an arrangement is quite useless in a practical point of view, it being sufficient to show that parts are either coloured or colourless, according to the size of the vessels with

THE ARTERIAL SYSTEM.

which they are supplied, and the blood which is circulating through them. To this system of vessels, invisible to the un¬ assisted eye. but directly demonstrated by the aid of the microscope, and indirectly observed through the presence of inflammation, ought we to restrict the term capillary. Under this head also, and with equally good reason, should be included the commencement of the veins ; so that we may describe the capillary system as made up of all those minute vessels which are interposed between the arteries and veins, forming the terminations of the one and the commencement of the other. No stricter definition can be given, as it is impossible to say where the arteries end and the veins begin; and, in all probability, the distinctive characters of either are here intimately blended together.

The capillaries have been usually arranged under two sets or orders — those interposed between the arteries and veins of the general system, and those forming the communications between the pulmonary vessels. In the first, the blood is changing from the scarlet colour we find it in the arteries to the modena hue it acquires in the veins ; in the second, it is purifying itself by expo¬ sure to the atmospheric air, reacquiring its vermilion tint, and along with it those properties which are necessary for the support of animal life. The capillary system is thus at once the most extensive and important in the body. Of the number of vessels included under this name, we cannot form the most remote con¬ ception. They exist in myriads wherever organised structure is found, and from the appearance under the microscope, or during the existence of inflammation, we might be almost led to suppose that the human body was one complete net-work of arteries and veins. Of its importance, it is sufficient to notice, that the capil¬ lary system is that in which the vital functions of secretion, nutri¬ tion, exhalation, and animal heat, are going forward — in which the blood in the general circulation is changed from crimson to dark, and again in the lungs from dark to crimson — in which the phenomena of inflammation more immediately reside — in which the earliest and most important deviations from health, leading to every species of morbid action, might probably be traced — and to which, insignificant as it may at first seem, the larger vessels are entirely subservient.

When a transparent texture in a living animal is placed under the microscope, the capillary circulation is readily brought into view. No definite arrangement of vessels, either as to size, number, direction, or mode of termination, can be perceived. In some of the vessels, three or four globules of blood are moving abreast; others seem only capable of admitting one. Some continue in a straight line; others are reflected back, and terminate immediately in a vein. Some send off lateral branches into veins running parallel to them ; in others, one artery ends in a corresponding vein ; while again, three or four branches may be observed to be continuous, with only one venous trunk. The capillaries anasto-

Morgan's principles of surgery.