The Role of Doppler Ultrasound Flow Volume Measurement in Predicting Arteriovenous Fistula Failure to Mature

The arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis; however, failure of AVF maturation is a significant clinical problem. Currently, there are no standard criteria to predict AVF failure. Our purpose was to evaluate the use of postoperative Doppler ultrasound (US) flow volume measurements to determine its role in predicting failure to mature. We conducted a single institution retrospective review of 186 patients who underwent AVF creation procedures between January 1, 2009, and December 31, 2011. Patients who never progressed to dialysis and patients who were lost to follow up were excluded (n = 177). Postoperative Doppler US flow volumes were collected. Outcomes were AVF failure to mature, and primary and secondary patency. Receiver operating characteristic (ROC) curve analysis was used to evaluate the utility of Doppler US for predicting AVF failure. The primary patency rate was 55%, and the secondary patency rate was 68%. First and second Doppler US measurements were taken on average at 3.6 weeks and 5.4 weeks postoperatively, respectively. Average time to outcome was 7.3 weeks (range, 5-9 weeks). ROC curve analysis of postoperative Doppler US flow volumes showed significant predictive capacity for fistulas that would fail to mature with ROC areas under the curve of 82.0% and 87.7% for first and second postoperative measurements, respectively. The flow volume with the greatest sensitivity and specificity for failure was 300 and 325 mL/s for the first and second measurements, respectively. The use of Doppler US flow volume measurements is an excellent predictor for fistulas that will fail to mature. Our data indicate that patients are at greatest risk for failure if the US flow volumes drop <325 mL/s on repeat flow volume measurement. This finding may be clinically important and suggests that Doppler US measurements could be used to predict a need to intervene during the maturation process to improve maturation rates.