Does prostate volume have an impact on the functional and oncological results of Retzius-sparing robot-assisted radical prostatectomy?

Background: The objective of our study is to evaluate the effect of prostatic volume on the outcomes of Retzius-sparing robot-assisted radical prostatectomy (RSP).

Methods: All the consecutive patients undergoing RSP up to January 2015 were included. The series was divided into three groups based on prostate weight at radical prostatectomy specimen (<40 g, 40-60 g, >60 g). Perioperative, oncological and functional data were prospectively recorded. Potency was defined as erections sufficient for penetration; continence as no pad or one safety liner. Oncological results were reported as positive surgical margins (PSMs) and 1-year biochemical disease-free survival (PSA<0.2 ng/mL).

Results: We evaluated 750 patients (366 with <40 g prostates, 272 with 40-60 g prostates, 112 with >60 g prostates). Median follow-up was 22 months; PSA was higher in larger prostates (6.6 vs. 6.8 vs. 8 ng/mL). Nerve-sparing and bladder-neck sparing procedures were in similar percentages. Larger prostates required longer surgeries (90 vs. 100 vs. 100 minutes, P=0.002). Perioperative results were similar (blood loss, discharge, complications, catheter removal). Larger prostates had more frequently localized disease (pT2 in 49.5% vs. 60.7% vs. 68.5%; P=0.001); PSMs were similar both in pT2 (15.5% vs. 9.4% vs. 11.8%) and in pT3 cases (40.1% vs. 42% vs. 34%). In the three study groups, immediate continence was reached by 88%, 89.5% and 81.3% (P=0.045), while no differences were observed concerning continence (93.4%, 94.1%, 94.7%; P=0.892) or potency after follow-up.

Conclusions: RSP is feasible in patients with prostates of any volume, with similar oncological and functional outcomes. Despite being inferior to the figures obtained in low volume prostates, the very high immediate continence rates observed in larger prostates encourage the use of this approach also in larger prostates.