Anastomotic aneurysms: facts and fancy.

One hundred and one anastomotic aneurysms were encountered in 74 patients over a 25-year period (1963 through 1988). Ninety-three anastomotic aneurysms (92 percent) were prosthesis-related, one followed a thromboendarterectomy, and seven (para-anastomotic aneurysms) occurred after the use of venous grafts. In the prosthesis-related anastomotic aneurysms, 50 percent of the patients had multiple anastomotic aneurysms. Most anastomotic aneurysms occurred at the femoral region (70.9 percent), but no suture line was immune. The most common cause of the anastomotic aneurysms was a defect in the host artery (90.2 percent), followed by suture failure (4.9 percent), and prosthetic failure (4.9 percent). Although most anastomotic aneurysms appeared about 5 years postoperatively, they may develop at any time. The early appearance of an anastomotic aneurysm (within 2 years) suggests infection as a cause. Because the incidence of complications of anastomotic aneurysms is high, regular follow-up assessment of all anastomoses is desirable. It is postulated that prostheses by virtue of their unphysiological characteristics cause abnormal stresses at the suture line leading to weakness of the host artery.