Ligation of the hypogastric (internal iliac) by the trans-peritoneal route is the most satisfactory method of treatment. Extirpation of the sac is difficult and dangerous, especially when the aneurysm has spread into the pelvis.
Femoral Aneurysm.—Aneurysm of the femoral artery beyond the origin of the profunda branch is usually traumatic in origin, and is more common in Scarpa's triangle than in Hunter's canal. Any of the methods already described is available for their treatment—the choice lying between Matas' operation and ligation of the external iliac.
Aneurysm of the profunda femoris is distinguished from that of the main trunk by the fact that the pulses beyond are, in the former, unaffected, and by the normal artery being felt pulsating over or alongside the sac.
In aneurysmal varix, a not infrequent result of a bullet wound or a stab, the communication with the vein may involve the main trunk of the femoral artery. Should operative interference become necessary as a result of progressive increase in size of the tumour, or progressive distension of the veins of the limb, an attempt should be made to separate the vessels concerned and to close the opening in each by suture. If this is impracticable, the artery is tied above and below the communication; gangrene of the limb may supervene, and we have observed a case in which the gangrene extended up to the junction of the middle and lower thirds of the thigh, and in which recovery followed upon amputation of the thigh.
Popliteal Aneurysm.—This is the most common surgical aneurysm, and is not infrequently met with in both limbs. It is generally due to disease of the artery, and repeated slight strains, which are so liable to occur at the knee, play an important part in its formation. In former times it was common in post-boys, from the repeated flexion and extension of the knee in riding.
The aneurysm is usually of the sacculated variety, and may spring from the front or from the back of the vessel. It may exert pressure on the bones and ligaments of the joint, and it has been known to rupture into the articulation. The pain, stiffness, and effusion into the joint which accompany these changes often lead to an erroneous diagnosis of joint disease. The sac may press upon the popliteal artery or vein and their branches, causing congestion and œdema of the leg, and lead to gangrene. Pressure on the tibial and common peroneal nerves gives rise to severe pain, muscular cramp, and weakness of the leg.
The differential diagnosis is to be made from abscess, bursal cyst, enlarged glands, and sarcoma, especially pulsating sarcoma of one of the bones entering into the knee joint.
The choice of operation lies between ligation of the femoral artery in Hunter's canal, and Matas' operation of aneurysmo-arteriorrhaphy. The success which attends the Hunterian operation is evidenced by the fact that Syme performed it thirty-seven times without a single failure. If it fails, the old operation should be considered, but it is a more serious operation, and one which is more liable to be followed by gangrene of the limb. Experience shows that ligation of the vein, or even the removal of a portion of it, is not necessarily followed by gangrene. The risk of gangrene is diminished by a course of digital compression of the femoral artery, before operating on the aneurysm.
Aneurysmal varix is sometimes met with in the region of the popliteal space. It is characterised by the usual symptoms, and is treated by palliative measures, or by ligation of the artery above and below the point of communication.
Aneurysm in the leg and foot is rare. It is almost always traumatic, and is treated by excision of the sac.