_Entry_ (Mauser), over centre of tibia 1 inch above the tubercle. _Exit_, about centre of popliteal s.p.a.ce. No haemorrhage of any importance occurred from the wound, but there was a typical haemarthrosis, which subsided slowly. Twelve days after the injury a pulsating swelling the size of a hen's egg, to which attention was drawn on account of pain, was noted in popliteal s.p.a.ce. The pulsation extended upwards in the line of the artery some 3 inches. The limb was placed on a splint and treated by rest, and a month later the aneurism had decreased to one half its former size, the wall having greatly increased in firmness. Pulsation was easily controlled by pressure above the tumour; there was no thrill present, but a high-pitched bellows murmur. The patient was sent home on February 1.

When admitted at Netley the patient came under the care of Major d.i.c.k, R.A.M.C., who ligatured the popliteal artery on the proximal side by an incision in the line of the tendon of the adductor magnus. The aneurism then consolidated.

(7) _Traumatic popliteal aneurism._--Wounded at Magersfontein.

_Entry_ (Mauser), centre of patella. _Exit_, centre of popliteal s.p.a.ce; the knee was bent at the time it was struck.

There was considerable primary external haemorrhage, and so much blood collected in the knee-joint that it was aspirated. On the eighth day secondary haemorrhage occurred from the exit wound and the femoral artery was tied in Hunter's ca.n.a.l. No further haemorrhage occurred, but at the end of three weeks feeble pulsation was palpable in the popliteal s.p.a.ce, suggesting an aneurism; the latter decreased and the patient was sent home apparently well.

(8) _Traumatic axillary aneurism._--Wounded at Karree. The bullet entered 2-1/2 inches below the acromial end of the right clavicle and emerged over the 9th rib in the posterior axillary line. The Mauser bullet was found in the patient's haversack.

Both apertures were of the slit form, and healed per primam.

Three weeks later at Wynberg a large arterial haematoma which pulsated was noted in the axilla. Signs of injury to the musculo-spiral nerve were also observed. The tumour altered little, but a fortnight later Major Burton, R.A.M.C., cut down upon it through the pectorals. The aneurism was of the third part of the axillary artery, and a ligature was applied at the lower margin of the pectoralis minor. The wound healed by primary union and the aneurism rapidly shrank. The patient left for England a month later; the musculo-spiral paralysis was improving. I am indebted to Major Burton for the notes of this case.

(9) _Traumatic popliteal aneurism._--Wounded in Natal. _Entry_ (Mauser), immediately above head of fibula. _Exit_, immediately inside semi-tendinosus tendon at level of central popliteal crease. Fulness but no pulsation was noted at end of three weeks; seven days later pulsation was evident, and an aneurism the size of a pigeon's egg, with firm walls, became localised and palpable. It gave rise to no symptoms, and patient refused operation during the three weeks he remained in hospital. The aneurism continued to contract, and the patient was sent home.

The aneurism has since spontaneously consolidated.

_Aneurismal varix and varicose (arterio-venous) aneurism._--Uncomplicated cases of aneurismal varix, as might be expected, were less common than those in which the arterio-venous communication was accompanied by the formation of a traumatic sac. The initial lesion accountable for each condition was, however, probably identical, and dependent on the pa.s.sage of a bullet of small calibre across the line of large parallel arteries and veins. Thus, obliquely coursing antero-posterior wounds of the neck produced carotid and jugular varices; vertically coursing tracks laid the subclavian vessels in communication; antero-posterior tracks the brachial, popliteal, and lower part of the femoral; and transverse tracks, the vessels of the calf and forearm. Given an arterial wound, the mode of development of the aneurismal sac in no way differs from that of the ordinary traumatic variety; the main point of interest, therefore, is to seek an explanation of the causes which may restrict the ultimate result to the formation of a pure aneurismal varix. The explanation is possibly to be found in some of the following circ.u.mstances.

_Size, position, and symmetry of the vascular wound._--It seems scarcely necessary to insist on the calibre of the projectile, since this alone determined the frequency of these conditions, but it must be borne in mind that in the diameter of the bullets, cla.s.sed as of small calibre during this war, a range of from 6.5-8 mm. existed. In the case of both the Krag-Jorgensen and Mauser, the shape of the bullet also was better adapted to pure perforation of the vessels. I saw no case of arterio-venous communication in which a larger bullet than one of the four types chosen had been responsible for the primary injury, but a difference of 1-1/2 mm. in calibre in the small projectile might well determine the division, the pure and symmetrical perforation of the two vessels, or the giving way of one side, so that they were deeply notched instead of perforated.

