Aneurysm

“ The aneurysm usually forms soon after the injury is inflicted; the blood slowly escapes into the surrounding tissues, gradually displacing and condensing them, until they form a sac enclosing the effused blood.
Less frequently a traumatic aneurysm forms some considerable time after the injury, from gradual stretching of the fibrous cicatrix by which the wound in the wall of the artery has been closed. The gradual stretching of this cicatrix results in condensation of the surrounding structures which form the sac, on the inner aspect of which laminated clot is deposited. ”

“ An aneurysm may prove _fatal_ by exerting pressure on important structures, by causing syncope, by rupture, or from the occurrence of suppuration. _Pressure_ symptoms are usually most serious from aneurysms situated in the neck, thorax, or skull. Sudden fatal _syncope_ is not infrequent in cases of aneurysm of the thoracic aorta. ”

“ The essential feature of a traumatic aneurysm is that it is produced by some form of injury which divides all the coats of the artery. The walls of the injured vessel are presumably healthy, but they form no part of the sac of the aneurysm. The sac consists of the condensed and thickened tissues around the artery. ”

“ Repeated and sudden raising of the arterial tension, as a result, for example, of violent muscular efforts or of excessive indulgence in alcohol, plays an important part in the causation of aneurysm. These factors probably explain the comparative frequency of aneurysm in those who follow such arduous occupations as soldiers, sailors, dock-labourers, and navvies. In these classes the condition usually manifests itself between the ages of thirty and fifty--that is, when the vessels are beginning to degenerate, although the heart is still vigorous and the men are hard at work. ”

“ The man who has chronic inflammation of a large artery, the result, for instance, of gout, arduous, straining work, or kidney-disease, and whose artery yields under cardiac pressure, has a spontaneous aneurysm; the barman or window-cleaner who has cut his radial artery, the soldier whose brachial or femoral artery has been bruised by a rifle bullet or grazed by a bayonet, and the boy whose naked foot is pierced by a sharp nail, are apt to be the subjects of traumatic aneurysm. ”

“ An aneurysm exerts pressure on the surrounding structures, which are usually thickened and adherent to it and to one another. Adjacent veins may be so compressed that congestion and oedema of the parts beyond are produced. Pain, disturbances of sensation, and muscular paralyses may result from pressure on nerves. Such bones as the sternum and vertebrae undergo erosion and are absorbed by the gradually increasing pressure of the aneurysm. ”

“ If a comparatively small escape of blood takes place into the tissues, the sudden alteration in the size, shape, and tension of the aneurysm, together with loss of pulsation, may be the only local signs. When the bleeding is profuse, however, the parts beyond the aneurysm become greatly swollen, livid, and cold, and the pulse beyond is completely lost. The arrest of the blood supply may result in gangrene. Sometimes the pressure of the extravasated blood causes the skin to slough and, later, give way, and fatal haemorrhage results. ”

“ Relative to the size of an aneurysm, Warren reported a case of the abdominal aorta which commenced at the origin of the celiac axis and passed on to the surfaces of the psoas and iliac muscles, descending to the middle of the thigh The total length of the aneurysm was 19 inches, and it measured 18 inches in circumference.
A peculiar sequence of an aortic aneurysm is perforation of the sternum or rib. Webb mentions an Irish woman who died of aneurysm of the aorta, which had perforated the sternum, the orifice being plugged by a large clot. ”

“ This method is suitable to sacculated aneurysm of the limbs, so long as they are circumscribed and free from complications. It has been successfully practised also in aneurysm of the subclavian, carotid, and external iliac arteries. It is not applicable to cases in which there is such a degree of atheroma as would interfere with the successful ligation of the artery. The continuity of the artery may be restored by grafting into the gap left after excision of the sac a segment of the great saphena vein. ”

“ Ligation of the aorta has so far been unsuccessful, but in one case operated upon by Keen the patient survived forty-eight days.
Innominate aneurysm may be of the fusiform or of the sacculated variety, and is frequently associated with pouching of the aorta. It usually grows upwards and laterally, projecting above the sternum and right clavicle, which may be eroded or displaced (Fig. 75) . Symptoms of pressure on the structures in the neck, similar to those produced by aortic aneurysm, occur. ”

