The Flow Volume and Resistance Index of Patent Arteriovenous Fistulas, With Proper Function, Compared to Unhealthy Arteriovenous Fistulas, Using Spectral Doppler

Abstract

Objective: This study was designed to use sonography and evaluate arteriovenous fistulas (AVFs) in dialysis patients. The aim was to determine criteria for distinguishing between patent AVFs with proper function (healthy) and unhealthy AVFs. Materials and Methods: This study enrolled 106 dialysis patients with an AVF. All fistulas were evaluated using spectral Doppler and grayscale sonography, assessing parameters such as draining vein diameter, distance of the venous vein from the skin surface, feeding artery diameter, presence of thrombosis, and fistula stenosis. Subsequently, Doppler criteria such as flow volume (FV) and resistance index (RI) were measured and compared between healthy and unhealthy AVFs. Results: This cohort’s spectral Doppler findings demonstrated lower FV and higher RI, in unhealthy AVFs, compared to healthy ones (283.5 ± 101.26 mL/min vs 1383.43 ± 756.76 mL/min; P = .006) and (0.55 ± 0.33 vs 0.37 ± 0.14; P = .004) respectively. Conclusion: The spectral Doppler and grayscale sonographic imaging made it possible to evaluate AVF performance and determine its quality. In this cohort, a decreased FV, increased RI, and decreased draining vein diameter were observed in unhealthy AVFs. These results would suggest that sonographers and clinicians should pay close attention to these parameters when assessing the function of an AVF, for patients undergoing hemodialysis.