Long-Term Outcomes of Nephron-Sparing Versus Radical Nephrectomy in Stage 4 Chronic Kidney Disease

<b>Background:</b> Partial nephrectomy (PN) and radical nephrectomy (RN) are surgical options for localized renal cell carcinoma; however, PN is p referred for preserving renal function in patients with chronic kidney disease (CKD). This study compares the risks of end-stage renal disease (ESRD), hemodialysis, and cardiovascular complications between PN and RN in patients with stable stage 4 CKD, with a further focus on postoperative electrolyte imbalances as outcome predictors. <b>Methods:</b> This retrospective cohort study used TriNetX data (between 2005 and 2023). Patients with stable stage 4 CKD undergoing nephron-sparing procedures or RN were included. Propensity-score matching ensured balanced baseline characteristics. The analyzed outcomes included renal function, hemodialysis, electrolyte imbalances, and cardiovascular events. Statistical analyses were hazard ratios (HRs) and risk ratios (RRs) with 95% confidence intervals (CIs). <b>Results:</b> The PN and RN groups showed no statistically significant differences in their progression to ESRD or need for long-term hemodialysis. Patients undergoing RN had a higher risk of pulmonary embolism (HR: 2.60; 95% CI: 1.12-6.02). Electrolyte imbalances, particularly abnormal calcium and phosphate levels, were more common in the RN cohort in the early postoperative period, but they stabilized over time. Notably, these electrolyte imbalances were associated with an increased risk of cardiovascular complications. The study limitations include the absence of tumor grade, tumor staging, and pathological information. <b>Conclusions:</b> Nephron-sparing PN did not reduce ESRD risk compared with RN, but provided a lower incidence of certain postoperative complications, such as pulmonary embolism and early electrolyte disturbances. Early postoperative electrolyte imbalances, especially abnormal calcium and phosphate levels, may predict adverse renal and cardiovascular outcomes.