Background
Retzius-sparing robot-assisted radical prostatectomy (RS-RARP) has been shown to improve continence. However, questions remain regarding feasibility and generalizability of technique and outcomes.
Objective
To compare the outcomes of 140 consecutive standard robot-assisted radical prostatectomy (S-RARP) versus RS-RARP.
Design, setting, and participants
A total of 70 S-RARPs were performed followed by 70 RS-RARPs. Demographic, pathologic, and functional outcomes were compared preoperatively and through 12 mo. Expanded Prostate Cancer Index Composite for Clinical Practice (EPIC-CP) was used to compare functional outcomes. Logistic and linear regression analyses were utilized to analyze variables associated with EPIC-CP urinary incontinence and overall quality of life (QOL) scores, and oncologic outcomes. Cox regression analysis was used to analyze incontinence at 12 mo.
Surgical procedure
RS-RARP versus S-RARP.
Measurements
Patient and tumor characteristics (age, body mass index, prostate-specific antigen, Charlson Comorbidity Index, Gleason group, clinical stage, and Prostate Imaging Reporting and Data System score), perioperative outcomes (console time, estimated blood loss, postoperative complications, and length of stay), oncologic outcomes (positive surgical margin [PSM], and biochemical recurrence), overall and 12-mo continence rates (zero pads and zero to one safety pad), time to continence, potency (erection sufficient for sexual activity), EPIC-CP urinary incontinence, sexual function, and overall QOL scores.
Results and limitations
Median follow-up for S-RARP versus RS-RARP was 46.3 versus 12.3 mo. RS-RARP versus S-RARP had improved overall continence rates at total follow-up (95.7% vs 85.7%, p = 0.042) and 12-mo follow-up (97.6% vs 81.4%, p = 0.002), and faster return to continence (zero to one safety pad, 44 vs 131 d, p < 0.001). RS-RARP EPIC-CP urinary incontinence and overall QOL scores remained significantly better at 12 mo. There were no differences in overall PSM rates, although RS-RARP had lower rates of nonfocal PSMs. There were no differences in sexual function. In multivariate analysis, RS-RARP was significantly associated with improved 12-mo EPIC-CP urinary incontinence and improved QOL scores, but was not associated with PSM or biochemical recurrence. Limitations include retrospective study design and unequal follow-up; however, significantly better RS-RARP continence at 12 mo is striking despite fewer patients attaining 12-mo follow-up.
Conclusions
RS-RARP significantly improves early and long-term continence without compromising oncologic outcomes and leads to overall improved QOL.
Retzius-sparing surgery has been suggested to improve early continence recovery after robot-assisted radical prostatectomy (RARP). Main concerns limiting this technique adoption were about the risk of increased surgical margins and the lack of long-term differences in urinary function. In the present series, the authors reported the comparison between 70 standard RARP (S-RARP) and the subsequent 70 Retzius-sparing RARP (RS-RARP) cases operated on by a single surgeon. For this study, 140 consecutive patients were included, the aim was to mitigate the potential impact of learning curve and surgeon experience on outcomes.
All outcomes were prospectively collected, and long-term functional outcomes were assessed using the EPIC-CP questionnaire. Time to continence and standard oncological outcomes were also reported. Median follow-up was 12 months for RS-RARP versus 46 months for S-RARP. No significant differences were seen in pre- and intraoperative features except for PIRADS, blood loss and Gleason grade which were higher in the S-RARP cohort. RS-RARP had fewer nonfocal positive surgical margins (7.1% versus 8.6%, p=0.016) compared with S-RARP. The main location of positive margins was different according to the technique: anterior in RS-RARP (54%) and posterior for S-RARP.
When considering the primary endpoint, there was no benefit to perform a RS-RARP when the 12-month continence rate was defined by zero pad. However, when continence was defined as zero to one safety pad, RS-RARP was associated with improved outcomes (95.7% versus 85.7%, p=0.042). Total EPIC-CP scores were better for RS-RARP at 9 and 12 months. Potency rates were comparable in both cohorts (63-65%).
The regression analysis confirmed that RS-RARP was an independent predictor for better 12-month continence results (hazard ratio 0.18, 95% CI: 0.05-0.67). The other factors independently correlated with continence were the pre-operative EPIC-CP score and the performance of nerve-sparing procedures. Time to continence was shorter with RS-RARP: 59 versus 182 (p<0.001).
The main limitations of this study were the lack of randomization, the single-surgeon, single-institution design, and the potential impact of surgeon experience on outcomes due to non-contemporary surgeries. Moreover, no validated questionnaire was used for assessing the potency recovery. However, despite these concerns, this series suggests that RS-RARP is safe in terms of short-term oncology outcomes and might improve early and mid-term urinary continence as compared with S-RARP.