A Novel Approach for Apical Dissection During Robot-assisted Radical Prostatectomy: The “Collar” Technique

Abstract

BackgroundApical dissection in robot-assisted radical prostatectomy (RARP) affects not only cancer control, but also continence recovery. ObjectiveTo describe a novel approach for apical dissection, the collar technique, to reduce apical positive surgical margins (PSMs). Design, setting, and participantsA total of 189 consecutive patients (81 in the control group, 108 in the collar technique group) underwent RARP at a single center. Primary outcome: rates of apical PSMs; secondary outcome: urinary continence. InterventionThe urethral sphincter complex is incised 2–3mm distally to the apex, to stay farther from it and reduce PSMs; the underlying smooth muscle is exposed and incised closer to the apex to preserve the maximal length of the lissosphincter. Outcome measurements and statistical analysisMann–Whitney U and chi-square tests compared median and proportions between the two groups, respectively. Univariate logistic regression tested the association between technique employed and risk of apical PSMs. Results and limitationsFourteen patients (7.4%) revealed apical PSMs (9.9% in the control group, 5.6% in the collar group; p=0.7). When the collar technique was used, significantly lower rates of apical PSMs occurred in pT2 disease (0% vs 7.1%; p=0.03). In case of apical tumor at preoperative magnetic resonance imaging (MRI; n=43), the collar technique determined significantly lower overall (9.7% vs 42%) and apical (3.2% vs 42%) PSMs (all p≤0.02). Continence recovery in the collar and control groups was similar. When preoperative MRI showed an apical tumor, the collar technique had a significantly lower risk of apical PSMs (odds ratio: 0.05, p=0.009). ConclusionsThe collar technique reduces the rates of apical PSMs in case of apical tumor, preserving the length of the lissosphincter. Patient summaryWe describe a novel approach for apical dissection during robot-assisted radical prostatectomy. Our technique reduces the rates of apical surgical margins in case of apical tumor at preoperative magnetic resonance imaging and leads to optimal continence recovery.