Lectures ON INJURIES OF NERVES

1887 The Lancet  
53 throat. In such cases nitrites fail to give complete relief, and they fail to silence the abnormal sounds. That they should fail is a confirmation rather than a refutation of the opinion which I wish emphatically to state-that stenosis of the bronchi due to spasmodic contraction of the bronchial muscles is a frequent cause of the dyspnoea of ordinary bronchitis. I have not obtained any facts that would justify the preference of any one of the nitrites because it possesses therapeutic
more » ... es over the others in the treatment of asthma or bronchitis. There are, however, conveniences of administration which lead me to give a preference to nitrite of sodium and to nitro-glycerine. They are both extremely stable, and they can readily be given in solution, either by the stomach or by subcutaneous injection. These advantages are not possessed by nitrite of amyl and nitrite of ethyl, and even the latter substance in the alcoholic solution of the spiritus aetheris nitrosi of the Pharmacopaeia is notoriously a very uncertain preparation. It is probable that the favour with which this preparation is, notwithstanding, regarded, is due not only to the action on the circulation which it shares with the other nitrites, but also to its previously unrecognised influence on dyspnoea, which is no doubt exerted when it is administered, as it so frequently is, in the treatment of bronchial catarrh. When the volatile nitrites are given by inhalation the effects are only of brief duration, but when they are given by the stomach the effects are similar in their relatively prolonged duration to those of the non-volatile nitrites. Nitrite of amyl, nitrite of ethyl, nitrite of sodium, and nitro-glycerine have each proved successful in my observations in relieving the dyspnoea of asthma and bronchitis. I believe they do so, gentlemen, by removing bronchial spasm, and the remarkable power which they possess in doing this will probably lead to their being more largely used than they hitherto have been in the treatment of disease. Where their administration is successful in removing the auscultatory evidences of such spasm, it is difficult to imagine anything more convincing of the beneficial influence that can be exerted upon the conditions of disease by pharmacological agents. The observer has presented to him a patient in whose thorax a continuous succession of varying sounds is heard. Within a few minutes after a nitrite has been administered, the endless succession of noisy breath accompaniments gives place to an almost complete silence, in which only the subdued quiet of normal respiration is heard, and at the same time, what to us is of even greater interest and importance, the distress of dyspnoea, or, it may be, the intense suffering and anxiety of orthopccea, is entirely removed. LECTURE m.—Cb'MMe TREATMENT OF NERVE INJURIES. FOR the proper and rational treatment of nerve injuries the first essential is an accurate knowledge of their pathology. It is to the want of this knowledge that the erroneous theories of nerve union and of the treatment requisite for nerve lesions are to be attributed. To the opinions held on this subject I shall now briefly refer, for they seem to me to be instructive. The conclusions of Galen " that nature was powerless to regenerate nerves" held unlimited sway until the time of Cruikshank and Haighton; and the experiments of these observers, published in the Philosophical Society's Transactions for 1795, completely subverted the doctrines taught up to that date. These surgeons experimented on dogs by dividing the pneumogastric nerve on the one side only, and having kept the animals alive for a varying number of days> they demonstrated that division of the opposite nerve trunk was not sufficient to cause death, prdvious experiment having shown that a simultaneous section of both vagi was inevitably fatal. They therefore concluded that the one nerve must have been reunited before the second operation was performed. Swan, Fontana, Descot, and Pr6vost arrived at the same conclusions, and the result was a very general belief that nerves when divided were z'Kea!My re,r;enerated-a belief which led to a corresponding carelessness in the treatment of such injuries, and which has been widely prevalent up till the most recent times, not only in England, but also in France and Germany, where Flourens and Steinrueck upheld the theories started in this country. The investigations of Waller, Vulpian, and Philippeaux about the year 1852, brought a new light to bear on this subject, and formed the first step in the accurate pathology of nerve lesions. It was shown by these physiologists that the peripheral end of a divided nerve underwent degenera.tion, and that some months intervened before the nervous substance was repaired. Theoretically, then, a corresponding time should always intervene before the nervous functions were re-established, and thus, though the theory of inevitable nerve regonera" tion was not relinquished, it was assumed that union never could take place by first intention. But the eyes of surgeons could no longer be shut to the cases which constantly came under their notice, and as experimental inquiry yielded to clinical observation, the fact was speedily established that in a large number of patients suffering from nerve lesions no union of any kind occurred. In this branch of pathology, however, as in many others, the discretion of pathologists speedily outran their wisdom, and the theory of "supplementary sensibility " and " supplementary motility" was, especially by French surgeons and physiologists, adopted to the exclusion of nerve regeneration, and more especially to that of reunion by first intention. In a former lecture I have discussed the probabilities and proofs in favour of union by this latter method, and also the evidence bearing upon the presence and amount of nerve anastomoses and supplementary sensation; I shall therefore take for granted that the possibility of immediate union is an established fact, and shall now pass on to consider the best means at our disposal for procuring the same. Sutrcre ofnerve8.