Biphasic decline in renal function after radical cystectomy with urinary diversion

Background We evaluated short- and long-term renal function in patients after radical cystectomy with urinary diversion and identified risk factors for the deterioration of renal function. Methods This retrospective study comprised 91 patients who underwent radical cystectomy and urinary diversion for bladder cancer and survived ≥3 years after surgery. The estimated glomerular filtration rate (eGFR) was calculated, and longitudinal changes of eGFR were assessed. Deterioration in renal function in early and late postoperative years was defined as a ≥25 % decrease in the eGFR from preoperative to postoperative year one, and a reduction in the eGFR of >1 mL/min/1.73 m 2 annually in subsequent years, respectively. Univariate and multivariate logistic regression analyses were used to evaluate its association with clinicopathologic features. Results The median follow-up period after surgery was 7 years (range 3–26). The mean eGFR decreased from preoperative 65.1 to 58.9 mL/min/1.73 m 2 1 year after the surgery, followed by a continuous decline of ~1.0 mL/min/1.73 m 2 per year thereafter. Multivariate analyses identified ureteroenteric stricture as the sole risk factor associated with early renal function deterioration [odds ratio (OR) 4.22, p = 0.037]. Diabetes mellitus (OR 8.24, p = 0.015) and episodes of pyelonephritis (OR 4.89, p = 0.038) were independently associated with the gradual decline in the late postoperative period. Conclusion In cystectomy patients with urinary diversion, the rapid deterioration of renal function observed during the first year after surgery and the gradual but continuous decline in function thereafter were found to be associated with different risk factors.