Chapter IV: Injuries to the Blood Vessels (1)

The small calibre of the modern bullet, and its tendency to take a direct course, naturally favour the occurrence of more or less uncomplicated wounds of the large vascular trunks, and both the nature of these wounds and the results which follow them are in some respects most characteristic.

NATURE OF THE LESIONS

1. _Contusion or laceration without perforation._--(_a_)The vessel may be struck laterally, the injured portion then forming a part of the bounding wall of the wound track, or (_b_) one or more layers of the vessel wall may be destroyed over a limited area. Given primary union, these conditions are only of importance in so far as subsequent contraction of the lumen of the vessel may result from implication in the neighbouring cicatrix. One of the most striking features of the wounds as a whole was seen in the hair-breadth escapes of the large limb vessels with no subsequent ill effects, and such injuries were seen in every situation.

In a certain proportion of wounds in close proximity to large vessels, however, a diminution of the normal calibre of the arteries was observed, either shortly after the injury or later in the advanced stages of cicatrisation. As an example of early obstruction, the following may be related. A Mauser bullet passed from the inner side of the thigh across the neck and great trochanter of the femur beneath the femoral vessels, and probably struck and grooved the bone, since the aperture of exit was large and irregular, some 3/4 of an inch in diameter. One week later no pulse was palpable in either anterior or posterior tibial arteries at the ankle, and pulsation which was strong in the common femoral artery was very weak in the superficial femoral. Slight fulness existed in the hollow of Scarpa's triangle, but not sufficient to make any serious difference in the contour of the two limbs. No thrill or abnormal murmur was discoverable. There was no oedema of the limb, which was also normal in temperature. The patient was kept at rest in the supine position for three weeks, during which time the tibial pulses gradually returned. Three weeks later he was invalided home, the pulses, however, still remaining considerably smaller than normal.

In the advanced stages of cicatrisation narrowing of the lumen of the trunk vessels was far from uncommon, especially in cases of wounds of the arm crossing the course of the brachial artery; in many of these the radial pulse was diminished almost to imperceptibility. How far this condition may prove permanent there has been little opportunity of judging; nor as to the possible ultimate weakening of the vessel wall and the development of a secondary aneurism has time allowed the acquisition of experience. In the light of the observation of so many cases in which large vessels were wounded without the occurrence of severe hæmorrhage, either primary or secondary, it is impossible to be certain whether some of the cases of arterial obstruction were not secondary to perforating lesions of the vessels.

Pressure on, or minor lesion of the vessel was sometimes evidenced by the development of a murmur, as in the following case. A Mauser bullet entered immediately within and below the left coracoid process, and emerged at the back of the arm at its inner margin, 2-1/2 inches above the junction of the right posterior axillary fold. During the first week dysphagia and some pain and soreness in the episternal notch, with pain and difficulty of respiration, were noticed. Eight weeks later no trouble with the pharynx or oesophagus remained, but a short sharp systolic murmur was audible over the first part of the left axillary artery, which could be extinguished by pressure on the subclavian; the radial pulse was normal.[14]

When primary union failed or was prevented by infection and suppuration, lesions, although incomplete, of the vessel coat naturally frequently gave rise to secondary hæmorrhage.

2. _Perforation of the vessels._--(_a_) This may be oblique or transverse to the long axis of a trunk; when the vessel is impinged upon laterally, an oval or circular notch, as the case may be, is produced; or (_b_) the bullet may strike more or less in the centre of the vessel, perforating both in front and behind, while lateral continuity is maintained; (_c_) beyond these degrees a vessel may, of course, be completely divided. Cases of notching of the vessel will be referred to under the heading of traumatic aneurism; those of perforation under that of aneurismal varix and varicose aneurism, the perforations in these cases affecting a parallel artery and vein.

RESULTS OF INJURY TO THE VESSELS

1. _Hæmorrhage._--The fact that hæmorrhage was not a prominent feature in the wounds received during this campaign can scarcely be regarded as an experience confined to injuries caused by bullets of small calibre. The same observation was often made in the case of larger bullets in old days, and the absence of severe hæmorrhage has previously been regarded as a special characteristic of gunshot wounds. None the less, as high a proportion as 50 per cent. of deaths occurring on the field in earlier days has been ascribed to this cause.

