#Axillary Aneurysm.#—­This is usually met with in the right arm of labouring men and sailors, and not infrequently follows an injury in the region of the shoulder.  The vessel may be damaged by the head of a dislocated humerus or in attempts to reduce the dislocation, by the fragments of a fractured bone, or by a stab or cut.  Sometimes the vein also is injured and an arterio-venous aneurysm established.

Owing to the laxity of the tissues, it increases rapidly, and it may soon attain a large size, filling up the axilla, and displacing the clavicle upwards.  This renders compression of the third part of the subclavian difficult or impossible.  It may extend beneath the clavicle into the neck, or, extending inwards may form adhesions to the chest wall, and, after eroding the ribs, to the pleura.

The usual symptoms of aneurysm are present, and the pressure effects on the veins and nerves are similar to those produced by an aneurysm of the subclavian.  Intra-thoracic complications, such as pleurisy or pneumonia, are not infrequent when there are adhesions to the chest wall and pleura.  Rupture may take place externally, into the shoulder-joint, or into the pleura.

Extirpation of the sac is the operation of choice, but, if this is impracticable, ligation of the third part of the subclavian may be had recourse to.

#Brachial aneurysm# usually occurs at the bend of the elbow, is of traumatic origin, and is best treated by excision of the sac.

Aneurysmal varix, which was frequently met with in this situation in the days of the barber-surgeons,—­usually as a result of the artery having been accidentally wounded while performing venesection of the median basilic vein,—­may be treated, according to the amount of discomfort it causes, by a supporting bandage, or by ligation of the artery above and below the point of communication.

Aneurysms of the vessels of the #forearm and hand# call for no special mention; they are almost invariably traumatic, and are treated by excision of the sac.

#Inguinal Aneurysm# (Aneurysm of the Iliac and Femoral Arteries).—­Aneurysms appearing in the region of Poupart’s ligament may have their origin in the external or common iliac arteries or in the upper part of the femoral.  On account of the tension of the fascia lata, they tend to spread upwards towards the abdomen, and, to a less extent, downwards into the thigh.  Sometimes a constriction occurs across the sac at the level of Poupart’s ligament.

The pressure exerted on the nerves and veins of the lower extremity causes pain, congestion, and oedema of the limb.  Rupture may take place externally, or into the cellular tissue of the iliac fossa.

These aneurysms have to be diagnosed from pulsating sarcoma growing from the pelvic bones, and from an abscess or a mass of enlarged lymph glands overlying the artery and transmitting its pulsation.

The method of treatment that has met with most success is ligation of the common or external iliac, reached either by reflecting the peritoneum from off the iliac fossa (extra-peritoneal operation), or by going through the peritoneal cavity (trans-peritoneal operation).