Artificial urinary sphincter urethral erosions: Temporal patterns, management, and incidence of preventable erosions

Natural History of Artificial Urinary Sphincter Erosion: Long-term Lower Urinary Tract Outcomes and Incontinence Management

OBJECTIVE

To describe long-term lower urinary tract outcomes and incontinence management after AUS erosion, including risk factors associated with each outcome.

METHODS

We retrospectively reviewed our prospectively maintained AUS database for men undergoing device explantation for urethral erosion from January 1, 1986 to October 10, 2023. Outcomes included development of urethral stricture and management of post-explant incontinence (eg, pads/clamp, catheter, salvage AUS, supravesical diversion). Risk factors were tested for association with stricture formation and repeat AUS erosion using logistic regression.

RESULTS

Around 1943 unique patients underwent AUS implantation during the study period, and 217 (11%) had a device explantation for urethral erosion. Of these, 194 had complete records available and were included for analysis. Median follow-up from implantation was 7.5 years (IQR 2.7-13.7) and median time to erosion was 2 yrs (IQR 0-6). Ninety-six patients (49%) underwent salvage AUS placement. Of those, 38/96 (40%) were explanted for subsequent erosion. On multivariable analysis, no factors were significantly associated with risk of salvage AUS erosion. On multivariable model, pelvic radiation (OR 2.7; 95% CI 1.0-7.4) and urethral reapproximation during explant for erosion (OR 4.2; 95% CI 1.5-11.2) were significantly associated with increased risk of urethral stricture (P <.05). At the time of last follow-up, 69/194 (36%) patients had a functioning salvage AUS, including both initial and subsequent salvage implants.

CONCLUSION

Following AUS erosion, radiation history and urethral reapproximation at explantation were risk factors for development of urethral stricture. Salvage AUS replacement can be performed, but has a higher rate of repeat urethral erosion.

In silico assessment of the reliability and performance of artificial sphincter for urinary incontinence

BACKGROUND

The standard artificial urinary sphincter (AUS) is an implantable device for the treatment of urinary incontinence by applying a pressure loading around the urethra through an inflatable cuff, often inducing no-physiological stimulation up to tissue degenerative phenomena. A novel in silico approach is proposed to fill the gap of the traditional procedures by providing tools to quantitatively assess AUS reliability and performance based on AUS-urethra interaction.

METHODS

The approach requires the development of 3D numerical models of AUS and urethra, and experimental investigations to define their mechanical behaviors. Computational analyses are performed to simulate the urethral lumen occlusion by AUS inflation under different pressures, and the lumen opening by applying an intraluminal pressure progressively increased under the AUS action (Abaqus Explicit solver). The AUS reliability is evaluated in terms of tissue stimulation by the mechanical fields potentially responsible for vasoconstriction and tissue damage, while the performance by the intraluminal pressure that causes the lumen opening for a specific occlusive pressure, showing the maximum urethral pressure for which continence is guaranteed.

RESULTS

The present study implemented the procedure considering the gold standard AMS 800 and a novel patented AUS. Results provided the comparison between two sphincteric devices and the evaluation of the influence of different building materials and geometrical features on the AUS functionality.

CONCLUSIONS

The approach was developed for the AUS, but it could be adapted also to artificial sphincters for the treatment of other anatomical dysfunctions, widening the analyzable device configurations and reducing experimental and ethical efforts.

Treatment strategies for revision surgery of artificial urinary sphincter: A review

Artificial urinary sphincters (AUS) are an effective treatment for male stress urinary incontinence (SUI). However, infection, erosion, mechanical failure, atrophy, and balloon deterioration cause device malfunction in approximately half of patients by 10 years after implantation. Many patients desire to regain urinary continence and require revision surgery (RS), including device removal and simultaneous or delayed implantation. Patients for whom RS is considered should be examined physically and by interview for signs of infection. Urethral erosion should be assessed using cystoscopy. If there is infection or erosion, all devices should be removed first, and a new device should be implanted several months later. During the RS, after strong adhesion around the urethra, transcorporal cuff implantation is a safe choice. Device removal and simultaneous implantation can be performed in the absence of infection or erosion. If a long time has passed since device implantation, the entire device should be replaced due to device aging and deterioration; however, if the time is short, only the defective component need be replaced. Intraoperative assessment of urethral health is necessary for device removal and implantation. If the urethra is healthy, a new cuff can be placed in the same position as the old cuff was removed from; however, if the urethra is unhealthy, the cuff can be implanted in a more proximal/distal position, or a transcorporal cuff implant may be chosen. This article reviews the literature on diagnostic and treatment strategies for recurrent SUI in male patients with AUS and proposes a flowchart for AUS revision.

