Postoperative complications increase the risk of long-term chronic kidney disease after nephron-sparing surgery in patients with renal cancer and normal preoperative renal function

Objectives: To investigate whether postoperative complications affect long-term functional outcomes of renal patients treated with nephron-sparing surgery (NSS). Materials and Methods: We performed an observational study, enrolling 596 patients with preoperative normal renal function treated with NSS for clinical T1abN0M0 renal masses. Cox regression models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for chronic kidney disease (CKD) including as covariates age, comorbidity (scored according to the Charlson comorbidity index), hypertension, tumour size, preoperative estimated glomerular filtration rate (eGFR), eGFR < 60 mL/min/1.73 m 2 at discharge, and ischaemia time. Results: A total of 137 patients (23%) developed postoperative complications. At a median (interquartile range) follow-up of 53 (26–91) months, CKD risk was 19% for patients with postoperative complications and 11% for those without complications. Patients experiencing postoperative complications (HR 1.90, 95% CI 1.26–2.86) were at increased risk of developing CKD during the follow-up at multivariable analysis, after accounting for confounders. Conclusions: Our data outline how postoperative complications might have a detrimental impact on postoperative renal function in patients submitted to NSS. Improper patient selection, increasing the risk of postoperative complications, could limit the benefit in terms of renal function brought by NSS.