The Risks and Benefits of Cavernous Neurovascular Bundle Sparing during Radical Prostatectomy: A Systematic Review and Meta-Analysis

Nerve-Sparing Gynecologic Surgery Enabled by A Near-Infrared Nerve-Specific Fluorophore Using Existing Clinical Fluorescence Imaging Systems

Patients undergoing gynecological procedures suffer from lasting side effects due to intraoperative nerve damage. Small, delicate nerves with complex and nonuniform branching patterns in the female pelvic neuroanatomy make nerve-sparing efforts during standard gynecological procedures such as hysterectomy, cystectomy, and colorectal cancer resection difficult, and thus many patients are left with incontinence and sexual dysfunction. Herein, a near-infrared (NIR) fluorescent nerve-specific contrast agent, LGW08-35, that is spectrally compatible with clinical fluorescence guided surgery (FGS) systems is formulated and characterized for rapid implementation for nerve-sparing gynecologic surgeries. The toxicology, pharmacokinetics (PK), and pharmacodynamics (PD) of micelle formulated LGW08-35 are examined, enabling the determination of the optimal imaging doses and time points, blood and tissue uptake parameters, and maximum tolerated dose (MTD). Application of the formulated fluorophore to imaging of female rat and swine pelvic neuroanatomy validates the continued clinical translation and use for real-time identification of important nerves such as the femoral, sciatic, lumbar, iliac, and hypogastric nerves. Further development of LGW08-35 for clinical use will unlock a valuable tool for surgeons in direct visualization of important nerves and contribute to the ongoing characterization of the female pelvic neuroanatomy to eliminate the debilitating side effects of nerve damage during gynecological procedures.

External validation of nomograms including MRI features for the prediction of side-specific extraprostatic extension

BACKGROUND

Prediction of side-specific extraprostatic extension (EPE) is crucial in selecting patients for nerve-sparing radical prostatectomy (RP). Multiple nomograms, which include magnetic resonance imaging (MRI) information, are available predict side-specific EPE. It is crucial that the accuracy of these nomograms is assessed with external validation to ensure they can be used in clinical practice to support medical decision-making.

METHODS

Data of prostate cancer (PCa) patients that underwent robot-assisted RP (RARP) from 2017 to 2021 at four European tertiary referral centers were collected retrospectively. Four previously developed nomograms for the prediction of side-specific EPE were identified and externally validated. Discrimination (area under the curve [AUC]), calibration and net benefit of four nomograms were assessed. To assess the strongest predictor among the MRI features included in all nomograms, we evaluated their association with side-specific EPE using multivariate regression analysis and Akaike Information Criterion (AIC).

RESULTS

This study involved 773 patients with a total of 1546 prostate lobes. EPE was found in 338 (22%) lobes. The AUCs of the models predicting EPE ranged from 72.2% (95% CI 69.1-72.3%) (Wibmer) to 75.5% (95% CI 72.5-78.5%) (Nyarangi-Dix). The nomogram with the highest AUC varied across the cohorts. The Soeterik, Nyarangi-Dix, and Martini nomograms demonstrated fair to good calibration for clinically most relevant thresholds between 5 and 30%. In contrast, the Wibmer nomogram showed substantial overestimation of EPE risk for thresholds above 25%. The Nyarangi-Dix nomogram demonstrated a higher net benefit for risk thresholds between 20 and 30% when compared to the other three nomograms. Of all MRI features, the European Society of Urogenital Radiology score and tumor capsule contact length showed the highest AUCs and lowest AIC.

CONCLUSION

The Nyarangi-Dix, Martini and Soeterik nomograms resulted in accurate EPE prediction and are therefore suitable to support medical decision-making.

Intraoperative technologies to assess margin status during radical prostatectomy - a narrative review

Positive surgical margin (PSM) is a frequent concern for surgeons performing radical prostatectomy for prostate cancer (PCa). PSM are recognized as risk factors for earlier biochemical recurrence and expose patients to adjuvant or salvage treatments such as external radiotherapy and hormonotherapy. Several strategies have been established to reduce PSM rate, while still allowing safe nerve-sparing surgery. Precise preoperative staging by multiparametric magnetic resonance imaging (mpMRI) and fusion biopsy is recommended to identify suspicious areas of extracapsular extension (ECE) that warrant special attention during dissection. However, even with optimal imaging, ECE can be missed, some cancers are not well defined or visible, and capsular incision during surgery remains an issue. Hence, intraoperative frozen section techniques, such as the neurovascular structure-adjacent frozen section examination (NeuroSAFE) have been developed and lately widely disseminated. The NeuroSAFE technique reduces PSM rate while allowing higher rate of nerve-sparing surgery. However, its use is limited to high volume or expert center because of its high barrier-to-entry in terms of logistics, human resources and expertise, as well as cost. Also, NeuroSAFE is a time-consuming process, even in expert hands. To address these issues, several technologies have been developed for an ex vivo and in vivo use. Ex vivo technology such as fluorescent confocal microscopy and intraoperative PET-CT require the extraction of the specimen for preparation, and digital images acquisition. In vivo technology, such as augmented reality based on mpMRI images and PSMA-fluorescent guided surgery have the advantage to provide an intracorporeal analysis of the completeness of the resection. The current manuscript provides a narrative review of established techniques, and details several new and promising techniques for intraoperative PSM assessment.

Development of a microultrasound-based nomogram to predict extra-prostatic extension in patients with prostate cancer undergoing robot-assisted radical prostatectomy

OBJECTIVES

To develop a microultrasound-based nomogram including clinicopathological parameters and microultrasound findings to predict the presence of extra-prostatic extension and guide the grade of nerve-sparing.

MATERIAL AND METHODS

All patients underwent microultrasound the day before robot-assisted radical prostatectomy. Variables significantly associated with extra-prostatic extension at univariable analysis were used to build the multivariable logistic model, and the regression coefficients were used to develop the nomogram. The model was subjected to 1000 bootstrap resamples for internal validation. The performance of the microultrasound-based model was evaluated using the area under the curve (AUC) of the receiver operating characteristic (ROC) curve, calibration plot, and decision curve analysis (DCA).

RESULTS

Overall, 122/295 (41.4%) patients had a diagnosis of extra-prostatic extension on definitive pathology. Microultrasound correctly identify extra-prostatic extension in 84/122 (68.9%) cases showing a sensitivity and a specificity of 68.9% and 84.4%, with an AUC of 76.6%. After 1000 bootstrap resamples, the predictive accuracy of the microultrasound-based model was 85.9%. The calibration plot showed a satisfactory concordance between predicted probabilities and observed frequencies of extra-prostatic extension. The DCA showed a higher clinical net-benefit compared to the model including only clinical parameters. Considering a 4% cut-off, nerve-sparing was recommended in 173 (58.6%) patients and extra-prostatic extension was detected in 32 (18.5%) of them.

CONCLUSION

We developed a microultrasound-based nomogram for the prediction of extra-prostatic extension that could aid in the decision whether to preserve or not neurovascular bundles. External validation and a direct comparison with mpMRI-based nomogram is crucial to corroborate our results.

Early recovery of urinary continence after robot-assisted radical prostatectomy is associated with membranous urethra and neurovascular bundle preservation

OBJECTIVES

We investigated the correlation between surgical outcomes and postoperative urinary continence recovery in robot-assisted radical prostatectomy (RARP).

METHODS

Patients who underwent RARP in our institution (n = 195) were included in this study. Preserved urethral length (PUL) was assessed during the procedure. Other outcomes of the surgical procedure were collected from operative records. Kaplan-Meier analysis with log-rank test was used to compare urinary continence recovery rate with the PUL, sparing of the neurovascular bundle (NVB), and other surgical procedures. Univariate and multivariate analyses were performed using Cox proportional hazards model, and p-values of <0.05 were considered significant.

RESULTS

Patients with a PUL ≥26 mm had 10.0%, 24.7%, 36.6%, and 89.0% continence recovery rates at 30, 60, 90, and 365 days after surgery, respectively, while patients with a PUL <26 mm had 0%, 17.8%, 26.1%, and 80.9% recovery rates, respectively. Kaplan-Meier curves showed significantly better postoperative urinary continence recovery at 30 days after RARP in patients with a PUL ≥26 mm than those with a PUL <26 mm (p = 0.0028) and in patients with NVB preservation than those with no NVB preservation (p = 0.014). Urinary continence recovery within 30, 60, and 90 days after surgery was 90.6% for patients with a PUL of ≥26 mm and NVB preservation, while only 82.3% for patients with a PUL of <26 mm or no NVB preservation.

CONCLUSION

Our results suggest that a PUL ≥26 mm and NVB preservation after RARP correlate with a significantly higher postoperative rate of recovery of urinary continence.

How Surgeons Think to Avoid Error: A Case Study of the Neurovascular Bundle Sparing During a Robotic Prostatectomy

OBJECTIVE

To illustrate how experts efficiently navigate a "slowing down moment" to obtain optimal surgical outcomes using the neurovascular bundle sparing during a robotic prostatectomy as a case study.

DESIGN

A series of semistructured interviews with four expert uro-oncologists were completed using a cognitive task analysis methodology. Cognitive task analysis, CTA, refers to the interview and extraction of a general body of knowledge. Each interview participant completed four 1 to 2-hour semistructured CTA interviews. The interview data were then deconstructed, coded, and analyzed using a grounded theory analysis to produce a CTA-grid for a robotic prostatectomy for each surgeon, with headings of: surgical steps, simplification maneuvers, visual cues, error/complication recognition, and error/complication management and avoidance.

SETTING

The study took place at an academic teaching hospital located in an urban center in Canada.

PARTICIPANTS

Four expert uro-oncologists participated in the study.

RESULTS

Visual cues, landmarks, common pitfalls, and technique were identified as the 4 key components of the decision-making happening during a slowing down moment in the neurovascular bundle sparing during a robotic prostatectomy.

