Impact of preoperative and postoperative membranous urethral length measured by 3 Tesla magnetic resonance imaging on urinary continence recovery after robotic-assisted radical prostatectomy

Association of bi-parametric MRI measures with continence after robot-assisted radical prostatectomy

OBJECTIVE

To investigate the association between pre- and postoperative magnetic resonance imaging (MRI) measurements of the membranous urethra and the prostate volume and continence following robot-assisted radical prostatectomy (RARP).

PATIENTS AND METHODS

From December 2018 to June 2022, 100 continent patients undergoing unilateral nerve-sparing or non-nerve-sparing RARP were included in this cohort study. Bi-parametric MRI scans were performed before and 12 months after RARP and measurements included the membranous urethral length (MUL) measured in cm (mMUL) and in the number of image slices (sMUL; 3 mm/slice), the membranous urethral diameter (MUD), and the prostate volume. Urinary function was evaluated by the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF) and continence, defined as the use of zero pads and the answer 'never' to the ICIQ-UI SF question regarding incontinence frequency or <8 g urine-loss per 24 h. Regression with robust variance estimates was used to analyse the association between measurements and outcomes.

RESULTS

At 12 months, continence and MRI data were available for 82 patients. The continence rate was 63% and the median (interquartile range) ICIQ-UI SF score was 4 (0-9). Both preoperative MUL measurements were associated with continence at 12 months. Every extra 5 mm of MUL increased the likelihood of being continent by 13 percentage points (P = 0.03) and every additional slice of sMUL increased it by 6 percentage points (P = 0.05). Both postoperative MUL measurements were associated with better continence and lower ICIQ-UI SF scores (P < 0.01). A larger prostate volume was associated with urinary incontinence at 12 months, with a small effect size. The MUD was not associated with continence.

CONCLUSION

Preoperative mMUL and sMUL are associated with continence at 12 months after RARP. The sMUL may be a useful measurement when only the axial plane is available, and the slice gap is known. Postoperative MUL measurements are strongly associated with continence, while MUD and prostate volume hold minimal prognostic value.

Factors Contributing to Early Recovery of Urinary Continence Following Radical Prostatectomy: A Narrative Review

Stress urinary incontinence (SUI) is a common condition in patients following radical prostatectomy (RP), which has a significant impact on all aspects of quality of life and is associated with significant social stigma. The factors that improve urinary incontinence in patients following surgery remain controversial. The aim of our narrative review was to identify and synthesise the latest evidence on pre-, intra- and post-operative factors and predictors that contribute to early continence recovery after RP. In this narrative review, primary resources were identified by searching PubMed, EMBASE and Medline, and secondary resources were collected by cross-referencing citations in the relevant articles. We started our review by searching for systematic reviews of factors and predictors that contribute to early recovery of urinary continence after RP. We then reviewed societal guidelines such as the American Urological Association and European Urological Association guidelines on male urinary incontinence. This review focuses on the pre-, intra and postoperative factors that influence postoperative SUI after RP, as well as highlighting modifications in surgical techniques that lead to early continence recovery. Increasing age, higher BMI, shorter membranous urethral length (MUL), and larger PV are independent prognostic factors for SUI within 3 months after RP. Factors such as modified surgical technique preservation of anatomical structure lead to influence postoperative early continence recovery. SUI after RP is influenced by various factors. These factors include not only anatomical landmarks and patient-related factors such as age, BMI, length of MUL and prostate volume, but also prior transurethral resection or laser enucleation of the prostate, the surgeon's expertise, the surgical approach and NS technique.

Integrating clinical and image-based parameters for prediction of early post-prostatectomy incontinence recovery: simplified nomogram approach

PURPOSE

This study aimed to develop a novel model that combines both clinical and image-based parameters to predict early recovery of urinary incontinence after robotic-assisted radical prostatectomy (RARP) more easily and precisely.

MATERIALS AND METHODS

We retrospectively enrolled data from patients who underwent RARP performed by a single surgeon. Clinical parameters were collected through medical chart review. All patients received cystography one week after RARP to evaluate the anastomosis healing condition. All cystography images were analyzed by a single radiologist who was blinded to the clinical status of the patients. Multivariate analysis was performed to select significant predictors for early post-prostatectomy incontinence (PPI) recovery, defined as being pad-free within four weeks after surgery.

RESULTS

A total of 293 patients were enrolled in this study. Among them, 26.7% experienced immediate dryness after surgery, while 47.6% achieved being pad-free within one month. The overall continence rate was over 90% six months after surgery. In univariate analysis, factors associated with early PPI recovery were BMI, T stage, NVB preservation, surgical margin status, downward bladder neck, and bladder neck angle on cystography. BMI, NVB preservation, and downward bladder neck remained significant in multivariate analysis (p-values = 0.041, 0.027, and 0.023, respectively). A nomogram model was established based on these three predictors.

CONCLUSION

This is the first model to combine preoperative clinical factors, peri-surgical factors, and postoperative image-based factors to predict PPI recovery after RARP. This model can assist clinicians in taking optimal actions for PPI and also reduce patient anxiety.

Impact of oral antithrombotic agents on urinary continence recovery following robot-assisted radical prostatectomy: a retrospective cohort study

BACKGROUND

Robot-assisted radical prostatectomy (RARP) is a preferred minimally invasive surgical treatment for prostate cancer. The number of elderly patients and those with cardiovascular and/or cerebrovascular issues undergoing surgery is increasing, and many of them are taking antithrombotic (AT) agents. However, the effect of AT agents on postoperative urinary recovery has not been adequately studied. In this study, we analyzed the differences in the postoperative recovery of urinary continence and oncological outcomes in patients undergoing RARP for localized prostate cancer between AT agent adherents and non-adherents.

METHODS

A total of 394 patients who underwent conventional anterior RARP between February 2015 and February 2021 were categorized into two groups: those taking oral AT agents (AT group) and the control group. Urinary continence recovery, complications, and oncological outcomes were compared between the groups. A Cox proportional hazards analysis was performed to identify clinical factors that affect urinary continence recovery.

