Impact of Hydrostatic Venous Dilatation during Operative Arterio-Venous Fistula Creation on Hemodialysis Access Maturation

Abstract

With the recent update in KDOQI guidelines recommending an arteriovenous fistula (AVF) first ca9theter last approach, the quest to increase AVF maturation is of utmost importance. This study aims at exploring the rate of intraoperative increase in absolute and percent of vein wall diameter as predictors for AVF maturation. Aim of the work: Evaluation of the impact of increase in vein diameter by hydrostatic dilatation during intraoperative AVF surgical creation and its effect on maturation of AVF in ESRD patient

Patient and Methods: This is a prospective cohort study involving 52 patients. Preoperative duplex mapping was done for both upper limbs to evaluate patency of superficial and deep venous systems in addition to diameter, depth, and flow velocity in the inflow artery as well as the vein conduit at the intended site of anastomosis, 3cm and 6cm proximal to it. This was repeated immediately postoperatively as well as 6 weeks postoperatively.

Results: A total of 52 procedures were performed, mean age was 55.4 years, mean preoperative vein diameter was 2.8mm at intended site of anastomosis. Median increase in vein diameter after hydrostatic dilatation was 0.5mm (17.45%) at site of anastomosis, 0.5mm (16.7%) and 0.4mm (11.75%) 3cm and 6cm proximal to it respectively. By 6 weeks, 48 (92.3%) AVFs were successfully mature and 4 (7.7%) failed to mature. Immediately postoperative vein diameter at 3cm proximal to the site of anastomosis was significantly larger in the successfully matured group (p-value 0.032), and an average increase in vein diameter of 0.59mm (p-value 0.035) equivalent to 20.5% compared to the unsuccessfully matured group (p-value 0.019). However, this increase was not statistically significant at the site of anastomosis (p-value 0.8) or at 6cm proximal to it (p-value 0.82).

Conclusion: Measuring the percent of average vein diameter increase after intraoperative hydrostatic dilatation can be a considerable predictor for AVF successful maturation rather than the absolute preoperative vein diameter. Larger scale studies are required to conclude a more sensitive cut off percent of vein dilatation for predicting AVF maturation.