Reply: Retzius‐sparing robot‐assisted radical prostatectomy (RARP) vs standard RARP

Abstract

Since the introduction of robotic surgery in the treatment of patients with prostate cancer (PCa), different surgical innovations have been implemented in order to preserve postoperative functional outcomes while maintaining oncological safety. Sparing the Retzius space during robot-assisted radical prostatectomy (RARP) was introduced early this decade by Galfano et al 1. Interestingly, 90% and 96% of patients treated with Retzius-sparing RARP (RS-RARP) were continent (no pad/safety pad) at 1 week and 1 year, respectively. Similarly, our group reported a 70% continence rate (no pad) at 1 month after RS-RARP 2. The fast urinary continence recovery after RS-RARP is related to several anatomical factors: the anterior Retzius space is kept intact; the urinary bladder is not dropped; the endopelvic fascia and puboprostatic ligaments are preserved; and there is minimal distortion of the supporting urethral tissues. A recent study reported that less bladder neck descent was observed during postoperative cystogram in patients treated with RS-RARP than in those treated with standard RARP 3. In a recent randomized controlled study, the postoperative continence rate at 1 week was 48% in standard RARP compared with 71% in RS-RARP (P = 0.01), and this difference was maintained at 3 months (86% standard RARP vs 95% RS-RARP; P = 0.02). At 1 year, however, the effect on urinary continence difference was muted (93.3% standard RARP vs 98.3% RS-RARP; P = 0.09) 4. Similarly, Chang et al. 3 found that the higher continence rate at 1 week (73.3% RS-RARP vs 26.7% standard RARP; P = 0.000) had vanished at 1 year (100% vs 93.3%; P = 0.15). By contrast, a large recent prospective series showed that the superiority of RS-RARP in terms of higher early urinary continence was maintained at 1 year (97.5% RS-RARP vs 68.5% standard RARP) 5. In addition to a higher early continence rate, RS-RARP has a lower incidence of postoperative inguinal hernia occurrence compared with standard RARP 6. Theoretically, RS-RARP may provide several other potential advantages. It may be advantageous if patients require future surgery necessitating access to the Retzius space and dropping of the bladder, such as an artificial urinary sphincter implantation, an inflatable penile prosthesis insertion, or kidney transplantation. In addition, in patients with previous inguinal hernia repair using mesh, it enables the avoidance of anterior adhesions by accessing the prostate directly from the Douglas pouch. Notably, large-size glands and/or middle-lobe, advanced/high-risk PCa, and patients with previous prostatic surgeries can be managed safely with RS-RARP in experienced hands. Undoubtedly, oncological safety is our main concern in treating cancer. To determine the effectiveness of new treatment methods, long-term follow-up is warranted. Biochemical recurrence (BCR) is widely used as a primary oncological outcome to assess PCa treatment success. To our knowledge, after radical prostatectomy, ~35% of patients are at risk of developing BCR in the next 10 years. Currently, there are insufficient data regarding the oncological outcomes of RS-RARP. Only four articles have compared early oncological outcomes between RS-RARP and standard RARP, and there was no significant difference (Table 1). More recently, we reported on the mid-term oncological outcomes of 359 patients who underwent RS-RARP. The median follow-up was 26 months. Although this period is not long enough to reach a meaningful conclusion on the oncological safety of RS-RARP, it is the longest follow-up period reported in literature. Overall, the positive surgical margin (PSM) rate was 30.6% (14.6% in pT2 and 40.8% in pT3a disease) and the BCR rate was 14.8%. In terms of functional outcomes, the urinary continence rate at 1 year was 93.9% 7. Interestingly, 164 patients (45.7%) of our cohort had high-risk PCa. In these patients, the PSM rate was 41.2%, the BCR rate was 22%, and the 3-year BCR-free survival (BCRFS) rate was 72%