Such positive evidence as was afforded by operation as to the exact condition of the vessels in two cases of femoral arterio-venous aneurism was, that in either case a clean perforation existed.

It is improbable that notching of the two vessels can primarily produce a pure varix, although it may result in the formation of an arterio-venous aneurism, especially if the bullet should have pa.s.sed between the two vessels in such a way as to notch the contiguous sides.

It is impossible to say, in any given case, what the result of secondary contraction of a sac produced in this manner may be in the determination of the ultimate relation of the vessels. In many of the cases clinically designated pure varix, the remains of such a sac may still actually persist. In the case also of pure perforation of the vessels, it is difficult to believe that a localised blood cavity has not originally existed. Given complete division of the vessels, as far as my experience went, arterial haematoma was the uniform result.

Under these circ.u.mstances I am inclined to believe that a symmetrical perforation of both vessels is the most common precursor of either condition; that the pure varix is the rarer and less likely result, and that its formation is dependent mainly on certain anatomical conditions.

The most important of these conditions are the proximity and degree of cohesion of the two vessels, the comparative s.p.a.ciousness or the opposite of the vascular cleft, and the degree of support afforded by surrounding structures.

Thus, the close proximity of the popliteal artery and vein, together with the particularly firm adhesion which exists between the vessels, probably favours the formation of a varix; again, a varix more readily forms if the femoral artery and vein are wounded in Hunter's ca.n.a.l than if the injury is situated high in Scarpa's triangle, where the vessels lie in a large areolar s.p.a.ce. The pa.s.sage of a bullet between an artery and vein may perhaps produce either condition, but wide separation of the two vessels, as for instance of the subclavian artery and vein, renders an aneurismal sac almost a certainty. These suggestions seem borne out by the cases recounted below, since the pure varices are one femoral, one popliteal, and one axillary. I cannot include the calf and forearm cases, as the existence of a small sac could not be disproved.

To these anatomical factors certain others must be added. In most cases a false sac exists at first, which tends to undergo contraction and spontaneous cure, as is observed in some of the ordinary traumatic sacs.

This history of development is moreover supported by the observation that proximal ligature of the artery usually converts an arterio-venous aneurism into an aneurismal varix. The process is no doubt favoured by cleanness and small size of the perforation, moderation in the amount of primary haemorrhage, the tone and resistance of the surrounding tissues, special points in the circulatory force and condition of the blood, and the possibility of maintaining the part at rest after the injury.

Aneurismal varix, when pure, was evidenced by the presence of purring thrill and machinery murmur alone. In none of the cases I saw was pain or swelling of the limb present. In one popliteal varix, slight varicosity of the superficial veins of the leg was present, but it was not certain that the development of this was not antecedent to the injury, as the patient did not notice it until his attention was drawn to its existence. In none of the cases under observation in South Africa had enough time elapsed for sufficient dilatation of the artery above the point of communication to give rise to any confusion from this cause as to the presence of a sac.

When an arterio-venous sac has once formed, clinical observation shows that the general tendency is towards extension in the direction of least resistance. This direction of course varies with the situation of the aneurism, and also with the nature of the wound track.

Speaking generally the direction of least resistance in a typically pure perforation is towards the vein. Initial flow of blood from the wounded artery is naturally favoured towards the potential s.p.a.ce afforded by a ca.n.a.l occupied by blood flowing at a lower degree of pressure. The partial collapse of the vein dependent on the wound in its wall also probably helps in determining the initial flow in its direction.

Examples are afforded by the carotid aneurisms (cases 10, 11, and 14), and here it must be borne in mind that the outer limits of the cervical vascular cleft are those least likely to offer resistance to extension of the sac. In each the aneurisms mainly occupied the exit segment of the track; this is the general rule, as in the case of external haemorrhage, and is determined by the same cause.

The latter rule however finds exceptions when the entry segment is so situated as to cross a region of lesser resistance, and case 12 ill.u.s.trates this point with regard to the cervical vascular cleft.

Examples of the tendency to spread in the anatomical direction of least resistance are also offered by the cases of aneurism at the root of the neck, where extension was into the posterior triangle.