Unfortunately no new facts can be furnished on this point, although a few cases of rapid death from primary hæmorrhage will be found recounted under the heading of visceral injuries. Beyond these the general evidence offered by observations on men brought in from the field with vascular injuries, was opposed to the frequent occurrence of death from hæmorrhage, at any rate of an external nature. This subject will be dealt with under the classical three headings of primary, recurrent, and secondary hæmorrhage.

_Primary hæmorrhage._--A marked distinction needs to be drawn between external and internal hæmorrhage. External hæmorrhage from the great vessels of the limbs, or even of the neck, proved responsible for a remarkably small proportion of the deaths on the battlefield. This statement may be made with confidence, since it is not only my own experience, but coincides with what I was able to glean from many medical officers with the Field bearer companies. It is, moreover, supported by the facts that cases in which primary ligature had been resorted to were extremely rare at the Base hospitals, while, on the other hand, traumatic aneurisms and aneurismal varices of any one of the great trunks of the neck and limbs were comparatively common. Again, primary amputation for small-calibre bullet wounds, except when complicated by severe injury to the bones, was so rare as to render more than doubtful the frequent occurrence of severe primary hæmorrhage on the field. Only one case of rapid death due to bleeding from a limb artery was recounted to me. In this a wound of the first part of the axillary artery proved fatal in the twenty minutes occupied by the removal of the patient to the dressing station. The amount of hæmorrhage in many instances was no doubt checked by the application of pressure at the time of the first field dressing; but it can scarcely be argued that such dressings as were applied were of sufficient firmness to control bleeding from such trunks as the brachial, femoral, or carotid arteries.

The spontaneous cessation of hæmorrhage is rather to be ascribed to the special method of production and the consequent nature of the wound. The lesions were the result of immense force strictly localised in its application, which might well induce very complete and rapid contraction of the vessel wall; while the track in the soft parts was not only narrow, but also lined by a thin layer of tissue possibly so devitalised superficially as to specially favour rapid coagulation of the blood. Beyond this the tracks were often sinuous when the position of the limb at the time of reception of the injury was replaced by one of rest. The influence of mere narrowness of the track is illustrated by classical experience in the development of aneurismal varices after stabs by knives or bayonets; and in the injuries under consideration the frequent development of large interstitial hæmorrhages into the tissues of the limbs indicated that blood does not readily travel along the wound track. It was noteworthy that when hæmorrhage did occur it was most free from, or often limited to, the wound of exit. This is due to the direction of the active current set up by the rush of the bullet through the tissues. The mechanical factor is, no doubt, the most important.

Control of primary hæmorrhage from a wounded vessel by the impaction of a foreign body was of much less frequent occurrence than appears to have been the case with the older bullets. I saw a case in which, on removal of a fragment of shell (Mr. S. W. F. Richardson), very free hæmorrhage occurred from a wound of one of the circumflex arteries of the thigh, but not a single one in which a similar result followed the extraction of a bullet of small calibre. The comparative infrequency of retention of modern bullets is probably one of the main elements in this relation. A very curious instance of provisional plugging of a wound in the upper part of the brachial artery by an inserted loop of the musculo-spiral nerve was related to me by Mr. Clinton Dent. This instance must, I think, be regarded as an accident definitely dependent on the size and outline of the bullet and on the nature of the force transmitted by it to neighbouring structures.

While, however, deaths from external primary hæmorrhage were rare, a considerable number resulted from primary internal hæmorrhage. In some of these, injury to the largest trunks in the thorax or abdomen led to an immediately fatal issue; in others wounds of the large visceral arteries, as of the lungs, liver, or mesentery, were scarcely less rapid in their results. In such cases the potential space offered by the peritoneal or pleural cavities favours the ready escape of blood from the wounded vessel, while the tendency of the blood effused into serous cavities to rapid coagulation is notably slight. Beyond this the comparative deficiency in direct support afforded by surrounding structures to vessels running in the large body cavities is also an important element in their behaviour when wounded.

These remarks receive support from the observation that few, if any, patients survived an injury to the external iliac vessels within the abdomen, while the remarkable instances of escape from fatal hæmorrhage from large vessels recorded below (cases 1-19) indicate that the mere size of a wounded vessel is not to be regarded as the sole factor in prognosis.

