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

Retzius-sparing versus standard robot-assisted laparoscopic prostatectomy: A two-year patient-reported and oncological assessment

PURPOSE

To evaluate the two-year functional and oncological outcomes of Retzius-sparing robot-assisted laparoscopic prostatectomy (rsRALP) and standard approach (sRALP).

METHODS

A total of 200 consecutive patients who underwent either sRALP (n = 100) or rsRALP (n = 100) for clinically localized PCa at a single referral European center between 2015 and 2020 were identified from a prospectively cohort, as part of the Belgian Cancer Registry. Primary outcomes included functional outcomes and quality of life (QoL) using validated patient-reported outcome measures (PROMs) assessed at 1-, 3-, 12-, and 24-months post-surgery. Secondary outcomes comprised oncological outcomes reported as positive surgical margins (PSM) and 5-year biochemical recurrence (BCR). Kaplan-Meier analysis with log-rank test and multivariable Cox regression were used.

RESULTS

The median follow-up was 60 months. No significant differences were observed between the surgical approaches in terms of patient and tumor characteristics. Urinary function and QoL were significantly better at each follow-up period (all p ≤ 0.01) with rsRALP, while sexual function was not significantly different 12 months after surgery. No significant difference in positive surgical margins rate was observed between surgical approaches (31% vs 32%, p = 0.9). Retzius-sparing RALP was associated with longer PSM lengths (5 mm vs 2.5 mm, p = 0.02), a higher multifocality rate (34% vs. 13%, p < 0.001), more occurrences in organ-confined disease (59% vs. 39%, p < 0.001) and at anterior locations (37% vs. 16%, p = 0.05). Five-year BCR-free survival was not significantly different, and surgical approach was not a predictor of BCR.

CONCLUSIONS

The rsRALP approach significantly improves both early and short-term urinary function and QoL compared to sRALP. Despite being associated with worse PSM characteristics, no significant decrease in BCR-free survival was observed with rsRALP.

Imaging of prostate micro-architecture using three-dimensional wide-field optical coherence tomography

Prostate cancer is a global health issue that requires new diagnostic methods to provide accurate and precise visualization of prostate tissue on the micro-scale. Such methods have the potential to improve nerve-sparing surgery and to provide image guidance during prostate biopsy. In this feasibility study, we assess the potential of en face three-dimensional wide-field optical coherence tomography (OCT), covering a volumetric imaging field-of-view up to 46 × 46 × 1 mm3, to visualize micro-architecture in 18 freshly excised human prostate specimens. In each case, validation of contrast in OCT images is provided by co-registered wide-field histology images. Using this co-registration, we demonstrate that OCT can distinguish between healthy and cancerous glands at different stages, as well as visualize micro-architecture in the prostate, such as epineurium and perineurium in nerves and the tunica intima and tunica media in blood vessels.

Nerve-sparing techniques in robot-assisted radical prostatectomy - anatomical approach

INTRODUCTION

Nerve-sparing (NS) techniques in robot-assisted radical prostatectomy (RARP) are foundational to preserving sexual function and urinary continence in prostate cancer (PCa) patients.

AREAS COVERED

This article aims to classify nerve-sparing (NS) techniques in RARP based on an anatomical approach to the prostate. We have identified three main NS approaches in RARP: anterior, lateral, and posterior. The anterior approach, which involves early retrograde nerve release, improves early potency rates. The lateral approach, using hybrid techniques and extra-fascial dissection, provides clear nerve visualization and reduces nerve injuries, enhancing continence and potency recovery. The posterior approach, particularly the hood technique, effectively preserves periurethral structures, leading to high continence rates within a year post-surgery. The posterior approach effectively balances nerve preservation with cancer control.

EXPERT OPINION

Re-classifying NS techniques in RARP based on an anatomical approach optimizes patient outcomes and the surgeon choice. A personalized approach to those techniques improves functional recovery and maintains oncological safety in PCa surgery. Further studies are needed to confirm those findings and refine the selection criteria.

