Can we Rely on the Presence of Dextranomer-Hyaluronic Acid Copolymer Mounds on Ultrasound to Predict Vesicoureteral Reflux Resolution After Injection Therapy?

Purpose: We determined whether the presence or absence of dextranomer-hyaluronic acid copolymer mounds on bladder ultrasound coincides with voiding cystourethrogram results after injection therapy in children with primary vesicoureteral reflux. Materials and Methods: We retrospectively reviewed consecutive cases of dextranomer-hyaluronic acid copolymer injection for primary vesicoureteral reflux. The primary outcome investigated was the appearance of dextranomer-hyaluronic acid copolymer mounds on ultrasound and their association with voiding cystourethrogram results postoperatively. An intramural dextranomer-hyaluronic acid copolymer mound on ultrasound was considered a negative test result for vesicoureteral reflux. Results: A total of 187 cases were identified, of which 132 had imaging available for evaluation. Intramural mounds were seen on ultrasound in 86 cases postoperatively, of which 34 (40%) had a positive voiding cystourethrogram. Of 46 cases in which no mound was identified 21 (46%) had a positive voiding cystourethrogram. The sensitivity of ultrasound to determine the presence or absence of vesicoureteral reflux was 38%, specificity was 67%, accuracy was 55%, the positive predictive value was 46% and the negative predictive value was 60%. Conclusions: Our results indicate poor correlation of dextranomer-hyaluronic acid copolymer mound appearance on ultrasound with voiding cystourethrogram results after injection. To adequately evaluate for the resolution of vesicoureteral reflux a voiding cystogram or nuclear medicine cystogram needs to be performed after injection therapy.