DUPLICATION OF THE URINARY COLLECTING SYSTEM WITH OBSTRUCTION

Duplication of the urinary collecting system (DUCS) is characterized by the presence of two ureters draining the same kidney. There are usually no symptoms. Obstruction occurs only in the event of abnormal ureteral termination, of which each type leads to specific manifestations. Sixty-nine pediatric patients with DUCS were treated between 1988 and 1993. Most were under one year of age, 23 had reflux into the lower pole ureter, 18 had ectopic ureteral insertion and 26 had a ureterocele involving the upper pole ureter (two also had obstruction of the lower ureteropelvic junction). The diagnosis was prenatal in 40 cases. The treatment of reflux and ectopic ureteral insertion proved simple; ureterovesical reimplantation was done in 16 cases, uretero-ureteral anastomosis in four, and heminephrectomy in 21, and no reoperations were needed. In contrast, the ureteroceles raised challenging therapeutic problems: of the nine patients treated by heminephrectomy, four required a second surgical procedure, and of the 14 patients treated by removal of the ureterocele with or without heminephrectomy and/or ureteral reimplantation, four developed complications requiring surgical treatment. Endoscopic treatment was done in 13 patients and allowed preservation of the upper pole in seven; however, surgery was required subsequently in ten of these 13 patients. Renal lesions were often severe: of the 73 renal poles involved (six patients had bilateral DUCS), 39 were nonfunctional and 21 were dysplastic. These findings, together with the fact that most of the patients were neonates, indicates that renal lesions in patients with DUCS are mainly the result of malformation.