Hemodynamics of an anastomotic arteriovenous fistula.

Various vascular surgical techniques have been employed to increase both graft patency and limb survival when the prognosis for limb salvage in arteriosclerotic patients is especially poor due to a diseased outflow tract. Ibrahim et al described the creation of an anastomotic arteriovenous fistula in distal tibial bypasses as the reconstructive procedure of choice in severely ischemic extremities unsalvageable by more conventional methods. This study presents the hemodynamics of an anastomotic arteriovenous fistula under such circumstances. Four adult mongrel dogs were anesthesized, and a femoral artery and vein were exposed from the groin to the knee. The femoral artery was ligated in midthigh, and the ligated segment was than bypassed using an umbilical vein graft. The distal anastomosis included an arteriovenous fistula. Flow was measured electromagnetically, and pressure was measured with intravascular catheters attached to strain gauges. The creation of an anastomotic arteriovenous fistula rapidly leads to a reversal of flow in the distal artery, distal arterial hypotension, and distal venous hypertension. Its clinical use in contraindicated as a result of our experimental observations.