Artificial urinary sphincter and stricture disease: surgical principles in management

Iatrogenic stress urinary incontinence (SUI) is the most common complication of surgical treatment of prostate cancer, regardless of operative approach, and has a major impact on patients' quality of life. Although SUI can occur after surgical treatment of benign prostatic hyperplasia, specifically transurethral prostate resection, laser enucleation of the prostate, and simple open prostatectomy, these therapeutic modalities play a much less significant role in the etiology of SUI. Artificial urethral sphincter (AUS) implantation is considered the standard treatment modality providing high success rates, including durable efficacy, and optimal patient satisfaction for moderate to severe urinary incontinence resulting mainly from radical prostatectomy. However, although complication rates are generally acceptably low, revision and/or explantation may be required due to mechanical failure and non-mechanical problems, specifically urethral atrophy/cuff deficient occlusion, infection, and cuff erosion. Several risk factors for AUS failure associated with a fragile, compromised urethra have been identified and these play a critical role in device cuff erosion and subsequent removal of the device. Among others, apparently the most impacting factors are irradiation, urethral stent placement, a previous AUS placement, and importantly presence of urethral stricture or prior urethroplasty. Generally, any clinical situation leading to a diseased urethra or lack of urethral integrity is associated with impaired local blood perfusion, and consequently lower success rates. The present review aims to evaluate the impact of the presence of prior urethral strictures and urethroplasty on the outcomes of AUS implantation on one hand, and vice-versa, the influence of AUS placement on later urethral stricture surgery, particularly following cuff erosion.

Radiologic feature of complications after artificial urinary sphincter implantation following total prostatectomy

Incontinence following total prostatectomy for prostate cancer significantly impairs patient's quality of life. In severe cases, implantation of an artificial urinary sphincter (AUS) has shown favorable outcomes, enhancing continence by constricting the bulbous urethra. The AUS system consists of a pressure-maintaining balloon, control pump serving as the operational switch, cuff that constricts the urethra, and tubes and connectors that link these components, maintaining a continuous circuit through an internal pressure medium. Most instances of AUS dysfunction are attributed to circuit leaks leading to a reduction in internal pressure, which is identifiable on imaging by fluid accumulation around the circuit, balloon collapse, control pump deformation, and air within the circuit. When the AUS circuit is uncompromised, dysfunction may arise from issues such as the inability to compress the pump due to pain or displacement outside the scrotum or urinary tract obstruction caused by bladder hemorrhage/hematoma. Imaging plays a pivotal role in the evaluation of urinary tract injuries, hematomas/seromas, and infections associated with AUS placement or replacement. Understanding the function of AUS and its appearance on CT imaging is essential for accurately assessing AUS dysfunction and post-implantation complications, guiding clinical decision-making and improving patient care outcomes.

Risk Factors for Artificial Urinary Sphincter Explantation and Erosion in Male Nonneurological Patients

PURPOSE

This study was performed to assess the risk factors for artificial urinary sphincter (AUS) explantation in a large multicenter cohort.

METHODS

We retrospectively reviewed the medical records for all 1,233 implantations of the AMS-800 AUS device in male nonneurological patients from 2005 to 2020 across 13 French centers. Patients with neurological conditions were excluded from the study. To identify factors associated with explantation-free survival, survival analysis was performed. Explantation was defined as the complete removal of the device, whereas revision referred to the replacement of the device or its components.

RESULTS

The study included 1,107 patients, of whom 281 underwent AUS explantation. The median survival without explantation was 83 months. The leading causes of explantation were infection and erosion. Univariate analysis revealed several significant risk factors for explantation: age above 75 years (34.6% in the explanted group vs. 25.8% in the nonexplanted group, P=0.007), history of radiotherapy (43.5% vs. 31.3%, P=0.001), and anticoagulant use (15% vs. 8.6%, P<0.001). In logistic regression analysis, the only significant risk factor was previous radiotherapy (odds ratio [OR], 2.05; P<0.05). Cox proportional hazards analysis revealed 2 factors associated with earlier explantation: transcorporal cuff implantation (hazard ratio [HR], 2.67; P=0.01) and the annual caseload of the center (HR, 1.08; P=0.02). When specifically examining explantation due to erosion, radiotherapy was the sole factor significantly associated with the risk of erosion (OR, 2.47; P<0.05) as well as earlier erosion (HR, 1.90; P=0.039).

