PEDIATRIC UROLOGY

Lack of Usefulness of Positioned Instillation of Contrast Cystogram after Injection of Dextranomer/Hyaluronic Acid
Pinto KJ, Pugach J, Saalfield J
Department of Pediatric Urology, Urology Associates of North Texas and Cook Children’s Medical Center, Fort Worth, Texas, USA
J Urol. 2006; 176: 2654-6

• Purpose: Positioned instillation of contrast cystograms have been touted as possibly being more sensitive than standard cystograms for evaluation of vesicoureteral reflux. We performed positioned instillation of contrast cystograms intraoperatively, immediately after the injection of dextranomer/hyaluronic acid to treat vesicoureteral reflux, to determine whether they might be predictive of operative success and obviate the need for the standard postoperative voiding cystourethrogram, which is usually performed at 3 months.
• Materials and Methods: Patients with vesicoureteral reflux and no confounding conditions were treated with dextranomer/hyaluronic acid and subsequent positioned instillation of contrast cystogram while under the same anesthesia between November 2003 and March 2005. The results of this intraoperative cystogram were compared to the results of the postoperative voiding cystourethrogram performed 3 to 4 months later.
• Results: A total of 61 patients met the inclusion criteria and underwent positioned instillation of contrast cystogram after dextranomer/hyaluronic acid injection. Only 53 patients (86 ureters) completed the necessary postoperative evaluation. Positioned instillation of contrast cystogram added 4 minutes to the procedure and required about 4 seconds of fluoroscopy per ureter evaluated. The overall success rate for correcting reflux was 84% (72 of 86 ureters cured). None of the 14 ureters with persistent postoperative reflux was identified by intraoperative cystogram, and 3 patients were misidentified as having reflux despite cure confirmed postoperatively. Intraoperative positioned instillation of contrast cystogram was predictive of treatment failure 0% of the time (sensitivity 0%). There were no complications.
• Conclusions: Positioned instillation of contrast cystogram performed immediately after injection of dextranomer/hyaluronic acid was not useful in predicting which patients would have persistent reflux postoperatively. Patients are best served with the extant protocol of conventional cystography 3 to 4 months postoperatively.
  
  
• Editorial Comment
  This study is an ingenious attempt to improve the efficacy of endoscopic Dx/HA injection for the treatment of vesicoureteral reflux. The authors proposed that by doing a “PICC” study intraoperatively they could identify those patients who were going to fail endoscopic treatment (and in theory they could re-treat them at the same setting). Furthermore, if they could predict those who would ultimately fail with certainty, they could avoid an uncomfortable postoperative cystogram. Unfortunately, their idea did not prove effective.
  Despite verbal reports to the contrary, correction of reflux in patients with endoscopic Dx/HA is effective in only 70-80% of patients on the first attempt. In this paper, as in many, the results were reported in terms of % ureters corrected. In this case it was 72 of 86 (84%). But of course patients and parents are much more concerned with the individual patient being cured of their reflux. In this study, reading between the lines, 14 of 53 patients had persistent reflux (in other words, 74% of patients were cured at 3 months). I believe this is typical of the results of most centers.
  The idea of finding reflux on an intraoperative test that could result in immediate correction of the problem is great. Similarly, a study that would allow avoidance of a postoperative VCUG would be great. However, the composition of Dx/HA is such that the HA is absorbed over time. Hence, the size of the implant is very likely to get smaller with time. This makes it likely that patients that do not demonstrate reflux at the time of the procedure, may well demonstrate reflux later, as the implant shrinks. What was interesting in this case was the fact that 3 patients had reflux demonstrated with PICC studies, but these same 3 did not show reflux at the later study. In this case, PICC appeared to be overly sensitive. Of course all types of cystograms miss about 20% of patients with reflux. Perhaps more important, the clinical course of these patients is not known, hence we really do not know whether the PICC study was clinically relevant or not or most important, whether the patients successfully treated with Dx/HA did better than those who failed. Much more work needs to be done in this area.

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