Arteriovenous fistulas for dialysis: Blood flow,viscosity, and long-term patency

A prospective study of the influence of blood flow at the time of operation on subsequent performance of dialysis fistulas is reported. Flow was measured in 33 consecutive arteriovenous fistulas using an electromagnetic flowmeter. During the mean follow-up time of 7 months (range, 2–12 months), 19 fistulas were used for dialysis, 9 have not yet been used, 4 were never used because of thrombosis or failure to develop adequately, and 1 patient died before using the fistula for hemodialysis. There were 9 complications (thrombosis, stenosis, and failure to develop). Operative blood flow for these 9 fistulas averaged 221 ml/min as compared to 214 ml/min for the group with no subsequent problems. No critical flow rate below which the fistula would not develop could be defined. An analysis of influences on flow rate at the time of operation showed that there was a significant correlation between flow and blood pressure, vessel dimensions, and whole blood viscosity, but it was not possible to predict fistula failure from these data.