Mechanism of Action of the Transobturator Sling for Post-Radical Prostatectomy Incontinence: A Multi-institutional Prospective Study Using Dynamic Magnetic Resonance Imaging

Management of Urinary Incontinence Following Radical Prostatectomy: Challenges and Solutions

Urinary incontinence is a common and debilitating problem in patients undergoing radical prostatectomy. Current methods developed to treat urinary incontinence include conservative treatments, such as lifestyle education, pelvic muscle floor training, pharmacotherapy, and surgical treatments, such as bulking agents use, artificial urinary sphincter implants, retrourethral transobturator slings, and adjustable male sling system. Pelvic floor muscle exercise is the most common management to improve the strength of striated muscles of the pelvic floor to try to recover the sphincter weakness. Antimuscarinic drugs, phosphodiesterase inhibitors, duloxetine, and a-adrenergic drugs have been proposed as medical treatments for urinary incontinence after radical prostatectomy. Development of new surgical techniques, new surgical tools and materials, such as male slings, has provided an improvement of outcomes after UI surgery. Such improvement is still ongoing, and the uptake of new devices might lead to even better outcomes after UI surgery.

The male sling for stress urinary incontinence: tips and tricks for success

Urethral slings are a good treatment option for mild male stress urinary incontinence. There are many different sling options, but herein our group describes our techniques with the Advance® and Virtue® slings. More important than technique, we strongly think that patient selection is paramount to sling success. We only offer slings to patients who have low 24 hour pad weights, high Valsalva leak point pressure, and no history of pelvic radiation. Still, like with any surgery, we recommend that the surgeons implant the device that they are most comfortable with along with their chosen techniques.

What if artificial urinary sphincter is not possible? Feasibility and effectiveness of ProACT for patients with persistent stress urinary incontinence after radical prostatectomy treated by sling

BACKGROUND

Stress urinary incontinence (SUI) is a major component of the post radical prostatectomy (RP) trifecta. Surgical treatments are sub-urethral slings, artificial urinary sphincter (AUS) and adjustable peri-urethral balloons (PUB) ProACT. All options are imperfect at best and persistent SUI is challenging when AUS is not manageable.

AIMS

This study analyzed the cumulate experience of our 2 centers with offering PUB implantation for SUI post RP in patients with insufficient improvement from slings.

MATERIALS & METHODS

This retrospective study reviewed all patients implanted with second line ProACT. The primary endpoint was continence, defined as 0 pads per day (PPD). The secondary endpoints were 50% decrease in PPD and increases in the Incontinence Quality of Life score (IQOL). Refilling and complications were reported.

RESULTS

Between 2007 and 2016, 26 patients were implanted. Five patients have had adjuvant radiotherapy (18%). The mean follow-up was 36 months (±20; min 14-max 128). All patient presented with persistent SUI, using 2.3 PPD (±1; min 1-max 6), and only one sling was removed due to infection. After ProACT with an average 3 mL refilling (±1.2 min 2-max 6), 18 patients (66.7%) were continent. Eight of the remaining patients (29.6%) were improved; their number of PPD decreased from 2.6 to 1. The average IQOL score of those 8 patients increased by 20 points, from 53.4 up to 74.2 (P = .005). Overall 26 patients (96.3%) were improved. The remaining patient was not implanted because of an intraoperative urethral injury and is considered a failed case (3.7%). He had instead an AUS implantation. Three patients (14.8%) needed PUB replacement.

CONCLUSION

The limited population of patients from both our centers who presented with persistent SUI after RP, despite sling placement, improved with PUB ProACT implantations without significant complications.

[Urodynamic evaluation of patients cured of their post-radical prostatectomy stress urinary incontinence following transobturator male sling implantation]

INTRODUCTION

The mechanism(s) responsible(s) for continence recovery after male sling implantation for post-radical prostatectomy incontinence are imperfectly known. The goal of this study was to evaluate urodynamic parameters before and after male sling insertion, only in patients cured of their stress urinary incontinence.

PATIENTS AND METHODS

In total, 10 continent patients after transobturator male sling, with no history of urethral stenosis or pelvic radiation, were randomly selected from a database for urodynamic studies. Urodynamic parameters included urethral pressure profiles (UPP), with measurements of maximal urethral closure pressure (MUCP) and functional urethral length (FUL), and were compared with preoperative urodynamic data. Paired sampled were compared with the use of the Wilcoxon signed-rank test (StatPlus®).

RESULTS

Urodynamic studies were performed after a median time of 9months (min 4 - max 34) following sling implantation. Postoperatively, a rise of 11cm H₂O in median MUCP (P=0.09) and an increase of 14mm in median FUL (P=0.13) were observed. None of the urodynamic changes was statistically significant.

CONCLUSIONS

Following sling implantation, modifications in UPPs were observed, with increases in MUCP and FUL but these increments were not statistically significant. Limitations to our study include biases inherent to the interpretation and reproducibility of urethral profilometry, the sample size, and the variable delay between sling implantation and postoperative urodynamic studies.

LEVEL OF EVIDENCE

4.

Magnetic resonance imaging as an assessment tool following intervention with an AdVance XP suburethral sling for postprostatectomy urinary incontinence

AIMS

The aim of this study was to compare magnetic resonance imaging (MRI) parameters in patients with mild incontinence after radical prostatectomy, who had undergone treatment with a suburethral sling. The objective was to compare patients who had been successfully treated with unsuccessful patients.

METHODS

This observational cohort study at a single institution evaluated consecutive patients treated with an AdVance XP sling. MRI was performed using a 1.5 Tesla system. Preoperative urodynamic assessment and flexible cystoscopy were performed. The qualitative analysis was based on sling indentation (complete vs incomplete). The quantitative analysis comprised the following three parameters: the sling-pubis distance, the thickness of the proximal urethral bulb, and the sling backward distance (SBD), defined as the distance between the prolongation of a line through the major axis of the pubis (the line-segment joining the vertices of the pubis) and the sling indentation. The primary outcome was pad count at 3 months; cure as zero pads. A logistic univariate regression model was employed to assess the potential predictors of successful outcomes. An adjusted multivariate logistic regression model using the significant univariate factors was developed.

RESULTS

Of the 83 patients enrolled, the univariate analysis revealed a relationship between failure and adverse urodynamics and between success and sling indentation, thickness of the proximal bulb and SBD. Only the association with SBD persisted in the multivariate analysis.

CONCLUSIONS

MRI revealed a strong relationship between proper positioning of the sling (small SBD) and continence outcome. These data have important implications for a second surgery following initial sling failure.