Development of Macroplastique® Bolus Calcification Detected During Long Term Follow-Up After Injection for Vesico-Ureteral Reflux

PurposeMacroplastique® gained acceptance in many parts of the world as an injectable bulking agent for correction of vesico-ureteral reflux. As with other substances, the long-term consequences of such intervention remain largely unknown. Herein we present one important complication detected during follow-up in a single institution series.Material and MethodsA total of 232 children underwent subureteric injection between 1998 and 2004, being regularly monitored since. Of these, all patients that have presented with submucosal stones in the prior area of injection have been prospectively captured. Clinical features and data on patient characteristics were obtained by chart review.ResultsThree patients ages 10, 13 and 15 developed submucosal bladder calcifications 5, 7 and 9 years following the initial injection for vesicoureteral reflux. In all the intervention was uneventful and no clinical or sonographic abnormalities were detected after the procedure. Patients subsequently presented with worsening hydronephrosis, hematuria and irritative lower urinary tract symptoms. On ultrasound and pelvis X-ray we encountered calcifications at the site of prior injection. At time of surgery the calcified material was extracted after unroofing the overlying eroded mucosa. To date no recurrences have been detected and none of the patients have undergone ureteral reimplantation.ConclusionsThis experience calls attention to a potentially important complication that can be encountered following endoscopic injection with Macroplastique®. Monitoring of these patients appears warranted as long-term issues with new injectable materials remains largely unknown.