CONCLUSION

In this series, conducted in a real-world setting across multiple centers with different volumes and levels of expertise, the median survival without AUS explantation was 83 months. This study confirms that radiotherapy represents the primary independent risk factor for AUS erosion in male nonneurological patients.

Urethral management after artificial urinary sphincter explantation due to cuff erosion

Introduction

The artificial urethral sphincter (AUS) is the gold standard treatment in cases of moderate-to-severe stress urinary incontinence in males. Cuff erosions are one of the most important distant complications of AUS implantation. The optimal urethral management has still not been established.

Material and methods

Search terms related to 'urethral stricture', 'artificial urinary sphincter', and 'cuff erosion' were used in the PubMed database to identify relevant articles.

Results

In this mini review we identified 6 original articles that assessed the urethral management after AUS explantation due to cuff erosion and included urinary diversion by transurethral and/or suprapubic catheterization, urethrorrhaphy, and in situ urethroplasty. We summarized the results of different management methods and their efficacy in terms of preventing urethral stricture formation. We highlight the need for better-quality evidence on this topic.

Conclusions

The available data do not provide a clear answer to the question of optimal urethral management during AUS explantation. There is a great need to provide higher-quality evidence on this topic.

Urethral Stricture Formation Following Cuff Erosion of AMS Artificial Urinary Sphincter Devices: Implication for a Less Invasive Explantation Approach

Objectives

The objective of this study is to describe a standardized less invasive approach in patients with artificial urinary sphincter (AUS) explantation due to cuff erosion and analyze success and urethral stricture rates out of a prospective database. Evidence regarding complication management is sparse with heterogenous results revealing high risk of urethral stricture formation despite simultaneous urethroplasty in case of AUS explantation.

Patients and Methods

Data of all patients undergoing AUS implantation due to stress urinary incontinence (SUI) in our tertiary center were prospectively collected from 2009 to 2015. In case of cuff erosion, AUS explantation was carried out in an institutional standardized strategy without urethroplasty, urethral preparation or mobilization nor urethrorrhaphy. Transurethral and suprapubic catheters were inserted for 3 weeks followed by radiography of the urethra. Further follow-up (FU) consisted of pad test, uroflowmetry, postvoiding residual urine (PVR), and radiography. Primary endpoint was urethral stricture rate.

Results

Out of 235 patients after AUS implantation, 24 (10.2%) experienced cuff erosion with consecutive explantation and were available for analysis. Within a median FU of 18.7 months after AUS explantation, 2 patients (8.3%) developed a urethral stricture. The remaining 22 patients showed a median Qmax of 17 ml/s without suspicion of urethral stricture. Median time to reimplantation was 4 months (IQR 3-4).

Conclusion

We observed a considerably low stricture formation and could not prove an indication for primary urethroplasty nor delay in salvage SUI treatment possibilities. Therefore, the presented standardized less invasive explantation strategy with consequent urinary diversion seems to be safe and effective and might be recommended in case of AUS cuff erosion.

Artificial urinary sphincter implantation with periprostatic cuff placement for urinary incontinence in men

INTRODUCTION

Artificial urinary sphincter (AUS) implantation is the treatment of choice for male urinary incontinence (UI). The aim of the present study was to evaluate treatment outcomes of UI in men using an AUS with a cuff placed around the prostatic urethra.

MATERIAL AND METHODS

Forty-three men with preserved prostatic urethra were selected for AUS implantation due to UI. Twenty patients had the cuff implanted around the prostate using the retropubic approach (Group 1), and 23 had the cuff placed around the bulbous urethra (Group 2). Both groups were compared in terms of continence quality as well as intra- and postoperative complications.

RESULTS

The groups were comparable with respect to age and duration of follow-up. Median time to complications was 90.3 and 10.7 months in Group 1 and Group 2, respectively (p = 0.007). The complication rate was 40% and 58.3% in Group 1 and 2, respectively (p = 0.001). Complete continence was obtained in 80% of patients from Group 1 and 33.3% of men from Group 2A (p = 0.001).

CONCLUSIONS

The analysis indicates that cuff placement around the prostatic urethra results in better continence and is characterised by fewer complications. This method is dedicated for patients who have not had the prostate gland removed. Due to the retrospective nature of this analysis and small groups of patients, it is not possible to formulate ultimate recommendations.

