The fate of the donor artery in extraanatomic revascularization.

Favorable long-term results have been reported after femorofemoral bypass in the treatment of iliofemoral occlusive disease. Functional alterations in the donor artery, occurring after the implantation of the graft, have been considered as having an arresting effect on the progress of the occlusive disease, which explains the favorable long-term results. However, until now, the intrinsic mechanism of this phenomenon has remained unexplained. Little attention has been devoted to the evaluation of the natural history of the donor artery. To achieve this purpose, 18 patients previously operated on for femorofemoral bypass, with a normal patent graft, were submitted to angiographic evaluation, from 8 to 57 months after the operation (mean 22 months). The angiograms were compared with the preoperative films to assess the progress of the occlusive disease in the donor artery. A slight but significant dilatation of the proximal donor arterial segment was documented in every case, affecting the external iliac and common femoral arteries. The pathogenesis of this phenomenon is discussed. It may be related to decreased peripheral resistance and increased blood flow occurring in the donor arterial segment, reported after the implantation of the shunt. This dilatation of the donor artery may have a compensatory effect for local atherosclerotic stenosis, thereby explaining the favorably long duration of the femorofemoral bypasses, which has been emphasized since the early days of extraanatomic revascularization. A similar phenomenon may occur in the vessels of the upper extremity, after axillofemoral revascularization.