Imaging Assessment of Prostate Cancer Extra-prostatic Extension: From Histology to Controversies

Prostate cancer (PCa) is the most common non-skin malignancy among men and the fourth leading cause of cancer-related deaths globally. Accurate staging of PCa, particularly the assessment of extra-prostatic extension (EPE), is critical for prognosis and treatment planning. EPE, typically evaluated using magnetic resonance imaging (MRI), is associated with higher risks of positive surgical margins, biochemical recurrence, metastasis, and reduced overall survival. Despite the widespread use of MRI, there is no consensus on diagnosing EPE via imaging. There are 2 main scores assessing EPE by MRI: the European Society of Urogenital Radiology score and an MRI-based EPE grading system from an American group. While both are widely recognized, their differences can lead to varying interpretations in specific cases. This paper clarifies the anatomical considerations in diagnosing locally advanced PCa, explores EPE's impact on treatment and prognosis, and evaluates the relevance of MRI findings according to different criteria. Accurate EPE diagnosis remains challenging due to MRI limitations and inconsistencies in interpretation. Understanding these variations is crucial for optimal patient management.

Evaluation of margins during radical prostatectomy: confocal microscopy vs frozen section analysis

OBJECTIVES

To test the performance of ex vivo fluorescence confocal microscopy (FCM; Vivascope 2500M-G4), as compared to intra-operative frozen section (IFS) analysis, to evaluate surgical margins during robot-assisted radical prostatectomy (RARP), with final pathology as the reference standard.

METHODS

Overall, 54 margins in 45 patients treated with RARP were analysed with: (1) ex vivo FCM; (2) IFS analysis; and (3) final pathology. FCM margins were evaluated by two different pathologists (experienced [M.I.: 10 years] vs highly experienced [G.R.: >30 years]) as strongly negative, probably negative, doubtful, probably positive, or strongly positive. First, inter-observer agreement (Cohen's κ) between pathologists was tested. Second, we reported the sensitivity, specificity, positive predictive (PPV) and negative predictive value (NPV) of ex vivo FCM. Finally, agreement between ex vivo FCM and IFS analysis (Cohen's κ) was reported. For all analyses, four combinations of FCM results were evaluated.

RESULTS

At ex vivo FCM, the inter-observer agreement between pathologists ranged from moderate (κ = 0.74) to almost perfect (κ = 0.90), according to the four categories of results. Indeed, at ex vivo FCM, the highly experienced pathologist reached the best balance between sensitivity (70.5%) specificity (91.8%), PPV (80.0%) and NPV (87.1%). Conversely, on IFS analysis, the sensitivity, specificity, PPV and NPV were, respectively, 88.2% vs 100% vs 100% vs 94.8%. The agreement between the ex vivo FCM and IFS analyses ranged from moderate (κ = 0.62) to strong (κ = 0.86), according to the four categories of results.

CONCLUSION

Evaluation of prostate margins at ex vivo FCM appears to be feasible and reliable. The agreement between readers encourages its widespread use in daily practice. Nevertheless, as of today, the performance of FCM seems to be sub-par when compared to the established standard of care (IFS analysis).

Accuracy of MRI in detecting seminal vesicle invasion in prostate cancer: a systematic review and meta-analysis

OBJECTIVE

To determine the diagnostic test accuracy of multiparametric magnetic resonance imaging (mpMRI) in detecting seminal vesicle invasion (SVI).

METHODS

The Medical Literature Analysis and Retrieval System Online (MEDLINE), PubMed, the Excerpta Medica dataBASE (EMBASE) and Cochrane databases were search up to May 2023. We included studies that investigated the accuracy of mpMRI in detecting SVI when compared to radical prostatectomy specimens as the reference standard. Data extraction was performed by two independent reviewers to construct 2 × 2 tables, as well as patient and study characteristics. The methodological quality of the included studies was assessed with the Quality of Assessment of Diagnostic Accuracy Studies-2 tool. Sensitivity and specificity were pooled and presented graphically with summary receiver operator characteristic (SROC) plots.

