Early prediction of hemodialysis arteriovenous fistula failure in end-stage kidney disease patients using ultrasonographic and color-Doppler assessment – an experience from a tertiary care centre in India
Purpose – Arterio-venous fistula (AVF) failure is a major concern in patients of end-stage kidney disease undergoing hemodialysis. Ultrasound Doppler is a sensitive modality for post-operative AVF assessment. The purpose of this study was to evaluate various objective ultrasonographic and color-Doppler criteria for early prediction of AVF outcomes. Methods and materials – A single-centre prospective cohort study over one year after obtaining ethical clearance. All patients undergoing native AVF creation surgery, and referred for routine post-operative around Doppler assessment were included. Patients were evaluated for fistula size, Cephalic vein area and diameter, AVF flow velocity, and flow rates at post-operative day 2, week 2, and week 6, respectively, and followed up to determine unassisted AVF outcomes. Initial findings were compared with subsequent outcomes. Results– Of our initial cohort of 40 patients, almost 75% developed AVF failure while 25% had successful unassisted AVF maturation. The two groups demonstrated significant differences in AVF flow rates as early as post-operative day 2. A cut-off value >246 ml/min predicted successful unassisted AVF maturation with a sensitivity of 80% and a specificity of 70%. Though the cephalic vein diameter at post-operative day 2 did not correlate strongly with the AVF outcome, when using a cut-off value of >3.4 mm and simultaneously testing with flow rate, the cumulative sensitivity increased to 92%. Conclusion– Ultrasound Doppler is a useful quantitative imaging modality in predicting AVF outcomes as early as post-operative day 2. A flow rate of >246 ml/min and a cephalic vein diameter >3.4 mm are significant parameters for the early prediction of successful AVF outcomes.