CONCLUSION

The data obtained from the CTA is novel information identifying patterns and cues that expert surgeons use to inform their surgical decision-making and avoid errors. This decision-making knowledge of visual cues, landmarks, common pitfalls and techniques is also generalizable for other surgical subspecialties. Surgeon educators, surgical teaching programs and trainees looking to improve their decision-making skills could use these components to guide their educational strategies.

Nerve Visualization using Phenoxazine-Based Near-Infrared Fluorophores to Guide Prostatectomy

Fluorescence-guided surgery (FGS) is poised to revolutionize surgical medicine through near-infrared (NIR) fluorophores for tissue- and disease-specific contrast. Clinical open and laparoscopic FGS vision systems operate nearly exclusively at NIR wavelengths. However, tissue-specific NIR contrast agents compatible with clinically available imaging systems are lacking, leaving nerve tissue identification during prostatectomy a persistent challenge. Here, it is shown that combining drug-like molecular design concepts and fluorophore chemistry enabled the production of a library of NIR phenoxazine-based fluorophores for intraoperative nerve-specific imaging. The lead candidate readily delineated prostatic nerves in the canine and iliac plexus in the swine using the clinical da Vinci Surgical System that has been popularized for minimally invasive prostatectomy procedures. These results demonstrate the feasibility of molecular engineering of NIR nerve-binding fluorophores for ready integration into the existing surgical workflow, paving the path for clinical translation to reduce morbidity from nerve injury for prostate cancer patients.

Clinical significance of location of perineural cancer invasion detected on prostate needle core biopsy

The clinical impact of site-specific perineural invasion (PNI) in prostate cancer remains poorly understood. We compared radical prostatectomy findings and oncologic outcomes in 434 patients with single-site PNI on systematic sextant biopsy. PNI was present in the right apex (n = 62; 14%), right mid (n = 70; 16%), right base (n = 89; 21%), left apex (n = 64; 15%), left mid (n = 58; 13%), and left base (n = 91; 21%). There were no significant differences in biopsy or prostatectomy findings, when comparing apex vs. mid vs. base PNI. Univariate analysis revealed that apex-localized PNI was associated with a significantly higher risk of progression, compared with base (P = 0.037) or mid/base (P = 0.024) PNI. Multivariable analysis showed that apex-localized PNI was an independent risk factor for progression (hazard ratio 2.049, P = 0.002). Among biopsies demonstrating PNI at one sextant site, apex-localized PNI is independently associated with poorer prognosis, though not worse histopathologic features on prostatectomy, compared with mid or base PNI.

Baseline factors and surgical procedures affecting changes in lower urinary tract symptoms after robot-assisted radical prostatectomy: the impact of nerve-sparing

PURPOSE

To determine baseline factors and surgical procedures associated with clinically meaningful improvement or deterioration of lower urinary tract symptoms (LUTS) after robot-assisted radical prostatectomy (RARP).

METHODS

We retrospectively reviewed our RARP database and analyzed the changes in the International Prostate Symptom Score (IPSS) at baseline and 1, 3, 6, and 12 months postoperatively. Multivariable ordinal logistic regression analysis was performed to determine variables that predicted clinically meaningful improvement (∆IPSS ≤ -5) or deterioration (∆IPSS ≥ 5) in LUTS after RARP.

RESULTS

A total of 172 patients were eligible for analysis. Patients aged ≥ 70 reported a higher IPSS before and after RARP (all p < 0.05). Patients with a prostate volume of > 30 mL or body mass index of < 24 kg/m2 had worse preoperative LUTS; however, the difference disappeared after RARP. While patients with or without nerve-sparing (NS) had a similar preoperative LUTS burden, the NS group reported significantly lower IPSS than the non-NS group at all postoperative time points (p < 0.05). Twelve months after RARP, LUTS improved in 27% and worsened in 6% of patients in the NS group, compared with 20% and 24% of those in the non-NS group, respectively (p = 0.018). Preoperative IPSS (OR, 0.84; 95% CI, 0.79-0.89) and NS (OR, 0.39; 95% CI, 0.18-0.83) were independently associated with clinically meaningful changes of LUTS at 12 months after RARP.

CONCLUSION

Other than baseline LUTS severity, NS was the only independent factor associated with clinically meaningful changes in LUTS after RARP.

Urinary Symptoms Change and Quality of Life After Robotic Radical Prostatectomy: A Secondary Analysis of a Randomized Controlled Trial

OBJECTIVE

To present the patient-reported quality of life (QoL) outcomes from a prospective, randomized controlled trial comparing the use of pelvic floor muscle training (PFMT) and duloxetine after robot-assisted radical prostatectomy (RARP).

METHODS

We identified 213 men with organ-confined disease having post-RARP urinary incontinence who were randomly assigned to received PFMT, duloxetine, combined PFMT-duloxetine and pelvic floor muscle home exercises. Urinary symptoms burden was measured by marked clinical important difference improvement (MCID) defined by using the International Prostate Symptom Score (IPSS) difference of - 8 points (ΔIPSS ≤-8). QoL was assessed according to Visual Analog Scale (VAS), King's Health Questionnaire (KQH), and International Index of Erectile Function (IIEF-5). Multivariable regression analyses aimed to predict MCID, burden of urinary symptoms (IPSS ≥8), and patients reporting to be satisfied (IPSS QoL ≤2) or comfortable (VAS ≤1) post-RARP.

RESULTS

Moderate to severe urinary symptoms decreased from 48% preoperatively to 40%, 34%, and 23% at 3, 6, and 12months post-RARP. After surgery, MCID improvement was observed in 19% of patients, and deterioration in 3.3%. Large prostate was the only factor associated to MCID (OR 1.03 [95%CI 1.01-1.05], P = .005). At 6months, patients reached the same degree of preoperative satisfaction. Neurovascular bundle preservation was the only predictor of being comfortable regarding urinary symptoms postoperatively (OR 12.8 [CI95% 1.47-111.7], P = .02 at 3months) and was also associated to higher median postoperative IIEF-5.

CONCLUSION

Despite urinary incontinence following RARP, patients with larger prostates experience a reduction of lower urinary tract symptoms within a year, which subsequently elevates QoL. Furthermore, nerve-sparing surgery augments erectile function and urinary outcomes, shaping postoperative QoL.

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.

Assessing the efficacy of pelvic floor muscle training and duloxetine on urinary continence recovery following radical prostatectomy: A randomized clinical trial

BACKGROUND

Urinary incontinence (UI) can negatively impact quality of life (QoL) after robot-assisted radical prostatectomy (RARP). Pelvic floor muscle training (PFMT) and duloxetine are used to manage post-RARP UI, but their efficacy remains uncertain. We aimed to investigate the efficacy of PFMT and duloxetine in promoting urinary continence recovery (UCR) after RARP.

METHODS

A randomized controlled trial involving patients with urine leakage after RARP from May 2015 to February 2018. Patients were randomized into 1 of 4 arms: (1) PFMT-biofeedback, (2) duloxetine, (3) combined PFMT-biofeedback and duloxetine, (4) control arm. PFMT consisted of pelvic muscle exercises conducted with electromyographic feedback weekly, for 3 months. Oral duloxetine was administered at bedtime for 3 months. The primary outcome was prevalence of continence at 6 months, defined as using ≤1 security pad. Urinary symptoms and QoL were assessed by using a visual analogue scale, and validated questionnaires.

RESULTS

From the 240 patients included in the trial, 89% of patients completed 1 year of follow-up. Treatment compliance was observed in 88% (92/105) of patients receiving duloxetine, and in 97% (104/107) of patients scheduled to PFMT-biofeedback sessions. In the control group 96% of patients had achieved continence at 6 months, compared with 90% (p = 0.3) in the PMFT-biofeedback, 73% (p = 0.008) in the duloxetine, and 69% (p = 0.003) in the combined treatment arm. At 6 months, QoL was classified as uncomfortable or worse in 17% of patients in the control group, compared with 44% (p = 0.01), 45% (p = 0.008), and 34% (p = 0.07), respectively. Complete preservation of neurovascular bundles (NVB) (OR: 2.95; p = 0.048) was the only perioperative intervention found to improve early UCR.

CONCLUSIONS

PFMT-biofeedback and duloxetine demonstrated limited impact in improving UCR after RP. Diligent NVB preservation, along with preoperative patient and disease characteristics, are the primary determinants for early UCR.

External validation of an algorithm to personalize nerve sparing approaches during robot-assisted radical prostatectomy in men with unilateral high-risk prostate cancer

Limited evidence exists about preserving neurovascular bundles during radical prostatectomy (RP) for high-risk prostate cancer (HRPCa) patients. Hence, we validated an existing algorithm predicting contralateral extraprostatic extension (cEPE) risk in unilateral high-risk cases. This algorithm aims to assist in determining the suitability of unilateral nerve-sparing RP. Among 264 patients, 48 (18%) had cEPE. The risk of cECE varied: 8%, 17.2%, and 30.8% for the low, intermediate, and high-risk groups, respectively. Despite a higher risk of cECE among individuals classified as low-risk in the development group compared to the validation group, our algorithm's superiority over always/never nerve-sparing RP was reaffirmed by decision curve analysis. Therefore, we conclude that bilateral excision may not always be justified in men with unilateral HRPCa. Instead, decisions can be based on our suggested nomogram.

