Pelvic magnetic resonance imaging parameters predict urinary incontinence after robot-assisted radical prostatectomy

Is early continence recovery related to the length of spared urethra? A prospective multicenter study comparing preoperative MRI and histologic specimen measurements after robotic radical prostatectomy

BACKGROUND

Urinary incontinence (UI) is a common complication after radical prostatectomy, significantly affecting patients' quality of life. This study aimed to correlate the length of preserved urethra in robotic radical prostatectomy (RALP) patients with short-term urinary continence rates within 90 days post-surgery.

METHODS

A prospective multicentric study enrolled 190 prostate adenocarcinoma patients undergoing RALP. Using preoperative magnetic resonance imaging (mpMRI), urethral length was measured from the external urethral sphincter to the bladder neck. After surgery, histological measurements of the removed urethra were compared to the preoperative mpMRI data. Patients were categorized into two groups at the three-month follow-up based on urinary continence assessed through Urodynamic Study (UDS): Group A (94 patients without UI) and Group B (96 patients with UI).

RESULTS

Results revealed a significant difference in mean UI recovery time (Group A: 12.35 days, SD: 3.09 vs. Group B: 93.86 days, SD: 34.8, p < 0.0001). A ROC curve identified a 16.5% cut-off value (p < 0.000, sensitivity 87.5%, specificity 91.8%). Both groups showed a significant negative correlation between preserved urethral percentage and UI recovery time (Group A: r -0.655, p < 0.0001; Group B: r -0.340, p: 0.017). Group A had an average of 21.52% preserved urethra, while Group B had 13.86% (p < 0.0001). At one-year follow-up, 93.2% overall patients reported urinary continence without pads.

CONCLUSIONS

This study emphasizes the positive correlation between preserved urethra percentage in RALP and early urinary continence recovery, highlighting its surgical significance.

Membranous urethral length and urinary incontinence following robot-assisted radical prostatectomy: a systematic review and meta-analysis

OBJECTIVE

To provide an update on the association between preoperative membranous urethral length (MUL) and postoperative urinary incontinence (UI) in men who undergo robot-assisted radical prostatectomy (RARP)/robot-assisted laparoscopic prostatectomy (RALP).

MATERIALS AND METHODS

Urinary incontinence is common after RARP/RALP, and early recovery of continence is one of the most important functional outcomes following surgery. MUL has been identified as a factor associated with continence recovery after RARP/RALP. A systematic review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, using PubMed, Embase, and Scopus databases. Inclusion criteria were English language full journal articles authored within the last 5 years that assessed continence using the Expanded Prostate Cancer Index Composite. The Critical Appraisal Skills Programme tool for retrospective cohort studies was used to evaluate study quality. A random-effects meta-analysis was performed to pool odds ratios (ORs) from available studies relating to continence as a function of MUL. The Grading of Recommendations, Assessment, Development and Evaluations framework was used to synthesise evidence.

RESULTS

Six studies including 970 patients reported an association between MUL and continence at 12 months. Longer MUL was associated with reduced UI odds at 12 months after surgery (pooled OR 0.74, 95% confidence interval 0.68-0.87, P < 0.001). Significant methodological and statistical heterogeneity was encountered.

CONCLUSIONS

Preoperative MUL measured on magnetic resonance imaging (MRI) is significantly associated with postoperative continence in men undergoing RARP/RALP. We recommend consideration of MRI measurement of MUL prior to RARP/RALP to guide treatment decisions in this population.

Membranous urethral length measurement on preoperative MRI to predict incontinence after radical prostatectomy: a literature review towards a proposal for measurement standardization

OBJECTIVES

To investigate the membranous urethral length (MUL) measurement and its interobserver agreement, and propose literature-based recommendations to standardize MUL measurement for increasing interobserver agreement. MUL measurements based on prostate MRI scans, for urinary incontinence risk assessment before radical prostatectomy (RP), may influence treatment decision-making in men with localised prostate cancer. Before implementation in clinical practise, MRI-based MUL measurements need standardization to improve observer agreement.

METHODS

Online libraries were searched up to August 5, 2022, on MUL measurements. Two reviewers performed article selection and critical appraisal. Papers reporting on preoperative MUL measurements and urinary continence correlation were selected. Extracted information included measuring procedures, MRI sequences, population mean/median values, and observer agreement.

RESULTS

Fifty papers were included. Studies that specified the MRI sequence used T2-weighted images and used either coronal images (n = 13), sagittal images (n = 18), or both (n = 12) for MUL measurements. 'Prostatic apex' was the most common description of the proximal membranous urethra landmark and 'level/entry of the urethra into the penile bulb' was the most common description of the distal landmark. Population mean (median) MUL value range was 10.4-17.1 mm (7.3-17.3 mm), suggesting either population or measurement differences. Detailed measurement technique descriptions for reproducibility were lacking. Recommendations on MRI-based MUL measurement were formulated by using anatomical landmarks and detailed descriptions and illustrations.