RESULTS

The background data and bleeding complications did not differ significantly between the groups. The recovery of continence was significantly poorer in the AT group in terms of complete pad free (HR: 0.53 [95% CI: 0.39-0.71]) and use of ≤ 1 safety pad (HR: 0.74 [95% CI: 0.59-0.94]). The rate of anastomotic leakage on cystography was significantly higher in the AT group (20.9% vs. 6.7%). A univariate analysis revealed that taking antithrombotic agents, higher prostate-specific antigen levels, and a more advanced clinical stage were associated with a poor urinary continence recovery; a multivariate analysis showed that taking AT agents was an independent factor negatively associated with urinary continence recovery. There was no significant difference between the groups in the positive surgical margin rate (19.0% vs. 23.8%) or the biochemical-recurrence-free rate.

CONCLUSION

Taking oral AT agents may be associated with poor urinary continence recovery after RARP.

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.

Predictors of Early Continence Recovery Following Radical Prostatectomy, Including Transperineal Ultrasound to Evaluate the Membranous Urethra Length (CHECK-MUL Study)

INTRODUCTION

To predict early continence recovery following radical prostatectomy (RP) using baseline demographic and clinical data, as well as dynamic transperineal ultrasound (TPUS) parameters of membranous urethral length (MUL).

PATIENTS AND METHODS

A retrospective CHECK-MUL (check of membranous urethral length) study was conducted. We evaluated 154 patients who underwent RP between August 2018 and April 2023. All patients underwent pre- and postoperative dynamic TPUS to measure MUL. Urinary continence was defined as the use of one safety pad or less 3 months post surgery. The International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) was used to assess urinary incontinence (UI). We used logistic regression to assess the association between MUL and early continence recovery. A multivariable logistic regression model was then constructed for the prediction of early continence recovery based on the MUL.

RESULTS

The median MUL observed pre- and postoperatively in this study were similar (14.6 mm and 12.9 mm). In the univariable logistic regression analysis, the pre- and postoperative MUL measured by TPUS (odds ratio (OR): 1.12; 95%-CI: 1.02-1.79; p = 0.05 and OR: 1.01; 95%-CI: 1.02-1.12; p < 0.01) directions were independent predictors of early continence recovery 3 months post surgery. In addition, age (OR: 1.23; 95%-CI: 1.11-1.42; p = 0.03), BMI (OR: 1.44; 95%-CI: 1.18-2.92; p = 0.05), and bilateral nerve sparing (OR: 1.24; 95%-CI: 1.02-1.9; p = 0.05) were independent predictors of urinary continence in univariable logistic regression models. Preoperative MUL >15 mm (95% CI 1.28-1.33; p = 0.03) and postoperative MUL >14 mm (95% CI 1.2-1.16; p = 0.05) were significantly associated with early continence recovery at 3 months post surgery.

CONCLUSIONS

The likelihood of continence recovery increases with membranous urethral length and decreases with age, BMI, and lack of nerve sparing. Preoperative MUL >15 mm and postoperative MUL >14 mm were significantly associated with early continence recovery at 3 months post surgery.

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.

Surgical techniques to preserve continence after robot-assisted radical prostatectomy

Radical prostatectomy significantly impacts the inherent anatomy of the male pelvis and the functional mechanisms of urinary continence. Incontinence has a considerable negative influence on the quality of life of patients, as well as their social and psychological wellbeing. Numerous surgical techniques have been demonstrated to support the preservation of continence during robot-assisted radical prostatectomy (RARP). In this in-depth analysis, we give a general summary of the surgical techniques used in RARP and their impact on incontinence rates.

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.

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.

Robot assisted laparoscopic radical prostatectomy with maximal urethral length preservation technique preserves penile length

Penile shortening is a recognized but neglected side effect of prostate cancer treatment. In this study we explore the effect of maximal urethral length preservation (MULP) technique on penile length preservation after robot assisted laparoscopic prostatectomy (RALP). In an IRB approved study, we prospectively evaluated the stretched flaccid penile length (SFPL) pre and post RALP in subjects with a diagnosis of prostate cancer. The multiparametric MRI (MP-MRI) was utilized for surgical planning if available preoperatively. Repeated measures t-test, linear regression and 2-way ANOVA analyses were performed. A total of 35 subjects underwent RALP. Mean age was 65.8 yr (SD: 5.9), preoperative SFPL was 15.57 cm (SD: 1.66) and postoperative SFPL was 15.41 cm (SD: 1.61) p = 0.68. No change in the postoperative SFPL was recorded among 27 subjects (77.1%) while 5 subjects (14.3%) had 0.5 cm shortening, and 3 subjects (8.6%) had 1 cm shortening. Pathologic stage, preoperative MP-MRI and body mass index (BMI) were significant predictors of postoperative SFPL on linear regression analysis, p = 0.001. Among 26 subjects with pathologic stage 2 disease, no statistical difference was seen in repeated measures t-test between pre and postoperative SFPL, 15.36 vs 15.3 cm, p = 0.08. All subjects were continent by 6 months postoperatively, with no complications. We demonstrate that incorporating MULP technique and preoperative MP-MRI preserves SFPL in subjects undergoing a RALP.