_Recurrent hæmorrhage_ was occasionally met with both in the case of the limb and trunk vessels. In the limbs it often necessitated ligature of the artery. I saw several cases in the lower extremity where recurrent hæmorrhage on the second or third day was treated by ligature of the femoral or popliteal artery, and it also occurred during the course of development of one of the carotid aneurisms recounted below. On two occasions I saw rapid death follow recurrent abdominal hæmorrhage; in one I was standing in a tent when a man who had been wounded the day before suddenly exclaimed: 'Why, I am going to die after all.' The appearance of the man was ghastly, and on examining the abdomen it was found greatly distended, and with dulness in the flanks; the patient expired a few minutes later. Another example of recurrent abdominal hæmorrhage is related in case 169, p. 432.

_Secondary hæmorrhage._--In simple wounds of the soft parts by _small-calibre bullets_ this was decidedly rare. In wounds complicated by fractures of the bones, especially when they exhibited the so-called 'explosive' character, secondary hæmorrhage was not uncommon, and this not necessarily in conjunction with infection and suppuration.

In the chapter on fracture some remarks will be found on the prolongation of healing often observed in the exit portion of the wound track, which is explained by the well-known fact that, given an aseptic condition of the wound, sloughs of tissue separate very slowly. Secondary hæmorrhage in these cases is due to lesions of the vessel short of perforation, but severe enough to so lower the vitality that local gangrene of the wall occurs. In such instances hæmorrhage most usually occurred on the tenth to the fourteenth day, but occasionally still later. In one instance of ligature of the anterior tibial artery for such hæmorrhage three-quarters of the whole lumen of the vessel had been devitalised. The resemblance of some cases of secondary hæmorrhage of this class to those occasionally observed after amputation, and due to accidental non-perforative injury of the artery at the time of operation above the point of ligature, was very striking.

In other cases secondary hæmorrhage was the result of perforation of the vessel by a sharp spicule of bone, but in the large majority sepsis and suppuration were the cause. Naturally therefore the accident was commoner in the more severe kinds of wound, and in those caused by _large_ bullets or fragments of shell. The symptoms in nearly all cases were the classical ones of repeated small hæmorrhages followed by a sudden copious gush.

The forms of secondary hæmorrhage, however, which afforded most interest were the interstitial and the internal, mainly on account of the scope they allowed for diagnosis.

Characteristic examples of internal secondary hæmorrhage are furnished by cases of chest injury accompanied by hæmothorax and fully dealt with under that heading (Chapter X.). Cases of interstitial secondary hæmorrhage are also described under the heading of traumatic aneurism and abdominal injuries (No. 194, p. 445). It therefore suffices here merely to remark on the diagnostic difficulties the condition gave rise to. These mainly depended upon the elevation of general bodily temperature by which the hæmorrhage was often accompanied. Further evidence of the condition was furnished by the development of local swellings, or physical signs indicative of the collection of fluid in a serous cavity. These signs developed rapidly, and the rise of temperature was sudden and decided enough to suggest commencing suppuration. In several cases incisions were made under the supposition that this had already occurred.

The fever accompanying blood effusions was generally a somewhat special feature in the wounds of the campaign. At first bearing in mind that in every case a track, even if closed, led from the surface to the effused blood, one was disposed to suspect an infection of the clot of a somewhat innocuous nature. The absence of subsequent suppuration, however, was definitely opposed to this view, and suggested that the fever resulted from absorption of some element of the blood, possibly the fibrin ferment, or some form of albumose. A pronounced illustration was in fact afforded of the evanescent rise of temperature usually the accompaniment of simple fractures in the case of the limbs, and of the more marked rise not uncommon in cases of traumatic blood effusion into the peritoneal cavity, or when the pleuræ or joints were the seats of the mischief. In the case of interstitial hæmorrhages I only remember to have seen fever of such marked continued type in the subjects of hæmophilia with recent effusions, although one is of course acquainted with it in a less pronounced form as a result of hæmorrhage into operation wounds.

In primary interstitial hæmorrhages a similar continued rise of temperature was also common, and I cannot perhaps better illustrate its character than by the brief relation of two instances.

