[Illustration:  FIG. 73.—­Radiogram of Innominate Aneurysm after treatment by the Moore-Corradi method.  Two feet of finely drawn silver wire were introduced.  The patient, a woman, aet. 47, lived for ten months after operation, free from pain (cf.  Fig. 75).]

Colt’s method of wiring has been mainly used in the treatment of abdominal aneurysm; gilt wire in the form of a wisp is introduced through the cannula and expands into an umbrella shape.

Subcutaneous Injections of Gelatin.—­Three or four ounces of a 2 per cent. solution of white gelatin in sterilised water, at a temperature of about 100 F., are injected into the subcutaneous tissue of the abdomen every two, three, or four days.  In the course of a fortnight or three weeks improvement may begin.  The clot which forms is liable to soften and be absorbed, but a repetition of the injection has in several cases established a permanent cure.

Amputation of the limb is indicated in cases complicated by suppuration, by secondary haemorrhage after excision or ligation, or by gangrene.  Amputation at the shoulder was performed by Fergusson in a case of subclavian aneurysm, as a means of arresting the blood-flow through the sac.

TRAUMATIC ANEURYSM

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.

The injury to the artery may be a subcutaneous one such as a tear by a fragment of bone:  much more commonly it is a punctured wound from a stab or from a bullet.

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.

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.  A traumatic aneurysm is liable to become diffuse—­a change which, although attended with considerable risk of gangrene, has sometimes been the means of bringing about a cure.

The treatment is governed by the same principles as apply to the pathological varieties, but as the walls of the artery are not diseased, operative measures dealing with the sac and the adjacent segment of the affected artery are to be preferred.