A total of 145 in-situ saphenous vein bypasses were studied postoperatively by Echo Doppler (Duplex) ultrasound scanning. Volumetric blood flow was measured transcutaneously in each case. Five patients did not clinically improve despite patency of their bypasses. Three other patients had persistent edema and arteriovenous fistulae. Surgical ligation of dominant fistulae in these 8 pa tients resulted in significant improvement of distal bypass flow in 7 patients (p < 0.01, Student's paired t-test) with a concomitant decrease in fistula flow and resolution of symptoms in all patients.
An occasional patient undergoing in-situ bypass may have a hemodynamic compromise postoperatively that is correctable by fistula ligation.