Functional Impact of Neuro-Vascular Bundle Preservation in High Risk Prostate Cancer without Compromising Oncological Outcomes: A Propensity-Modelled Analysis

Nerve sparing (NS) is a surgical technique to optimize functional outcomes of radical prostatectomy (RP). However, it is not recommended in high risk (HR) cases because of the risk of a positive surgical margin that may increase the risk of cancer recurrence. In the last two decades there has been a change of perspective to the effect that in well-selected cases NS could be an oncologically safe option with better functional outcomes. Therefore, we aim to compare the functional outcomes and oncological safety of NS during RP in men with HR disease. A total of 1340 patients were included in this analysis, of which 12% (n = 158) underwent non-NSRP and 39% (n = 516) and 50% (n = 666) uni- and bilateral NSRP, respectively. We calculated a propensity score and used inverse probability of treatment weighting (IPTW) to balance the baseline characteristics of Pca patients undergoing non-NSRP and those having uni- and bilateral NSRP, respectively. NS improved functional outcomes; after IPTW, only 3% of patients having non-NSRP reached complete erectile function recovery (without erectile aid) at 24 months, whereas 22% reached erectile function recovery (with erectile aid), while 87% were continent. Unilateral NS increased the probability of functional recovery in all outcomes (OR 1.1 or 1.2, respectively), bilateral NS slightly more so (OR 1.1 to 1.4). NSRP did not impact the risk of any recurrence (HR 0.99, 95%CI 0.73-1.34, p = 0.09), and there was no difference in survival for men who underwent NSRP (HR 0.65, 95%CI 0.39-1.08). There was no difference in cancer-specific survival (0.56, 95%CI 0.29-1.11). Our study found that NSRP significantly improved functional outcomes and can be safely performed in carefully selected patients with HR-PCa without compromising long term oncological outcomes.

Development and Validation of Nomograms Based on Nutritional Risk Index for Predicting Extracapsular Extension and Seminal Vesicle Invasion in Patients Undergoing Radical Prostatectomy

Background

The aim of the study was to investigate the predictive value of the nutritional risk index (NRI) for extracapsular extension (ECE) and seminal vesicle invasion (SVI) in prostate cancer (PCa) patients undergoing radical prostatectomy (RP), and further develop and validate predictive nomograms for ECE and SVI based on the NRI.

Methods

We retrospectively analyzed 734 PCa patients who underwent RP between 2010 and 2020 in the Department of Urology at Peking University Third Hospital. The enrolled patients were randomly divided into a primary cohort (n = 489) and a validation cohort (n = 245) in a 2:1 manner. The baseline NRI of patients was calculated using serum albumin level and body mass index, and a malnutrition status was defined as NRI ≤ 98. Univariate and multivariate logistic regression analyses were conducted to identify predictors for ECE and SVI. Nomograms for predicting ECE and SVI were established based on the results of the multivariate logistic regression analysis. The performance of the nomograms was estimated using Harrell's concordance index (C-index), the area under curve (AUC) of receiver operating characteristic (ROC) curves and the calibration curves.

Results

In the primary cohort, 70 (14.3%) patients with NRI ≤ 98 were classified as malnutrition, while the remaining 419 (85.7%) patients with NRI > 98 were considered to have normal nutrition. The nomograms for predicting ECE and SVI shared common factors including NRI, percentage of positive biopsy cores (PPC) and biopsy Gleason score, while prostate-specific antigen (PSA) levels and PSA density (PSAD) were only incorporated in ECE nomogram. The C-indexes of the nomograms for predicting ECE and SVI were 0.785 (95% confidence interval (CI): 0.745 - 0.826) and 0.852 (95% CI: 0.806 - 0.898), respectively. The calibration curves demonstrated excellent agreement between the predictions by the nomograms and the actual observations. The results remained reproducible when the nomograms were applied to the validation cohort.

Conclusions

The NRI is significantly associated with ECE and SVI in PCa patients. The nomogram established based on the NRI in our study can provide individualized risk estimation for ECE and SVI in PCa patients, and may be valuable for clinicians in making well-informed decisions regarding treatment strategies and patient management.

Early and late urinary continence outcomes after unilateral and bilateral nerve-sparing robot-assisted radical prostatectomy: A retrospective multicentre cohort study in Japan (the MSUG94 group)

BACKGROUND

The impact of unilateral and bilateral nerve-sparing robot-assisted laparoscopic radical prostatectomy (NS-RARP) procedures on continence and the time to continence recovery have not been established.

MATERIAL AND METHODS

We retrospectively reviewed a total of 2801 patients who underwent RARP in 9 institutions. Procedures were classified as NS or non-NS; NS procedures were further classified as unilateral or bilateral. The recovery of continence was analysed using propensity score matching method.

RESULTS

The pad-free rates at 12 months after surgery were higher in the NS group (95% confidence interval of odds ratio, 1.06-1.51). Pad-free rates at all time points within 12 months of surgery did not significantly differ between the unilateral and bilateral NS groups.

CONCLUSIONS

NS-RARP resulted in better urinary continence outcomes than non-NS-RARP in the first 12 months after surgery. Urinary recovery rates did not significantly differ between unilateral and bilateral NS-RARP.

Retrospective evaluation of the improvement in the urinary status-related quality of life after robot-assisted radical prostatectomy

OBJECTIVES

This study aimed to investigate the characteristics of patients who report improvement in quality of life (QOL) related to urinary status after undergoing robot-assisted radical prostatectomy (RARP) for localized prostate cancer.

METHODS

We retrospectively reviewed the patients who underwent RARP between May 2010 and May 2021 at our institution and were preoperatively unsatisfied with their urinary status. Patients were grouped as Group 1 (improved patients: "satisfied" with urinary status based on international prostate symptom score QOL [IPSS-QOL] = 0-2 at 12 months after RARP) and Group 2 (unimproved group: "unsatisfied"-IPSS-QOL 3-6). Additionally, the Expanded Prostate Cancer Index Composite (EPIC) urinary subdomains (urinary function, urinary bother [UB], urinary incontinence, and urinary irritation/obstruction [UIR]) and IPSS were evaluated preoperatively and till 12 months after RARP.

RESULTS

Of the 237 patients, 72 (30.4%) were Group 1, and 165 (69.6%) were Group 2. Only UB and UIR improved at 12 months after RARP in Group 1, while other EPIC urinary subdomains remained unimproved at 12 months in both groups. On the other hand, IPSS improved at 12 months in both groups. Univariate and multivariate analysis revealed that the nerve-sparing, preoperative low IPSS (<11 vs. ≥11), and low IPSS-QOL (3 vs. 4-6) were associated with improvement in urinary status-related QOL (p < 0.05).

CONCLUSIONS

Improvement in UB and UIR are important factors to ascertain improvement in urinary status-related QOL after RARP. Nerve-sparing and preoperative IPSS/IPSS-QOL values are useful predictors of this improvement.

Differences in long-term continence rates between prostate cancer patients with extraprostatic vs. organ-confined disease undergoing robotic-assisted radical prostatectomy: An observational studys

OBJECTIVES

Within the tertiary-case database, the authors tested for differences in long-term continence rates (≥ 12 months) between prostate cancer patients with extraprostatic vs. organ-confined disease who underwent Robotic-Assisted Radical Prostatectomy (RARP).

METHOD

In the institutional tertiary-care database the authors identified prostate cancer patients who underwent RARP between 01/2014 and 01/2021. The cohort was divided into two groups based on tumor extension in the final RARP specimen: patients with extraprostatic (pT3/4) vs. organ-confined (pT2) disease. Additionally, the authors conducted subgroup analyses within both the extraprostatic and organ-confined disease groups to compare continence rates before and after the implementation of the new surgical technique, which included Full Functional-Length Urethra preservation (FFLU) and Neurovascular Structure-Adjacent Frozen-Section Examination (NeuroSAFE). Multivariable logistic regression models addressing long-term continence were used.

RESULTS

Overall, the authors identified 201 study patients of whom 75 (37 %) exhibited extraprostatic and 126 (63 %) organ-confined disease. There was no significant difference in long-term continence rates between patients with extraprostatic and organ-confined disease (77 vs. 83 %; p = 0.3). Following the implementation of FFLU+ NeuroSAFE, there was an overall improvement in continence from 67 % to 89 % (Δ = 22 %; p < 0.001). No difference in the magnitude of improved continence rates between extraprostatic vs. organ-confined disease was observed (Δ = 22 % vs. Δ = 20 %). In multivariable logistic regression models, no difference between extraprostatic vs. organ-confined disease in long-term continence was observed (Odds Ratio: 0.91; p = 0.85).

CONCLUSION

In this tertiary-based institutional study, patients with extraprostatic and organ-confined prostate cancer exhibited comparable long-term continence rates.

Technical surgical skill assessment of neurovascular bundle dissection and urinary continence recovery after robotic-assisted radical prostatectomy

Purpose

To examine the association between the quality of neurovascular bundle dissection and urinary continence recovery after robotic-assisted radical prostatectomy.

Materials and Methods

Patients who underwent RARPs from 2016 to 2018 in two institutions with ≥1-year postoperative follow-up were included. The primary outcomes were time to urinary continence recovery. Surgical videos were independently assessed by 3 blinded raters using the validated Dissection Assessment for Robotic Technique (DART) tool after standardized training. Cox regression was used to test the association between DART scores and urinary continence recovery while adjusting for relevant patient features.

Results

121 RARP performed by 23 surgeons with various experience levels were included. The median follow-up was 24 months (95% CI 20 - 28 months). The median time to continence recovery was 7.3 months (95% CI 4.7 - 9.8 months). After adjusting for patient age, higher scores of certain DART domains, specifically tissue retraction and efficiency, were significantly associated with increased odds of continence recovery (p<0.05).

Conclusions

Technical skill scores of neurovascular bundle dissection vary among surgeons and correlate with urinary continence recovery. Unveiling the specific robotic dissection skillsets which impact patient outcomes has the potential to focus surgical training.

Development, multi-institutional external validation, and algorithmic audit of an artificial intelligence-based Side-specific Extra-Prostatic Extension Risk Assessment tool (SEPERA) for patients undergoing radical prostatectomy: a retrospective cohort study

BACKGROUND

Accurate prediction of side-specific extraprostatic extension (ssEPE) is essential for performing nerve-sparing surgery to mitigate treatment-related side-effects such as impotence and incontinence in patients with localised prostate cancer. Artificial intelligence (AI) might provide robust and personalised ssEPE predictions to better inform nerve-sparing strategy during radical prostatectomy. We aimed to develop, externally validate, and perform an algorithmic audit of an AI-based Side-specific Extra-Prostatic Extension Risk Assessment tool (SEPERA).

