Early access flow rate predicts vascular access patency‐related intervention in the first year: A retrospective cohort study

Abstract Introduction Arteriovenous fistulas and grafts are lifelines for most hemodialysis patients, and a low access flow rate often requires patency‐related intervention, such as angioplasty or thrombectomy, to prevent access failure. We examined whether early access flow rate, measured after initial fistula/graft cannulation, predicts vascular access patency‐related intervention within 1 year. Methods This was a single‐center retrospective cohort study. Among 172 patients undergoing surgical creation of a fistula/graft, 52 (30.2%) had documented access flow rates measurement by the Transonic™ ultrasound dilution technique, performed within an average of 48 days from initial access cannulation. The need for a patency‐related intervention, defined as undergoing a fistulogram, angioplasty, thrombectomy, or surgical revision, was ascertained within 1 year. A receiver‐operating characteristic curve (ROC) was generated to evaluate the diagnostic performance of first and average access flow rates for predicting patency‐related intervention within 1 year. Findings Twenty‐eight (53.8%) of the 52 study subjects required a patency‐related intervention within 1 year. Their characteristics were not significantly different from those who did not require patency‐related interventions. However, first access flow rates were significantly lower in patients requiring patency‐related intervention compared to those who did not (898 vs. 1471 mL/min; p = 0.003), as were average access flow rates (841 vs. 1506 mL/min; p < 0.001). The ROC analyses revealed that first access flow rates and average access flow rates predicted the need for patency‐related intervention within 1 year, with an area under‐the‐ROC curve of 0.743 (95% confidence interval [CI] 0.608, 0.877) and 0.775 (95% CI 0.648, 0.903), respectively, demonstrating acceptable discrimination. Discussion In adults undergoing hemodialysis, early access flow rate measurement can predict patency‐related intervention within 1 year after initial vascular access cannulation. Additional studies are required to confirm these findings and identify optimal access flow rate cut‐off values to predict vascular accesses at higher risk of stenosis.