In a patient wounded at Kamelfontein the bullet entered four inches below the acromion, pierced the deltoid, splintered the humerus, and crossed the axilla. A large blood extravasation developed in the axilla, accompanied by cutaneous ecchymosis extending halfway down the arm. There was no perceptible pulsation in either the brachial or radial artery, but the limb was warm. There was partial paralysis of the parts supplied by the ulnar and musculo-spiral nerves and complete loss of power and sensation in the area of distribution of the median nerve. Six months later the radial pulse was still absent in this patient, but there was no sign of the development of an aneurism.

The accompanying temperature chart is characteristic. The blood effusion gradually gained in consistency and underwent steady diminution in size. No suppuration occurred.

The median paralysis was found to be accompanied by the inclusion of the nerve in a sort of foramen of callus, when the patient was explored at a later date by Mr. Ballance.

In a patient wounded at Paardeberg, a Mauser bullet entered by the left buttock, pierced the venter ilii, traversed the pelvis, and emerging at the brim of the latter, crossed the back, fractured the spine of the fourth lumbar vertebra, and escaped below the twelfth right rib. The track suppurated where it crossed the back, but the man did well until the twentieth day, when a swelling developed in the left iliac fossa and the general temperature rose to 102°. An abscess was at once suspected and the swelling incised by Major Lougheed, R.A.M.C. A large subperitoneal hæmatoma only was discovered, and evacuated. The temperature at once fell and the after progress was uneventful, the wound healing by primary union.

TREATMENT OF HÆMORRHAGE

_Primary._--No deviation from the ordinary rules of surgery should be necessary in the majority of cases, but in a certain number the conditions are so unusual that the special considerations must be taken into account. The natural tendency to spontaneous cessation of primary hæmorrhage in small-calibre wounds is the first of these. Experience has shown that often mere dressing, or at any rate slight pressure, suffices to efficiently stanch immediate bleeding. Although, however, immediate control is to be obtained by such means, the cases of traumatic aneurism of every variety related in the next section show that the ultimate result is in many such cases by no means satisfactory.

Under these circumstances it may be said that the classical rule of ligation at the point of injury should never be disregarded. Against this, however, certain objections may be at once raised; thus in many cases both artery and vein need ligature, a consideration of much importance in the case of such vessels as the carotid and femoral arteries. Again in many of the injuries to the popliteal artery the wound directly communicated with the knee joint, a complication which, while it may be disregarded in civil practice, must take a much more important place in the circumstances under which many operations in military surgery are performed.

On the whole, it seems clear that the military surgeon must be guided by circumstances, since it may be far better to risk the chances of recurrent hæmorrhage, or the development of an aneurism or varix, all of which are amenable to successful treatment later, than those of gangrene of a limb or softening of the brain. As a general rule, therefore, on the field or in a Field hospital, primary ligature of the great vessels is best reserved for those cases only in which hæmorrhage persists, while in those in which spontaneous cessation has occurred, or in which bleeding is readily controlled by pressure, rest and an expectant attitude are to be preferred.

A word must be added as to the objections to distant proximal ligature for primary or recurrent hæmorrhage. In some situations this may be unavoidable, and it is sometimes successful, but none the less it is opposed to all rules of good surgery and a most uncertain procedure. It leaves the patient exposed to all the risks attendant on the employment of simple pressure. In one case which I saw, the third part of the subclavian artery had been ligatured for axillary bleeding; secondary hæmorrhage, as might have been expected, occurred, and that as late as five weeks after the operation. In another case ligature of the femoral artery for popliteal hæmorrhage was followed by the development of a traumatic aneurism in the ham.

_Secondary._--In secondary hæmorrhage the treatment to be adopted depends upon the nature of the case. When the wound is aseptic, and bleeding the result of the separation of sloughs, local ligature is the proper treatment, and this was often successfully adopted, especially in the case of such arteries as the tibials. In septic cases, on the other hand, it is usually far better if possible to amputate, unless the general state of the patient and the local conditions are especially favourable.

When neither amputation nor direct local ligature is practicable, proximal ligature may be of use. Sometimes this may be obligatory in consequence of the difficulties attendant on direct local treatment. I saw a few cases successfully treated in this manner: in one the common carotid was tied (Mr. Jameson) for hæmorrhage from an arterial hæmatoma in connection with the internal maxillary artery. Although ligature of the external carotid would perhaps have been preferable, the result was excellent. When even this expedient is impracticable, local pressure is the only resort.