Recognition of Postoperative Cystography Features by Artificial Intelligence to Predict Recovery from Postprostatectomy Urinary Incontinence: A Rapid and Easy Way to Predict Functional Outcome

Purpose: Post-operative cystography has been used to predict the recovery of postprostatectomy urinary incontinence (PPI) in patients with localized prostate cancer. This study aimed to validate the predictive value of cystography for PPI and utilize a deep learning model to identify favorable and unfavorable features. Methods: Medical records and cystography images of patients who underwent robotic-assisted radical prostatectomy for localized prostate cancer were retrospectively reviewed. Specific cystography features, including anastomosis leakage, a downward bladder neck (BN), and the bladder neck angle, were analyzed for the prediction of PPI recovery. Favorable and unfavorable patterns were categorized based on the three cystography features. The deep learning model used for transfer learning was ResNet 50 and weights were trained on ImageNet. We used 5-fold cross-validation to reduce bias. After each fold, we used a test set to confirm the model’s performance. Result: A total of 170 consecutive patients were included; 31.2% experienced immediate urinary continence after surgery, while 93.5% achieved a pad-free status and 6.5% were still incontinent in the 24 weeks after surgery. We divided patients into a fast recovery group (≤4 weeks) and a slow recovery group (>4 weeks). Compared with the slow recovery group, the fast recovery group had a significantly lower anastomosis leakage rate, less of a downward bladder neck, and a larger bladder neck angle. Test data used to evaluate the model’s performance demonstrated an average 5-fold accuracy, sensitivity, and specificity of 93.75%, 87.5%, and 100%, respectively. Conclusions: Postoperative cystography features can predict PPI recovery in patients with localized prostate cancer. A deep-learning model can facilitate the identification process. Further validation and exploration are required for the future development of artificial intelligence (AI) in this field.

Preoperative predictive model of early urinary continence recovery after laparoscopic radical prostatectomy

PURPOSE

To develop and validate a predictive model include magnetic resonance imaging (MRI) parameters preoperatively which can assess the risk of incontinence after laparoscopic radical prostatectomy (LRP) accurately.

METHODS

We retrospectively reviewed and included 170 patients with prostate cancer who underwent LRP between July 2015 and June 2018 in our institution. All 170 patients were randomly resampled and divided into training set (n = 124) and verification set (n = 46) according to the ratio of 7:3. The Nomogram prediction model of the risk of incontinence after LRP was established through the training set and verified by the verification set. Baseline patient characteristics were obtained, including age, body mass index, and prostate volume. Perioperative characteristics such as pre-biopsy prostate specific antigen, biopsy Gleason score, clinical staging, and NVB sparing status were also collected. MRI parameters preoperatively including membranous urethral length (MUL), prostate apex depth ratio (PADR), and intravesical prostatic protrusion length (IPPL) were obtained. The C index and visual inspection of calibration curve were used to evaluate the discrimination and calibration of the model.

RESULTS

According to the urinary incontinence (UI) at 3 months postoperatively, the patients were divided into 104 cases (61.2%) in the group with no incontinence and 66 patients (38.8%) in the group with incontinence. Multivariate logistic regression analysis of training set showed that cT3a (OR = 0.427, 95% CI 0.142-1.281, P = 0.1288), MUL (OR = 0.237, 95% CI 0.102-0.551, P < 0.01), PADR (OR = 0.276, 95% CI 0.116-0.655, P < 0.01), and IPPL (OR = 0.073, 95% CI 0.030-0.179, P < 0.01) were independent predictors of urinary incontinence at 3 months postoperatively. The model showed good discrimination with an area under the receiver operating characteristic (ROC) curve of 0.880, with the sensitivity and specificity 0.800 and 0.816, respectively, and good calibration (Hosmer-Lemeshow test result of 5.57, P = 0.695). Decision curve analysis demonstrated that the model was clinically useful.

CONCLUSION

This study developed and validated a preoperative model in the form of a nomogram to predict the risk of UI after LRP at 3 months. MUL, PADR, and IPPL were significant independent predictive factors of the postoperative early urinary continence.

A standardized method to measure the membranous urethral length (MUL) on MRI of the prostate with high inter- and intra-observer agreement

OBJECTIVES

The membranous urethral length (MUL), defined as the length between the apex and penile base as measured on preoperative prostate magnetic resonance imaging (MRI), is an important predictor for urinary incontinence after radical prostatectomy. Literature on inter- and intra - observer agreement of MUL measurement is limited. We studied the inter- and intra-observer agreement between radiologists using a well-defined method to measure the MUL on the prostate MRI.

METHODS

Prostate cancer patients underwent a preoperative MRI and robot-assisted radical prostatectomy (RARP) at one high-volume RARP center. MUL measurement was based on well-defined landmarks on sagittal T2-weighted (anatomical) images. Three radiologists independently performed MUL measurements retrospectively in 106 patients blinded to themselves, to each other, and to clinical outcomes. The inter- and intra-observer agreement of MUL measurement between the radiologists were calculated, expressed as intra-class correlation coefficient (ICC).

RESULTS

The initial inter-observer agreement was ICC 0.63; 95% confidence interval (CI) 0.28-0.81. Radiologist 3 measured the MUL mean 3.9 mm (SD 3.3) longer than the other readers, interpreting the caudal point of the MUL (penile base) differently. After discussion on the correct anatomical definition, radiologist 3 re-assessed all scans, which resulted in a high inter-observer agreement (ICC 0.84; 95% CI 0.66-0.91). After a subsequent reading by radiologists 1 and 2, the intra-observer agreements were ICC 0.93; 95% CI 0.89-0.96, and ICC 0.98; 95% CI 0.97-0.98, respectively. Limitation is the monocenter design.

CONCLUSIONS

The MUL can be measured reliably with high agreement among radiologists.

KEY POINTS

• After discussion on the correct anatomical definition, the inter- and intra - observer agreements of membranous urethral length (MUL) measurement on magnetic resonance imaging (MRI) were high. • A reproducible method to measure the MUL can improve the clinical usefulness of prediction models for urinary continence after RARP which may benefit patient counselling.

Significance of postoperative membranous urethral length and position of vesicourethral anastomosis for short-term continence recovery following robot-assisted laparoscopic radical prostatectomy

BACKGROUND

We assess whether short-term recovery of urinary incontinence following robot-assisted laparoscopic radical prostatectomy (RARP) is associated with postoperative membranous urethral length (MUL) and position of vesico-urethral anastomosis (PVUA).