The further clinical history and signs are as follows. A local swelling is found, usually at first diffuse, often commencing to develop with cessation of the external haemorrhage. It increases, for the first few days maintaining its diffuse character. If near the surface, it may be superficially ecchymosed. At the end of this time a tendency to localisation, as evidenced by increasing firmness and more definite margination, takes place, and this is followed by general contraction and rounding off of the tumour. The latter process may be continuous, and eventually the sac may become small and stationary or ultimately disappear and a pure varix be the result. The latter is only likely to be the case under the most satisfactory of the conditions enumerated above. Occasionally an opposite course may be followed, and fresh extension take place, as evidenced by enlargement of the tumour, disappearance of sharp definition, softening, and pain. The natural termination of such cases in the absence of interference would no doubt be rupture, and possibly death in some positions, loss of the limb in others. The former I never saw.

_Purring thrill._--This, the pathognomonic sign of either condition, was always present in the fully developed stage, and is probably present from the first unless a temporary thrombosis obstructs the vascular openings. It was noted as early as the third day in case 13. In many of the other patients it was palpable only with the subsidence of the primary swelling attendant on the injury. In some of the forearm and calf aneurisms, and in some of the popliteal, it was only discovered by accident some weeks even after the injury, but this often because no serious vascular lesion had been suspected. The thrill was widely conducted, often apparently superficial on palpation, and much more p.r.o.nounced with light than with forcible digital pressure.

In case 10 the _visible_ vibration in consonance with the thrill when the vein was exposed during the operation of ligature of the carotid was a novel experience to me.

_Murmur._--The typical 'bee in the bag,' or 'machinery' murmur was present in every case, and was often very widely distributed, especially over the thorax. (Cases 13, 14, and 20.)

In all three carotid cases the murmur was troublesome, being audible to the patient at night when the head was rested on the side corresponding to the aneurism.

_Expansile pulsation._--Pulsation in combination with the existence of a tumour is the main feature in the diagnosis between the conditions of pure varix and varicose aneurism. It was not always existent or prominent in the earliest stages, probably from temporary blocking of the artery, or from the diffuse and irregular nature of the cavity offering conditions unsuitable to the satisfactory transmission of the wave. When localisation had occurred it was always present.

EFFECTS OF ANEURISMAL VARIX OR VARICOSE ANEURISM ON THE CIRCULATION

(_a_) _General._--The most striking feature in these injuries is the remarkable effect of the disturbance to the even flow of the circulation on the heart. This first struck me in two of the cases of carotid arterio-venous aneurism recorded below (Nos. 10 and 11). In these I was inclined at first to attribute the rapid and irritable character of the pulse solely to injury to the vagus, as in each laryngeal paralysis pointed to concussion or contusion of the nerve. The pulse reached a rate of 120-140 to the minute. This disturbance was not of a transitory nature, for in the two cases referred to the rapid pulse persists, in spite of entire recovery of the laryngeal muscles, and the fact that in one case the aneurismal sac has been absolutely cured, and in the second only a small sac remains, in each as a result of proximal ligature of the carotid artery. In the former a varix still exists, and at the end of seven months the pulse is still over 100. In the latter, in which a sac is still present, the pulse rate varies from 110 to 130. In each case the condition has now existed twelve months. My attention once directed to this point, I noted a similar acceleration of the pulse in the case of these aneurisms elsewhere; thus in a femoral aneurism the rate was 120, and in an axillary varix of twenty years' standing which came under my observation the pulse rate varied from 110 to 120, according to the position of the patient. Unfortunately I had not directed my attention to this point in the early series of cases which came under observation.

It will be remarked in cases 13 and 14 that at the expiration of a year the pulse rate was still high, but these again are cervical aneurisms each in contact with or near the vagus.

In a case of aneurismal varix of the femoral artery of three years'

standing, which was under the charge of Mr. Mackellar, the pulse rate was normal. In this instance great dilatation of the vessels had occurred.

These observations raise the interesting question whether the irritable circulation which has been cla.s.sically considered one of the predisposing causes of spontaneous aneurism should not rather be regarded as a result of the condition.

(_b_) _Local._--In none of the cases of varix was the period of observation long enough to allow me to determine the development of dilatation of the arterial trunk above the point of obstruction. This, however, is the common sequence, and no doubt will occur in those patients who resume active occupation without operation.

The effects of either condition on the distal circulation were remarkably slight. The distal pulses were little, if at all, modified in strength or volume, and signs of venous obstruction, if present at first, disappeared with much rapidity. In one case (No. 15) of a large arterio-venous popliteal aneurism there was considerable swelling of the leg, but in this case the sac was large and situated at the apex of the s.p.a.ce, and no doubt exercised external pressure on the vein.

In the case of the carotid aneurisms, especially that probably on the internal carotid, transient faintness was a symptom in the early stages of the case. All three of the cases recorded here, however, had been the subjects of very free haemorrhage, either primary or recurrent.

