Preoperative magnetic resonance imaging in predicting early continence recovery after robotic 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 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.

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.

Comparison of Retzius-sparing versus standard robot-assisted radical prostatectomy for prostate cancer

INTRODUCTION AND OBJECTIVES

We aim to compare the first year oncological and functional outcomes of Retzius-sparing robot-assisted radical prostatectomy (Rs-RARP) and standard robot-assisted radical prostatectomy (RARP).

MATERIALS AND METHODS

Eighty-eight patients who underwent robotic radical prostatectomy between 2018-2019 were included. We compared the minimum one-year follow-up results of patients who underwent Rs-RARP or RARP in terms of oncological and functional outcomes. Potency was assessed with the Sexual Health Inventory for Men (SHIM) score and was defined as an erection sufficient for penetration. Continence was defined as the absence of urinary incontinence with no safety pad. Patients were evaluated in the first month of follow-up and subsequently, every three months.

RESULTS

Forty-six patients in Rs-RARP and 42 patients in the RARP group were enrolled. Catheter removal time was shorter in the Rs-RARP group (12 vs. 14 days, p = 0.001). At the 1st month visit, 41 patients (%89) were continent (no pads) in the Rs-RARP group while 25 patients (%59) were continent in the RARP group (p = 0.001). Patients who underwent Rs-RARP achieved faster recovery of urinary continence (Log-rank, p = 0.001). After one year of follow-up, 43 patients (93%) in Rs-RARP group and 38 patients (90%) in RARP group were continent (p = 0.6). Potency rates were 38.7% in Rs-RARP and 34.4% in RARP group (p = 0.28). There were no cases of biochemical recurrence in any group.

CONCLUSIONS

Rs-RARP is a feasible technique, providing early return of continence. However, overall continence rates were similar at the end of the one-year follow-up.

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.

Is pre-operative urodynamic bladder function the true predictor of outcome of male sling for post prostatectomy incontinence?

PURPOSE

To investigate pre-operative urodynamic parameters in male sling patients to ascertain whether this might better predict surgical outcomes and facilitate patient selection.

METHODS

We performed a retrospective, case notes and video-urodynamics, review of men who underwent AdVanceXP male sling in three London hospitals between 2012 and 2019. Urodynamics were performed in all centres, while retrograde leak point pressure (RLPP) was performed in one centre.

RESULTS

Successful outcome was seen in 99/130 (76%) of men who required one pad or less per day. The dry rate was 51%. Pad usage was linked to worse surgical outcomes, mean 2.6 (range 1-6.5) for success vs 3.6 (range 1-10) although the ranges were wide (p = 0.002). 24 h pad weight also reached statistical significance (p = 0.05), with a mean of 181 g for success group versus 475 g for the non-successful group. The incidence of DO in the non-successful group was significantly higher than in successful group (55% versus 29%, p = 0.0009). Bladder capacity less than 250 ml was also associated with worse outcomes (p = 0.003). Reduced compliance was not correlated with outcomes (31% for success groups vs 45% for non-successful group, p = 0.15). Preoperative RLPP was performed in 60/130 patients but did not independently reach statistical significance (p = 0.25).

CONCLUSION

Urodynamic parameters related to bladder function-detrusor overactivity and reduced maximum cystometric capacity predict male sling outcomes and may help in patient selection for male sling (or sphincter) surgery; whereas urodynamic parameters of sphincter incompetency (RLPP) were not predictive. Further larger scale studies are required to confirm these findings.

Early continence after radical prostatectomy: A systematic review

BACKGROUND AND OBJECTIVE

Urinary incontinence is the adverse effect with more impact on patients' quality of life after undergoing radical prostatectomy. The objective of this study is to review the present evidence that describes the variations on surgical techniques which aim to preserve urinary continence after radical prostatectomy.

EVIDENCE ACQUISITION

We searched the literature on PubMed, Cochrane, and ScienceDirect according to the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) statement, using the PICO review protocol. The search terms were urinary continence, urinary incontinence, urinary leakage, radical prostatectomy, open radical prostatectomy, laparoscopic prostatectomy, robot-assisted laparoscopic prostatectomy, robotic prostatectomy. We identified 1,603 registers, and 27 articles were reviewed for meeting the inclusion criteria. Six of them are randomized clinical trials and 4 of them, meta-analysis.

EVIDENCE SYNTHESIS

The surgical techniques more frequently used to achieve early urinary continence are bladder neck and neurovascular bundles preservation, as well as the reconstruction of the rhabdosphincter. The latter has been presented in three randomized clinical trials. Even though some approaches have obtained improved functional outcomes, the lack of consensus on the definition of urinary incontinence and its measurement methods have not advocated for the creation of technical recommendations based on scientific evidence.

CONCLUSIONS

The reconstruction of the rhabdosphincter is the only technique that has shown improved functional results through randomized trials. The current evidence is limited and heterogenous, and more studies with consistent criteria are needed in order to establish a standard surgical technique.