-ln order that any tissues which may have been divided by the surgeon or else by accident should unite as speedily as possible, it is plainly of the first importance that they shall be closely approximated. How should this approximation be maintained in the case of divided nerves ? To this question there can be, in my opinion, but one answer -" By suture"; and the reason that this answer has not been given very many years ago is to be found in the erroneous views as to the probable results-e.g., tetanus, &c.-of the irritation which the stitches might set up, as well as in the mistaken ideas of nerve repair just alluded to. Putting aside the more than doubtful assertion that nerve suture was performed in the middle ages by Lanfranc, G-uy de Chauliac, &c., the operation is said to have been performed by Arnemann in 182G and by Flourens in 1828. At a later date it was practised in several instances by Dupuytren at the Hotel Dieu. But although these cases are interesting from a historical point of view, the time when nerve suture came to be practised in surgery on a definite physiological basis is much more recent, and may be said to date from 1864,when Laugier, a French surgeon, sutured the ends of a recently divided median nerve. Laugier claimed that immediate union resulted, but whether this was or was not the case is not sufficiently clear. In 1865 MM. Eulenberg and Landois made numerous experiments on animals, and concluded that after suture not only does the peripheral end of the divided nerve degenerate in a manner precisely similar to that noticed when no sutures are used, but that the sutures themselves are absolutely harmful, producing neuritis and perineuritis, and may even give rise to suppuration and secondary abscesses in the lungs. These statements, combined with the ever-present dread of tetanus, naturally dissuaded surgeons from universally adopting such measures, and in 1868 Boeckel of Strasburg related a case in which, after division of the median at the wrist, there was a recurrence of sensation in two months, except in the index finger; no sutures had been used, and the author rather illogically concluded that they were never necessary. Some years later Le Dentu noted that bullse occurred on the fingers after an attempt 54 had been made to procure immediate union by suture of a recently divided median; this lesion he attributed 1 to the irritation caused by the sutures, and not to the J cutting off of the nervous influence. There can be 1 but httle doubt that this conclusion was an erroneous i one, for as I have already endeavoured to prove, these t trophic lesions are not of an irritative nature, and s the bullse were no doubt due to a failure of union by first intention, and not to the presence of the catgut. But the 1 results obtained by Eulenberg and Landois are entirely I different to those of other experimenters, some of whom in 1 vain attempted to induce neuritis by means of setons and ( other irritants, and, what is of much more importance, i amongst a large number of cases in which sutures were 1 applied to human nerves these much-dreaded consequence I were conspicuous by their absence. The result of further f u r t h e r experience has thus come to be that, as far as any danger is f concerned, no surgeon would hesitate to use the most obvious I means of approximating the ends of a divided nerve, and i would fearlessly insert as many stitches as might be neces-i sary without any dread. But, putting the danger out of the i question, is the patient any more likely to have the con-i tinuity of his nerve restored if the ends are sutured than if 1 they are left to nature? To this I would answer most I unhesitatingly in the affirmative, for, judging by accounts c published by various authors and by my own observations, I can have no doubt but that in the vast majority of untreated I nerve wounds either no union at all or but a most imperfect 1 one can be expected. That the ends are sometimes united even if left to themselves is proved by some of the cases already i narrated, but under these circumstances a primary union can but rarely occur, for the ends are but seldom in apposition ; a state which is absolutely necessary for this method of healing. And again, in cases where primary union fails, by the time when degeneration and regeneration have occurred in the distal fragment, it very frequently happens that in the process of cicatrisation the nerve ends have either become adherent to the surrounding muscles and tendons, or else are widely separated by fibrous tissue, which forms an impenetrable obstacle to further attempts at reunion. These latter conditions, at any rate, can be obviated by the employment of sutures, and, even if union by first intention fails, the nerve is left in a much more favourable condition for subsequent regeneration than is otherwise the case. Now, the experiments by Griiick proved very clearly that in fowls, rabbits, &c., the use of sutures was followed by a primary union of the divided nerve, and on these grounds an analogous result in man might fairly be expected. The records, however, of cases in which such treatment has been adopted supplies information of a much more valuable nature, and it is to the evidence afforded by such cases that I would rather direct attention. Primary nerve sutures.