Mound Calcification After Endoscopic Treatment of Vesicoureteral Reflux With Autologous Chondrocytes—A Normal Variant of Mound Appearance?

Endoscopic treatment of vesicoureteral reflux has gained popularity and is frequently used as a first-line therapy. Reports of potential long-term complications from this treatment modality are lacking. We review the development of mound calcification in a cohort of patients undergoing endoscopic treatment of vesicoureteral reflux with autologous chondrocytes.All patients who underwent endoscopic treatment of vesicoureteral reflux with autologous chondrocytes at our institution were included in this study. All available renal and bladder ultrasounds, as well as any other imaging studies of the urinary tract, were reviewed by a staff radiologist (HJP) and 2 urologists (PCG, DAD) to assess for the presence of mound calcification. A variety of clinical factors were assessed, including grade and laterality of initial reflux, volume of autologous chondrocytes injected, number of injections, postoperative mound appearance and mode of presentation. Statistical comparison between groups was performed by paired sample t test and Fisher's exact test. Univariate and multivariate analysis was used to identify potential risk factors for the development of mound calcification.Total median followup was 9 years (range 7 to 11). Mound calcifications developed in 10 of our 27 patients (37%) at a median interval of 2.1 years after injection (range 1 to 5). More females (40%) than males (28%) had calcifications, although the difference was not statistically significant. Of the 10 patients with mound calcifications 7 presented with gross or microscopic hematuria, with or without flank pain. Three of these patients were initially thought to have ureterovesical junction stone(s). The remaining 3 cases were found incidentally. Hydroureteronephrosis was absent in all patients with mound calcifications. Univariate and multivariate analyses revealed no relationship between the presence or absence of calcification when controlled for gender, initial reflux grade, amount of autologous chondrocytes injected, number of injections used or total followup time from initial injection.Mound calcifications have now been reported after endoscopic therapy for vesicoureteral reflux with autologous chondrocytes as well as dextranomer/hyaluronic acid copolymer. The etiology of these calcifications remains unknown, and it is unclear whether mound calcification after endoscopic treatment will have any associated morbidity in long-term followup. Urologists, patients and other health care providers should be aware that mound calcification is a potential risk after endoscopic treatment of vesicoureteral reflux, and that these calcified mounds may mimic ureterovesical junction stones.