CONCLUSIONS

In order to improve on measurement variability, a literature-based measuring method of the MUL was proposed, supported by several illustrative case studies, in an attempt to standardize MRI-based MUL measurements for appropriate urinary incontinence risk preoperatively.

CLINICAL RELEVANCE STATEMENT

Implementation of MUL measurements into clinical practise for personalized post-prostatectomy continence prediction is hampered by lack of standardization and suboptimal interobserver agreement. Our proposed standardized MUL measurement aims to facilitate standardization and to improve the interobserver agreement.

KEY POINTS

• Variable approaches for membranous urethral length measurement are being used, without detailed description and with substantial differences in length of the membranous urethra, hampering standardization. • Limited interobserver agreement for membranous urethral length measurement was observed in several studies, while preoperative incontinence risk assessment necessitates high interobserver agreement. • Literature-based recommendations are proposed to standardize MRI-based membranous urethral length measurement for increasing interobserver agreement and improving preoperative incontinence risk assessment, using anatomical landmarks on sagittal T2-weighted images.

Automated pelvic MRI measurements associated with urinary incontinence for prostate cancer patients undergoing radical prostatectomy

BACKGROUND

Pelvic morphological parameters on magnetic resonance imaging (MRI), such as the membranous urethral length (MUL), can predict urinary incontinence after radical prostatectomy but are prone to interobserver disagreement. Our objective was to improve interobserver agreement among radiologists in measuring pelvic parameters using deep learning (DL)-based segmentation of pelvic structures on MRI scans.

METHODS

Preoperative MRI was collected from 167 prostate cancer patients undergoing radical prostatectomy within our regional multicentric cohort. Two DL networks (nnU-Net) were trained on coronal and sagittal scans and evaluated on a test cohort using an 80/20% train-test split. Pelvic parameters were manually measured by three abdominal radiologists on raw MRI images and with the use of DL-generated segmentations. Automated measurements were also performed for the pelvic parameters. Interobserver agreement was evaluated using the intraclass correlation coefficient (ICC) and the Bland-Altman plot.

RESULTS

The DL models achieved median Dice similarity coefficient (DSC) values of 0.85-0.97 for coronal structures and 0.87-0.98 for sagittal structures. When radiologists used DL-generated segmentations of pelvic structures, the interobserver agreement for sagittal MUL improved from 0.64 (95% confidence interval 0.28-0.83) to 0.91 (95% CI 0.84-0.95). Furthermore, there was an increase in ICC values for the obturator internus muscle from 0.74 (95% CI 0.42-0.87) to 0.86 (95% CI 0.75-0.92) and for the levator ani muscle from 0.40 (95% CI 0.05-0.66) to 0.61 (95% CI 0.31-0.78).

CONCLUSIONS

DL-based automated segmentation of pelvic structures improved interobserver agreement in measuring pelvic parameters on preoperative MRI scans.

RELEVANCE STATEMENT

The implementation of deep learning segmentations allows for more consistent measurements of pelvic parameters by radiologists. Standardized measurements are crucial for incorporating these parameters into urinary continence prediction models.

KEY POINTS

• DL-generated segmentations improve interobserver agreement for pelvic measurements among radiologists. • Membranous urethral length measurement improved from substantial to almost perfect agreement. • Artificial intelligence enhances objective pelvic parameter assessment for continence prediction models.

An artificial intelligence method for predicting postoperative urinary incontinence based on multiple anatomic parameters of MRI

Background

Deep learning methods are increasingly applied in the medical field; however, their lack of interpretability remains a challenge. Captum is a tool that can be used to interpret neural network models by computing feature importance weights. Although Captum is an interpretable model, it is rarely used to study medical problems, and there is a scarcity of data regarding MRI anatomical measurements for patients with prostate cancer after undergoing Robotic-Assisted Radical Prostatectomy (RARP). Consequently, predictive models for continence that use multiple types of anatomical MRI measurements are limited.

Methods

We explored the energy efficiency of deep learning models for predicting continence by analyzing MRI measurements. We analyzed and compared various statistical models and provided reference examples for the clinical application of interpretable deep-learning models. Patients who underwent RARP at our institution between July 2019 and December 2020 were included in this study. A series of clinical MRI anatomical measurements from these patients was used to discover continence features, and their impact on continence was primarily evaluated using a series of statistical methods and computational models.

Results

Age and six other anatomical measurements were identified as the top seven features of continence by the proposed model UINet7 with an accuracy of 0.97, and the first four of these features were also found by primary statistical analysis.

Conclusions

This study fills the gaps in the in-depth investigation of continence features after RARP due to the limitations of clinical data and applicable models. We provide a pioneering example of the application of deep-learning models to clinical problems. The interpretability analysis of deep learning models has the potential for clinical applications.

Combination of deep learning and ensemble machine learning using intraoperative video images strongly predicts recovery of urinary continence after robot-assisted radical prostatectomy

BACKGROUND

We recently reported the importance of deep learning (DL) of pelvic magnetic resonance imaging in predicting the degree of urinary incontinence (UI) following robot-assisted radical prostatectomy (RARP). However, our results were limited because the prediction accuracy was approximately 70%.

