The Quantitively Link between Baseline Chronic Kidney Disease and Functional Decline after Minimal Invasive Partial Nephrectomy: a multicenter study

ABSTRACT Background: Baseline renal function plays a crucial role in influencing postoperative functional decline following minimal invasive partial nephrectomy (PN), yet its impact remains inadequately understood. This study aims to elucidate the relationship between baseline renal function and postoperative decline in renal function. Materials and Methods: A retrospective study was conducted on patients undergoing PN for renal tumor from 2014 to 2021 in prospectively maintained cohorts. Patients were divided into CKD (eGFR <60 mL/min/1.73 m²) and normal (eGFR ≥60 mL/min/1.73 m²) renal function groups. Restricted cubic spline (RCS) and multivariate Cox proportional hazard regressions were used to explore the relationship between baseline and postoperative renal function decline. Results: 546 patients were included for analysis. The average eGFR percent decline was found to be -8.0% (-12.1%, -4.3%), with an eGFR absolute decline of -8.2 (-16.5, -3.0) mL/min/1.73 m². Patients with severe compromised baseline function experienced higher postoperative complications and CKD-upstage compared to those with normal function (34.5% vs. 16.1%; -23.1% vs. 12.2%). Patients with CKD 3a stage were revealed to experiencing lowest functional decline even after adjusting with other well-known covariates. RCS plotted the risk of reaching >25% decline as a "U"-shaped pattern among patients with different baseline renal function. Conclusion: Patients with severe compromised baseline renal function have higher risk of perioperative complications and functional decline. The exact relationship between baseline renal function and postoperative functional decline is non-linear.