RESULTS

A total of 27 articles with 4862 patients were included for analysis. The summary sensitivity and specificity were 0.57 (95% confidence interval [CI] 0.45-0.68) and 0.95 (95% CI 0.92-0.99), respectively. Meta-regression indicated that there was no evidence that coil strength (P = 0.079), coil type (P = 0.589), year of publication (P = 0.503) or use of the Prostate Imaging-Reporting and Data System (P = 0.873) significantly influenced these results. The summary diagnostic odds ratio was 28.3 (95% CI 15.0-48.8) and the area under the curve for the SROC curve was 0.87. The I2 statistic was a modest 11.9%. In general, methodological quality was good.

CONCLUSION

The use of mpMRI in detecting SVI has excellent specificity but poor sensitivity. Both endorectal coils and magnetic field strength do not significantly impact the accuracy of MRI. These findings suggest that mpMRI cannot reliably rule out SVI in patients with prostate cancer.

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.

Molecular characterization of human peripheral nerves using desorption electrospray ionization mass spectrometry imaging

Desorption electrospray ionization mass spectrometry imaging (DESI-MSI) is a molecular imaging method that can be used to elucidate the small-molecule composition of tissues and map their spatial information using two-dimensional ion images. This technique has been used to investigate the molecular profiles of variety of tissues, including within the central nervous system, specifically the brain and spinal cord. To our knowledge, this technique has yet to be applied to tissues of the peripheral nervous system (PNS). Data generated from such analyses are expected to advance the characterization of these structures. The study aimed to: (i) establish whether DESI-MSI can discriminate the molecular characteristics of peripheral nerves and distinguish them from surrounding tissues and (ii) assess whether different peripheral nerve subtypes are characterized by unique molecular profiles. Four different nerves for which are known to carry various nerve fiber types were harvested from a fresh cadaveric donor: mixed, motor and sensory (sciatic and femoral); cutaneous, sensory (sural); and autonomic (vagus). Tissue samples were harvested to include the nerve bundles in addition to surrounding connective tissue. Samples were flash-frozen, embedded in optimal cutting temperature compound in cross-section, and sectioned at 14 μm. Following DESI-MSI analysis, identical tissue sections were stained with hematoxylin and eosin. In this proof-of-concept study, a combination of multivariate and univariate statistical methods was used to evaluate molecular differences between the nerve and adjacent tissue and between nerve subtypes. The acquired mass spectral profiles of the peripheral nerve samples presented trends in ion abundances that seemed to be characteristic of nerve tissue and spatially corresponded to the associated histology of the tissue sections. Principal component analysis (PCA) supported the separation of the samples into distinct nerve and adjacent tissue classes. This classification was further supported by the K-means clustering analysis, which showed separation of the nerve and background ions. Differences in ion expression were confirmed using ANOVA which identified statistically significant differences in ion expression between the nerve subtypes. The PCA plot suggested some separation of the nerve subtypes into four classes which corresponded with the nerve types. This was supported by the K-means clustering. Some overlap in classes was noted in these two clustering analyses. This study provides emerging evidence that DESI-MSI is an effective tool for metabolomic profiling of peripheral nerves. Our results suggest that peripheral nerves have molecular profiles that are distinct from the surrounding connective tissues and that DESI-MSI may be able to discriminate between nerve subtypes. DESI-MSI of peripheral nerves may be a valuable technique that could be used to improve our understanding of peripheral nerve anatomy and physiology. The ability to utilize ambient mass spectrometry techniques in real time could also provide an unprecedented advantage for surgical decision making, including in nerve-sparing procedures in the future.

Theranostic Robot-Assisted Radical Prostatectomy: Things Understood and Not Understood

OBJECTIVE

This study aimed to explore the benefits of theranostic robot-assisted radical prostatectomy (T-RARP) for clinically highly suspicious prostate cancer (PCa) without proven biopsies.

