Long-term outcomes of cutaneous ureterostomy with the aim of stent-free stoma

Objectives: We evaluated post-surgical renal function and risk factors for renal function deterioration (RFD), defined as a > 25% decrease in the estimated serum creatinine-based glomerular filtration rate (eGFR), after cutaneous ureterostomy (CU) and collected follow-up data on hydronephrosis after CU construction. Patients and methods: CU was performed following radical cystectomy in 46 patients (90 renal units [RUs]) with a minimum follow-up period of 12 months. The median follow-up period was 102.1 months. The stoma was created using the Toyoda method. A surgical stabilization step for the abdominal tunnel of the ureters was added. Post-surgical changes in renal function and hydronephrosis were reviewed. Results: At the end of follow-up, RFD was observed in 19 (41.3%) of 46 patients. The 5- and 10-year RFD-free survivals were 61.3% and 47.2%, respectively. Seventy-six RUs (84.4%) exhibited no hydronephrosis, whereas six RUs (6.7%) in six patients progressed to atrophic kidneys. Stent catheters were inserted in eight RUs (8.9%) in six patients. After excluding 10 patients with progression to atrophic kidneys (six patients) or ureteral obstruction attributable to retroperitoneal lymph node metastasis by cancer progression (four patients), RFD was identified in 13 (36.1%) out of 36 patients. These patients were categorized into Group 1 (without RFD, 23 patients) and Group 2 (with RFD, 13 patients). Stent insertion was identified as a significant predictor of post-surgical RFD by univariate (p = 0.001) and multivariate analyses (p = 0.001). Conclusions: RFD was observed in 41.3% patients during follow-up. We achieved an 84.4% hydronephrosis-free rate following CU construction. Stent insertion was identified as a significant risk factor for RFD after CU construction.