Endoscopic treatment for vesicoureteral reflux: how important is technique?

Endoscopic dextranomer/hyaluronic acid (Dx/HA) injection by subureteric transurethral injection (STING) or hydrodistention implantation technique (HIT) for treatment of vesicoureteral reflux (VUR) has variable results with HIT reporting better outcomes. We determined outcomes with each technique comparing reflux resolution rates and evaluating predictors of treatment success and failure.

Univariate and multivariate analysis compared 163 patients (246 ureters) who underwent a single endoscopic Dx/HA injection from December 2001 to April 2010. Data on pre, peri, and post-operative variables were prospectively collected. Resolution was defined as no reflux on voiding cystourethrogram (VCUG) at 3 month follow up. Calculated ellipsoid volume (CEV) of Dx/HA mounds was defined as (4/3π(height/2) × (length/2) × (width/2)) based on post-operative ultrasound dimensions.

Ureter resolution was 79.75% and 80.84% for STING and HIT, respectively (p = 0.86). Patient resolution was 70.0% and 74.3% for STING and HIT, respectively (p = 0.57). Multivariate ureter analysis revealed lower pre-operative grade (p = 0.004) and injected Dx/HA volume 0.80-1.00 mL (p = 0.039) as predictors of success. CEV <0.20 mL (p = 0.002) and CEV/injected-volume <25% (p = 0.006) were predictors of failure. Volcano morphology (p = 0.004) and lower pre-op grade (p = 0.015) were predictors of success for STING and HIT, respectively.

We found no differences in ureter or patient resolution between endoscopic Dx/HA injection techniques STING or HIT. Lower pre-operative grade and moderated Dx/HA volume were predictors of success regardless of technique.