Which factors can influence post-operative renal function preservation after nephron-sparing surgery for kidney cancer: a critical review

Introduction The aim of this article was to compare different surgical approaches to perform nephron- sparing surgery (NSS) in terms of preservation of renal function. Material and methods We critically reviewed the literature from January 2000 to December 2020 including studies comparing different surgical techniques. Results A total of 51 studies met the inclusion criteria. Functional outcomes were evalutated in terms of percentual change of estimated glomerular filtration rate (eGFR) and impaired renal function (IRF) on scintigraphy. In cases with a mean age <60 years, the mean decrease in eGFR after NSS was 11.7% and that of IRF 10.0%, whereas higher changes were found in cases with a mean age ≥60 years. For open NSS, the mean eGFR and IRF changes were 15.3% and 21.1%, respectively; using the laparoscopic approach, the mean percentual eGFR and IRF changes were 13.9% and 11.1%, respectively; in robotic cases, the mean eGFR and IRF changes were 10.8% and 13.1%, respectively. In cases performed with global ischemia, the mean eGFR and IRF changes were 12.7% and 15.1%, respectively. Similar results were found distinguishing ischemia time ≤20 and >20 minutes, whereas using the off-clamp technique the mean decreases in eGFR and IRF were only 4.2% and 6%, respectively. Conclusions Patients’ age, tumor size, off-clamp technique, and robot-assisted approach were signifi- cant independent predictive factors able to influence renal function changes after NSS. A lower reduc- tion of eGFR and IRF after NSS was reported in patients aged <60 years, submitted to a robot-assisted procedure, and using selective and cold ischemia <20 minutes or an off-clamp technique.