Outcomes of arteriovenous fistula and role of duplex ultrasound for its assessment in pre-dialysis patients; a single center longitudinal study

Abstract

Introduction: Arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis; however, it has a primary failure rate of 20%–60%. Analyzing the factors associated with AVF failure is crucial for planning appropriate management strategies. Objectives: We aimed to identify the AVF outcomes and associated factors along with the role of duplex ultrasound (DUS) in preoperative and postoperative AVF assessment at a tertiary care hospital. Patients and Methods: This prospective observational study was conducted on pre-dialysis patients who underwent AVF creation between January 2020 and December 2021.AVF outcomes and associated clinical and vascular factors were analyzed using pre- and post-operative DUS. Results: Of 171 patients, males were predominant (83.6%), and diabetic nephropathy (42.7%) was the predominant cause of chronic kidney disease (CKD). AVF outcomes showed, 109 (63.7%) had unassisted mature AVF and 29 (16.9%) had AVF failure wherein early dialysis suitability failure was predominant (17; 9.94%). Among clinical factors, only a history of smoking correlated with AVF failure (P=0.04). On pre-and post-operative DUS assessment, the absence of distensibility and immediate post-operative vein diameter strongly correlated with AVF failure (P<0.001). A unit increase (1 mm) in outflow vein diameter immediately after surgery emerged as an independent predictor of AVF outcome in both univariate (OR 0.98, 95% CI: 0.35-3.99; P<0.001) and multivariate analysis (OR: 0.313, 95% CI: 0.148-0.663; P<0.001). Conclusion: Most patients in our setting had unassisted AVF fistula. We additionally found that smoking correlated with AVF failure. Predominant factors determining AVF success were cephalic vein diameter, distensibility, and increase in draining vein diameter and flow volume at six weeks. This study highlights using DUS in pre- and post-operative periods, along with conventional examination to improve AVF outcomes.