True aneurysm in a femoro-popliteal dacron graft -- a case report and literature review.

Infection and anastomotic pseudo-aneurysm formation are the usually reported complications in the use of dacron prosthesis in arterial by-pass surgery. We report a case of true aneurysm formation in the body of a knitted dacron graft used to by-pass a symptomatic above knee occlusion of the superficial femoral artery when suitable long saphenous vein was not available. This was diagnosed 10 years after surgery. A true aneurysm may be a result of pre-implantation trauma to the graft or to late fibre degeneration. Microscopic examination revealed that the dacron fibres had stretched to form a local aneurysm before rupturing to form an associated false aneurysm. Two other areas of the graft had small saccular aneurysms without rupture. The damaged portion was excised and replaced by an interposition graft of the same material.