Lastly, as to the treatment of secondary interstitial blood effusions, I believe the best initial treatment is the expectant. If interference is needed, it is much more likely to be satisfactory the more chronic the condition has become, since the source of the bleeding may be impossible to discover. I never saw a patient's life endangered by the amount of such hæmorrhage, but if this should seem to be likely, local treatment is of course unavoidable. In several cases quoted below, incision and evacuation were followed by excellent results; in any such operation too much care to ensure asepsis is impossible.

TRAUMATIC ANEURISMS

The experience of the campaign fully bears out that of the past as to the steady increase of the number of aneurisms from gunshot wounds in direct ratio to diminution in the size of the projectiles employed. Every variety of traumatic aneurism was met with, and most frequently of all, perhaps, aneurismal varices and varicose aneurisms. While so experienced a military surgeon as Pirogoff could say, in 1864, that he had never seen a case of aneurismal varix, every young surgeon lately in South Africa has met with a series. Again, although the condition is a well-known one, it has been rather in connection with civil life; for the great majority of recorded cases were the result of stabs or punctured wounds such as are liable to be received in street brawls, or as a result of accidents with the tools of mechanics. Thus of ninety cases collected by K. Bardeleben in 1871, only 12 or 13.33 per cent. were the result of gunshot wound.

_False traumatic aneurism or arterial hæmatoma._--This condition was met with comparatively frequently, and bears a very close relation to that already described under the heading of interstitial hæmorrhages. The latter might almost have been included here, since the difference between the two conditions depended merely on the size of the vessels implicated. The exact correspondence in the period of development of some of the arterial hæmatomata, and of the occurrence of the aseptic form of secondary hæmorrhage, also explains the pathology of the two conditions as identical; except that in the former the effused blood is retained in the tissues, while in the latter it escapes externally. The history of these cases was uniform and characteristic. A wound of the soft parts, or sometimes a fracture, was accompanied by a certain degree of primary interstitial hæmorrhage, which might or might not have been associated with external bleeding. A hæmatoma resulted in connection with the wounded vessel, the general tendency in the effusion being to coagulation at the margins and subsequent contraction. Meanwhile the opening in the artery became more or less securely closed by the development of thrombus, and possibly by retraction of the inner and middle coats of the vessel. With the return of full circulatory force as shock passed off, or with the resumption of activity and consequent freer movement of the limb, the temporary thrombus became washed away. The newly formed wall of soft clot bounding the effusion proved insufficient to withstand the full force of the blood pressure, and extension of the cavity resulted. In the more rapidly developing hæmatomata, temporary pressure by the effused blood on the bleeding vessels was also, no doubt, a common explanation of temporary cessation of increase in size.

A diffuse soft fluctuating swelling, sometimes accompanied by pulsation, but oftener without, developed, and not uncommonly diffusion was accompanied by some discoloration of the surface and elevation of the general temperature. Such arterial hæmatomata commonly developed from ten days to three weeks after the original wound. A few examples will suffice.

(1) A patient wounded at Elandslaagte was sent down to Wynberg.
The antero-posterior wound in the upper third of the arm was
healed, but a month after the injury a large fluctuating
arterial hæmatoma developed in the axilla and upper third of
the arm. This was incised (Colonel Stevenson) and a wound of
the axillary artery in its third part discovered, and the
vessel ligatured. The patient made an excellent recovery.

(2) A patient received a wound at Doornkop which traversed the
calf in an obliquely antero-posterior longitudinal direction.
Three weeks later a soft fluctuating swelling developed at the
inner margin of the tendo Achillis occupying the lower third of
the leg. Neither pulsation nor murmur was detected. There was
anæsthesia in the area of distribution of the posterior tibial
nerve. No tendency to further increase was observed, and
operation was postponed. The temperature was normal.

(3) An Imperial Yeoman was struck at Zwartskopfontein at a
range of one hundred yards. The man rode four miles on his
horse after being hit, but the horse then fell and rolled over
him twice. The man was treated successively in the Van Alen,
Boshof, and Kimberley Hospitals, and from the last he was sent
to Wynberg which place he reached on the twenty-third day. When
admitted into No. 2 General Hospital the wounds of type form
and size (_entry_, in posterior fold of axilla; _exit_, 1-1/2
inch below junction of anterior fold with arm) were healed. The
whole upper arm was swollen and discoloured, while an indurated
mass extended along the line of the vessels into the axilla.
This was considered a blood effusion; it was not obviously
distensile, and pulsation was very slight. The brachial radial
and ulnar pulses were absent. A fluctuating swelling was
present along the anterior border of the deltoid. There were
some signs of nerve contusion, but no paralysis, beyond tactile
anæsthesia in the area of distribution of the median nerve.