METHODS

Each prostatic lobe was treated as an individual case such that each patient contributed two cases to the overall cohort. SEPERA was trained on 1022 cases from a community hospital network (Trillium Health Partners; Mississauga, ON, Canada) between 2010 and 2020. Subsequently, SEPERA was externally validated on 3914 cases across three academic centres: Princess Margaret Cancer Centre (Toronto, ON, Canada) from 2008 to 2020; L'Institut Mutualiste Montsouris (Paris, France) from 2010 to 2020; and Jules Bordet Institute (Brussels, Belgium) from 2015 to 2020. Model performance was characterised by area under the receiver operating characteristic curve (AUROC), area under the precision recall curve (AUPRC), calibration, and net benefit. SEPERA was compared against contemporary nomograms (ie, Sayyid nomogram, Soeterik nomogram [non-MRI and MRI]), as well as a separate logistic regression model using the same variables included in SEPERA. An algorithmic audit was performed to assess model bias and identify common patient characteristics among predictive errors.

FINDINGS

Overall, 2468 patients comprising 4936 cases (ie, prostatic lobes) were included in this study. SEPERA was well calibrated and had the best performance across all validation cohorts (pooled AUROC of 0·77 [95% CI 0·75-0·78] and pooled AUPRC of 0·61 [0·58-0·63]). In patients with pathological ssEPE despite benign ipsilateral biopsies, SEPERA correctly predicted ssEPE in 72 (68%) of 106 cases compared with the other models (47 [44%] in the logistic regression model, none in the Sayyid model, 13 [12%] in the Soeterik non-MRI model, and five [5%] in the Soeterik MRI model). SEPERA had higher net benefit than the other models to predict ssEPE, enabling more patients to safely undergo nerve-sparing. In the algorithmic audit, no evidence of model bias was observed, with no significant difference in AUROC when stratified by race, biopsy year, age, biopsy type (systematic only vs systematic and MRI-targeted biopsy), biopsy location (academic vs community), and D'Amico risk group. According to the audit, the most common errors were false positives, particularly for older patients with high-risk disease. No aggressive tumours (ie, grade >2 or high-risk disease) were found among false negatives.

INTERPRETATION

We demonstrated the accuracy, safety, and generalisability of using SEPERA to personalise nerve-sparing approaches during radical prostatectomy.

FUNDING

None.

Erectile Dysfunction Treatment Using Stem Cell Delivery Patch in a Cavernous Nerve Injury Rat Model

Erectile dysfunction (ED) is a common and feared complication of radical prostatectomy (RP) for prostate cancer. Recently, tissue engineering for post-prostatectomy ED has been attempted in which controlled interactions between cells, growth factors, and the extracellular matrix (ECM) are important for the structural integrity if nerve regeneration. In this study, we evaluated the effects of a biomechanical ECM patch on the morphology and behavior of human bone marrow-derived mesenchymal stem cells (hBMSCs) in a bilateral cavernous nerve injury (BCNI) rat model. The ECM patch, made of decellularized human fibroblast-derived ECM (hFDM) and a biocompatible polyvinyl alcohol (PVA) hydrogel, was tested with human bone marrow-derived mesenchymal stem cells (hBMSCs) on a bilateral cavernous nerve injury (BCNI) rat model. In vitro analysis showed that the hFDM/PVA + hBMSCs patches significantly increased neural development markers. In vivo experiments demonstrated that the rats treated with the hFDM/PVA patch had higher ICP/MAP ratios, higher ratios of smooth muscle to collagen, increased nNOS content, higher levels of eNOS protein expression, and higher cGMP levels compared to the BCNI group. These results indicate that the hFDM/PVA patch is effective in promoting angiogenesis, smooth muscle regeneration, and nitrergic nerve regeneration, which could contribute to improved erectile function in post-prostatectomy ED.

Salvage Radical Prostatectomy after Primary Focal Ablative Therapy: A Systematic Review and Meta-Analysis

CONTEXT

Focal therapy (FT) has been gaining popularity as a treatment option for localized intermediate-risk prostate cancer (PCa) due to the associated lower morbidity compared to whole-gland treatment. However, there is an increased risk of local cancer recurrence requiring subsequent treatment in a small proportion of patients.

OBJECTIVE

To conduct a systematic review and meta-analysis to better describe and analyze patient postoperative, oncologic, and functional outcomes for those who underwent salvage radical prostatectomy (sRP) to manage their primary FT failure.

EVIDENCE ACQUISITION

A systematic review was completed using three databases (PubMed, Embase, and CINAHL) from October to December 2021 to identify data on outcomes in patients who received sRP for cancer recurrence after prior focal treatment.

EVIDENCE SYNTHESIS

12 articles (482 patients) were included. Median time to sRP was 24 months. Median follow-up time was 27 months. A meta-analysis revealed a postoperative complication rate of 15% (95% CI: 0.09, 0.24), with 4.6% meeting criteria for a major complication Clavien (CG) grade ≥3. Severe GU toxicity was seen in 3.6% of the patients, and no patients had severe GI toxicity. Positive surgical margins (PSM) were found in 27% (95% CI: 0.19, 0.37). Biochemical recurrence (BCR) after sRP occurred in 23% (95% CI: 0.17, 0.30), indicating a BCR-free probability of 77% at 2 years. Continence (pad-free) and potency (ability to have penetrative sex) were maintained in 67% (95% CI: 0.53, 0.78) and 37% (95% CI: 0.18, 0.62) at 12 months, respectively.

CONCLUSION

Our evidence shows acceptable complication rates and oncologic outcomes; however, with suboptimal functional outcomes for patients undergoing sRP for recurrent PCa after prior FT. Inferior outcomes were observed for salvage treatment compared to primary radical prostatectomy (pRP). More high-quality studies are needed to better characterize outcomes after this sequence of PCa treatments.

PATIENT SUMMARY

We looked at treatment outcomes and toxicity for men treated with sRP for prior FT failure. We conclude that these patients will have significant detriment to genitourinary function, with outcomes being worse than those for pRP patients.

Erectile function, urinary continence and oncologic outcomes of neurovascular bundle sparing robot-assisted radical prostatectomy for high-risk prostate cancer: A systematic review and meta-analysis

Background

The nerve-sparing (NS) effect of robot-assisted radical prostatectomy (RARP) on patients with a high-risk prostate cancer remains unclear. The objective of this study was to compare the urinary continence, erectile function and oncology outcomes of the nerve-sparing and non-nerve-sparing (NNS) group during RARP surgeries.

Methods

We systematically searched databases including PubMed, Embase, Cochrane Library and Web of Science to identify relevant studies published in English up to December 2022. Newcastle-Ottawa Scale (NOS) was used as a quality evaluation tool to evaluate the quality of the literature parameters involved, including urinary continence, erectile function and oncologic outcomes, which were compared using the Stata 15.1 software (StataSE, USA).

Results

A total of 8 cohort studies involving 2499 patients were included. A meta-analysis of results showed that the NS group was beneficial to the recovery of urinary continence (RR 0.46, 95%CI 0.22, 0.96; p=0.045&lt;0.05) and erectile function (RR 0.32, 95%CI 0.16, 0.63; p=0.001&lt;0.05) 12 months after surgeries, which showed a better oncological outcome (RR 1.31, 95%CI 1.01, 1.69; p=0.01&lt;0.05).

Conclusions

The current study results indicate that intraoperative NS during RARP is beneficial to long-term postoperative functional recovery and tumor prognosis of patients with high-risk prostate cancers. Due to interstudy interferences, the results should be interpreted with caution.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022384647.

Surgical gestures as a method to quantify surgical performance and predict patient outcomes

How well a surgery is performed impacts a patient's outcomes; however, objective quantification of performance remains an unsolved challenge. Deconstructing a procedure into discrete instrument-tissue "gestures" is a emerging way to understand surgery. To establish this paradigm in a procedure where performance is the most important factor for patient outcomes, we identify 34,323 individual gestures performed in 80 nerve-sparing robot-assisted radical prostatectomies from two international medical centers. Gestures are classified into nine distinct dissection gestures (e.g., hot cut) and four supporting gestures (e.g., retraction). Our primary outcome is to identify factors impacting a patient's 1-year erectile function (EF) recovery after radical prostatectomy. We find that less use of hot cut and more use of peel/push are statistically associated with better chance of 1-year EF recovery. Our results also show interactions between surgeon experience and gesture types-similar gesture selection resulted in different EF recovery rates dependent on surgeon experience. To further validate this framework, two teams independently constructe distinct machine learning models using gesture sequences vs. traditional clinical features to predict 1-year EF. In both models, gesture sequences are able to better predict 1-year EF (Team 1: AUC 0.77, 95% CI 0.73-0.81; Team 2: AUC 0.68, 95% CI 0.66-0.70) than traditional clinical features (Team 1: AUC 0.69, 95% CI 0.65-0.73; Team 2: AUC 0.65, 95% CI 0.62-0.68). Our results suggest that gestures provide a granular method to objectively indicate surgical performance and outcomes. Application of this methodology to other surgeries may lead to discoveries on methods to improve surgery.

Effect of Preoperative Multiparametric Magnetic Resonance Imaging on Oncologic and Functional Outcomes Following Radical Prostatectomy

Background

Advancements in imaging technology have been associated with changes to operative planning in treatment of localized prostate cancer. The impact of these changes on postoperative outcomes is understudied.

Objective

To compare oncologic and functional outcomes between men who had computed tomography (CT) and those who had multiparametric magnetic resonance imaging (mpMRI) prior to undergoing radical prostatectomy.