MATERIAL AND METHODS

Between February 2016 and December 2020, we included men with clinically highly suspicious PCa in this study. They were assessed to have possible localized PCa without any initial treatments, and were categorized into previous benign biopsies or without biopsies. Furthermore, another group of malignant biopsies with RARP in the same time frame was adopted as the control group. The endpoints were to compare the oncological outcome and functional outcome between malignant biopsies with RARP and T-RARP. p < 0.05 was considered to be significant.

RESULTS

We included 164 men with proven malignant biopsies treated with RARP as the control group. For T-RARP, we included 192 men. Among them, 129 were preoperatively benign biopsies, and 63 had no biopsies before T-RARP. Approximately 75% of men in the T-RARP group had malignant pathology in their final reports, and the other 25% had benign pathology. T-RARP provides several oncological advantages, such as a higher initial pathological T stage, lower Gleason grade, and lower odds of positive surgical margins. However, the biochemical recurrence rates were not significantly decreased. From our cohort, T-RARP (odds ratio with 95% confidence interval; erectile recovery: 3.19 (1.84-5.52), p < 0.001; continence recovery: 2.25 (1.46-3.48), p < 0.001) could result in better recovery of functional outcomes than malignant biopsies with RARP.

CONCLUSIONS

For clinically highly suspicious PCa, T-RARP was able to detect around 75% of PCa cases and preserved their functional outcomes maximally. However, in 25% of men with benign pathology, approximately 6% would have incontinence and 10% would have erectile impairment. This part should be sufficiently informed of the potential groups considering T-RARP.

Radical Prostatectomy and Anatomical Controversies: The Urethral Sphincter and the Elusive Continence Mechanisms

Prostate cancer incidence is rising [...].

Spider silk erectile nerve reconstruction in robot-assisted radical prostatectomy: a first-in-men feasibility analysis

PURPOSE

To investigate the safety and feasibility of spider silk interposition for erectile nerve reconstruction in patients undergoing robotic radical prostatectomy (RARP).

METHODS

The major-ampullate-dragline from Nephila edulis was used for spider silk nerve reconstruction (SSNR). After removal of the prostate with either uni- or bilateral nerve-sparing, the spider silk was laid out on the site of the neurovascular bundles. Data analysis included inflammatory markers and patient reported outcomes.

RESULTS

Six patients underwent RARP with SSNR. In 50% of the cases, only a unilateral nerve-sparing was performed, bilateral nerve-sparing could be performed in three patients. Placement of the spider silk conduit was uneventful, contact of the spider silk with the surrounding tissue was mostly sufficient for a stable connection with the proximal and distal ends of the dissected bundles. Inflammatory markers peaked until postoperative day 1 but stabilized until discharge without any need for antibiotic treatment throughout the hospital stay. One patient was readmitted due to a urinary tract infection. Three patients reported about erections sufficient for penetration after three months with a continuous improvement of erectile function both after bi- and unilateral nerve-sparing with SSNR up to the last follow-up after 18 months.

CONCLUSION

In this analysis of the first RARP with SSNR, a simple intraoperative handling without major complications was demonstrated. While the series provides evidence that SSNR is safe and feasible, a prospective randomized trial with long-term follow-up is needed to identify further improvement in postoperative erectile function due to the spider silk-directed nerve regeneration.

Erectile Dysfunction in Pelvic Cancer Survivors and Current Management Options

Pelvic malignancies, including prostate, rectal, and bladder cancers, are among the most frequent malignancies found in the male population. These issues are most effectively and commonly treated with radiotherapy and/or surgery. However, these treatments can cause collateral damage, resulting in significant impacts on quality of life, with erectile dysfunction being one of the most frequent postoperative complications. Currently, there are several treatment options for erectile dysfunction, including oral phosphodiesterase type 5 inhibitors, vacuum erection devices, intracorporeal injections, and penile prosthesis. The latter has shown to be an effective and safe technique, with results comparable to those obtained by patients without pelvic surgery or radiotherapy. The results of early penile rehabilitation programs are promising and they have been incorporated into a greater proportion of treatment plans more recently, with varying degrees of success. In this narrative review, we summarize the literature on erectile dysfunction after pelvic cancer treatments and its management.