AIM

To develop a more precise prediction model that can inform patients about UI recovery post-RARP surgery using a DL model based on intraoperative video images.

METHODS AND RESULTS

The study cohort comprised of 101 patients with localized prostate cancer undergoing RARP. Three snapshots from intraoperative video recordings showing the pelvic cavity (prior to bladder neck incision, immediately following prostate removal, and after vesicourethral anastomosis) were evaluated, including pre- and intraoperative parameters. We evaluated the DL model plus simple or ensemble machine learning (ML), and the area under the receiver operating characteristic curve (AUC) was analyzed through sensitivity and specificity. Of 101, 64 and 37 patients demonstrated "early continence (using 0 or 1 safety pad at 3 months post-RARP)" and "late continence (others)," respectively, at 3 months postoperatively. The combination of DL and simple ML using intraoperative video snapshots with clinicopathological parameters had a notably high performance (AUC, 0.683-0.749) to predict early recovery from UI after surgery. Furthermore, combining DL with ensemble artificial neural network using intraoperative video snapshots had the highest performance (AUC, 0.882; sensitivity, 92.2%; specificity, 78.4%; overall accuracy, 85.3%) to predict early recovery from post-RARP incontinence, with similar results by internal validation. The addition of clinicopathological parameters showed no additive effects for each analysis using DL, EL and simple ML.

CONCLUSION

Our findings suggest that the DL algorithm with intraoperative video imaging is a reliable method for informing patients about the severity of their recovery from UI after RARP, although it is not clear if our methods are reproducible for predicting long-term UI and pad-free continence.

Predictors of Long-Term Urinary Incontinence After Robot-Assisted Laparoscopic Prostatectomy

Introduction

Urinary incontinence is a major complication after radical prostatectomy. We analyzed the predictors of urinary incontinence after robot-assisted radical prostatectomy.

Material and Methods

One hundred twenty-one patients, whose urinary continence status was evaluable at 3 months, 6 months, and 12 months after robot-assisted radical prostatectomy, were included from October 2016 to September 2021. Data were retrospectively collected from electronic medical records. The continence status was evaluated by interviewing the patients about the number of urinary pads used per day. We compared the patients' age, body mass index, prostate volume, membranous urethral length on preoperative magnetic resonance imaging, surgeon experience, and pathological findings between patients with and without regained continence at 12 months after robot-assisted radical prostatectomy.

Results

The urinary continence rates were 30%, 57.8% and 79.3% at 3 months, 6 months, and 12 months, respectively, after robot-assisted radical prostatectomy. Twelve months after robot-assisted radical prostatectomy, 96 patients had regained continence and did not require urinary pads, whereas 25 patients had persistent urinary incontinence and required urinary pads. Membranous urethral length and surgeon experience were significantly different between patients with and without regained continence at 12 months after robot-assisted radical prostatectomy (P=0.05). However, no significant differences existed in age, body mass index, prostate volume, and pathological findings between patients with and without regained continence at 12 months after robot-assisted radical prostatectomy.

Conclusion

Membranous urethral length and surgeon experience are predictors of urinary incontinence after robot-assisted radical prostatectomy. Measuring the membranous urethral length is recommended before performing the operation.

Inter-observer variability in male pelvic-floor MRI measurements that might predict post-prostatectomy incontinence

INTRODUCTION

Current studies are focusing on the relationship between anatomical variables in preoperative prostate MRI and the development of post-prostatectomy incontinence (PPI). Nevertheless, there is little evidence regarding the reliability of these measurements. The objective of this study was to analyze the concordance between urologists and radiologists for anatomical measurements that might be PPI predictors.

MATERIAL AND METHODS

Pelvic floor measurements with 3T-MRI were performed by two radiologists and two urologists independently and blindly. Interobserver agreement was determined using the intraclass correlation coefficient (ICC) and the Bland-Altman plot.

RESULTS

The concordance was good-acceptable for most measurements, except for the levator ani and puborectalis muscle thickness (some ICC values  < 0.20/p value > 0.05). The anatomical parameters with the highest degree of agreement were intravesical prostatic protrusion (IPP) and prostate volume (most of the ICC values > 0.60). The membranous urethral length (MUL) and the angle of the membranous urethra-prostate axis (aLUMP) presented ICC > 0.40. The obturator internus muscle thickness (OIT), urethral width and intraprostatic urethral length presented a fair-moderate degree of agreement (ICC > 0.20). Regarding the agreement between different specialists, the highest degree was obtained for the two radiologists and for urologist 1-radiologist 2 (moderate median agreement), while urologist 2 with each of the radiologists had a regular median agreement.

CONCLUSIONS

MUL, IPP, prostate volume, aLUMP, OIT, urethral width and prostatic length show acceptable inter-observer concordance and they would be reliable as possible predictors of PPI. Levator ani and puborectalis muscle thickness show bad agreement. Interobserver agreement might not be greatly influenced by previous professional experience.

