Increased reintervention in radial-cephalic arteriovenous fistulas with anastomotic angles of less than 30 degrees

Objective: Although radial-cephalic (RC) and brachial-cephalic (BC) fistulas are the recommended primary accesses for hemodialysis, access failure is frequently due to juxta-anastomotic stenosis (JAS). Because increased turbulence at the anastomosis may lead to JAS, we hypothesized that an acute angle at the arteriovenous anastomosis is associated with JAS, reduced fistula patency, and increased reinterventions.

Methods: Between February 2013 and September 2014, the anastomotic angle and vessel diameters were prospectively collected for all patients who underwent RC or BC fistula creation. The primary end point was reintervention on the juxta-anastomotic segment. Secondary end points were primary and secondary patency of the fistula.

Results: A total of 149 patients (median age, 72 years) received 73 RC and 76 BC fistulas; the median follow-up was 7 months (range, 1-22 months) for RC and 12 months (range, 2-24 months) for BC fistulas. The median anastomotic angle in RC fistulas, was 30°. Anastomotic angles of <30° were associated with reduced primary patency (38% vs 66%, P = .003) and secondary patency (84% vs 97%, P = .02) and increased numbers of reinterventions (67% vs 34%, P = .001). Cox analysis showed that an anastomotic angle of <30° was an independent factor predicting decreased primary patency (P = .009) and secondary patency (P = .03) as well as increased reinterventions (P = .004). In BC fistulas, the median anastomotic angle was 90°. Patients with anastomotic angles <90° and ≥90° had similar rates of primary patency (67% vs 67%, P = .39) and secondary patency (93% vs 94%, P = .89) at 6 months, with a similar reintervention rate at 12 months (31% vs 32%, P = .56). Vein diameter was the only factor that predicted reintervention (P < .0001).

Conclusions: RC fistulas with anastomotic angles of <30° have reduced primary and secondary patency and increased numbers of reinterventions, suggesting that, if possible, surgeons should avoid an anastomotic angle of <30° when creating RC fistulas. Anastomotic angles of <90° or ≥90° may not play a role in outcome of BC fistulas.