METHODS

Clinical variables including PVUA and pre-and postoperative MUL were evaluated in 251 patients who underwent RARP from August 2019 to February 2021. Continence recovery was defined as no pad or one security liner per day assessed by patient interview at least 6 months follow-up. Univariate and multivariate logistic regression analyses were used to assess variables associated with continence recovery at 3 months after the operation.

RESULTS

Continence recovery rates at 3 and 6 months were 75% and 84%, respectively. Lower BMI (< 25 kg/m2) (p = 0.040), longer preoperative MUL (≥ 9.5 mm) (p = 0.013), longer postoperative MUL (≥ 9 mm) (p < 0.001), higher PVUA (< 14.5 mm) (p = 0.019) and shorter operating time (< 170 min) (p = 0.013) were significantly associated with continence recovery at 3 months in univariate analysis. Multivariate analysis revealed that postoperative MUL (OR 3.75, 95% CI 1.90-7.40, p < 0.001) and higher PVUA (OR 2.02, 95% CI 1.07-3.82, p = 0.032) were independent factors for continence recovery. Patients were divided into 3 groups based on the multivariate analysis, with urinary continence recovery rates found to have increased in turn with rates of 43.7% versus 68.2% versus 85.0% (p < 0.001) at 3 months.

CONCLUSIONS

PVUA and postoperative MUL were significant factors for short-term continence recovery. Preservation of urethral length might contribute to continence recovery after RARP.

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.

[Relationship between recovery of urinary continence after laparoscopic radical prostatectomy and preoperative/postoperative membranous urethral length]

OBJECTIVE

To evaluate the relationship between recovery of urinary continence after laparoscopic radical prostatectomy (LRP) and preoperative/postoperative membranous urethral length (MUL) on magnetic resonance imaging.

METHODS

We retrospectively analyzed 69 patients with pathologic confirmed prostate carcinoma who underwent laparoscopic radical prostatectomy. Preoperative MUL was defined as the distance from the apex of prostate to the level of the urethra at penile bulb on the coronal image. Postoperative MUL was defined as the distance from the bladder neck to the level of the urethra at the penile bulb on the coronal image. MUL-retained rate was defined as the percentage of postoperative MUL to preoperative MUL. All patients received extraperitoneal LRP. Patients reported freedom from using safety pad (0 pad/d) were defined as urinary continence. Multivariate Logistic regression analyses were used to identify independent predictors of early continence recovery after LRP. Kaplan-Meier analyses and log-rank test were used to compare time to continence recovery between the groups.

RESULTS

For all the 69 patients, the average age was (71.4±8.6) years. The prostate specific antigen before biopsy was (23.40±30.31) μg/L, and the mean preoperative prostatic volume by magnetic resonance imaging was (39.48±22.73) mL. The mean preoperative MUL was (13.0±3.3) mm, the mean postoperative MUL was (12.3±3.4) mm, and the mean MUL-retained rate was 93.9%±6.2%. The continence rate for all the patients after LRP was 57.9% and 97.1% in three months and one year, respectively. The patients achieving early continence recovery had significant smaller prostatic volume (P=0.028), longer preoperative MUL and postoperative MUL (P < 0.001). Multivariate Logistic regression analyses revealed postoperative MUL (P < 0.001) were predictors of continence recovery after LRP. Kaplan-Meier analyses and Log-rank test revealed that preoperative MUL (≥14 mm vs. < 14 mm, P < 0.001) and postoperative MUL (≥13 mm vs. < 13 mm, P < 0.001), MUL-retained rate (< 94% vs. ≥94%, P < 0.001) were all significantly associated with continence recovery.

CONCLUSION

Post-operative MUL was independently predictors of early continence recovery after LRP. Preoperative MUL, postoperative MUL and MUL retained rate were significantly associated with recovery of urinary continence.

[Relationship between recovery of urinary continence after laparoscopic radical prostatectomy and preoperative/postoperative membranous urethral length]

OBJECTIVE

To evaluate the relationship between recovery of urinary continence after laparoscopic radical prostatectomy (LRP) and preoperative/postoperative membranous urethral length (MUL) on magnetic resonance imaging.

METHODS

We retrospectively analyzed 69 patients with pathologic confirmed prostate carcinoma who underwent laparoscopic radical prostatectomy. Preoperative MUL was defined as the distance from the apex of prostate to the level of the urethra at penile bulb on the coronal image. Postoperative MUL was defined as the distance from the bladder neck to the level of the urethra at the penile bulb on the coronal image. MUL-retained rate was defined as the percentage of postoperative MUL to preoperative MUL. All patients received extraperitoneal LRP. Patients reported freedom from using safety pad (0 pad/d) were defined as urinary continence. Multivariate Logistic regression analyses were used to identify independent predictors of early continence recovery after LRP. Kaplan-Meier analyses and log-rank test were used to compare time to continence recovery between the groups.

RESULTS

For all the 69 patients, the average age was (71.4±8.6) years. The prostate specific antigen before biopsy was (23.40±30.31) μg/L, and the mean preoperative prostatic volume by magnetic resonance imaging was (39.48±22.73) mL. The mean preoperative MUL was (13.0±3.3) mm, the mean postoperative MUL was (12.3±3.4) mm, and the mean MUL-retained rate was 93.9%±6.2%. The continence rate for all the patients after LRP was 57.9% and 97.1% in three months and one year, respectively. The patients achieving early continence recovery had significant smaller prostatic volume (P=0.028), longer preoperative MUL and postoperative MUL (P < 0.001). Multivariate Logistic regression analyses revealed postoperative MUL (P < 0.001) were predictors of continence recovery after LRP. Kaplan-Meier analyses and Log-rank test revealed that preoperative MUL (≥14 mm vs. < 14 mm, P < 0.001) and postoperative MUL (≥13 mm vs. < 13 mm, P < 0.001), MUL-retained rate (< 94% vs. ≥94%, P < 0.001) were all significantly associated with continence recovery.