“ A traumatic aneurysm is almost always sacculated, and, so long as it remains circumscribed, has the same characters as a pathological sacculated aneurysm, with the addition that there is a scar in the overlying skin. ”

“ He demonstrated the minute structure of blood-vessels, showed before the Royal Society experiments proving that the inner and middle coat of an artery could be ruptured while the outer remained entire, and thus made clear the method of formation of chronic aneurysm, which had not before been understood. ”

“ Longitudinal wounds show little tendency to gape, and are therefore not attended with much bleeding. They usually heal rapidly, but, like punctured wounds, are liable to be followed by the formation of an aneurysm.
When, however, the incision in the vessel wall is oblique or transverse, the retraction of the muscular coat causes the opening to gape, with the result that there is haemorrhage, which, even in comparatively small arteries, may be so profuse as to prove dangerous. When the associated wound in the soft parts is valvular the haemorrhage is arrested and an aneurysm may develop. ”

“ Compression of the artery makes no difference in the size or tension of the swelling.
Vascular tumours, such as sarcoma and goitre, may yield an expansile pulsation and a soft, whifling bruit, but they differ from an aneurysm in that they are not diminished in size by compression of the main artery, nor can they be emptied by pressure.
The exaggerated pulsation sometimes observed in the abdominal aorta, the "pulsating aorta" seen in women, should not be mistaken for aneurysm. ”

“ This case was particularly interesting as it was accompanied by a postmortem examination. Pye-Smith reports an extremely interesting case in which death occurred from traumatic aneurysm of an aberrant subclavian artery. The patient fell from a height of 28 feet, lost consciousness for a few minutes, but soon recovered it. There was no evidence of any fracture, but the man suffered greatly from dyspnea, pain between the shoulders, and collapse. The breath-sounds on auscultation and the difficulty in swallowing led to the belief that one of the bronchi was blocked by the pressure of a hematoma. ”

“ The condition may be treated by excision or by electrolysis. In excision the haemorrhage is controlled by an elastic tourniquet applied horizontally round the head, or by ligation of the feeding trunks. In large tumours the bleeding is formidable. In many cases electrolysis is to be preferred, and is performed in the same way as for naevus. The positive pole is placed in the centre of the tumour, while the negative is introduced into the main affluents one after another.
ANEURYSM
An aneurysm is a sac communicating with an artery, and containing fluid or coagulated blood. ”

“ The presence of diseased patches in the wall of an artery diminishes its elasticity and favours aneurysmal dilatation. Such a vessel also is liable to be ruptured by external violence and so give rise to traumatic aneurysm. Thrombosis is liable to occur when calcareous plates are exposed in the lumen of the vessel by destruction of the endothelium, and this predisposes to embolism. Arterio-sclerosis also interferes with the natural arrest of haemorrhage, and by rendering the vessels brittle, makes it difficult to secure them by ligature. ”

“ When an artery and its companion vein are injured simultaneously an arterio-venous aneurysm (p. 310) may develop. This frequently takes place without the formation of a hæmatoma as the arterial blood finds its way into the vein and so does not escape into the tissues. Even if a hæmatoma forms it seldom assumes a great size. In time a swelling is recognised, with a palpable thrill and a systolic bruit, loudest at the level of the communication and accompanied by a continuous venous hum. ”

“ Cardiac failure accounts for most of the deaths, whether developed gradually with dropsy, which proves to be intractable; or progressing rapidly with great cardiac distress, including angina; or occurring suddenly, as it often does. Aneurysm makes its appearance in other instances, of which the patient dies, or he is carried off by general paralysis or Bright's disease.
What prospect have we to hold out to the man who has strained the walls of his heart by muscular effort? ”

