Forearm Venous Distensibility Predicts Successful Arteriovenous Fistula

Background: The success of a newly created arteriovenous fistula (AVF) depends on sufficient maturation of the forearm vein used. This maturation fails in up to 50%. We hypothesize that impairment of forearm venous distensibility, ie, the ability of veins to adjust to increased pressure, is related to AVF failure.

Methods: Forearm venous distensibility was measured by using strain-gauge plethysmography in 27 patients with end-stage renal failure awaiting vascular access surgery; either AVF or graft (AVG) formation. Ultrasound duplex scanning of the upper-extremity circulation was performed 4 weeks before surgery. Failure to mature is defined as inability to use the AVF for hemodialysis within 8 weeks after surgery.

Results: Venous distensibility in patients receiving an AVG (n = 10) was 0.44 +/- 0.05 mL/mm Hg, and in patients receiving an AVF (n =17), 0.56 +/- 0.04 mL/mm Hg (P = 0.2). Venous distensibility was 0.46 +/- 0.03 mL/mm Hg in patients with an unsuccessful AVF (n = 9) and 0.66 +/- 0.05 mL/mm Hg in patients with a successful AVF (n = 8; P = 0.003). All 7 patients with venous distensibility of 0.50 mL/mm Hg or less had a nonfunctional AVF (100%), whereas only 2 of 10 patients with venous distensibility greater than 0.50 mL/mm Hg had a nonfunctional AVF (20%; P = 0.002). No differences were found in arterial and venous luminal diameters between functional and nonfunctional AVFs.

Conclusion: These preliminary results suggest that forearm venous distensibility is a predictor of AVF success, whereas luminal diameters are not. Measurement of venous distensibility may be helpful in choosing the most suitable access type for each individual patient, possibly improving access patency.