(10) _Carotid arterio-venous aneurism._--Wounded at Paardeberg.

_Entry_ (Mauser) to the right side of the Pomum Adami, _exit_ at anterior margin of left trapezius, two inches below the angle of the jaw. There was some haemorrhage at the time from the exit wound, but no haemoptysis; about four hours later, however, in the Field hospital bleeding was so free that an incision was made with the object of tying the common carotid.

During the preliminary stages of the operation bleeding ceased and the wound was closed without exposing the vessel. The patient remained a week in the Field hospital, and then made a three day and night's journey in a bullock waggon to Modder River (40 miles), and fourteen days later he was transferred to the Base hospital at Wynberg, when the condition was as follows. Operation and bullet wounds healed. Considerable extravasation of blood in the posterior triangle. Beneath the sterno-mastoid in the course of the bullet track, swelling, thrill and pulsation over an area 1-1/2 inch wide in diameter.

Loud machinery murmur audible to the patient when the left side of the head is placed on the pillow, and widely distributed on auscultation. The left eye appears prominent, but the pupils are normal and equal in size. Voice weak and husky, and there is cough. Laryngoscopic examination showed the cords to be untouched, but some swelling still persisted. No headache, but giddiness is troublesome at times. Pulse 100, regular but somewhat irritable.

The patient was kept quiet in the supine position for a month, and during this time the condition in many ways improved. The voice improved in strength, the pulse steadied, falling to 80, the prominence of the left eye disappeared, and all the blood effusion in the posterior triangle became absorbed. Meanwhile the aneurism contracted at first, until it became oval in outline, with a long axis of 2 inches by 1-1/2 broad extending in the line of the wound track, but mainly situated in the exit half. During the last fortnight, however, it remained quite stationary in size, and as it showed no further signs of diminution in spite of the favourable conditions under which the patient had been placed, it was considered best to try to ensure its consolidation by a proximal ligature. Thrill had become slightly less p.r.o.nounced, and was less evident to the patient himself, but was otherwise unchanged. The probabilities in this case seemed rather in favour of wound of the internal carotid artery, and it was decided to bare the upper part of the common carotid, follow up the main trunk, and if possible apply the ligature to the internal branch. On April 12, 61 days after the injury, the cla.s.sical incision for securing the common carotid was made, and the sterno-mastoid slightly retracted. It was found that the sac of the aneurism extended over the bifurcation of the artery, reaching to the wall of the larynx. The omo-hyoid muscle was therefore divided, and the artery ligatured beneath, in order to ensure against any interference with the sac. Some difficulty was met with, for on opening the vascular cleft the vein was exposed and found to completely overlie the artery: although it was on the left side of the neck, the position of the vein was so completely superficial that there seemed no doubt that it had been displaced by the development of the aneurismal sac. A striking appearance was noted on exposure of the vein, the coats of which vibrated visibly, quivering in exact consonance with the palpable thrill. On tightening the silk ligature all pulsation ceased in the aneurism, and the vibratory thrill in the vein became much lessened.

The patient made a good recovery, only disturbed by a slight attack of vomiting, and at the end of a week the wound had healed, and pulsation in the aneurism had completely ceased.

The thrill persisted as before.

Six months later, a small sac still exists beneath the sterno-mastoid.

The pulse still reaches 110-120 in pace. The purring thrill is very slight. The condition gives rise to little or no trouble. Pulsation is strong in the external carotid artery, there is little in the common carotid. The voice is strong and good. This aneurism is either at the bifurcation of the common carotid, or on the immediate commencement of the internal carotid. Ligature of the external carotid will probably cure it.

