Factors associated with complications of the ureteral stump after proximal ureteroureterostomy

PURPOSE: Ureteroureterostomy is a treatment modality for managing an ectopic ureterocele or ectopic ureter and preserving upper pole kidney function. However, the development of urinary tract infection at the residual ureteral stump is a concern. We analyzed factors affecting the development of urinary tract infection at the residual ureteral stump after proximal ureteroureterostomy. MATERIALS AND METHODS: Between January 2002 and December 2009 proximal ureteroureterostomy was performed in 80 patients with ectopic ureterocele or ectopic ureter associated with a duplex system. Excluding 6 patients who did not meet the study inclusion criteria, we investigated age at operation, diameter of the upper pole ureter on ultrasonography, differential renal function and the presence of vesicoureteral reflux in 74 patients. Risk factors for residual ureteral stump infection and decreased differential renal function were analyzed. RESULTS: During a median followup of 5.0 years an additional operation was required in 9 patients (12.2%) due to urinary tract infection at the residual ureteral stump a median of 2.4 years after initial proximal ureteroureterostomy. The preoperative maximal diameter of the upper pole ureter was significantly greater in patients with infection complications. The postoperative maximal diameter of the upper pole ureter was also significantly greater on postoperative ultrasonography performed a median 43.0 days after the operation. Median preoperative and postoperative differential renal function was 47.8% and 47.0%, respectively. No preoperative factors were significantly related to the decrease in differential renal function. CONCLUSIONS: Proximal ureteroureterostomy is a safe treatment for ectopic ureterocele or ectopic ureter with a low postoperative complication rate. Upper pole ureter diameter was correlated with the development of a urinary tract infection at the residual ureteral stump.ope