Long-term preservation of dextranomer/hyaluronic acid copolymer implants after endoscopic treatment of vesicoureteral reflux in children: a sonographic volumetric analysis.

Abstract

We compared injected volume of dextranomer/hyaluronic acid with sonographic volumes obtained 2 weeks to 36 months postoperatively to evaluate the amount of volume retention with time and to correlate volume retention with voiding cystourethrogram results. We retrospectively reviewed sonographic volume measurements of dextranomer/hyaluronic acid implants in children at 2 weeks to 36 months postoperatively. Hydronephrosis and percentage of dextranomer/hyaluronic acid retained at each interval were recorded. Average change in volume at each interval was used to compare volume retention with time. The fraction of dextranomer/hyaluronic acid retained was compared to voiding cystourethrogram at 3 months. No patient had new or worsened hydronephrosis. Volumetric data were available for 296, 150, 42, 23 and 20 ureters at 2, 3, 6 and 12 weeks, and 24 to 36 months postoperatively, respectively. Percentage of dextranomer/hyaluronic acid retained was 79% at 2, 74% at 3, 70% at 6 and 78% at 12 weeks, and 65% at 24 to 36 months (p >0.05). While there was no significant difference in mean volume retained between cures (74%) and treatment failures (67%), the 94% cure rate with mega-implants (greater than anticipated volume retention) was higher than that with micro-implants (75%) or nonvisualized implants (70%). After the initial volume reduction at 2 weeks dextranomer/hyaluronic acid implants remained durable with insignificant volume reduction for up to 36 months postoperatively. Although overall mean volume retention did not correlate with cure, mega-implants were associated with high cure rates and may justify elimination of postoperative voiding cystourethrography.