Design setting and participants

In this retrospective cohort study, we identified all men who underwent radical prostatectomy (n = 1259) for localized prostate cancer at our institution between 2009 and 2016. Of these, 917 underwent preoperative CT and 342 mpMRI.

Outcome measurements and statistical analysis

Biochemical recurrence-free survival, positive margin status, postoperative complications, and 1-yr postprostatectomy functional scores (using the 26-item Expanded Prostate Cancer Index Composite [EPIC-26] questionnaire) were compared between those who underwent preoperative CT and those who underwent mpMRI using propensity score weighted Cox proportional hazard regression, logistic regression, and linear regression models.

Results and limitations

Baseline and 1-yr follow-up EPIC-26 data were available for 449 (36%) and 685 (54%) patients, respectively. After propensity score weighting, no differences in EPIC-26 functional domains were observed between the imaging groups at 1-yr follow-up. Positive surgical margin rates (odds ratio 1.03, 95% confidence interval [CI] 0.77-1.38, p = 0.8) and biochemical recurrence-free survival (hazard ratio 1.21, 95% CI 0.84-1.74, p = 0.3) were not significantly different between groups. Early and late postoperative complications occurred in 219 and 113 cases, respectively, and were not different between imaging groups. Our study is limited by a potential selection bias from the lack of functional scores for some patients.

Conclusions

In this single-center study of men with localized prostate cancer undergoing radical prostatectomy, preoperative mpMRI had minimal impact on functional outcomes and oncologic control compared with conventional imaging. These findings challenge the assumptions that preoperative mpMRI improves operative planning and perioperative outcomes.

Patient summary

In this study, we assessed whether the type of prostate imaging performed prior to surgery for localized prostate cancer impacted outcomes. We found that urinary and sexual function, cancer control, and postoperative complications were similar regardless of whether magnetic resonance imaging or computed tomography was utilized prior to surgery.

Guidelines for Sexual Health Care for Prostate Cancer Patients: Recommendations of an International Panel

BACKGROUND

Patients with prostate cancer suffer significant sexual dysfunction after treatment which negatively affects them and their partners psychologically, and strain their relationships.

AIM

We convened an international panel with the aim of developing guidelines that will inform clinicians, patients and partners about the impact of prostate cancer therapies (PCT) on patients' and partners' sexual health, their relationships, and about biopsychosocial rehabilitation in prostate cancer (PC) survivorship.

METHODS

The guidelines panel included international expert researchers and clinicians, and a guideline methodologist. A systematic review of the literature, using the Ovid MEDLINE, Scopus, CINAHL, PsychINFO, LGBT Life, and Embase databases was conducted (1995-2022) according to the Cochrane Handbook for Systematic Reviews of Interventions. Study selection was based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Each statement was assigned an evidence strength (A-C) and a recommendation level (strong, moderate, conditional) based on benefit/risk assessment, according to the nomenclature of the American Urological Association (AUA). Data synthesis included meta-analyses of studies deemed of sufficient quality (3), using A Measurement Tool to Assess Systematic Reviews (AMSTAR).

OUTCOMES

Guidelines for sexual health care for patients with prostate cancer were developed, based on available evidence and the expertise of the international panel.

RESULTS

The guidelines account for patients' cultural, ethnic, and racial diversity. They attend to the unique needs of individuals with diverse sexual orientations and gender identities. The guidelines are based on literature review, a theoretical model of sexual recovery after PCT, and 6 principles that promote clinician-initiated discussion of realistic expectations of sexual outcomes and mitigation of sexual side-effects through biopsychosocial rehabilitation. Forty-seven statements address the psychosexual, relationship, and functional domains in addition to statements on lifestyle modification, assessment, provider education, and systemic challenges to providing sexual health care in PC survivorship.

CLINICAL IMPLICATIONS

The guidelines provide clinicians with a comprehensive approach to sexual health care for patients with prostate cancer.

STRENGTHS & LIMITATIONS

The strength of the study is the comprehensive evaluation of existing evidence on sexual dysfunction and rehabilitation in prostate cancer that can, along with available expert knowledge, best undergird clinical practice. Limitation is the variation in the evidence supporting interventions and the lack of research on issues facing patients with prostate cancer in low and middle-income countries.

CONCLUSION

The guidelines document the distressing sexual sequelae of PCT, provide evidence-based recommendations for sexual rehabilitation and outline areas for future research. Wittmann D, Mehta A, McCaughan E, et al. Guidelines for Sexual Health Care for Prostate Cancer Patients: Recommendations of an International Panel. J Sex Med 2022;19:1655-1669.

Clinicopathological Significances of Positive Surgical Resection Margin after Radical Prostatectomy for Prostatic Cancers: A Meta-Analysis

Background and Objectives: This study aims to elucidate the positive rate and the clinicopathological significance of surgical margin after radical prostatectomy (RP) through a meta-analysis. Materials and Methods: This meta-analysis finally used 59 studies, including the information about the positive surgical margin (PSM) and those clinicopathological significances after RP. The subgroup analysis for the estimated rates of PSM was evaluated based on types of surgery, grade groups, and pathological tumor (pT) stages. We compared the clinicopathological correlations between positive and negative surgical margins (NSM). Results: The estimated PSM rate was 25.3% after RP (95% confidence interval [CI] 21.9-29.0%). The PSM rates were 26.0% (95% CI 21.5-31.1%) 28.0% (95% CI 20.2-37.5%) in robot-assisted RP and nerve-sparing RP, respectively. The PSM rate was significantly higher in high-grade groups than in low-grade groups. In addition, the higher pT stage subgroup had a high PSM rate compared to the lower pT stage subgroups. Patients with PSM showed significantly high PSA levels, frequent lymphovascular invasion, lymph node metastasis, and extraprostatic extension. Biochemical recurrences (BCRs) were 28.5% (95% CI 21.4-36.9%) and 11.8% (95% CI 8.1-16.9%) in PSM and NSM subgroups, respectively. Patients with PSM showed worse BCR-free survival than those with NSM (hazard ratio 2.368, 95% CI 2.043-2.744%). Conclusions: Our results showed that PSM was significantly correlated with worse clinicopathological characteristics and biochemical recurrence-free survival. Among the results in preoperative evaluations, grade group and tumor stage are useful for the prediction of PSM.

Impact of nerve sparing in robot-assisted radical prostatectomy on the risk of positive surgical margin and biochemical recurrence

OBJECTIVES

Nerve sparing may increase positive surgical margin rate during radical prostatectomy. Our objective was to analyze the positive surgical margin rate and location as well as its impact on biochemical recurrence according to nerve sparing procedure in robot-assisted radical prostatectomy.

METHODS

We included 814 patients treated with robot-assisted radical prostatectomy between 2009 and 2021, and evaluated the impact of nerve sparing on positive surgical margin and biochemical recurrence using logistic regression and Cox models.

RESULTS

Unilateral nerve sparing and bilateral nerve sparing were performed in 152 (18.6%) cases and 118 (14.5%) cases, respectively. On multivariable analysis, in addition to nerve sparing, bilateral nerve sparing, but not unilateral nerve sparing was associated with an increased risk of positive surgical margin compared with non-nerve sparing. Positive surgical margin at any location increased the risk of biochemical recurrence. During unilateral nerve sparing, positive surgical margin in nerve sparing side, but not in non-nerve sparing side was associated with increased risk of biochemical recurrence on multivariate analysis.

CONCLUSIONS

Taken together, surgeons need to notice an increased risk of biochemical recurrence associated with positive surgical margin when performing nerve sparing in robot-assisted radical prostatectomy, and then need to choose the patients suitable for nerve sparing.

Explainable artificial intelligence to predict the risk of side-specific extraprostatic extension in pre-prostatectomy patients

INTRODUCTION

We aimed to develop an explainable machine learning (ML) model to predict side-specific extraprostatic extension (ssEPE) to identify patients who can safely undergo nerve-sparing radical prostatectomy using preoperative clinicopathological variables.

METHODS

A retrospective sample of clinicopathological data from 900 prostatic lobes at our institution was used as the training cohort. Primary outcome was the presence of ssEPE. The baseline model for comparison had the highest performance out of current biopsy-derived predictive models for ssEPE. A separate logistic regression (LR) model was built using the same variables as the ML model. All models were externally validated using a testing cohort of 122 lobes from another institution. Models were assessed by area under receiver-operating-characteristic curve (AUROC), precision-recall curve (AUPRC), calibration, and decision curve analysis. Model predictions were explained using SHapley Additive exPlanations. This tool was deployed as a publicly available web application.

RESULTS

Incidence of ssEPE in the training and testing cohorts were 30.7 and 41.8%, respectively. The ML model achieved AUROC 0.81 (LR 0.78, baseline 0.74) and AUPRC 0.69 (LR 0.64, baseline 0.59) on the training cohort. On the testing cohort, the ML model achieved AUROC 0.81 (LR 0.76, baseline 0.75) and AUPRC 0.78 (LR 0.75, baseline 0.70). The ML model was explainable, well-calibrated, and achieved the highest net benefit for clinically relevant cutoffs of 10-30%.

CONCLUSIONS

We developed a user-friendly application that enables physicians without prior ML experience to assess ssEPE risk and understand factors driving these predictions to aid surgical planning and patient counselling (https://share.streamlit.io/jcckwong/ssepe/main/ssEPE_V2.py).

Importance of considering interest in sex when evaluating satisfaction after robot-assisted radical prostatectomy

OBJECTIVES

To assess the impact of patients' interest in sex on the satisfaction after robot-assisted radical prostatectomy, longitudinal changes of urinary and sexual functions and bothers were evaluated.

