A Comparative Analysis of the Functional Outcomes Between Retzius-Sparing and Conventional Robot-Assisted Radical...

Robot-assisted radical prostatectomy (RARP) has emerged as the predominant surgical approach globally, and various techniques have been proposed to improve functional outcomes. Despite these advances, however, functional impairment associated with surgery remains a major concern that affects patients' quality of life. Retzius-sparing RARP (RS-RARP) has been proposed as a surgical technique to preserve the Retzius space, and increasing evidence has demonstrated its effectiveness. However, the effect of RS-RARP on other functions remains unknown. Although some reports show the positive effect of Retzius-sparing RARP (RS-RARP) on urinary incontinence, the effects on other functions remain unknown.

The present study retrospectively analyzed 132 patients who underwent RARP at Kitasato University Hospital between January 2020 and July 2021 (49 and 83 patients in the RS-RARP and conventional RARP groups, respectively). We compared the functional outcomes of RS-RARP and conventional RARP (C-RARP) using the Expanded Prostate Cancer Index Composite (EPIC). In addition, sexual function was compared among patients who underwent nerve-sparing procedures.

Our findings revealed that, even at 12 months postoperatively, RS-RARP demonstrated significant preservation of urinary continence (p < 0.01) and sexual function compared to C-RARP (p = 0.03). No significant differences were observed in the bowel or hormonal domains. Even in patients who underwent nerve-sparing surgery, the EPIC score 12 months postoperatively was significantly higher with RS-RARP than with C-RARP (p < 0.01). RS-RARP tended to result in positive surgical margins more often than C-RARP (RS-RARP: 44.9%, C-RARP: 28.9%, p = 0.06), without affecting the rate of biochemical recurrence (RS-RARP: 14.2%, C-RARP: 15.7%, p = 0.81).

Our results suggest a potential advantage of RS-RARP in preserving both urinary and sexual function.