(11) _Arterio-venous aneurism, probably affecting both carotids._ Wounded at Paardeberg. _Entry_ (Mauser), at dimple of chin immediately below mandibular symphysis. _Exit_, at margin of right trapezius, the track crossing the carotids about the level of normal bifurcation. The patient was lying on his back with the head down when struck. Some haemorrhage from the exit wound occurred at the time, and later on the way to Jacobsdal this was so profuse as to be nearly fatal. A considerable haemorrhage also occurred on the tenth day. The patient made the journey to Modder River safely, and was then under the charge of Mr. Cheatle. A large diffuse pulsating swelling developed on the right side of the neck, with well-marked thrill and machinery murmur. During the next three weeks the swelling steadily contracted, and the patient was sent down to the Base one month after receiving the wound, when the condition was as follows. There is no evidence of any fracture of the jaw. On the right side of the neck a large aneurism fills the carotid triangle, extending from the mid-line backwards to the margin of the trapezius, and from the level of the top of the larynx upwards to the margin of the mandible. The wall is fairly firm, pulsation is both visible and palpable, and a well-marked thrill and machinery murmur are present. The latter annoys him by its buzzing when the head rests on the right side. The pupils are equal. Pulse somewhat irritable, about 100. The voice is weak and husky, and there is difficulty in swallowing solids. The actual swelling is somewhat remarkable in outline, on the one hand following up the course of the external carotid and facial arteries, and on the other extending backwards in the line of the wound track towards the exit. The patient was kept on his back with sandbags around the head during the next fortnight. For the first eight days such change as occurred was in the direction of localisation and contraction, but during the last six, evident extension occurred both backwards and downwards; this extension was accompanied by severe pain in the cutaneous cervical nerve area of the neck. The larynx became pushed over 3/4 of an inch to the left of the median line, and the extension beneath the sterno-mastoid downwards raised a doubt as to whether the common carotid could be exposed without encroaching on the walls of the sac. Owing to indisposition I had not been able to see the patient for some days, but now, after consultation with Major Simpson and Mr. Watson, it was decided that the best plan would be to expose and tie the common carotid as high as could be safely done. The operation was performed six weeks after the injury, and somewhat to our surprise offered little difficulty. The carotid was exposed at the upper border of the omo-hyoid, only a small amount of infiltration having occurred in the vascular cleft. No dilatation of the jugular was noticeable, and when a silk ligature was applied to the artery all pulsation was controlled, and the thrill in the vein disappeared completely.

The after progress was satisfactory, but four days later the wound was dressed, as the patient's temperature had risen above 100. The tumour was consolidated: no pulsation could be felt, but there was little apparent diminution in its size. A loud blowing murmur was audible, especially at the posterior part of the swelling.

On the morning of the fifth day the patient mentioned that he again heard the whirr during the night. There had been no sign of any cerebral disturbance and the pupils had remained equal throughout.

A week after the operation the st.i.tches were removed, there was evidence of some blood clot in the lower part of the wound, and this later liquefied and was let out on the eleventh day. At that time a slight bubbling thrill could be felt at the upper part of the tumour, also slight pulsation in the line of the external carotid and at the most posterior part of the sac. The latter was much contracted, diminished in size and apparently solid, so that it was hoped that such pulsation as existed was communicated. Ten months later, no trace of the aneurismal sac exists. Neck normal, except for purring thrill. Voice strong and good. Pulse 100. Following his usual work.

(12) _Carotid arterio-venous aneurism_.--Wounded at Paardeberg.

Aperture of _entry_ (Mauser), at the posterior border of the left sterno-mastoid, 1 inch above the clavicle; _exit_, near the posterior border of the right sterno-mastoid, 2 inches from the sterno-clavicular joint. The injury was followed by very free haemorrhage, mainly from the wound of entry, some 'quarts'

of blood escaping; at any rate his clothes were saturated. The voice was hoa.r.s.e and weak, and there was much difficulty in swallowing; for the first twenty-four hours he could swallow nothing, but gradual improvement took place. The patient was carried two miles to the Field hospital, and three days later travelled 36-40 miles in a bullock waggon to Modder River.

Thence he travelled to Orange River 55 miles by train on the next day. A swelling was first noted when the wound was dressed some seven days after the injury. No evidence was ever existent of gross damage to either trachea or oesophagus beyond the initial dysphagia. The hoa.r.s.eness of voice due to left laryngeal paralysis slowly improved, and was probably the effect of concussion or contusion of the left recurrent laryngeal nerve. During the patient's stay at Orange River a large pulsating swelling with a strong thrill developed. This was at first diffuse, but under the influence of rest it steadily contracted and localised. During this period the patient was seen several times by Mr. Cheatle, who noted considerable temporary enlargement of the thyroid gland.

At the end of eight weeks he had been allowed up some days, and travelled 570 miles to Wynberg. The aneurism was about 1-1/2 inch in diameter, smooth and rounded, extending just beneath the left clavicle and nearly the whole width of the sterno-mastoid, but well defined in all directions. There was well-marked expansile pulsation, purring thrill along the jugular vein and over the tumour, and loud machinery murmur widely diffused along the whole neck and into the thorax. The voice was still weak and husky, but there was no dysphagia or dyspnoea. The left pupil was larger than the right.

The patient acquired enteric fever at Wynberg and when convalescent was sent to Netley, whence he returned home. The aneurism caused little discomfort. It may possibly have been of the inferior thyroid artery.