METHODS

A total of 101 patients underwent robot-assisted radical prostatectomy in our institution. Based on sexual interest, they were divided into the high-interest and low-interest groups. Overall satisfaction, urinary function, urinary bother, sexual function, and sexual bother were evaluated using the expanded prostate cancer index composite questionnaire preoperatively and at 1, 3, 6, and 12 months after robot-assisted radical prostatectomy. We investigated the associations between the overall satisfaction and urinary function/urinary bother/sexual function/sexual bother scores (with higher score indicating better function and less impairment).

RESULTS

In the high-interest group (n = 45), satisfaction correlated with high urinary function and urinary bother scores early after robot-assisted radical prostatectomy (urinary function: 1 and 3 months, urinary bother: 3 months postoperatively; P < 0.05) and then with high sexual bother score thereafter (sexual bother at 6 and 12 months after surgery; P < 0.05). Sexual function score did not correlate with satisfaction. In the low-interest group (n = 56), satisfaction correlated with high urinary function and urinary bother scores over time (urinary function: 3 and 6 months, urinary bother: at 3, 6 and 12 months postoperatively; P < 0.05). Neither sexual function nor sexual bother correlated with satisfaction postoperatively in the low-interest group.

CONCLUSIONS

The impact of urinary and sexual functions and bothers on patients' overall satisfaction differed between patients with high- and low-interest in sex. The patient's interest in sex should be considered when assessing satisfaction after robot-assisted radical prostatectomy.

Efficacy of Tadalafil in Penile Rehabilitation Started Before Nerve-Sparing Robot-Assisted Radical Prostatectomy: A Double-Blind Pilot Study

Background

Despite the widespread practice of nerve-sparing robot-assisted radical prostatectomy (nsRARP) for the treatment of localized prostate cancer (PCa), erectile dysfunction remains a significant sequela of radical prostatectomy.

Aim

This study aimed to compare the efficacy of tadalafil 5 mg once daily for erectile function recovery in patients who underwent nsRARP according to the timing of rehabilitation initiation.

Methods

In this double-blind, prospective pilot study, a total of 41 patients who underwent nsRARP were randomly assigned into 2 groups according to the timing of rehabilitation initiation. In the preRARP group (n = 20), tadalafil was started 2 weeks before nsRARP, and in the postRARP group (n = 21), it was started 4 weeks after nsRARP. Erectile function recovery after nsRARP was defined as an International Index of Erectile Function (IIEF-5) score of ≥17.

Outcomes

The measures of EF recovery were the changes in IIEF-5 score.

Results

The rate of erectile function recovery at 12-month follow-up was 80.0% and 71.4% in the preRARP and postRARP groups, respectively. The mean differences between baseline and postoperative IIEF-5 scores at 1-, 3-, 6-, and 12-month follow-up were −11.7 ± 3.2, −7.4 ± 3.2, −5.6 ± 1.5, and −4.1 ± 1.1 in the preRARP group and −14.7 ± 4.7, −12.0 ± 5.0, −9.7 ± 3.9, and −6.0 ± 3.1 in the postRARP group, respectively (1-month, P = .259; 3-months, P = .077; 6-months, P = .014; 12-months, P = .007).

Clinical implications

Preoperative tadalafil 5 mg once a day could be used effectively and safely as a strategy for penile rehabilitation after nsRARP.

Strengths and Limitations

This study is the first prospective trial of penile rehabilitation with tadalafil 5 mg once a day prior to nsRARP. This is a pilot study with the limitations of a small sample; further and large-scale studies with multiple cohorts, such as an untreated control group and an early immediate rehabilitation group for EF recovery, are needed.

Conclusion

This study suggests that preoperative penile rehabilitation using tadalafil may lead to better erectile function recovery than postoperative penile rehabilitation using tadalafil.

Noh T, Shim JS, Kang SG, et al. Efficacy of Tadalafil in Penile Rehabilitation Started Before Nerve-Sparing Robot-Assisted Radical Prostatectomy: A Double-Blind Pilot Study. Sex Med 2022;10:100508.

Concordance between Preoperative mpMRI and Pathological Stage and Its Influence on Nerve-Sparing Surgery in Patients with High-Risk Prostate Cancer

Background: We aimed to determine the concordance between the radiologic stage (rT), using multiparametric magnetic resonance imaging (mpMRI), and pathologic stage (pT) in patients with high-risk prostate cancer and its influence on nerve-sparing surgery compared to the use of the intraoperative frozen section technique (IFST). Methods: The concordance between rT and pT and the rates of nerve-sparing surgery and positive surgical margin were assessed for patients with high-risk prostate cancer who underwent radical prostatectomy. Results: The concordance between the rT and pT stages was shown in 66.4% (n = 77) of patients with clinical high-risk prostate cancer. The detection of patients with extraprostatic disease (≥pT3) by preoperative mpMRI showed a sensitivity, negative predictive value and accuracy of 65.1%, 51.7% and 67.5%. In addition to the suspicion of extraprostatic disease in mpMRI (≥rT3), 84.5% (n = 56) of patients with ≥rT3 underwent primary nerve-sparing surgery with IFST, resulting in 94.7% (n = 54) of men with at least unilateral nerve-sparing surgery after secondary resection with a positive surgical margin rate related to an IFST of 1.8% (n = 1). Conclusion: Patients with rT3 should not be immediately excluded from nerve-sparing surgery, as by using IFST some of these patients can safely undergo nerve-sparing surgery.

A multi-surgeon learning curve analysis of overall and site-specific positive surgical margins after RARP and implications for training

Robot-assisted radical prostatectomy (RARP) is the most adopted treatment for localized prostate cancer. The aim of this study was to explore the learning curves (LC) for overall and site-specific positive surgical margins (PSM) occurrence after RARP of multiple surgeons within a step-structured mentor-initiated training program. The study included consecutive patients undergoing RARP between January 2013 and March 2020, by three surgeons: a mentor and his two trainees. Prospectively collected patients' data were retrospectively analyzed. The cumulative summation (CUSUM) method was used to generate the LCs, with turning points indicating the number of cases to reach proficiency levels. Furthermore, the association between PSM and surgical experience was evaluated, adjusting for case mix. A total of 761 consecutive patients were included, 370 treated by the Mentor surgeon, 247 and 144 treated, respectively, by the two Trainees. Mentor and Trainees had similar PSM rates (31.6% vs 28.0% vs 31.3%, p = 0.6). CUSUM charts showed different LC shapes for different PSM locations (postero-lateral, bladder neck, apex, and multifocal/> 3 mm). Surgical experience was significantly associated with overall, postero-lateral, and multifocal/> 3 mm PSMs, in the Mentor series only. Trainees reached their turning points after far fewer cases then the Mentor, both for overall (12 and 31 vs 153), postero-lateral (24 and 30 vs 120), and multifocal/> 3 mm PSMs (9 and 31 vs 153). The achievement of stable SM proficiency takes involved different LCs depending on the prostatic location being considered. Monitoring site-specific LC can indicate the surgical steps for which there may be still room for further technical refinements, even when an apparent proficiency status seems achieved.

Longer preserved urethral length in robot‐assisted radical prostatectomy significantly contributes to post‐operative urinary continence recovery

Objectives

To assess the relationship between the surgical procedure of robot‐assisted radical prostatectomy (RARP) and urinary continence recovery by reviewing the video database.

Methods

Video and data about men diagnosed with prostate cancer and underwent RARP were extracted and reviewed. Preserved urethral length (PUL) was semi‐quantitatively measured using the lateral width of a 16‐Fr urethral balloon catheter while cutting the urethra on a video screen. In addition, by reviewing intraoperative RARP video database, other surgical skill outcomes were also collected. Kaplan–Meier analysis with log‐rank test was used to compare the urinary continence recovery rate, stratified by the PUL. Univariate and multivariate analyses were performed using the Cox proportional hazards model, and p‐values of <0.05 were considered significant.

Results

The number of patients included in this study was 213. In univariate analysis, a PUL of ≥16 mm, a body mass index of <23.1 kg/m² and a resected prostate volume of <44.3 g were statistically significant factors that influenced urinary continence recovery [hazard ratio (HR) 1.58, p = 0.036; HR 0.67, p = 0.021; and HR 0.58, p = 0.005, respectively]. Those factors also remained statistically significant in the multivariate analysis (HR 1.87, p = 0.022; HR 0.54, p = 0.001; and HR 0.57, p = 0.005, respectively). One year post‐operatively, the recovery rate from urinary continence was 79.0% for patients with a PUL of ≥16 mm and 66.5% for patients with a PUL of <16 mm.

Conclusion

These results suggest that patients with longer PUL in RARP have a significantly higher rate of post‐operative urinary continence recovery.

Selection of patients for nerve sparing surgery in robot‐assisted radical prostatectomy

Context

Robot‐assisted radical prostatectomy (RARP) has become the standard surgical procedure for localized prostate‐cancer (PCa). Nerve‐sparing surgery (NSS) during RARP has been associated with improved erectile function and continence rates after surgery. However, it remains unclear what are the most appropriate indications for NSS.

Objective

The objective of this study is to systematically review the available parameters for selection of patients for NSS. The weight of different clinical variables, multiparametric magnetic‐resonance‐imaging (mpMRI) findings, and the impact of multiparametric‐nomograms in the decision‐making process on (side‐specific) NSS were assessed.

Evidence acquisition

This systematic review searched relevant databases and included studies performed from January 2000 until December 2020 and recruited a total of 15 840 PCa patients. Studies were assessed that defined criteria for (side‐specific) NSS and associated them with oncological safety and/or functional outcomes. Risk of bias assessment was performed.

Evidence synthesis

Nineteen articles were eligible for full‐text review. NSS is primarily recommended in men with adequate erectile function, and with low‐risk of extracapsular extension (ECE) on the side‐of NSS. Separate clinical and radiological variables have low accuracy for predicting ECE, whereas nomograms optimize the risk‐stratification and decision‐making process to perform or to refrain from NSS when oncological safety (organ‐confined disease, PSM rates) and functional outcomes (erectile function and continence rates) were assessed.