Four days later little alteration had been noticed beyond a
tendency to variation in firmness of the different parts of the
swelling. On the thirty-first day considerable enlargement was
observed. This enlargement, together with continued rise of
temperature, aroused the suspicion of suppuration, and an
exploratory puncture with a von Graefe's knife was made by
Major Lougheed, R.A.M.C., after consultation with Professor
Chiene. Blood clot first escaped, followed by free arterial
hæmorrhage. The incision was enlarged while compression of the
third part of the subclavian was maintained; a large quantity
of clot was turned out, and an obliquely oval wound half an
inch in long diameter was found in the axillary artery.
Ligatures were applied above and below the opening between the
converging heads of the median nerve. The veins were not
damaged. The wound healed by first intention. On the twelfth
day a feeble radial pulse was perceptible, and shortly
afterwards the man left for England, diminished median tactile
sensation being the only remnant of the original symptoms.

(4) A private of the 2nd Rifle Brigade was struck while
doubling at Geluk, at a range of one hundred yards. The Mauser
bullet entered four inches above the upper border of the left
patella, internal to the mid line of the limb, and escaped in
the centre of the popliteal space. The man lay in a farmhouse
during the night and bled considerably from both wounds. He did
not fall when struck, but could not walk. He was sent to No. 2
General Hospital in Pretoria. On arrival there the external
wounds were scabbed over, and a large tumour existed beneath
the entrance wound. There was much discoloration from
ecchymosis, but no pulsation could be detected. The posterior
tibial pulse was good. At the end of ten days pulsation became
marked both in the front of the limb and in the popliteal
space. There were no symptoms of nerve injury. On the
thirteenth day an Esmarch's bandage was applied and Major
Lougheed laid the tumour open opposite the opening in the
adductor magnus. Much clot was removed, and both artery and
vein, which were found divided in the adductor canal, were
ligatured.

The foot remained very cold for the first twenty-four hours,
but otherwise progress was satisfactory, the wound healing by
first intention. No pulsation was palpable in the tibials at
the end of a month.

For the last two cases I am very much indebted to Major Lougheed. I am glad to include them, as they illustrate one or two points of special importance. No. 3 shows the tendency to variation in the tension and firmness of the tumours, the tendency to primary contraction of the sac, followed by diffusion, and the rise of temperature often accompanying the latter occurrence. This is of great interest in relation to the similar rise of temperature seen with the increase of hæmorrhage in cases of hæmothorax. For purposes of comparison, the progress may well be considered alongside of that in the case related on p. 119, in which the wounded vessel was probably also the main trunk itself.

No. 4 differs from any of the others in depending on a complete division of a large artery and vein. The development of the hæmatoma was consequently more rapid and continuous. Another point of interest was the maintenance of pulsation in the tibial vessels, in spite of complete solution of continuity in the parent trunk. That this was independent of the collateral circulation seems evident from its complete disappearance and slowness of return after ligation of the wounded vessels.

_Prognosis and treatment._--The treatment in these cases is sufficiently obvious, and consists in direct incision and ligature of the wounded vessels. The cases related show the success with which this procedure was attended, since uniformly good results were obtained. When possible, an Esmarch's tourniquet should be applied in the case of the lower limb. In the upper, compression of the subclavian is necessary during interference with axillary hæmatomata, combined with direct pressure on the bleeding spot after the clot has been removed. In the case of the arm, digital compression is always to be preferred, in view of the well-known danger of damage to the brachial nerves from the tourniquet.

Proximal ligature is always to be avoided. It is inadequate, and proved more dangerous as far as the vitality of the limb was concerned, the latter point probably depending on the interference with the collateral circulation by pressure from the extravasated blood, which is unrelieved by the operation. I know of at least two cases of gangrene which occurred consecutively to proximal ligature of the femoral artery for this condition.

