Accuracy of Early Postoperative Clinical and Ultrasound Examination of Arteriovenous Fistulae to Predict Dialysis Use

Abstract

Aim The aim of this article is to assess the accuracy of early clinical and ultrasound (US) examination in terms of predicting arteriovenous fistula (AVF) dialysis use. Methods Physical and US examination of patent AVF was performed 4 weeks after fistula creation. AVF dialysis use was defined as subsequent use of an AVF for at least six consecutive dialysis sessions with two needles and a blood flow of more than 200 mL/min. Results Of 119 AVF patent at 4 weeks, 26 (22%) failed. Clinical examination was 96% sensitive for predicting successful dialysis, but only 21% specific for failure. Vein diameter above 5 mm and an arterial end-diastolic velocity above 110 cm/s were the best US predictors for dialysis use. Vein diameter was slightly better than arterial velocity in terms of predicting maturity (sensitivity: 83% vs 67%, specificity: 68% vs 65%). All assessments predicted AVF maturity (positive predictive value: clinical = 81%, US diameter = 90%, US velocity = 87%) much better than AVF failure (negative predictive value: clinical = 63%, US diameter = 53%, US velocity = 37%). Conclusion One month after surgery, a new AVF with a thrill or a vein diameter >5 mm is likely to be used for dialysis. An AVF not meeting these criteria has an increased risk of failure and further investigations may be required.