Value of Different Magnetic Resonance Imaging-based Measurements of Anatomical Structures on Preoperative Prostate Imaging in Predicting Urinary Continence After Radical Prostatectomy in Men with Prostate Cancer: A Systematic Review and Meta-analysis

CONTEXT

Measurements of anatomical structures on preoperative prostate magnetic resonance imaging (MRI) are used in risk models for treatment decisions to predict urinary continence (UC) following radical prostatectomy (RP). However, the association between these parameters and UC is unclear.

OBJECTIVE

To systematically summarize the literature on prognostic preoperative prostate MRI measurements of (peri)prostatic structures in relation to time to recovery of postoperative UC in men with prostate cancer.

EVIDENCE ACQUISITION

Online libraries were searched up to August 27, 2021. Article selection and critical appraisal were performed by two reviewers. All papers reporting on preoperative MRI measurements with UC correlation in univariable or multivariable analyses were included.

EVIDENCE SYNTHESIS

In the 50 studies included (mostly retrospective), 57 MRI parameters were evaluated. The pooled analyses showed that greater membranous urethra length (MUL) was prognostic for regaining UC at 1 mo (odds ratio [OR] 1.15, 95% confidence interval [CI] 1.10-1.21), 3 mo (OR 1.23, 95% CI 1.16-1.31), 6 mo (OR 1.16, 95% CI 1.08-1.25), and 12 mo (OR 1.19, 95% CI 1.10-1.29). Several other anatomical structures showed at least in one study a significant correlation with later return to UC: four prostate-related parameters (greater depth, apical protrusion, larger intravesical protrusion, small dorsal vascular complex), five urethra-related parameters (thicker wall, severe fibrosis, smaller volume, larger preoperative angle between the prostate axis and membranous urethra, shorter minimal residual MUL), and six musculoskeletal-related parameters (lower perfusion ratio, thinner levator ani muscle, larger inner or outer levator distance, shorter pelvic diaphragm length, and larger midpelvic area).

CONCLUSIONS

Greater MUL as measured on preoperative MRI was an independent prognostic factor for return to UC within 1 mo after RP and remained prognostic at 12 mo. Other anatomical structures may potentially be predictive, but these would need to be substantiated in prospective trials before being adopted in postoperative UC risk models for treatment decisions in men with prostate cancer.

PATIENT SUMMARY

We summarized study data on the relation between measurements of anatomical structures on preoperative magnetic resonance imaging scans and urinary continence after removal of the prostate. Greater length of one part of the urethra (membranous urethra) is associated with faster return to continence. Other anatomical structures have potential for predicting postoperative continence, but need further investigation.

The key role of levator ani thickness for early urinary continence recovery in patients undergoing robot-assisted radical prostatectomy: A multi-institutional study

BACKGROUND

Urinary continence (UC) recovery dramatically affects quality of life after robot-assisted radical prostatectomy (RARP). Membranous urethral length (MUL) has been the most studied anatomical variable associated with UC recovery.

OBJECTIVE

To investigate whether levator ani thickness (LAT), assessed with multi-parametric magnetic resonance imaging (mpMRI), correlates with UC recovery after RARP.

DESIGN, SETTING, AND PARTICIPANTS

The study included 209 patients treated with RARP by expert surgeons with extensive robotic experience from 2017 to 2019. All patients had complete, clinical, mpMRI, pathological, and postoperative data including pelvic floor muscle training (PFMT) protocols.

INTERVENTION

After a radiologist-specific training, two urologists independently examined the files, blinded to clinical and pathological findings as well as to postoperative continence status.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

On mpMRI, LAT, bladder neck (BN) shape, MUL, and apex overlapping (AO) were measured. UC recovery was defined as use of 0 or 1 safety pad at follow-up. Multivariable models were used to assess the association between variables and UC recovery.

RESULTS AND LIMITATIONS

Overall, 173 (82.8%) patients were continent after a median follow-up of 23 months (interquartile range [IQR]: 17-28). Of these, 98 (46.9%) recovered within 3 months after surgery, 42 (20.1%) from 3 to 6 months, and 33 (15.8%) from 6 months onwards. A significant higher rate of patients with LAT > 10 mm (88.1 vs.75.8%; p = 0.03) experienced UC recovery, compared to those with LAT < 10 mm. This difference was observed in the first 3 months after surgery. At multivariable analysis, LAT (odds ratio [OR]: 1.18, 95% confidence interval [CI]: 1.02-1.37; p = 0.02), Preoperative ICIQ score (OR: 0.91, 95% CI: 0.82-0.98, p = 0.03) and PFMT (OR: 1.98, 95% CI: 1.01-3.93; p = 0.04) independently predict higher UC recovery within 3 months, after accounting for age, BMI, preoperative PSA, D'Amico risk group, MUL, BN shape and AO.

CONCLUSIONS

LAT greater than 1 cm was associated with greater UC recovery. Specifically, LAT greater than 1 cm seems to be associated with higher UC rate at 3 months after RARP, compared to those with LAT < 1 cm.

PATIENT SUMMARY

Magnetic resonance features can help in predicting the risk of incontinence after robot-assisted radical prostatectomy and should be taken into account when counseling patients before surgery.