_True traumatic aneurisms._--The cases met with differed so little from those seen in ordinary civil practice, that but slight notice of them is necessary. They differed from the last variety mainly in the more localised nature of the tumour, the greater firmness of its walls, and the more pronounced expansile pulsation. The development of this form of aneurism was probably influenced by several circumstances, such as the more complete rest secured for the patient, the locality in the limb as affecting movement of the spot in the vessel actually wounded, the size of the opening in the vessel, and the degree of support afforded by surrounding structures. (Examples are furnished by cases 6-9.)

Under the influence of rest, all that I saw tended to contract and become firmer, and they so far resembled spontaneous aneurisms as to be readily cured by proximal ligature of the artery. The ideal treatment no doubt consists in local incision and ligature on either side of the wounded spot, with or without ablation of the sac. The choice of direct or proximal ligature in any case depends on the position of the aneurism, and the ease with which the former operation can be carried out. In all these cases a very great advantage in the localisation and diminution of the tumours was gained by postponing interference until they became stationary. I need scarcely add that any evidence of diffusion indicated immediate operation. The preference of direct or proximal ligation will probably, to a certain extent, always depend on the personal predilection of the surgeon, but while proximal ligature has often given good immediate results during this campaign, it cannot be with certainty decided whether the patients are definitely protected from the dangers of recurrence.

Reference to cases 7 and 9 as illustrating the possible spontaneous cure of traumatic aneurisms is of great interest.

I saw a number of cases successfully treated by proximal ligature; also a number where continuous improvement followed rest, and which were sent home for further treatment. None of these demand any special mention.

One case of a very special nature, which terminated fatally, is of great interest:--

(5) In a man wounded at Belmont the bullet entered the second
left intercostal space and was retained in the thorax. He was
sent directly to the Base and came under the care of Mr.
Thornton at No. 1 General Hospital, Wynberg. Signs of wound of
the lung developed in the form of hæmoptysis and left
hæmothorax. The left radial pulse was almost imperceptible.

The entry wound did not close by primary union, and three weeks
later an incision was made into the chest in consequence of the
presence of fever, progressive emaciation, and weakness.
Breaking down blood clot was evacuated: general improvement
followed, and the radial pulse increased considerably in
volume.

A fortnight later sudden severe hæmorrhage occurred from the
external wound, and the man rapidly collapsed and died. At the
post-mortem a traumatic aneurism the size of an orange was
found in connection with an oval wound in the first portion of
the left subclavian artery which admitted the tip of the
forefinger.

This case is noteworthy as an illustration of the magnitude of an artery which can be wounded without leading to rapid death from primary hæmorrhage, even when in communication with a serous sac, and still more as emphasising the importance of weakening of the radial pulse as a sign in connection with a wound of the upper part of the chest on the left side. It is somewhat surprising that this sign was not marked in two cases (Nos. 13 and 14, p. 140) recorded below, in which the innominate and right carotid arteries respectively were probably perforated.

(6) _Traumatic popliteal aneurism._--Wounded at Modder River.
_Entry_ (Mauser), over centre of tibia 1 inch above the
tubercle. _Exit_, about centre of popliteal space. No
hæmorrhage of any importance occurred from the wound, but there
was a typical hæmarthrosis, 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 space. 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 Dick, 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 space; the knee was bent at the time it was struck.
There was considerable primary external hæmorrhage, and so much
blood collected in the knee-joint that it was aspirated. On the
eighth day secondary hæmorrhage occurred from the exit wound
and the femoral artery was tied in Hunter's canal. No further
hæmorrhage occurred, but at the end of three weeks feeble
pulsation was palpable in the popliteal space, 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 hæmatoma 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 passage 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 circumstances.

_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, classed as of small calibre during this war, a range of from 6.5-8 mm. existed. In the case of both the Krag-Jörgensen 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 passed 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 hæmatoma was the uniform result.

Under these circumstances 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 spaciousness 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 canal than if the injury is situated high in Scarpa's triangle, where the vessels lie in a large areolar space. The passage 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 hæmorrhage, 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 space afforded by a canal 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 hæmorrhage, 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 illustrates 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 hæmorrhage. 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 pronounced 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 classically 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 space, 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 hæmorrhage, 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 hæmorrhage at the time from
the exit wound, but no hæmoptysis; 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.