“ The exact lesion would appear to have been that one of the cerebral arteries that supplied the left side of Johnson’s brain had for some reason been thrown into a state of spasm, and caused temporary softening of the brain owing to interference with its blood-supply. If an artery had actually [35] burst on the site of a tiny aneurysm, as occasionally happens in cases of arteriosclerosis, the old man would not have recovered so soon, even temporarily. ”

“ When an artery is wounded a firm hæmatoma may form, with an expansile pulsation and a palpable thrill—whether such a hæmatoma remains circumscribed or becomes diffuse depends upon the density or laxity of the tissues around it. In course of time a traumatic arterial aneurysm may develop from such a hæmatoma. ”

“ Aneurysm by Anastomosis is the name applied to a vascular tumour in which the arteries, veins, and capillaries are all involved. It is met with chiefly on the upper part of the trunk, the neck, and the scalp. It tends gradually to increase in size, and may, after many years, attain an enormous size. The tumour is ill-defined, and varies in consistence. It is pulsatile, and a systolic bruit or a “thrilling” murmur may be heard over it. The chief risk is hæmorrhage from injury or ulceration. ”

“ The internal and middle coats being already damaged, or, it may be, destroyed, by the primary disease, the stress falls on the external coat, which in the majority of cases constitutes the sac. To withstand the pressure the external coat becomes thickened, and as the aneurysm increases in size it forms adhesions to surrounding tissues, so that fasciæ, tendons, nerves, and other structures may be found matted together in its wall. The wall is further strengthened by the deposit on its inner aspect of blood-clot, which may eventually become organised. ”

“ It not infrequently happens that such haemoptysis may be the first symptom that seriously attracts attention. At a later period hemorrhage frequently takes place in large or small amounts from the rupture of vessels, which frequently are dilated and form small aneurysms in the walls of cavities. ”

“ Aneurism may become very large; as it increases in size it presses upon and causes the destruction of neighboring tissues. The cavity of the aneurismal sac is filled with fluid or clotted blood or with layers of fibrin which adhere closely to its wall. Death is produced usually by the pressure and interference of the aneurism with adjoining organs or by rupture. In worm aneurism we usually find large thrombi within the aneurismal dilatation of the artery, which sometimes plug the whole vessel or extend into the aorta. ”

“ The most important factor of all is, however, the contraction of venereal disease, especially of that form known as syphilis.
The termination of aneurism cases is usually by rupture with profuse hemorrhage. Death takes place in a moment or two. Aneurisms often cause intense pain, which is sometimes thought to be rheumatic in origin. If the aneurism, in its enlargement, meets with bony structure, it produces absorption of the bone by pressure upon it and so finds a way even through the bone to the overlying skin. ”

“ This adhesion will not take place unless the portion of the artery to which the ligature is applied be in a sound state. If it be diseased, as it almost always is near the seat of the aneurism, when the process of nature is completed by which the ligature is removed, hemorrhage takes place, and the patient dies just as if the aneurism had been left to itself. For a long time the ligature was applied as close as possible to the seat of the aneurism: the aneurismal sac was laid open in its whole extent, and the blood it contained was scooped out. ”

“ Vesalius was consulted about a tumor in the back, which he pronounced to be an aneurism; but an ignorant practitioner having made an opening into it, the patient instantly bled to death. Nothing can be more easy than to confound an aneurism of the artery of the neck with the swelling of the glands in its neighborhood: with a swelling of the cellular substance which surrounds the artery; with abscesses of various kinds; but if a surgeon were to fall into this error, and to open a carotid aneurism, his patient would certainly be dead in the space of a few moments. ”

“ The Pressure and Ligature Methods of treating Aneurism.—In the course of a lecture on aneurism of the femoral artery Mr. Paget, adverting to these two methods, speaks of them thus: “Taking large numbers of cases of aneurism together, they are very nearly balanced, on the one side for pressure, and on the other for ligature. In favour of pressure there is the experience of the surgeons in Dublin. They seem to have a much larger number of aneurisms, especially of aneurisms of the popliteal artery, to treat than we have in England, and they have certainly a large amount of success. ”