Comparative impact of continent and incontinent urinary diversion on long-term renal function after radical cystectomy in patients with preoperative chronic kidney disease 2 and chronic kidney disease 3a

Objectives: To evaluate the differences in estimated glomerular filtration rate decline by urinary diversion type (incontinent diversion vs continent diversion) and preoperative estimated glomerular filtration rate among patients undergoing radical cystectomy and urinary diversion. Methods: We evaluated 1383 patients treated with radical cystectomy between 1980-2006 who had a preoperative estimated glomerular filtration rate of 45-89mL/min/1.73m². Estimated glomerular filtration rate was estimated using Chronic Kidney Disease Epidemiology Collaboration equations, and patients were stratified by preoperative estimated glomerular filtration rate into chronic kidney disease2 (estimated glomerular filtration rate 60-89mL/min/1.73m²) and chronic kidney disease3a (estimated glomerular filtration rate 45-59mL/min/1.73m²). Multiple definitions of estimated glomerular filtration rate decline were evaluated: (i) 10-point decline in estimated glomerular filtration rate; (ii) 20% decline in estimated glomerular filtration rate; and (iii) 10% decline in estimated glomerular filtration rate. Time to estimated glomerular filtration rate decline was compared using the Kaplan-Meier method stratified by diversion type. Cox regression models were used to evaluate the association of diversion type with estimated glomerular filtration rate decline risk. Results: In total, 74% (1021/1383) of patients underwent incontinent diversion and 26% (362/1383) underwent continent diversion. Preoperative chronic kidney disease2 and chronic kidney disease3a were noted among 59% and 41% of patients who underwent incontinent diversion, versus 74% and 26% with continent diversion. Median follow up after RC was 11.2years. The rate of estimated glomerular filtration rate decline in patients with incontinent diversion versus continent diversion was similar when stratified by preoperative chronic kidney disease2 and preoperative chronic kidney disease3a, regardless of estimated glomerular filtration rate decline definition. On multivariable analysis, continent diversion was not associated with estimated glomerular filtration rate decline for patients with preoperative chronic kidney disease3a.