-The operations which may be undertaken for the suture of divided nerves are conveniently divided into two classes: 1st, primary; 2nd, secondary. The operation of " primary suture" consists in stitching together the ends of a divided nerve either immediately after injury, or else very shortly afterwards-before, in fact, the process of healing of the wound has commenced. This operation should, in my opinion, be performed in every case of nerve injury in which it is possible. There are, of course, cases in which such an extent of nerve has been removed that it becomes a physical impossibility to bring the severed ends into apposition, and in such alone should the operation be omitted. I have no doubt that the operation of nerve suture is absolutely harmless, and that when the nerve ends are left unsutured union is most unlikely to occur at all, and at best is very imperfect. Lastly, that when the nerve ends are carefully sutured and maintained in apposition, a restoration of function is the mos':. frequent result. Under this belief, I cannot agree with those surgeons who consider that in cases of clean-cut wounds sutures should not be inserted. I believe these are just the cases best quited for suture. M. Nicaise, in his article on Injuries of Nerves in the " International Encyclopaedia, of Surgery" says: "When the section is clean cut and simple, without extensive wound of the integument, then suture should not be resorted to unless the separation is considerable," and other surgeons, especially on the Continent, express the same opinion. I am perfectly convinced that such advice should not be followed. No possible liarm c'-tn resott from suture, and the prognosis of the case of a wounded nerve left to itself is most unsatisfactory. The mode of application of the suture is a matter which has received much more attention than it really deserves. For a long time it was taught that the sutures should only be passed through the nerve sheath, and that it was dangerous to pass the needle through the bundles of nerve tubes themselves. This, again, was all due to theory, and gradually surgeons have learnt that the thought of danger is one with which they need not trouble themselves when considering the best method of fixing the separated nerve ends in apposition. I have myself passed sutures completely through human nerves, and have frequently seen them passed by others without the slightest evil result, and in the now numerous cases recorded in surgical literature the same treatment has been followed without a single recorded instance of any complication. The method which I would recommend is the following: A small needle armed with the suture should be passed completely through the nerve trunk at right angles to its long axis, about a quarter of an inch from the cut surface in each end, and in large trunks another suture may be passed at right angles to the first. These sutures should then be drawn tight until the opposing cut surfaces are brought into contact, and finally the edges of the sheath should be neatly stitched by three or four more sutures passed through it, so as to include within it all the cut tubules. The material for suture.-The choice of a material for suture is naturally influenced by the same considerations as those which obtain in the simi!ar operation of ligature of vessels, and just as in the latter its is advisable to use a tissue which will not act as an irritant and will be absorbed, so is a similar material indicated in the suture of nerves. In the majority of recorded cases catgut has been used, and I am inclined to consider that for small nerves carbolised catgut is the best material. In those cases, however, in which there is any unusual tension, or in which it is anticipated that, on account of any complication, it may be necessary to disturb the wound, I think that carbolised gut does not possess the proper amount of resisting power, and does not last a sufficient length of time. In such cases I should use by preference a more stable ligature, such as chromicised catgut, kangaroo tendon split into sufficiently small filaments, horsehair, or fine silk; I prefer the two former to the latter. After apposition has been obtained by suture, the limb should be fixed on a splint in such a position as to keep the injured nerve in a state of the least possible tension. The wound should be thoroughly cleansed, all sutures used should be first rendered aseptic, and every endeavour should be made to ensure healing by first intention. The value of primm<y suture of nerves.-Clinical facts must furnish the basis on which an opinion may be formed as to the value of primary nerve suture. Ib is useless to argue from any other than a clinical standpoint. The investigations of experimenters on animals of various kinds possess a value of their own, but the conclusions arrived at in this way cannot possibly be directly applied to man. When we consider that after the section of the spinal cord of a pigeon there may be a complete restoration of continuity, when we are told that in a monkey three or four inches of nerve may be remade in as many months, the absurdity of applying to man the conclusions arrived at by experiment is very obvious. The cases of primary suture which have been observed by myself at St. Bartholomew's Hospital may be summarised as follows :-The median nerve was sutured on eight occasions, each time with success. The ulnar nerve was sutured eight times, of these, two cases were completely successful, two were partially successful, and three were failures. In one case primary suture failed, and a secondary suture seven months later was followed by complete success. The median and ulnar nerves were sutured at the same time in one patient, with success. The total number of cases observed by myself thus stands at seventeen. Of these, twelve were successful, two were partially successful, and three were failures. In two of these cases union by first intention without previous degeneration ensued. In each case the median nerve bad been divided. In other cages ! some fibres appeared to unite by first intention, although I the bulk of the nerve did not do so. Cases already recorded.-I have found much difficulty in summarising the cases reported in medical literature, for in ,
doi:10.1016/s0140-6736(01)54291-9 fatcat:kvhubigf3vafzgxvk6ype2jdzq