The performance and optimum cutoff value for pelvic cavity index as a predictor of early continence after extraperitoneal single-port robotic radical prostatectomy: Role of pelvic anatomical characteristics

PURPOSE

To assess the value of pelvic cavity index (PCI), as an objective pelvimetry feature, to predict operative time, margin status and early urine continence after extraperitoneal single-port robotic radical prostatectomy (RP). We sought to define an optimal cutoff point for PCI in predicting postoperative outcomes.

METHODS

Data on 94 patients who underwent extraperitoneal single-port robotic RP and had preoperative cross-sectional imaging were enrolled. PCI was calculated as (Pelvic inlet diameter×Pelvic outlet diameter)/(Pelvic depth). The predictive value of PCI on operative time, surgical margin status and 3-month urinary continence recovery was assessed using regression models. To report the optimum cutoff value, on ROC analysis, we calculated the performance of PCI cutoff points ranging from 5.56 to 10.80 cm by every 0.01 increment.

RESULTS

No significant associations were noted between clinical characteristics (including PCI) and operative time. Similarly, other than pathological stage, no clinical variables (including PCI) were predictive of positive surgical margin. However, a higher PCI was associated with a significantly higher rates of continence 3-month after surgery (OR 2.44 (1.75 - 5.33); p= 0.01). On ROC- analysis, a PCI cutoff value=8.21 cm yielded the best accuracy (AUC= 0.733, %95 CI 0.615-0.851; p=0.001). No association was noted between variables and 6-month continence rate.

CONCLUSION

Using a single-port robotic system, operative time, positive surgical margin rate and long-term continence after prostatectomy would be independent of bony pelvis cavity. However, a higher PCI is associated with a higher rate of early continence after the surgery. PCI at a cutoff of 8.21 cm has the optimum performance to predict postoperative urine continence recovery. If validated, this information may be helpful regarding patient counseling before single-port robotic RP.

Evaluation of the effect of levator ani muscle contraction on post-prostatectomy urinary incontinence using cine MRI

AIM

Post-prostatectomy urinary incontinence (PPI) is the greatest concern for urologists after radical prostatectomy (RP). It is thought that PPI is composed of multiple factors including static and dynamic components. The purpose of this study is to show visually levator ani muscle (LAM) contraction during pelvic floor muscle contraction and to evaluate the dynamic differences in its contraction between men with and without PPI.

METHODS

This study was a case-control study of the urinary continent or incontinent men. It investigated whether LAM contraction was involved in urinary leakage based on examination of LAM contraction by cine magnetic resonance imaging.

RESULTS

The LAM contracted from the coccyx to the pubis in the same manner before and after surgery. The degree of contraction of the LAM in post-prostatectomy groups was smaller than that in the healthy adult group. The contraction distances of each part of the pelvic floor were decreased by 50%-70% in the incontinence group compared to those in the continence group. The bladder neck moved 2.5-fold further in the continence group and the direction of movement was more vertical than in the incontinence group. Urethral compression was attenuated by about 40% in the incontinence group compared to that in the continence group.

CONCLUSIONS

RP can cause damage to the LAM. LAM contraction is reduced after RP compared with that in healthy adult men. In men with PPI, the reduced muscle contraction might not compress the urethra sufficiently when abdominal pressure is raised. Pelvic floor muscle training might provide a meaningful method for the recovery of LAM contraction in patients with PPI.

Myosteatosis as a novel predictor of urinary incontinence after robot-assisted radical prostatectomy

OBJECTIVES

To evaluate the impact of sarcopenia and myosteatosis on urinary incontinence after prostatectomy.

METHODS

We retrospectively reviewed consecutive patients who underwent robot-assisted radical prostatectomy without nerve sparing between December 2012 and March 2019. Psoas muscle index and average total psoas density, which were measured on preoperative computed tomography images at level L3, were used to evaluate sarcopenia and myosteatosis, respectively. In addition, several magnetic resonance imaging variables associated with pelvic muscles, the urethra and the prostate were measured. Urinary continence was defined as non-use or use of just one incontinence pad per day. Logistic regression analyses aimed to identify the predictors of urinary incontinence 3 and 12 months after surgery.

RESULTS

Overall, 121 patients were included in the analysis. The incidence rates of urinary incontinence 3 and 12 months after surgery were 42% (51/121 cases) and 16% (19/121 cases), respectively. Logistic multivariable analysis showed that low average total psoas density was the only significant independent predictor of urinary incontinence 3 months after surgery (P < 0.01), and low obturator internus muscle thickness (P = 0.01), short membranous urethral length (P = 0.01) and low average total psoas density (P < 0.01) were significant independent predictors of urinary incontinence 12 months after surgery. By contrast, psoas muscle index was not statistically associated with urinary incontinence after surgery.

CONCLUSIONS

Myosteatosis (low average total psoas density) could be a novel predictor of urinary incontinence after robot-assisted radical prostatectomy.

