Results of uretero-ureteral anastomosis in pathological duplex kidney

Introduction Duplex renal collecting system or duplex kidney (DK) commonly is associated with uropathy, with upper pole obstruction or lower pole vesicoureteral reflux (VUR). Its management is variable, ranging from therapeutic abstention to total nephrectomy. In case of damage to a single renal pole, uretero-ureteral anastomosis (UUA) is one of the surgical techniques for preserving the pathological pole. It can be performed by laparotomy, laparoscopy, or both. The aims of this study are to report the results of UUA in pathological DK, and compare outcomes depending on the surgical approach. Methods This is a retrospective analysis study over 20 years, from April 2002 to July 2022, including all children from 0 to 15 years old who underwent UUA for a DK. Outcome measure included per- and post-operative complications, the occurrence of urinary tract infections and ultrasound measurements during follow-up. Results Thirty-three children underwent an UUA over 20 years. The median age at diagnosis was 25 days (range: 1 day-12 years). The median age at surgery was 13 months (range: 2 months - 13 years). The sex ratio was 0.22. Prenatal diagnosis was made in 87.9% of cases (n=29). The left kidney was affected in 72.7% of cases. Twenty-seven children (81.8%) had an ectopic ureteral opening of the upper pole ureter; four children (12.1%) had ureterocele of the upper pole and 2 children (6.1%) had vesicoureteral reflux of the inferior pole. UUA was performed by inguinal approach (laparotomy) in 17 children (51.5%), by laparoscopy in 9 cases (27.3%), and by laparoscopy combined with laparotomy in 7 cases (21.2%). The complication rate was 12.1% (n=4), including recurrent pyelonephritis with superior polar hydronephrosis (n=2); iatrogenic injury of the lower pole ureter (n=1) and a urinoma (n=1), that all required surgical management with a polar nephrectomy. Between each surgical approach, there were no significant differences in operative time, hospital stay, complications. Conclusion UUA is an effective therapeutic option in duplex kidneys as it allows the preservation of the pathological pole with low complication rates, regardless of the surgical approach.