Higher preoperative eGFR is a predictor of worse renal function decline after robotic assisted radical cystectomy: Implications for postoperative management

In patients with muscle invasive bladder cancer or high risk noninvasive bladder cancer, renal function decline is a concern after radical cystectomy with urinary diversion. The pathophysiology of this decline is multifactorial, with subclinical acidosis and metabolic derangements from the diversion thought to contribute. It is unknown whether patients with baseline chronic kidney disease (CKD) are at increased risk of further decline in renal function.We performed a retrospective review of two high volume robotic assisted radical cystectomy (RARC) centers between 2016 and 2020. Preoperative demographics and comorbidities were collected. Postoperative estimated glomerular filtration rate (eGFR) was calculated at 12 and 24 months to determine short-term rate in decline of eGFR. Absolute and percent changes in eGFR were calculated.There were a total of 555 patients who underwent RARC. Men comprised 76.2% of the cohort. Neoadjuvant chemotherapy was given in 31% of patients and adjuvant chemotherapy was given in 4.81% of patients. Higher preoperative eGFR (B -0.549, 95% CI -0.708 to -0.391, P < 0.001) and presence of diabetes mellitus (B -15.414, 95% CI -24.820 to -6.008, P = 0.001) were significant predictors of eGFR decline at 12 months. At 24 months, presence of diabetes mellitus (B -11.799, 95% CI -21.816 to -1.782, P = 0.021) and higher preoperative eGFR (B -0.621, 95% CI -0.796 to -0.446, P < 0.001) were correlated with a steeper decline in eGFR. Higher preoperative eGFR was also predictive of upstaging to CKD3 or higher post operatively (OR 1.019, 95% CI 1.004-1.034, P = 0.015). Intracorporeal diversion was protective, whereas presence of hypertension, diabetes mellitus, and higher preoperative eGFR predicted greater decline in eGFR.Patients with higher preoperative eGFR and diabetes are at increased risk of renal function decline post RARC at 12 and 24 months. This suggests that patients with risk factors for renal function decline, but otherwise normal renal function at baseline, are a particularly vulnerable population for progression to CKD after RARC and should be counseled and closely followed postoperatively for renal function deterioration.