Selection of patients for nerve sparing surgery in robot-assisted radical prostatectomy

Robot-assisted radical prostatectomy (RARP) has become the standard surgical procedure for localized prostate-cancer (PCa). Nerve-sparing surgery (NSS) during RARP has been associated with improved erectile function and continence rates after surgery. However, it remains unclear what are the most appropriate indications for NSS.

The objective of this study is to systematically review the available parameters for selection of patients for NSS. The weight of different clinical variables, multiparametric magnetic-resonance-imaging (mpMRI) findings, and the impact of multiparametric-nomograms in the decision-making process on (side-specific) NSS were assessed.

This systematic review searched relevant databases and included studies performed from January 2000 until December 2020 and recruited a total of 15 840 PCa patients. Studies were assessed that defined criteria for (side-specific) NSS and associated them with oncological safety and/or functional outcomes. Risk of bias assessment was performed.

Nineteen articles were eligible for full-text review. NSS is primarily recommended in men with adequate erectile function, and with low-risk of extracapsular extension (ECE) on the side-of NSS. Separate clinical and radiological variables have low accuracy for predicting ECE, whereas nomograms optimize the risk-stratification and decision-making process to perform or to refrain from NSS when oncological safety (organ-confined disease, PSM rates) and functional outcomes (erectile function and continence rates) were assessed.

Consensus exists that patients who are at high risk of ECE should refrain from NSS. Several multiparametric preoperative nomograms were developed to predict ECE with increased accuracy compared with single clinical, pathological, or radiological variables, but controversy exists on risk thresholds and decision rules on a conservative versus a less-conservative surgical approach. An individual clinical judgment on the possibilities of NSS set against the risks of ECE is warranted.

NSS is aimed at sparing the nerves responsible for erection. NSS may lead to unfavorable tumor control if the risk of capsule penetration is high. Nomograms predicting extraprostatic tumor-growth are probably most helpful.