Conclusions

Consensus exists that patients who are at high risk of ECE should refrain from NSS. Several multiparametric preoperative nomograms were developed to predict ECE with increased accuracy compared with single clinical, pathological, or radiological variables, but controversy exists on risk thresholds and decision rules on a conservative versus a less‐conservative surgical approach. An individual clinical judgment on the possibilities of NSS set against the risks of ECE is warranted.

Patient summary

NSS is aimed at sparing the nerves responsible for erection. NSS may lead to unfavorable tumor control if the risk of capsule penetration is high. Nomograms predicting extraprostatic tumor‐growth are probably most helpful.

Implementation of radioguided surgery in prostate cancer

With the development of new imaging technologies and tracers, the applications of radioguided surgery for prostate cancer are growing rapidly. The current paper aims to give an overview of the recent advances of radioguided surgery in the management of prostate cancer. We performed a literature search to give an overview of the current status of radioguided surgery for prostate cancer. Three modalities of radioguided surgery, the sentinel node procedure, Cerenkov Luminescence / beta-radio-guided surgery and radio-guided salvage surgery in recurrent prostate cancer, were reviewed in detail. Radioguided surgery for prostate cancer has shown promising value in the treatment of primary diagnosed prostate cancer and recurrent loco-regional lymph node positive prostate cancer. Advances have been made into minimal invasive (robot-assisted) laparoscopic surgery. The sentinel node procedure for prostate cancer has been further developed and is currently performed with high diagnostic sensitivity. Cerenkov luminescence imaging is a feasible and encouraging technique for intraoperative margin assessment in prostate cancer. Radioguided surgery in recurrent prostate cancer has shown to be feasible, yielding high sensitivity and specificity for detecting small local recurrences and metastases. With the availability of different new tracers, the road has been paved towards clinically feasible radioguided surgery for prostate cancer. Novel technologies now being developed for minimal invasive surgery are speeding up clinical research. Currently, none of the radioguided surgery techniques mentioned have been accepted as standard of care.

Impact of Nerve-Sparing Status on Positive Surgical Margin Location and Biochemical Recurrence in Patients with Prostate Cancer Post Radical Prostatectomy

PURPOSE

This study was designed to assess the relationship between nerve-sparing (NS) status, positive surgical margin (PSM) location, and biochemical recurrence (BCR) based on a multicenter, radical prostatectomy (RP) database.

METHODS

We retrospectively reviewed data from 726 patients who underwent RP without any neoadjuvant or adjuvant treatment between 2010 and 2014. We statistically assessed the impact of NS sides on PSM location and BCR.

RESULTS

PSM rates were 21.9% in the 726 patients studied, 13.2% in patients with ≤pT2, and 46.8% in patients with ≥pT3. Regarding PSM locations, the anterior-apex (AA) was the most common site for PSM (43.3%). After adjusting for confounding factors, bilateral nerve sparing (BNS) had a significantly higher odds ratio of PSM than the absence of NS did (odds ratio [OR] 3.04, 95% confidence interval [CI] 1.85-4.99). In the UNS RP in patients with ≤pT2, non-AA PSM on the non-NS side was significantly higher than that on the NS side (92.9% vs. 45.5%, p = 0.009). In all patients, 5.8% experienced BCR during a median follow-up of 43.5 months. PSM was significantly associated with BCR-free survival in patients with ≤pT2 (p = 0.013), but not in patients with ≥pT3 (p = 0.185). Non-AA PSM at the non-NS side was an independent risk factor for BCR (hazard ratio [HR] 2.56, 95% confidence interval [CI] 1.12-5.85), whereas AA PSMs, including NS/non-NS sides and non-AA PSM at the NS side, were not associated with BCR-free survival.

CONCLUSIONS

Avoidance of non-AA PSM on the non-NS side may be rather important for maintaining BCR-free survival after RP.

Domain adaptation for segmentation of critical structures for prostate cancer therapy

Preoperative assessment of the proximity of critical structures to the tumors is crucial in avoiding unnecessary damage during prostate cancer treatment. A patient-specific 3D anatomical model of those structures, namely the neurovascular bundles (NVB) and the external urethral sphincters (EUS), can enable physicians to perform such assessments intuitively. As a crucial step to generate a patient-specific anatomical model from preoperative MRI in a clinical routine, we propose a multi-class automatic segmentation based on an anisotropic convolutional network. Our specific challenge is to train the network model on a unique source dataset only available at a single clinical site and deploy it to another target site without sharing the original images or labels. As network models trained on data from a single source suffer from quality loss due to the domain shift, we propose a semi-supervised domain adaptation (DA) method to refine the model's performance in the target domain. Our DA method combines transfer learning and uncertainty guided self-learning based on deep ensembles. Experiments on the segmentation of the prostate, NVB, and EUS, show significant performance gain with the combination of those techniques compared to pure TL and the combination of TL with simple self-learning ([Formula: see text] for all structures using a Wilcoxon's signed-rank test). Results on a different task and data (Pancreas CT segmentation) demonstrate our method's generic application capabilities. Our method has the advantage that it does not require any further data from the source domain, unlike the majority of recent domain adaptation strategies. This makes our method suitable for clinical applications, where the sharing of patient data is restricted.

Artificial intelligence is a promising prospect for the detection of prostate cancer extracapsular extension with mpMRI: a two-center comparative study

PURPOSE

A balance between preserving urinary continence as well as sexual potency and achieving negative surgical margins is of clinical relevance while implementary difficulty. Accurate detection of extracapsular extension (ECE) of prostate cancer (PCa) is thus crucial for determining appropriate treatment options. We aimed to develop and validate an artificial intelligence (AI)-based tool for detecting ECE of PCa using multiparametric magnetic resonance imaging (mpMRI).

METHODS

Eight hundred and forty nine consecutive PCa patients who underwent mpMRI and prostatectomy without previous radio- or hormonal therapy from two medical centers were retrospectively included. The AI tool was built on a ResNeXt network embedded with a spatial attention map of experts' prior knowledge (PAGNet) from 596 training patients. Model validation was performed in 150 internal and 103 external patients. Performance comparison was made between AI, two experts using a criteria-based ECE grading system, and expert-AI interaction.

RESULTS

An index PAGNet model using a single-slice image yielded the highest areas under the receiver operating characteristic curve (AUC) of 0.857 (95% confidence interval [CI], 0.827-0.884), 0.807 (95% CI, 0.735-0.867), and 0.728 (95% CI, 0.631-0.811) in training, internal, and external validation data, respectively. The performance of two experts (AUC, 0.632 to 0.741 vs 0.715 to 0.857) was lower (paired comparison, all p values < 0.05) than that of AI assessment. When experts' interpretations were adjusted by AI assessments, the performance of two experts was improved.

CONCLUSION

Our AI tool, showing improved accuracy, offers a promising alternative to human experts for ECE staging using mpMRI.

Transvesical Retzius-Sparing Versus Standard Robot-Assisted Radical Prostatectomy: A Retrospective Propensity Score-Adjusted Analysis

Objectives

To estimate the safety and efficiency of transvesical Retzius-sparing robot-assisted radical prostatectomy (T-RARP) compared with standard robot-assisted radical prostatectomy (S-RARP) for localized prostate cancer (PCa).

Materials and Methods

174 patients bearing localized PCa and undergoing T-RARP or S-RARP between October 2017 and January 2020 were retrospectively enrolled in our analysis. All potential baseline confounders were strictly restrained with propensity-score matching (PM) method (1: 1). Within the matched setting, the perioperative and functional outcomes were compared between the T-RARP and S-RARP groups, while the oncological results and functional recovery of the two arms were presented with Kaplan-Meier curves.

Results

Finally, 114 and 60 eligible patients harbouring localized PCa were identified in the S-RARP and T-RARP group, respectively. No significant differences between the two groups were found in all baseline characteristics after PM. Within the matched cohort, no case was converted to open surgery in either group. The T-RARP group was significantly related to a higher mean operative time (p = 0.001) and shorter median hospital stay length (p < 0.001). There were not significant differences in the median estimated blood loss and specimen Gleason score between the two arms. The proportions of transfusion, pT3a disease, postoperative complication, and positive surgical margin in the T-RARP group were also comparable to that in the S-RARP group. The mean prostate-specific antigen and median erectile functional scores did not differ significantly between the two groups at postoperative 3 months and last follow-up. T-RARP vs. S-RARP had significantly improved urinary continence (UC) rates at the removal of catheter (p < 0.001) and postoperative 3 months (p < 0.001), but the significant difference between the two groups in UC recovery disappeared at last follow-up (p = 0.119). No significant difference in biochemical recurrence-free survival was observed following the two surgeries (p = 0.727).

Conclusions

T-RARP by experienced hands was feasible for selected patients with clinically localized PCa, yielding significantly improved early return to UC and similar erectile functional preservation without compromising oncological control when compared with the standard approach.

Transvesical Versus Posterior Approach to Retzius-Sparing Robot-Assisted Radical Prostatectomy: A Retrospective Comparison With a 12-Month Follow-Up

Objectives

To assess the perioperative, functional, and oncological outcomes of transvesical robot-assisted radical prostatectomy (T-RARP) and posterior robot-assisted radical prostatectomy (P-RARP) for localized prostate cancer.

Materials and Methods

We analyzed the data of 96 patients who underwent T-RARP or P-RARP for localized prostate cancer between January 2017 and June 2019 in a retrospective fashion.

Results

No significant differences in the baseline characteristics existed between the T-RARP and P-RARP arms. Both interventions were successfully performed without open conversion in either group. T-RARP was associated with a slightly more operative time (135.3 vs. 127.3 min) and estimated blood loss (105.2 vs. 94.2 mL) than P-RARP, but the differences were not significant (both p > 0.05). The likelihood of transfusion, ≤Grade II, and >Grade II postoperative complications, pT3a disease and positive surgical margins in the T-RARP group was comparable with that in the P-RARP group. No significant differences were noted between these two arms in terms of UC at the removal of catheter and nocturia (p = 0.750 and p = 0.684, respectively), and all included patients recovered UC at 3 months postoperatively. The median International Index of Erectile Function-5 score in both groups remains comparable before and after RARP. The patients in the T-RARP and P-RARP groups had a similar biochemical recurrence-free survival (p = 0.387).

