Study on prediction of arterio-venous fistula maturation by flow mediated dilatation and AVF blood flow

Background: The physiology and pathology of AVF maturation depends on the vessels characteristics and its ability to remodel. Outcome of AVF using flow mediated dilatation (FMD), AVF blood flow and diameter has been studied. Methodology: Present observational study included single stage AVF (both Radiocephalic and Brachiocephalic) in consecutive CKD five patients (n = 158) prospectively over 1 year. Demographic and Doppler ultrasound parameters of upper limb (for vessel diameter and FMD) at baseline were recorded. Blood flow, diameter and depth of AVF were studied at 2, 6 and 12 weeks and their association with clinical maturation (usage of fistula with two needles for 75% of dialysis sessions during 15 day period) was studied (n = 129, after excluding lost to followup and expired patients; accordingly cohort was divided in matured (M) or non-matured (NM) groups. Clinical and radiological parameters between both groups were compared; receiver operator curve (ROC) and correlation of Doppler parameters were analysed. Results: Of 129 AVF, 67.4% were matured and 32.5% non-matured. Mean age was 40 years with male predominance75% in both the groups. The mean arterial diameter for distal (NM = 1.96 +/- 0.58 and M = 2.02 +/- 0.41) and proximal AVF (NM = 3.37 +/- 0.82 and M = 3.36 +/- 0.75) was not statistically different in both the groups. The matured fistula group had a mean FMD of 11.67 +/- 4.09 as against FMD value of 9.365 +/- 3.55 in the failed fistula group (p value 0.01). For maturation prediction, sensitivity and specificity of blood flow at 2 weeks were 86.2% and 59.5% and at 6 weeks 96.6% and 64.3%, respectively. In multivariate analysis predictors for AVF maturation were FMD (adjusted odds ratio (AOR) = 1.15) and blood flow (AOR = 1.67). Conclusion: Second and Sixth week AVF blood flow was found to be predicting AVF maturation. Higher baseline FMD correlated with the AVF maturation, but not with vessel diameter.