Introduction

Complications following nephron sparing surgery might stress renal function with multiple mechanisms. However, information regarding a detrimental effect of post-operative complications following nephron sparing surgery [NSS] on long term renal function is scarce. The aim of the study was to investigate the impact of post-operative complications on the long-term risk of chronic kidney disease [CKD] after NSS.

Methods

595 patients with estimated glomerular filtration rates [eGFR] ≥60 ml/min/1.73m2 diagnosed with a cT1 cN0 cM0 renal mass and elected for NSS were assessed in a prospective institutional database. Cox regression models were fitted to estimate hazard ratios [HR] and 95% confidence intervals [CI] for CKD defined as estimated glomerular filtration rates <60 ml/min/1.73m2. The variable of interest was any postoperative complication, defined according to the Clavien-Dindo classification system. Covariates included age, Charlson comorbidity index [CCI], hypertension, diabetes, tumour size, ischemia time, and preoperative eGFR.

Results

Mean patient age was 59 years (Inter-quartile range [IQR] 50-67). Median clinical tumour size was 3 cm (IQR 2-4). Median ischemia time was 15 minutes (IQR 9-20). Forty-eight (8%) patients had diabetes, 236 (40%) had hypertension, 23 (4%) had uncontrolled hypertension. Median follow-up was 53 months (IQR 26-91). Overall, 118 (20%) developed grade 1-2 and 19 (3%) grade 3-4 complications. The most common complication was anaemia/haematoma (9%). No difference was recorded between patients with or without post-operative complications with respect to age, comorbidities, tumour size and ischemia time (all p >0.05). Overall, 142 patients (24%) developed any grade of CKD during the follow-up period. Patients experiencing either grade 1-2 (HR 1.74; CI 1.11-2.72; p=0.02) or grade 3-4 complications (HR 2.52; CI 1.20-5.30; p=0.01) were at increased risk of developing CKD during the follow up at multivariate analysis, after accounting for the aforementioned covariates.

Conclusions

Our findings outline how post-operative complications may have a detrimental impact on post-operative renal function in men submitted to NSS. Efforts aiming at limiting the occurrence of post-operative complications might be advantageous for reducing the rate of long-term CKD. Moreover, those patients who experienced a complication deserve a more stringent functional follow-up after NSS.

Funding

none