CONCLUSION

Post-operative MUL was independently predictors of early continence recovery after LRP. Preoperative MUL, postoperative MUL and MUL retained rate were significantly associated with recovery of urinary continence.

Urethral Sphincter Length but Not Prostatic Apex Shape in Preoperative MRI Is Associated with Mid-Term Continence Rates after Radical Prostatectomy

Background: To test the impact of urethral sphincter length (USL) and anatomic variants of prostatic apex (Lee-type classification) in preoperative multiparametric magnet resonance imaging (mpMRI) on mid-term continence in prostate cancer patients treated with radical prostatectomy (RP). Methods: We relied on an institutional tertiary-care database to identify patients who underwent RP between 03/2018 and 12/2019 with preoperative mpMRI and data available on mid-term (>6 months post-surgery) urinary continence, defined as usage 0/1 (-safety) pad/24 h. Univariable and multivariable logistic regression models were fitted to test for predictor status of USL and prostatic apex variants, defined in mpMRI measurements. Results: Of 68 eligible patients, rate of mid-term urinary continence was 81% (n = 55). Median coronal (15.1 vs. 12.5 mm) and sagittal (15.4 vs. 11.1 mm) USL were longer in patients reporting urinary continence in mid-term follow-up (both p < 0.01). No difference was recorded for prostatic apex variants distribution (Lee-type) between continent vs. incontinent patients (p = 0.4). In separate multivariable logistic regression models, coronal (odds ratio (OR): 1.35) and sagittal (OR: 1.67) USL, but not Lee-type, were independent predictors for mid-term continence. Conclusion: USL, but not apex anatomy, in preoperative mpMRI was associated with higher rates of urinary continence at mid-term follow-up.

Impact of Bladder Neck Angle Measured by Postoperative Magnetic Resonance Imaging on Midterm Recovery of Urinary Continence in Prostate Cancer Patients Undergoing Robot-Assisted Radical Prostatectomy

Introduction: MRI has helped clarify the relationship between pelvic anatomical structures and functional outcomes after robot-assisted radical prostatectomy (RARP). The objective of this study was to assess the impact of the bladder neck angle (BNA) measured by postoperative MRI on midterm recovery of urinary continence (UC) in patients undergoing RARP. Patients and Methods: This study retrospectively included 200 consecutive patients with prostate cancer who were treated by RARP and received MRI 3 months after RARP. Based on postoperative MRI, the BNA was measured as the angle between the anterior and posterior bladder walls. The midterm recovery of UC was defined as the use of either no pad or an occasional security pad at 6 months after RARP. Results: One hundred forty-four of the 200 patients (72.0%) achieved midterm recovery of UC and the median BNA was 70°. There were no significant differences in several parameters, including age, body mass index, total prostate volume, preservation of the neurovascular bundle, and postoperative membranous urethral length (MUL), between patients with BNA ≥70° and <70°. Of these parameters, only the BNA and postoperative MUL were independently associated with the midterm recovery of UC. The optimal cutoff points of the BNA and MUL (65° and 9 mm, respectively) were calculated by the receiver operating characteristics curve, and a scoring model for the prediction of midterm recovery of UC was developed according to the logistic regression analysis. This scoring model was demonstrated to be satisfactorily calibrated (p for Hosmer-Lemeshow test = 0.49) and provide good discrimination (area under the curve: 0.723; p < 0.001). Conclusions: These findings suggest that midterm recovery of UC after RARP is favorably affected by the large BNA and long postoperative MUL, and our scoring model can be used as a reliable tool for predicting the midterm continence status after RARP.

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.

Surgical techniques to improve continence recovery after robot-assisted radical prostatectomy

Radical prostatectomy directly affects urinary continence dynamics with incontinence being a major factor in patients’ quality of life, social and psychological status. In order to help maintain continence after robot-assisted radical prostatectomy (RARP), a number of surgical techniques have been described. In the present narrative review, we summarize the surgical techniques that have been applied during RARP and their effects on incontinence rates and time to continence recovery.

Surgical techniques to improve continence recovery after robot-assisted radical prostatectomy

Radical prostatectomy directly affects urinary continence dynamics with incontinence being a major factor in patients' quality of life, social and psychological status. In order to help maintain continence after robot-assisted radical prostatectomy (RARP), a number of surgical techniques have been described. In the present narrative review, we summarize the surgical techniques that have been applied during RARP and their effects on incontinence rates and time to continence recovery.

Characteristics of urodynamic study parameters associated with intermediate-term continence after robot-assisted radical prostatectomy in elderly patients

PURPOSE

To investigate the relationship between urodynamic study (UDS) data and recovery of urinary incontinence (UI) in elderly patients who underwent robot-assisted radical prostatectomy (RARP).

MATERIALS AND METHODS

Seventy-five prostate cancer (PCa) patients received UDS before and at 3 months after RARP. They were divided into two groups; a younger group (<70 years old, n = 47) and older group (≥70 years, n = 28), and each was classified according to urinary continence (UC) or UI at 3 months post-RARP. Continence was defined as being pad-free or 1-safety pad usage per day.

RESULTS

In the older group, preoperative maximum urethral closure pressure (MUCP) in the UI group was significantly lower than that in the UC group. Detrusor overactivity (DO) rate was significantly higher in the older UI group than in the older UC group at both pre- and 3 months post-RARP. Persistent DO rate pre- and post-RARP was significantly higher in the older group than in the younger group. Regardless of age, postoperative DO was an independent predictor of UI 6 months post-RARP.

CONCLUSIONS

In elderly patients, low preoperative MUCP and both pre- and postoperative DO are associated with postoperative UI.

Effect of puboprostatic ligament preservation during robotic-assisted laparoscopic radical prostatectomy on early continence: Randomized controlled trial

Objective

To prove the effectiveness of puboprostatic ligament-preserving robotic-assisted laparoscopic radical (RARP) on enhancing early continence.