Evaluation of image-based prognostic parameters of post-prostatectomy urinary incontinence: A literature review

Prostate cancer is the second most common male cancer, and radical prostatectomy is a highly effective treatment for intermediate and high-risk disease. However, post-prostatectomy urinary incontinence remains a major functional side-effect in patients undergoing radical prostatectomy. Despite recent improvements in preoperative imaging quality and surgical techniques, it remains challenging to predict or prevent occurrence of this complication. The aim of this research was to review the current published literature on pre- and postoperative imaging evaluation of the prostate and pelvic structures, to identify added value in the prediction of post-prostatectomy urinary incontinence. A computerized bibliographic search of the PubMed library was carried out to identify imaging-based articles evaluating the pelvic floor and surrounding structures pre- and/or postradical prostatectomy to predict post-prostatectomy urinary incontinence. A total of 32 articles were included. Of these, 29 papers assessed the importance of magnetic resonance imaging evaluation, with a total of 16 parameters evaluated. The most common parameters were intravesical protrusion, the membranous urethral length, prostatic volume and periurethral fibrosis. Preoperative membranous urethral length and its preservation after surgery showed the strongest correlation with urinary incontinence. Three studies evaluated ultrasound, with all carried out postoperatively. This technique benefits from a dynamic evaluation, and the results are promising for proximal urethral hypermobility and the degree of bladder neck funneling on the Valsalva maneuver. Several imaging studies evaluated the predictors of post-prostatectomy urinary incontinence, with preoperative membranous urethral length offering the most promise. However, the current literature is limited by the single-center nature of studies, and the heterogeneity in patient populations and methodologies used.

Patient- and Tumour-related Prognostic Factors for Urinary Incontinence After Radical Prostatectomy for Nonmetastatic Prostate Cancer: A Systematic Review and Meta-analysis

CONTEXT

While urinary incontinence (UI) commonly occurs after radical prostatectomy (RP), it is unclear what factors increase the risk of UI development.

OBJECTIVE

To perform a systematic review of patient- and tumour-related prognostic factors for post-RP UI. The primary outcome was UI within 3 mo after RP. Secondary outcomes included UI at 3-12 mo and ≥12 mo after RP.

EVIDENCE ACQUISITION

Databases including Medline, EMBASE, and CENTRAL were searched between January 1990 and May 2020. All studies reporting patient- and tumour-related prognostic factors in univariable or multivariable analyses were included. Surgical factors were excluded. Risk of bias (RoB) and confounding assessments were performed using the Quality In Prognosis Studies (QUIPS) tool. Random-effects meta-analyses were performed for all prognostic factor, where possible.

EVIDENCE SYNTHESIS

A total of 119 studies (5 randomised controlled trials, 24 prospective, 88 retrospective, and 2 case-control studies) with 131 379 patients were included. RoB was high for study participation and confounding; moderate to high for statistical analysis, study attrition, and prognostic factor measurement; and low for outcome measurements. Significant prognostic factors for postoperative UI within 3 mo after RP were age (odds ratio [OR] per yearly increase 1.04, 95% confidence interval [CI] 1.03-1.05), membranous urethral length (MUL; OR per 1-mm increase 0.81, 95% CI 0.74-0.88), prostate volume (PV; OR per 1-ml increase 1.005, 95% CI 1.000-1.011), and Charlson comorbidity index (CCI; OR 1.28, 95% CI 1.09-1.50).

CONCLUSIONS

Increasing age, shorter MUL, greater PV, and higher CCI are independent prognostic factors for UI within 3 mo after RP, with all except CCI remaining prognostic at 3-12 mo.

PATIENT SUMMARY

We reviewed the literature to identify patient and disease factors associated with urinary incontinence after surgery for prostate cancer. We found increasing age, larger prostate volume, shorter length of a section of the urethra (membranous urethra), and lower fitness were associated with worse urinary incontinence for the first 3 mo after surgery, with all except lower fitness remaining predictive at 3-12 mo.

Anatomical predictors of long-term urinary incontinence after robot-assisted laparoscopic prostatectomy: A systematic review

AIMS

There is scarce evidence of anatomical risk factors that might affect long-term post-prostatectomy incontinence (PPI) in patients undergoing robot-assisted laparoscopic prostatectomy (RALP). This systematic review aims to identify anatomical measurements in preoperative magnetic resonance imaging (MRI) that might be associated with increased risk of urinary incontinence (UI) 1 year after RALP.

METHODS

A comprehensive search on Pubmed and Scopus databases up to November 2020 was performed. Eight articles met the inclusion criteria and were finally selected.

RESULTS

The selected studies included 1146 patients. Seven articles focused on membranous urethral length (MUL); all of them related MUL to long-term PPI in univariate analysis and five of them in multivariate analysis. Four studies presented MUL difference to measure the magnitude of the effect. Average MUL (mm) was 15.9 (SD, 2.6), 16.1 (95% confidence interval [CI]: 13.9-18.9), 12.1 (95% CI 9.7-14.9) and 14.5 in continent patients and 13.9 (SD, 2.9), 10 (95% CI: 8.7-12.1), 10.3 (95% CI: 8.7-12.4) and 9.3 in incontinent patients, with statistically significant differences in all cases. Five studies presented the odds ratio as a result; although there was substantial heterogeneity in the methods used to obtain it, there was consistency in finding an inverse association between MUL and PPI. Other measurements including prostatic-urethral angle, membranous urethral thickness, intraprostatic urethral length and intravesical prostatic protrusion have been reported in few studies, and no association with long-term PPI was found. Levator ani muscle thickness was related to long-term PPI in one article.

