Application of hyaluronic acid/carboxymethyl cellulose membrane for early continence after nerve-sparing robot-assisted radical prostatectomy

Is there any difference in urinary continence between bilateral and unilateral nerve sparing during radical prostatectomy? A systematic review and meta-analysis

CONTEXT

In men with prostate cancer, urinary incontinence is one of the most common long-term side effects of radical prostatectomy (RP). The recovery of urinary continence in patients is positively influenced by preserving the integrity of the neurovascular bundles (NVBs). However, it is still unclear if bilateral nerve sparing (BNS) is superior to unilateral nerve sparing (UNS) in terms of post-RP urinary continence. The aim of this study is to systematically compare the differences in post-RP urinary continence outcomes between BNS and UNS.

METHODS

The electronic databases of PubMed and Web of Science were comprehensively searched. The search period was up to May 31, 2023. English language articles comparing urinary continence outcomes of patients undergoing BNS and UNS radical prostatectomy were included. Meta-analyses were performed to calculate pooled relative risk (RR) estimates with 95% confidence intervals for urinary continence in BNS and UNS groups at selected follow-up intervals using a random-effects model. Sensitivity analyses were performed in prospective studies and robotic-assisted RP studies.

RESULTS

A meta-analysis was conducted using data from 26,961 participants in fifty-seven studies. A meta-analysis demonstrated that BNS improved the urinary continence rate compared to UNS at all selected follow-up points. RRs were 1.36 (1.14-1.63; p = 0.0007) at ≤ 1.5 months (mo), 1.28 (1.08-1.51; p = 0.005) at 3-4 mo, 1.12 (1.03-1.22; p = 0.01) at 6 mo, 1.08 (1.05-1.12; p < 0.00001) at 12 mo, and 1.07 (1.00-1.13; p = 0.03) at ≥ 24 mo, respectively. With the extension of the follow-up time, RRs decreased from 1.36 to 1.07, showing a gradual downward trend. Pooled estimates were largely heterogeneous. Similar findings were obtained through sensitivity analyses of prospective studies and robotic-assisted RP studies.

CONCLUSION

The findings of this meta-analysis demonstrate that BNS yields superior outcomes in terms of urinary continence compared to UNS, with these advantages being sustained for a minimum duration of 24 months. It may be due to the real effect of saving the nerves involved. Future high-quality studies are needed to confirm these findings.

Different Nerve-Sparing Techniques during Radical Prostatectomy and Their Impact on Functional Outcomes

Simple Summary

Optimum preservation of potency and continence after radical prostatectomy (RP) are equally important surgical endpoints as cancer control itself. Nerve-sparing technique during RP has a major impact to both oncological and functional outcomes of the procedure and various different techniques have been developed aiming to optimize its outcomes. This literature review aims to summarize all different nerve-sparing techniques applied during RP from its first description from Patrick C. Walsh to its newer trends. The review underlines that optimum nerve-sparing expands far beyond recognising and preserving the anatomical integrity of the neurovascular bundles. It also emphasises that nerve-sparing is a field under constant development, with new technologies entering continuously the nerve-sparing field corresponding to the evolving open, laparoscopic and robotic-assisted RP approaches.

Abstract

The purpose of this narrative review is to describe the different nerve-sparing techniques applied during radical prostatectomy and document their functional impact on postoperative outcomes. We performed a PubMed search of the literature using the keywords “nerve-sparing”, “techniques”, “prostatectomy” and “outcomes”. Other potentially eligible studies were retrieved using the reference list of the included studies. Nerve-sparing techniques can be distinguished based on the fascial planes of dissection (intrafascial, interfascial or extrafascial), the direction of dissection (retrograde or antegrade), the timing of the neurovascular bundle dissection off the prostate (early vs. late release), the use of cautery, the application of traction and the number of the neurovascular bundles which are preserved. Despite this rough categorisation, many techniques have been developed which cannot be integrated in one of the categories described above. Moreover, emerging technologies have entered the nerve-sparing field, making its future even more promising. Bilateral nerve-sparing of maximal extent, athermal dissection of the neurovascular bundles with avoidance of traction and utilization of the correct planes remain the basic principles for achieving optimum functional outcomes. Given that potency and continence outcomes after radical prostatectomy are multifactorial endpoints in addition to the difficulty in their postoperative assessment and the well-documented discrepancy existing in their definition, safe conclusions about the superiority of one technique over the other cannot be easily drawn. Further studies, comparing the different nerve-sparing techniques, are necessary.

Comprehensive approach for preserving cavernous nerves and erectile function after radical prostatectomy in the era of robotic surgery

A nerve-sparing procedure during robot-assisted radical prostatectomy has been considered one of the most important techniques for preserving postoperative genitourinary function. The reason is that adequate nerve-sparing procedures could preserve both erectile function and lower urinary tract function after surgery. When a nerve-sparing procedure is carried out, the cavernous nerves themselves cannot be visualized, despite the magnified viewing field during robot-assisted radical prostatectomy. Thus, nerve-sparing procedures have been considered challenging operations, even now. However, because not all surgeons have carried out a sufficient number of nerve-sparing procedures, the development of new nerve-sparing procedures or new methods for mapping the cavernous nerves is required. Recently, various new operative techniques, for example, Retzius-sparing robot-assisted radical prostatectomy, transvesical robot-assisted radical prostatectomy and retrograde release of neurovascular bundle technique during robot-assisted radical prostatectomy, have been developed. In addition, new surgical devices, for example, biological/bioengineering solutions for cavernous nerve protection and devices for identifying the cavernous nerves during radical prostatectomy, have developed to preserve the cavernous nerves. In contrast, limitations or problems in preserving cavernous nerves and postoperative erectile function have become apparent. In particular, the recovery rate of erectile function, the positive surgical margin rate at the site of nerve-sparing and the indications for nerve sparing have become obvious with the accumulation of much evidence. Furthermore, predictive factors for postoperative erectile function after nerve-sparing procedures have also been clarified. In this article, the importance of a comprehensive approach for early recovery of erectile function in the robot-assisted radical prostatectomy era is discussed.