Methods

Ninety-two patients with localized adenocarcinoma of the prostate scheduled for RARP from April 2018 to January 2019 were prospectively single-blinded and randomized into two groups, standard RARP (Group A) and puboprostatic ligament-sparing RARP (Group B). The outcomes were continent status at Foley catheter removal and 3 months after surgery using the score from the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF), pad usage, pathological margin status, blood loss, operative time, and complications.

Results

Ninety-six patients were randomized (46 patients in each group), with a mean±SD age of 67.30±6.07 years. There were no differences in baseline characteristics. At 3 months after surgery, ICIQ-UI SF score (mean±SD) in Group A was significantly higher than Group B (8.74±4.28 vs. 6.93±3.96, p=0.038) but no difference at Foley catheter removal. Group A also had a significant higher score for interference with daily life (median [interquartile range, IQR]: 4 [1, 5] vs. 2 [0, 4]; p=0.041) and higher pad use (median [IQR]: 2 [0, 3] vs. 1 [1, 2]; p=0.041) at 3 months. One case in Group A had complete or severe incontinence (>5 pads/day) at 3 months. Groups A and B did not exhibit significant difference in margin status (p=0.828). There were no differences in operative time, blood loss, drain output or complications.

Conclusions

Use of puboprostatic ligament-sparing RARP could be a method to accelerate early continence without affecting the final oncological outcome.

Identifying the relationship between postoperative urinary continence and residual urethra stump measurements in robot assisted radical prostatectomy patients

OBJECTIVE

To investigate the feasibility of urethral stump length and width measurements in recorded videos of robot assisted radical prostatectomy procedures using the Kinovea software and to assess if these measurements could be used as predictors of postoperative urinary continence.

METHODS

Fifty-three patients were selected from an institutional database of 1400 cases and included in the study. All videos were analysed using the computer software 'Kinovea'. All measurements were performed using the inserted bladder catheter as a reference point.

RESULTS

The reference point (bladder catheter) was available in 33 out of 53 patients. The median surgical urethral length (SUL) was significantly higher in the continent group (1050 vs. 1294 mm, p = 0.018). The urethral width measurements did not show a difference between the groups. In order to validate the Kinovea software as an accurate tool for the measurement of the urethral stump length and width results were correlated with the magnetic resonance imaging measurements of the urethra.

CONCLUSIONS

The results of this study showed a significantly longer median SUL incontinent patients.

Intravesical prostatic protrusion may affect early postoperative continence undergoing robot-assisted radical prostatectomy

Background

In this study, we investigated the effect of preoperative prostate morphology, especially intravesical prostatic protrusion (IPP), on continence after robot-assisted radical prostatectomy (RARP).

Methods

Retrospective analysis was applied to patients who underwent RARP between October 2010 and July 2014. The following parameters were assessed in all patients: age, body mass index (BMI), prostate-specific antigen, magnetic resonance imaging and pressure-flow studies findings. The impact of preoperative and intraoperative factors on postoperative urinary incontinence (UI) was assessed using multivariate logistic regression analysis. To evaluate the effects of IPP, the patients were divided into groups according to the IPP length: Group 1, < 5 mm and Group 2, ≥ 5 mm. The International Prostate Symptom Score (IPSS), Overactive Bladder Symptom Score, Quality of Life index and the number of pads used were assessed.

Results

A total of 119 patients were eligible for this study. Multivariate analyses showed that IPP (odds ratio (OR) 1.14, 95% confidence interval (CI) 1.02–1.28, p < 0.05) and nerve-sparing (NS) (OR 0.23, 95% CI 0.18–0.61, p < 0.01) were significant factors related to UI in the first month after RARP. Twelve months after RARP, multivariate analyses revealed that only NS is a factor related to postoperative UI (OR 0.23, 95% CI 0.18–0.61, p < 0.01). The comparison of Groups 1 and 2 indicated significant differences in age (p < 0.01), prostate volume (p < 0.01), total IPSS and voiding symptom score (p < 0.05), compliance (p < 0.01), and detrusor pressure at maximum flow (p < 0.01). Group 1 had a higher continence rate (38.0%) than Group 2 (20.8%) in the first month after RARP (p < 0.05), but the difference was no longer significant from the third month after RARP. The total IPSS and voiding symptom scores were significantly different between the two groups before RARP, however, the significant difference disappeared from the first month after RARP.

Conclusions

The data suggest that IPP affects early postoperative UI. Although NS was strongly involved in UI in the early and later stages after RARP, IPP had no effect on UI in the later stages.

Cine magnetic resonance imaging provides novel predictors of early continence recovery after radical prostatectomy: Assessment of the dynamics of pelvic floor muscles

AIMS

Postprostatectomy incontinence is a major complication of prostatectomy. Although pelvic floor muscle training can successfully treat postprostatectomy incontinence, evidence for how muscle movement affects continence recovery is lacking. We evaluated dynamic factors of prostatectomy patients using cine magnetic resonance imaging to identify risk factors for postprostatectomy incontinence and reveal the contribution of pelvic floor muscles to continence recovery.

METHODS

A total of 128 prostate cancer patients who underwent robot-assisted laparoscopic surgery were enrolled. Cine magnetic resonance imaging was performed preoperatively and 6 months after surgery. Continence was defined as pad-free or use of safety pads. We defined the bladder neck elevation distance during pelvic floor muscle training as the bladder elevation distance. Patients with continence recovery within 1 month comprised the continence group (n = 48); other patients comprised the incontinence group (n = 80).

RESULTS

The preoperative bladder elevation distance was significantly longer in the continence group than in the incontinence group (10.4 vs. 8.2 mm; p < .001). The postoperative bladder elevation distance of the continence group tended to be longer (9.9 vs. 8.9 mm; p = .057). Multivariate analysis showed that the preoperative bladder elevation distance significantly contributed to continence recovery (p = .016). Patients with a longer preoperative bladder elevation distance (>8.5 mm) experienced continence recovery significantly faster than patients with a shorter distance (<8.5mm) (p = .038).