CONCLUSION

Greater MUL on preoperative MRI is associated with lower risk of UI 1 year after RALP.

A second opinion pathology review improves the diagnostic concordance between prostate cancer biopsy and radical prostatectomy specimens

Objectives:

The Gleason scoring system is an essential tool for determining the treatment strategy in prostate cancer (PCa). However, the Gleason grade group (GGG) often differs between needle-core biopsy (NCB) and radical prostatectomy (RP) specimens. We investigated the diagnostic value of a second opinion pathology review using NCB specimens in PCa.

Materials and Methods:

We retrospectively evaluated 882 patients who underwent robot-assisted RP from January 2012 to September 2019. Of these, patients whose original biopsy specimens were obtained from another hospital and reviewed by the urological pathology expert at our institution were included in the study. Patients who received neoadjuvant hormonal therapy were excluded from the study. Weighted kappa (k) coefficients were used to evaluate the diagnostic accuracy of each review.

Results:

A total of 497 patients were included in this study. Substantial agreement (weighted k = 0.783) in the GGG between initial- and second-opinion diagnoses based on NCB specimens was observed in 310 cases (62.4%). Although diagnoses based on a single opinion showed moderate agreement with the GGG of RP specimens (initial: 35.2%, weighted k = 0.522; second opinion; 38.8%, weighted k = 0.560), matching initial and second opinion diagnoses improved the concordance (42.9%, 133/310 cases) to substantial agreement (weighted k = 0.626).

Conclusions:

A second opinion of PCa pathology helps to improve the diagnostic accuracy of NCB specimens. However, over half of diagnoses that matched between the initial and second opinions differed from the diagnosis of RP specimens.

The value of magnetic resonance imaging geometric parameters in pre-assessing the surgical approaches of pelvic fracture urethral injury

Background

To investigate the correlation between the magnetic resonance urethrography and the surgical approach and complexity for the patients with pelvic fracture urethral injury (PFUI) by combining the geometry with magnetic resonance imaging (MRI).

Methods

Forty-three male patients with PFUI (part of the patients complicated with rectal injury) from January 2016 to December 2018 were analyzed in this retrospective research. All the patients underwent a delayed anastomotic urethroplasty and were divided into 2 groups according to the approaches (simple perineal approach or inferior pubectomy). For magnetic resonance urethrography, we measured and calculated the geometric parameters such as the gap distance between two urethral ends, the pubourethral vertical distance (PUVD), and the rectourethral median distance (RUMD).

Results

Of the 43 patients, 16 underwent inferior pubectomy and 27 underwent simple perineal approach. The numbers of patients with and without rectal injury history were 17 and 26, respectively. The operation time and intraoperative blood loss was significantly higher in the inferior pubectomy group. Multivariate logistic analysis revealed that gap distance and PUVD were independent factors of the surgical approaches. The accuracies were 83.7% and 67.4% respectively in the ROC curve analysis. In addition, the RUMD was significantly shorter in the patients with rectal injury history (1.4, 1.8 cm).

Conclusions

Longer gap distance and shorter PUVD were the two independent factors of the inferior pubectomy approach. Furthermore, among the patients with rectal injury history, the tissue posterior to the urethra was often weaker and should be carefully handled during the surgery.

Trial registration

This research has been registered on the Chinese Clinical Trial Registry. The registration number is ChiCTR2000030573.

Impact of Sarcopenia on Erectile Function after Nerve-Sparing Robot-Assisted Radical Prostatectomy

PURPOSE

To determine the impact of sarcopenia on erectile functional outcomes after a nerve-sparing (NS) robot-assisted radical prostatectomy (RARP) using patient-reported validated questionnaires.

MATERIALS AND METHODS

In this retrospective study, RARP was performed on 841 patients at Okayama University Hospital, of which 132 underwent NS RARP. Erectile functional outcomes were assessed using the 5-item version of the International Index of Erectile Function (IIEF-5) and the Expanded Prostate Cancer Index Composite before and 1, 3, 6, and 12 months after surgery. Automated measurement of skeletal muscle at L3 was achieved using volume analyzer software and normalizing for height (cm²/m²) to calculate skeletal muscle index (SMI). Patients who had an IIEF-5≤4 comprised the group with erectile dysfunction (ED), and those with an IIEF-5≤5 made up the non-ED group.

RESULTS

This study enrolled 95 patients of median age 65 years with a preoperative IIEF-5 of 16. There were no significant differences between patients with and without sarcopenia among those with preoperative IIEF-5. Postoperatively, in the ED group, SMI and preoperative IIEF-5 were significantly lower than in the non-ED group. Multiple linear regression analysis revealed that (1) both SMI and preoperative IIEF-5 were independent predictors of ED, and (2) sarcopenia and preoperative IIEF-5 were predictors of ED at 12 months after NS RARP.