Management of urethral atrophy after implantation of artificial urinary sphincter: what are the weaknesses?

The use of artificial urinary sphincter (AUS) for the treatment of stress urinary incontinence has become more prevalent, especially in the "prostate-specific antigen (PSA)-era", when more patients are treated for localized prostate cancer. The first widely accepted device was the AMS 800, but since then, other devices have also entered the market. While efficacy has increased with improvements in technology and technique, and patient satisfaction is high, AUS implantation still has inherent risks and complications of any implant surgery, in addition to the unique challenges of urethral complications that may be associated with the cuff. Furthermore, the unique nature of the AUS, with a control pump, reservoir, balloon cuff, and connecting tubing, means that mechanical complications can also arise from these individual parts. This article aims to present and summarize the current literature on the management of complications of AUS, especially urethral atrophy. We conducted a literature search on PubMed from January 1990 to December 2018 on AUS complications and their management. We review the various potential complications and their management. AUS complications are either mechanical or nonmechanical complications. Mechanical complications usually involve malfunction of the AUS. Nonmechanical complications include infection, urethral atrophy, cuff erosion, and stricture. Challenges exist especially in the management of urethral atrophy, with both tandem implants, transcorporal cuffs, and cuff downsizing all postulated as potential remedies. Although complications from AUS implants are not common, knowledge of the management of these issues are crucial to ensure care for patients with these implants. Further studies are needed to further evaluate these techniques.

Artificial Urinary Sphincter Cuff Size Predicts Outcome in Male Patients Treated for Stress Incontinence: Results of a Large Central European Multicenter Cohort Study

PURPOSE

The aim was to study the correlation between cuff size and outcome after implantation of an AMS 800 artificial urinary sphincter.

METHODS

A total of 473 male patients with an AMS 800 sphincter implanted between 2012 and 2014 were analyzed in a retrospective multicenter cohort study performed as part of the Central European Debates on Male Incontinence (DOMINO) Project.

RESULTS

Single cuffs were implanted in 54.5% and double cuffs in 45.5% of the patients. The cuffs used had a median circumference of 4.5 cm. Within a median follow of 18 months, urethral erosion occurred in 12.8% of the cases and was associated significantly more often with small cuff sizes (P<0.001). Multivariate analysis showed that, apart from cuff size (P=0.03), prior irradiation (P<0.001) and the penoscrotal approach (P=0.036) were associated with an increased erosion rate. Continence rate tended to be highest with median cuff sizes (4-5.5 cm).

CONCLUSION

Apart from irradiation and the penoscrotal approach, small cuff size is a risk factor for urethral erosion. Results are best with cuff sizes of 4.5-5.5 cm.

What is the fate of artificial urinary sphincters among men undergoing repetitive bladder cancer treatment?

Purpose

Functional characteristics and durability of the artificial urinary sphincter (AUS) among patients who develop bladder cancer has been poorly characterized. We sought to evaluate AUS outcomes among patients subsequently diagnosed with bladder cancer, in order to describe device survivability when subject to diagnostic and therapeutic procedures such as cystoscopy, transurethral resection, and cystectomy.

Materials and Methods

We retrospectively reviewed 1,803 male patients treated with AUS surgery at a single institution between 1983-2014. We describe AUS device outcomes among patients undergoing surveillance and treatment for bladder cancer.

Results

Following AUS placement, 14 (0.8%) patients were subsequently diagnosed with and treated for bladder cancer and 4 patients with bladder cancer undergoing treatment and screening, subsequently received AUS placement. The median follow-up from device placement was 7.2 years (interquartile range [IQR], 2.8-11.5), and the median time from AUS placement to bladder cancer diagnosis was 6 (IQR, 0-9). There were a total of 8 primary and 1 secondary devices failures. Despite a median of 2 diagnostic cystoscopies (IQR, 1-6) and 0 bladder tumor resections (IQR, 0-0) per patient following device implantation, only 1 (5.6%) patient experienced an iatrogenic erosion related to urethral manipulation. Among those undergoing cystectomy (n=4), 1 device was left in situ without complication.

Conclusions

Bladder cancer surveillance and treatment with an AUS device in place appears to confer minimal additional risk to AUS survival. Careful attention should be given to device deactivation and use of the smallest caliber instruments available to minimize the risk of iatrogenic urethral erosion.