CONCLUSIONS

Bladder elevation distance, a novel dynamic parameter, was strongly associated with early continence recovery. Cine magnetic resonance imaging can assess a patient's risk of postprostatectomy incontinence and guide pelvic floor muscle training.

Impact of surgically maximized versus native membranous urethral length on 30-day and long-term pad-free continence after robot-assisted radical prostatectomy

BACKGROUND

Pelvic multiparametric magnetic resonance imaging (mpMRI)-determined membranous urethral length (MUL) and its surgical maximization have been reported to impact early- and long-term pad-free urinary continence after robot-assisted radical prostatectomy (RARP).

OBJECTIVE

The objective of this study was to present evidence (data and video) of important effects on post-RARP continence recovery from both innate mpMRI-assessed and surgical preservation of MUL.

DESIGN SETTING AND PARTICIPANTS

Of 605 men undergoing RARP, 580 with complete follow-up were included: Group 1, prior (N = 355), and Group 2, subsequent (N = 225) to technique change of MUL maximization. Effect of innate, mpMRI-assessed MUL on postoperative continence was assessed.

SURGICAL PROCEDURE

Before technique change, the dorsal venous complex was stapled before transection of the membranous urethra. After the change, the final step of extirpation was transection of the dorsal venous complex and periurethral attachments, thus facilitating surgical maximization of MUL.

MEASUREMENTS

Primary and secondary outcomes for technique change and mpMRI-assessed MUL were both patient-reported 30-day and 1-year pad-free continence after RARP, respectively.

RESULTS

Preoperative prostate-specific antigen, age, and disease aggressiveness were significantly higher in Group 2. After technique change and surgical maximization of MUL, 30-day and 1-year pad-free continence were both significantly improved (p < 0.05). In multivariate analysis, maximization of MUL significantly increased the likelihood of both early- and long-term continence recovery. For men undergoing MUL preservation, mpMRI-assessed MUL>1.4 cm also independently predicted higher 30-day (odds ratio: 4.85, 95% confidence interval: 1.24-18.9) and 1-year continence recovery (odds ratio: 11.26, 95% confidence interval: 1.07-118).

CONCLUSIONS

Prostatic rotation and circumferential release of apical attachments and maximization of MUL improves continence after RARP. Separately, innate MUL>1.4 cm independently increased 30-day and 1-year continence recovery.

PATIENT SUMMARY

Surgeon efforts to maximize MUL during radical prostatectomy are highly encouraged, as maximally preserved MUL likely improves post-RARP continence recovery. In addition, individual patients' mpMRI-assessed MUL (approximately >1.4 cm) independently limits continence recovery.

Anatomical robotic prostatectomy: technical factors to achieve superb continence and erectile function

Debate continues as to the superiority of robotic versus open radical prostatectomy for the surgical treatment of localized prostate cancer. Despite this controversy, retrospective data from high volume centres has demonstrated RARP is associated with improved pentafecta outcomes with lower transfusion rates, less incontinence, lower positive surgical margins and improved potency. Advocates of robotic assisted radical prostatectomy (RARP) believe an enhanced visual field, the precision afforded by robotic technology as well as lack of bleeding, sharp dissection and delicate tissue handling lead to improved outcomes. Prostate Cancer is the second most common cancer diagnosed in men, and as the number of post-surgical patients increases, the complications of urinary incontinence and erectile dysfunction not only have a significant negative impact on patients' quality of life, but have become an expanding part of clinical practice. This article outlines what are believed to be the most important strategies based on anatomical knowledge and technical expertise, that allow robotic prostatectomists to achieve superb outcomes in urinary and erectile function.

Improvement in early urinary continence recovery after robotic-assisted radical prostatectomy based on postoperative pelvic anatomic features: a retrospective review

Background

We investigated the impact of postoperative membranous urethral length and other anatomic characteristics of the pelvic floor shape as measured by magnetic resonance imaging on the improvement in continence following robotic-assisted radical prostatectomy.

Methods

We retrospectively reviewed data from 73 patients who underwent postoperative prostate magnetic resonance imaging following robotic-assisted radical prostatectomy between 2013 and 2018. Patient demographics; pre-, peri-, and post-operative parameters; and pelvic anatomic features on magnetic resonance imaging were reviewed. Patients who used no urinary incontinence pads or pads for protection were considered to have achieved complete continence.

Results

Urinary continence was restored in 27.4, 53.4, 68.5, and 84.9% of patients at 1, 3, 6, and 12 months after robotic-assisted radical prostatectomy, respectively. When patients were divided into early and late continence groups based on urinary continence at 3 months after robotic-assisted radical prostatectomy, no significantly different clinical characteristics or surgical outcomes were found. However, the mean membranous urethral length (18.5 mm for the early continence group vs. 16.9 mm for the late continence group), levator muscle width (7.1 vs. 6.5 mm, respectively), and bladder neck width on the trigone side (7.2 mm vs. 5.4 mm, respectively) were significantly different between groups (all p < 0.05). Multivariate logistic regression analysis showed that membranous urethral length (odds ratio, 1.227; 95% confidence interval, 1.011–1.489; p = 0.038) and bladder neck width (odds ratio, 1.585; 95% confidence interval, 1.050–2.393; p = 0.028) were associated with the period of early urinary continence.

Conclusions

Postoperative membranous urethral length and bladder neck width were significantly associated with early urinary continence recovery after robotic-assisted radical prostatectomy. It is highly recommended that surgeons focus on preserving the membranous urethral length and increasing the bladder neck width on the trigone side during surgery to achieve optimal continence outcomes after robotic-assisted radical prostatectomy.

Three novel methods to measure the postoperative displacement of lower urinary tract structures following radical prostatectomy in a sample of Korean patients

BACKGROUND

There is a change in the position of the remaining anatomical structures of the lower urinary tract system following radical prostatectomy. The aims of this investigation were to describe three novel methods used to measure the displacement of i) the vesico-urethral junction (VUJ), proximal membranous urethra (PMU) and anorectal junction (ARJ) and ii) the VUJ angle of displacement in men following radical prostatectomy and determine their intra- and interrater reliability.

