Reply by Authors: Acute Kidney Injury Within 90Days of Radical Cystectomy for Bladder Cancer: Incidence and Risk Factors.

OBJECTIVE:To report incidence of acute kidney injury (AKI) following radical cystectomy (RC) for bladder cancer and evaluate risk factors for AKI as well as the impact of AKI on development of long-term renal insufficiency. METHODS:A retrospective analysis of patients undergoing RC between 2010 and 2020 at a high-volume tertiary referral center. AKI was graded according to the Kidney Disease Improving Global Outcome (KDIGO) criteria within 90days of surgery. Long-term renal insufficiency was defined as estimated glomerular function <45 mL/min. Cumulative incidence and Cox Proportional Hazards models were used to evaluate both short- and long-term loss of renal function and investigate their association with pre- and perioperative variables. RESULTS:AKI occurred in 332 out of 755 patients (44%) within 90days. Preoperative chronic hypertension and obesity were independent preoperative risk factors. Robot-assisted RC was associated with a higher risk of AKI compared to open RC in multivariable analyses. The absolute risk of developing long-term renal insufficiency was 8.7% (95%CI: 5.6-12) after 5years in patients without AKI and 26% (95%CI: 16-36) in patients with KDIGO-stage ≥2. In multivariable analysis, both KDIGO-stage 1 and ≥2 were independently associated with long-term estimated glomerular filtration rate <45 mL/min. CONCLUSION:A significant number of patients experienced AKI after RC, and even patients with KDIGO-stage 1 were at increased risk of long-term renal insufficiency. Recognizing pre- and perioperative risk factors can identify patients where close surveillance and early intervention may help minimize renal function decline following RC.