Characterizing flow distributions in AV fistulae for haemodialysis access

The arteriovenous fistula is the most widely used means of enabling vascular access for chronic haemodialysis. When interest in vascular access was at its height, in the 1970s, a substantial amount of work was carried out on the physiology of arteriovenous fistulae and on the relationship between fistula flow and patency. One omission in the catalogue of studies was research into the distribution of flow in the fistula and the effects on surgical outcome.

To address this issue, 30 patients with end-to-side radiocephalic fistulae were studied. Flow measurements were made intraoperatively, and at various intervals postoperatively using colour-flow ultrasonography.

In 22 cases, the development of the fistula was monitored at regular intervals for periods of up to 27 months. In seven of the 30 fistulae, flow in the distal artery was antegrade, while in the remaining 23, distal artery flow was retrograde. The proportion of fistula flow supplied by the proximal and distal arteries varied considerably.

Despite the wide range of flow distributions in the fistulae studied, flow distribution did not appear to affect fistula maturation or long-term function.