Flow Rates at Thirty Days after Construction of Radiocephalic Arteriovenous Fistula Predict Hemodialysis Function

Abstract

Background: Construction of radiocephalic arteriovenous fistula (RC-AVF) results in successful hemodialysis (HD) in approximately 40% of end-stage renal disease patients. We investigated whether RC-AVF flow measured by ultrasound 30 days postoperative predicted successful HD.

Methods: In this prospective study, color Doppler ultrasound was used to measure cephalic vein outflow volume at 3 forearm sites at 1 and 3 months postoperatively.

Results: Of 45 consecutive patients screened for feasibility of RC-AVF by physical examination and US arterial and vein mapping, 41 were considered suitable for construction of RC-AVF. Mean age was 70 (60-78) years. Of the 41 patients who had a forearm RC-AVF, 25 (61%) proceeded to successful AVF dialysis, 4 (10%) had HD via central venous catheter, and 12 (29%) ceased function within the first 30 days postoperatively. The mean flow at 30 days for patent fistulas was 629 ± 305 ml/min and by the third month had increased to 663 ± 367 mL/min. At 1 month, 8/29 (27.6%) patients had a flow rate <400 mL/min. Two (25%) of these clotted, 2 of 3 with closed revisions went on to HD, and 1 died. Of the 21 patients with a flow rate ≥400 mL/min, 19 (90%) functioned for HD, and 2 (10%) AVF occluded before 1 year, resulting in 17 functioning at 1 year (81% 1-year patency). Sixty-two percent of the low-flow fistulas had successful patency within 1 year.

Conclusions: An RC-AVF flow rate of ≥400 mL/min in the first month predicted more successful HD than low flow (<400 mL/min) (81% vs. 62%). Without intervention, low flow rates do not improve significantly and maturation is unlikely. We recommend imaging for all patients at 30 days to identify and promptly correct stenosis in those with low flow rates.