The effect of arteriovenous fistulas on in situ saphenous vein bypasses

Intraoperative identification and later development of arteriovenous fistulas were investigated prospectively in 70 in situ saphenous vein bypass procedures. Surveillance was performed by completion arteriography and intra- and postoperative continuous wave Doppler examination. The intraoperative Doppler examination identified 89% of those branches with sufficient flow to opacify the deep venous system on completion arteriogram. Half of the missed fistulas underwent spontaneous thrombosis, and in only one case did the arteriovenous fistula lead to hemodynamic symptoms demanding surgical closure of the fistula. Pursuing a policy of selectively ligating fistulas that only fill the deep venous system on completion arteriography led to an additional nine arteriovenous fistulas. Developed over an average follow-up of six months, four patients presented symptoms of edema and swelling and were relieved upon closure of the fistulas. The incidence of bypass thrombosis did not differ significantly among patients with remaining arteriovenous fistulas, patients who developed fistulas during follow-up, and patients who had no signs of arteriovenous fistulas. It seems justified to continue selective intraoperative ligation of arteriovenous fistulas based on continuous wave Doppler.