Rats, Neuregulins and Radical Prostatectomy: A Conceptual Overview

In the contemporary era of early detection, with mostly curative initial treatment for prostate cancer (PC), mortality rates have significantly diminished. In addition, mean age at initial PC diagnosis has decreased. Despite technical advancements, the probability of erectile function (EF) recovery post radical prostatectomy (RP) has not significantly changed throughout the last decade. Due to virtually unavoidable intraoperative cavernous nerve (CN) lesions and operations with younger patients, post-RP erectile dysfunction (ED) has now begun affecting these younger patients. To address this pervasive limitation, a plethora of CN lesion animal model investigations have analyzed the use of systemic/local treatments for EF recovery post-RP. Most promisingly, neuregulins (NRGs) have demonstrated neurotrophic effects in both neurodegenerative disease and peripheral nerve injury models. Recently, glial growth factor 2 (GGF2) has demonstrated far superior, dose-dependent, neuroprotective/restorative effects in the CN injury rat model, as compared to previous therapeutic counterparts. Although potentially impactful, these initial findings remain limited and under-investigated. In an effort to aid clinicians, our paper reviews post-RP ED pathogenesis and currently available therapeutic tools. To stimulate further experimentation, a standardized preparation protocol and in-depth analysis of applications for the CN injury rat model is provided. Lastly, we report on NRGs, such as GGF2, and their potentially revolutionary clinical applications, in hopes of identifying relevant future research directions.

Efficacy and safety evaluation of complete intrafascial prostatectomy in suspected prostate cancer patients with dysuria: a retrospective cohort study

Background

Suspected localized prostate cancer (PCa) patients with dysuria Complete intrafascial prostatectomy (CIP) can remove the whole prostate gland with the maximal retain of adjacent normal tissues around the prostate, and can be applied in some suspected localized prostate cancer (PCa) patients with dysuria. However, precious few studies have assessed the efficacy and safety of CIP in these patients without preoperative needle biopsies.

Methods

In this retrospective single-arm cohort study, all 22 suspected PCa patients with dysuria who underwent CIP at our hospital were enrolled. The clinical data including age, prostate-specific antigen (PSA), free-serum PSA, prostate volume, perioperative and postoperative complications were collected. The PSA level at 6 weeks after CIP and recoveries of urinary continence and erectile function were acquired in the follow-up procedures, and were used as the main measurements of efficacy and safety for CIP respectively.

Results

The patients had an average age of 71.91±8.29 years and an average preoperative PSA level of 10.75±4.25 ng/mL. The operations for all 22 patients were successfully completed. The average operation time was 135.20±41.44 min (range, 40.0-215.0 min), and the average blood loss volume was 128.64±145.09 mL. In total, 17 patients (77.27%) had PCa confirmed by postoperative pathology, and 5 patients (22.73%) had benign prostatic hyperplasia. The PSA level dropped to 0.010±0.004 ng/mL at 6 weeks after surgery. According to the loose criteria to assess urinary incontinence, the patients achieved continence rates of 63.6% immediately after the operation, 95.5% at 1 month, and 100% at 3 months. According to the strict criteria, the continence rates immediately, and at 1, 3, 6, and 9 months after surgery were 27.3%, 63.6%, 90.9%, 95.5%, and 100%, respectively. None of the patients complained of urinary obstruction symptoms after surgery. Before CIP, all the patients had erectile dysfunction and an International Index of Erectile Function 5 (IIEF-5) score of 9.64±5.91. After surgery, the patients had IIEF-5 scores at 3, 6, and 12 months of 5.45±4.43, 6.95±5.30, and 7.57±5.69, respectively.

Conclusions

Although the study had some limitations, CIP may be a prudent option for patients with suspected localized PCa who also present with dysuria.