METHODS

Retrospective comparative measurement of twenty pre- and postoperative MRI scans was undertaken by one observer on two separate occasions and on one occasion by another observer. Three standardized midsagittal pelvimetry reference lines were used to describe three X, Y axis measurement systems. The displacement (mm) of the VUJ, PMU and ARJ, and the angle of displacement (degrees) of the VUJ was measured for each of the three methods. Interrater reliability of VUJ, PMU and ARJ displacement and the VUJ angle of displacement measurements was assessed using a two-way mixed-effects agreement intra-class correlation coefficient (ICC) with 95% confidence intervals (CI). Test-retest (intrarater) reliability was calculated using a two-way random effects consistency ICC with 95% CI for all displacement measures of the VUJ, PMU and ARJ for one observer between two days.

RESULTS

The pubococcygeal line (PCL) axis measurement system demonstrated good to excellent intrarater and interrater reliability (ICC 95% interval lower bound > 0.75) for the VUJ and PMU displacement and the VUJ angle of displacement measurements. Other measurement systems were less reliable and more variable.

CONCLUSIONS

In this sample of 20 Korean patients with median prostate volume 27.5 mL and maximum volume 70 mL, the measurement methodology using the PCL consistently demonstrated good to excellent reliability and the lowest variability for the measurement of the displacement of the VUJ and PMU and the VUJ angle of displacement. The PCL methodology is recommended as the method of choice. Further studies should validate these results in patients with large prostate volumes.

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

OBJECTIVE

Urinary incontinence (UI) is a major prostate cancer (PCa) treatment-related morbidity. It has been reported that post-prostatectomy UI is related to the width of the pelvic floor muscles (PFM) and the length of the urethra. However, the details of these anatomical parameters are unknown. The aim of this study was to investigate whether preoperative pelvic parameters or anatomical parameters of the urethra, as measured by magnetic resonance imaging (MRI), are correlated with UI.

METHODS

Between 2010 and 2017, 571 patients with localized PCa underwent robot-assisted radical prostatectomy (RARP) at Okayama University Hospital. Patients treated by a single experienced surgeon were included in the study. Preoperative prostate volume, obturator internal muscle, anal sphincter muscle, levator ani muscle (LAM), urethra wall thickness (UWT), and membranous urethral length (MUL) were measured by MRI. Patients were divided into two groups depending on leakage status 1 year after RARP using Expanded Prostate Index Composite Item 1.

RESULTS

Seventy patients were included in this retrospective study. Based on leakage status, 37 and 33 patients were allocated to the no-leakage and leakage groups, respectively. There were significant differences between the two groups in age (P = 0.03), MUL (P < 0.001), UWT (P = 0.03), and LAM (P = 0.001). Multivariate logistic regression analyses revealed that MUL and LAM predicted UI 1 year after RARP.

CONCLUSIONS

Pelvic parameters measured by MRI before RARP may be useful in the prediction of UI. In particular, MUL and LAM can predict postoperative UI by strict definition.

The measurement of membranous urethral length using transperineal ultrasound prior to radical prostatectomy

OBJECTIVE

To compare preoperative membranous urethral length (MUL) measurements using magnetic resonance imaging (MRI) with two-dimensional transperineal ultrasound imaging (TPUS) in two supine positions on two separate days in men prior to radical prostatectomy.

MATERIALS AND METHODS

MUL was prospectively measured in 18 male volunteers using MRI and on two separate occasions in two different patient positions using TPUS; the patient supine with the knees extended (Supine) and supine with the knees flexed to 70 degrees (Supine KF). Agreement between TPUS and MRI measurements of MUL was assessed using Bland-Altman method comparison techniques and a two-way mixed-effects single measures intraclass correlation (ICC). Test-retest reliability was assessed using a two-way random effects single measures ICC.

RESULTS

The mean difference in MUL measurements between MRI and i) TPUS Supine was -0.8 mm (95% limits of agreement (LOA): -3.2, 1.7) and ii) TPUS Supine KF was -0.8mm (95% LOA: -3.5, 1.9). ICC indicated a point estimate of excellent agreement between MRI and TPUS Supine ICC 0.93 (95% CI: 0.76, 0.98) and TPUS Supine KF ICC 0.91 (95%CI 0.79, 0.97). There was excellent agreement between TPUS Supine and TPUS Supine KF (ICC 0.98, 95% CI: 0.96, 0.99) with a mean difference of 0.3mm (95% LOA: -1.2 to 1.3mm).

CONCLUSIONS

Preoperative MUL can be reliably measured using TPUS and demonstrates excellent agreement with MRI measurements of MUL. TPUS provides clinicians with an accessible non-invasive alternative to MRI for the measurement of MUL that can be used in outpatient urological settings and for patients where MRI is contraindicated.

Surgical Techniques to Optimize Early Urinary Continence Recovery Post Robot Assisted Radical Prostatectomy for Prostate Cancer

Purpose of Review

A variety of different surgical techniques are thought to impact on urinary continence (UC) recovery in patients undergoing robot assisted radical prostatectomy (RARP) for prostate cancer. Herein, we review current evidence and propose a composite evidence-based technique to optimize UC recovery after RARP.

Recent Findings

A literature search on studies reporting on surgical techniques to improve early continence recovery post robotic prostatectomy was conducted on PubMed and EMBASE. The available data from studies ranging from randomized control trials to retrospective cohort studies suggest that minimizing damage to the internal and external urinary sphincters and their neural supply, maximal sparing of urethral length, creating a secure vesicourethral anastomosis, and providing anterior and posterior myo- fascio-ligamentous support to the anastomosis can improve early UC recovery post RARP.

Summary

A composite evidence-based surgical technique incorporating the above principles could optimize early UC recovery post RARP. Evidence from randomized studies is required to prove benefit.