PEDIATRIC UROLOGY

Subureteral injection of Deflux for correction of reflux: analysis of factors predicting success
Lavelle MT, Conlin MJ, Skoog SJ
Oregon Health Sciences University, Portland, Oregon 97239-3098, USA
Urology. 2005; 65: 564-7

• Objective: To review, prospectively, our experience with endoscopic Deflux injection and evaluate the volume injected, grade, endoscopic appearance after injection, and presence or absence of voiding dysfunction as predictors of success. Subureteral injection of dextranomer/hyaluronic acid copolymer (Deflux) has become an effective treatment of vesicoureteral reflux.
• Methods: A total of 52 patients (50 females and 2 males; 80 ureters) were treated with a single subureteral injection of Deflux. The mean patient age was 7.6 years (range 14 months to 22 years). The presence or absence of voiding dysfunction was evaluated with a preoperative questionnaire and patient history. The volume of Deflux injected in each ureter was recorded. The endoscopic appearance after injection was recorded as “volcano” or “other.” Success was defined as no reflux on postoperative voiding cystourethrography.
• Results: The success rate by grade of reflux in individual ureters was 82%, 84%, 78%, and 73% for grade 1, 2, 3, and 4 vesicoureteral reflux, respectively. No statistically significant difference was found in the cure rate by grade (P = 0.76). The overall cure rate by ureter was 80% and by patient was 71%. New contralateral reflux developed in 12.5% of patients. No statistically significant difference was found in the cure rate with respect to the volume injected or the presence or absence of voiding dysfunction. The ureteral cure rate with volcano and alternate morphology was 87% and 53%, respectively (P = 0.004).
• Conclusions: Mound morphology was the only statistically significant predictor of a successful outcome, with an associated cure rate of 87%. Concomitant voiding dysfunction did not have an adverse effect on the cure rate. In our experience, no statistically significant difference was found in the cure rate for grades 1 through 4 vesicoureteral reflux after a single injection of Deflux.
  
  
• Editorial Comment
  This paper reviews a relatively small experience with using subureteral injection of Deflux for the treatment of reflux. In the sense that this is a report that is representative of a typical pediatric urologist, it is quite interesting. The authors report good results in that they were able to cure (no reflux at 3 months) about 80% of ureters and 70% of patients using this minimally invasive technique.
  Several other findings were interesting in their study. First the grade of reflux had no relationship to the degree of success (Grade V patients were excluded). Second, there was a 12.5% rate of new contralateral reflux. Third, a history of voiding dysfunction had no influence on the results. Finally, and perhaps most important, the configuration of the ureter immediately after injection had the most to do with ultimate success.
  There are several important caveats to this study. The average age of the patients was over 7 and the study included primarily girls. Older patients and girls may be easier to inject, partially skewing the results. Most important though s the question of how to judge success. One measure of success is whether the reflux is gone. However, is a 3 month VCUG adequate? Some of the Deflux is absorbed with time. Would less Deflux mean a recurrence of the reflux over time? How about the effect of voiding dysfunction? This would likely increase over time. Although voiding dysfunction had no effect on the 3 month VCUG, would it have a stronger effect if a VCUG were done at 12 or 24 months? Furthermore, we have pretty good evidence that open surgery prevents reflux for many years. What about Deflux? Clearly, there are no data on VCUGs 5-10 years after Deflux. Finally, is the resolution of reflux really the correct end-point? We really are trying to prevent recurrent pyelonephritis. Reflux resolution is in some ways a “proxy endpoint.” We really need a study of the rate of pyelonephritis with and without Deflux treatment. Hopefully one will be forthcoming soon.

Dr. Barry A. Kogan
Chief and Professor of Urology and Pediatrics
Albany Medical College
Albany, New York, USA