Conclusions

Both T-RARP and P-RARP by experienced hands are feasible for well-selected patients with prostate cancer, obtaining similar outcomes in terms of perioperative results, UC and erectile function, and oncological control within short-term follow-up.

Preoperative multiparametric MRI does not lower positive surgical margin rate in a large series of patients undergoing robot-assisted radical prostatectomy

To optimize functional outcomes after robot-assisted radical prostatectomy (RARP), surgical preservation of the neurovascular bundle is desired. However, nerve-sparing surgery (NSS) is only feasible in the absence of extraprostatic tumour extension (T-stage 3) to avoid the risk of positive surgical margins (PSM). Multiparametric magnetic-resonance imaging (MRI) is increasingly performed for primary prostate cancer and provides information on local tumour stage. In this study, we evaluated whether the availability of information from MRI influenced the incidence of PSM. A total of 523 patients undergoing RARP for localized prostate cancer in a single Dutch reference centre for prostate-cancer surgery were retrospectively evaluated (2013-2017). Patient characteristics and postoperative outcomes were retrieved. Patients were stratified according to the presence of a preoperative MRI. The incidence of PSM and proportion of patients receiving NSS was analysed using Chi-square tests and logistic regression analysis. N = 139 of 523 (26.6%) patients had a preoperative MRI scan available. Patients with MRI had identical preoperative characteristics compared to the patients without MRI, except for a higher percentage of patients having a prostate-specific antigen value ≥ 20 ng/mL (20.1% versus 9.4%, p = 0.004). PSM were present in 107/384 (27.9%) patients without MRI compared to 36/139 (25.9%) patients with an MRI scan before surgery (p = 0.66). Unilateral NSS was performed more often in the MRI group (26.6% vs. 11.7%), but NSS on both sides was more frequently performed in patients without MRI (57.6% versus 69.8%) (p < 0.001). MRI was not associated with PSM in multivariate analysis (p = 0.265). Preoperative mpMRI imaging was not associated with lower rates of positive surgical margins in patients undergoing RARP for localized prostate cancer.

Neurolysis of the Dorsal Nerve to the Penis to Restore Function After Trauma

BACKGROUND

Loss of penile sensation or development of a painful penis and erectile dysfunction can occur after injury to the dorsal branch of the pudendal nerve. Although recovery of genital sensibility has been discussed frequently in transmen, this subject has been reported rarely in cismen. The purpose of this report is to review our experience with recovery of sensation in men after decompression of the dorsal branch of the pudendal nerve after trauma.

METHODS

A retrospective chart review of men who have had decompression of the dorsal branch of the pudendal nerve was carried out from 2014 to 2018. Patients were included in the cohort if they had a loss of penile sensation or the development of a painful penis after trauma. Primary outcomes measured were the change in penile symptoms, including erection, ejaculation, ejaculatory pain, erogenous sensation, numbness, and penile pain.

RESULTS

For the 7 men included in this study, the mean follow-up time was 57 weeks (range, 28-85 weeks). Bilateral surgery was done in 71% (5/7). Of the 6 patients with loss of penile sensation, complete recovery of erogenous sensibility occurred in 5 (83%) patients, with partial relief in 1 (17%) patient. Of the 3 men who had erectile dysfunction, normal erections were restored in 2 (67%) patients. Of the 2 patients unable to ejaculate, 1 (50%) patient regained ejaculatory function. Of the 4 patients with ejaculatory pain, complete relief of pain occurred in 2 (50%) patients, with partial relief in 2 (50%) patients. Of the 6 patients with penile pain in the absence of ejaculation, complete relief of pain occurred in 3 (50%) patients, with partial relief in 3 (50%) patients.

CONCLUSION

Neurolysis of the dorsal nerve to the penis at the inferior pubic ramus canal can be successful in relieving pain, and restoring sensation and erectile function in men who sustained an injury along the inferior pubic ramus.

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.

A systematic review of nerve-sparing surgery for high-risk prostate cancer

INTRODUCTION

We provide a systematic analysis of nerve-sparing surgery (NSS) to assess and summarize the risks and benefits of NSS in high-risk prostate cancer (PCa).

EVIDENCE ACQUISITION

We have undertaken a systematic search of original articles using 3 databases: Medline/PubMed, Scopus, and Web of Science. Original articles in English containing outcomes of nerve-sparing radical prostatectomy (RP) for high-risk PCa were included. The primary outcomes were oncological results: the rate of positive surgical margins and biochemical relapse. The secondary outcomes were functional results: erectile function (EF) and urinary continence.

EVIDENCE SYNTHESIS

The rate of positive surgical margins differed considerably, from zero to 47%. The majority of authors found no correlation between NSS and a positive surgical margin rate. The rate of biochemical relapse ranged from 9.3% to 61%. Most of the articles lacked data on odds ratio (OR) for positive margin and biochemical relapse. The presented results showed no effect of nerve sparing (NS) on positive margin (OR=0.81, 0.6-1.09) or biochemical relapse (hazard ratio [HR]=0.93, 0.52-1.64). A strong association between NSS and potency rate was observed. Without NSS, between 0% and 42% of patients were potent, with unilateral 79-80%, with bilateral - up to 90-100%. Urinary continence was not strongly associated with NSS and was relatively good in both patients with and without NSS.

CONCLUSIONS

NSS may provide benefits for patients with urinary continence and significantly improves EF in high-risk patients. Moreover, it is not associated with an increased risk of relapse in short- and middle-term follow-up. However, the advantages of using such a surgical technique are unclear.

Cavernous Branched Nerve Regeneration Using Non-Tubular Artificial Nerve Sheets Using Freeze-Dried Alginate Gel Combined With Polyglycolic Acid Mesh in a Rat Model

Introduction

Neuroprotection and neuroregeneration of cavernous nerve plexus by biological/bioengineering solutions may have the potential to maintain erectile function.

Aims

We evaluated the efficacy of a newly developed artificial nerve sheet using freeze-dried alginate (ALG) with polyglycolic acid (PGA) mesh in a rat model. Methods: Bilateral cavernous nerves of male rats were excised to make an approximately 2 mm gap. A piece of the sponge-like freeze-dried sheet created by covalent cross-linking of ALG gel combined with PGA mesh was placed over the gap to cover each stump without any neural anastomosis. We compared erectile functions in the ALG groups with those in the sham group and the bilateral nerve excision group (n = 12, each).

Main Outcome Measures

Main outcome measure was a rat model with cavernous nerve excision.

Results

All rats in the sham group had erection at 63 or 64 days, and mating behavior was confirmed in 10 rats (83.3%) of the sham group at 56 to 62 days. No erection and mating behavior was observed in the excision group. Ten of the 12 (83.3%) rats in the ALG group had a mating behavior and an erection, and the rates of erection and mating behavior were significantly higher in the ALG group than those in the excision group (P < .01, P < .01, respectively). Using a retrograde FluoroGold, the rate of FluoroGold positive pelvic ganglia proximal to the gap at 61 or 62 days was significantly higher in the ALG group than that in the excision group (P = .014).

Conclusion

The results of our animal study have demonstrated that simply filling the cavernous nerve gap using the non-tubular artificial nerve sheets made of ALG with PGA mesh restored erectile function after cavernous nerve excision.

Narita S, Obara T, Ishikawa N, et al. Cavernous Branched Nerve Regeneration Using Non-Tubular Artificial Nerve Sheets Using Freeze-Dried Alginate Gel Combined With Polyglycolic Acid Mesh in a Rat Model. Sex Med 2021;9:100308.

Extracapsular extension on multiparametric magnetic resonance imaging better predicts pT3 disease at radical prostatectomy compared to perineural invasion on biopsy

INTRODUCTION

Risk assessment for non-organ-confined prostate cancer (PCa) is important in the surgical planning for radical prostatectomy (RP). Perineural invasion (PNI) on prostate biopsy has been associated with adverse pathological outcomes at prostatectomy. Similarly, the identification of suspected extracapsular extension (ECE) on multiparametric magnetic resonance imaging (mpMRI) has been shown to predict non-organ-confined disease. However, no prior study has compared these factors in predicting adverse pathology at prostatectomy. We evaluated mpMRI ECE and prostate biopsy PNI on multivariable analysis to determine their ability to predict pathological stage at time of RP.

METHODS

We retrospectively investigated the prostatectomy database at our institution to identify men who underwent prostate biopsy with pre-biopsy mpMRI and subsequent RP from 2013-2017. Multivariable regression analysis was performed to compare the association of mpMRI ECE (mECE) and PNI on prostate biopsy on the likelihood of finding pT3 disease on pathology post-prostatectomy.

RESULTS

Of a total 454 RP between 2013 and 2017, 191 patients met our inclusion criteria. Stage pT2 and pT3+ were found in 120 (62.8%) and 71 (37.2%) patients, respectively. Patients with mECE had 4.84 cumulative odds of worse pathological stage on RP (p=0.045) compared to PNI on biopsy, which showed cumulative odds of 2.25 (p=0.048). When controlling only for those patients without PNI, mECE was still found to be a significant predictor of pT3 disease at RP (p=0.030); however, in patients without mECE, PNI was not significant (p=0.062).

CONCLUSIONS

While mECE and biopsy PNI were both associated with worse pathological stage on RP, mECE had significantly higher cumulative odds compared to PNI. The significant predictive ability of mECE adds further clinical value to the use of mpMRI in PCa management. While validation in a larger cohort is required, these factors have important clinical implications with regards to early diagnosis of advanced disease and surgical planning.