CONCLUSIONS

Patients with sarcopenia can have worse erectile functional outcomes after NS RARP. Sarcopenia and a lower preoperative IIEF-5 score may be predictive of postoperative ED.

Correlation between lumbar skeletal muscle size and urinary incontinence after radical prostatectomy

OBJECTIVES

Urinary incontinence is a major concern after radical prostatectomy because it can decrease quality of life. The aim of the present study was to explore the effect of preoperative skeletal muscle on urinary quality of life after robot-assisted radical prostatectomy.

METHODS

A total of 762 patients underwent robot-assisted radical prostatectomy. Longitudinal health-related quality of life was evaluated using the Expanded Prostate Cancer Index Composite instrument. The skeletal muscle area at the level of the third lumbar vertebra was assessed preoperatively by computed tomography and was standardized to height to obtain the skeletal muscle index. Reduced skeletal muscle size (RSMS) was defined as a skeletal muscle index ≤ 53 or ≤ 43 cm² /m² in patients with a body mass index (BMI) ≥25 or < 25, respectively.

RESULTS

A total of 301 patients were included in this study, of whom 91 were classified as having RSMS (30.2%). Non-RSMS patients exhibited better urinary function at 12 months (P = .012) and better urinary continence recovery at 2 weeks and 12 months (P = .033 and P = .014, respectively) after prostatectomy compared with RSMS patients. Univariate and multivariate analyses identified preoperative RSMS as a significant and independent predictor of urinary incontinence (odds ratio = 1.77, P = .028).

CONCLUSIONS

Patients with RSMS had a lower urinary quality of life compared with non-RSMS patients after robot-assisted radical prostatectomy, and RSMS, independent of age or BMI, was predictive of postoperative urinary incontinence.

The Effectiveness of Cystography-Measured Bladder Neck Elevation at Predicting the Return of Continence After Robot-Assisted Radical Prostatectomy

Purpose

To analyze the clinical parameters correlated with early recovery of urinary continence after radical prostatectomy, with a focus on urethral mobility during pelvic contraction at catheter removal.

Methods

We prospectively analyzed 67 patients who underwent prostatectomy for prostate cancer at Jeju National University Hospital from January 2015 to June 2018. At the time of catheter removal, a cystography was performed in 67 men (median age, 65 years; range, 55–76 years) who had undergone robot-assisted laparoscopic prostatectomy. The vertical length of bladder neck movement between relaxing and contracting the pelvic muscles was measured. The correlation between the rate of continence recovery and the length of urethral movement was also assessed. All participants were divided into 2 groups according to the length of bladder neck elevation. Group 1 had ≥0.6 cm of elevation, while group 2 demonstrated <0.6 cm of elevation.

Results

A reverse correlation existed between the length of urethral movement and the recovery rate of urinary continence (r=–0.488, P<0.001). The optimal cutoff value for length of urethral movement was found to be 0.6 cm among patients (area under the curve, 0.703). A statistically significant difference was observed between group 1 (length≥0.6 cm) and group 2 (<0.6 cm) (P<0.05). Multivariate regression analysis showed that urethral movement predicted the postoperative urinary incontinence.

Conclusions

The extent of bladder neck elevation after robot-assisted laparoscopic prostatectomy, which can be easily evaluated using cystography, may be a good predictor of the recovery of urinary continence.

Comparison of longitudinal health-related quality-of-life outcomes between anterior and posterior surgical approaches to robot-assisted radical prostatectomy

Increasingly, studies have explored health-related quality-of-life (HRQOL) outcomes after robot-assisted radical prostatectomy (RARP). Nevertheless, no study has compared differences between anterior and posterior surgical approaches. The aim of this study is to assess differences of HRQOL following these two surgical approaches. From January 2012 to September 2017, 653 patients underwent RARP at our institution. We included patients who underwent operations by three experienced surgeons with interchangeability of role as console operator, and who could evaluate preoperatively the Expanded Prostate Cancer Index Composite (EPIC) score. Patients treated with neoadjuvant hormonal therapy were excluded. HRQOL was assessed using the EPIC score, and the questionnaire was administered at 6 timepoints: the baseline survey was conducted within 3 months before the surgery, and follow-up surveys were conducted at 2 weeks, 1, 3, 6, and 12 months after surgery. We defined the minimal clinically important difference (MCID) as half the standard deviation of the baseline score for each domain. A total of 201 patients were included in this retrospective study. Of these, 146 patients underwent RARP using an anterior surgical approach and 55 patients underwent a posterior approach. The clinical characteristics had no significant differences except for median prostate volume between the anterior and posterior groups (27 ml vs 29 ml, p = 0.049). There were no significant differences between the two groups in score decline beyond the MCID in any domain at any timepoint. Our study demonstrates no significant differences in HRQOL between anterior and posterior surgical approaches to RARP.