Complications of Urethral Bulking Agents for Stress Urinary Incontinence: An Extensive Review Including Case Reports

A Clinical Learning Curve Study of Polydimethylsiloxane Urolastic for Stress Urinary Incontinence: Does Safety Improve when Expertise Grow?

OBJECTIVES

The aim of the study was to characterize the learning curve of bulk injection therapy polydimethylsiloxane Urolastic (PDMS-U) for stress urinary incontinence.

DESIGN

Secondary analysis from three clinical studies on efficacy and safety outcomes of PDMS-U was performed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

PDMS-U-certified physicians who performed ≥4 procedures were included. The primary outcome was the number of PDMS-U procedures needed to achieve acceptable failure rates for "complications overall," "urinary retention," and "excision," using the LC-CUSUM method. For the primary outcome, physicians who performed ≥20 procedures were used. For the secondary outcome, logistic and linear regression analysis was used to assess the relationship between number of procedures, complications (complications overall, urinary retention, pain, exposure, excision of PDSM-U), and duration of treatment.

RESULTS

In total, 203 PDMS-U procedures were performed by nine physicians. Five physicians were used for the primary outcome. For "complications overall," "urinary retention," and "excision," two physicians reached a level of competence: one at procedure 20 and one at procedure 40. The secondary outcome showed no statistically significant association between procedure number and complications. There was a statistically significant increase in the duration of treatment with more physician experience (mean difference 0.83 min per 10 additional procedures, 95% CI: 0.16-1.48).

LIMITATIONS

One limitation is that retrospectively collected data might have underreported the number of complications. Secondly, there was variation in the way the technique was applied between physicians.

CONCLUSIONS

Physicians' experience in the PDMS-U procedure did not influence safety outcomes. There was large inter-physician variability and most physicians did not reach acceptable failure rates. There was no relationship between PDMS-U complications and the number of performed procedures.

Long-Term Surveillance and Management of Urological Complications in Chronic Spinal Cord-Injured Patients

Bladder dysfunction is a common complication after chronic spinal cord injury (SCI). Patients may experience renal function loss, urinary tract infection (UTI), urolithiasis, bladder cancer, and even life-threatening events such as severe sepsis or renal failure. Suitable patient care may prevent UTI and urinary incontinence, decrease medication use, and preserve renal function. As the primary goal is to preserve renal function, management should be focused on facilitating bladder drainage, the avoidance of UTI, and the maintenance of a low intravesical pressure for continence and complete bladder emptying. Currently, several bladder management options are available to SCI patients: (1) reflex voiding; (2) clean intermittent catheterization; (3) indwelling catheterization. The target organ may be the bladder or the bladder outlet. The purposes of intervention include the following: (1) increasing bladder capacity and/or decreasing intravesical pressure; (2) increasing bladder outlet resistance; (3) decreasing bladder outlet resistance; (4) producing detrusor contractility; (5) urinary diversion. Different bladder management methods and interventions may have different results depending on the patient's lower urinary tract dysfunction. This review aims to report the current management options for long-term bladder dysfunction in chronic SCI patients. Furthermore, we summarize the most suitable care plans for improving the clinical outcome of SCI patients.

Foreign body granuloma development after calcium hydroxylapatite injection for stress urinary incontinence: A literature review and case report

Objectives

To present a case of foreign body granuloma (FBG) development after injection of calcium hydroxylapatite as a urethral bulking agent and to review all documented cases of this phenomenon in the literature.

Methods

We analyzed a new case of calcium hydroxylapatite-induced FBG. We also conducted a literature review of the PubMed, Embase, CINAHL, and Web of Science databases through March 2022. Reports were included if they contained stress urinary incontinence patients that developed an FBG after calcium hydroxylapatite injection. The cases were reviewed for presenting symptoms, patient demographics, granuloma details, and surgical treatment.

Results

We screened 250 articles and included six articles between 2006 and 2015 in addition to the present case. The median age of the patients was 65.5 years (range 45-93), and all patients were female. The most common presenting symptoms and the proportion of patients affected were difficulty voiding (4/8), recurrent urinary incontinence (3/8), and dyspareunia (2/8). The median time between the first CaHA injection and discovery of the FBG was 5 months (range 1-50). The median longest dimension of the FBGs was 1.85 cm (range 1.0-3.0). The 8 masses observed were evenly distributed throughout the urethra, with 3 in the bladder neck, 2 in the midurethra, and 3 in the distal urethra. Surgical excision was the predominant management choice, with some variation in technique.

Conclusions

Severe, persistent lower urinary tract symptoms after calcium hydroxylapatite injection may indicate an FBG, which has been successfully managed with surgical excision.

Medical malpractice in stress urinary incontinence management: A 30-year legal database review

BACKGROUND

The purpose of this study is to investigate the most common reasons for and judicial outcomes of malpractice claims related to stress urinary incontinence (SUI) management.

MATERIALS AND METHODS

Using the Westlaw database, a search was performed using the terms "medical malpractice" or "negligence" in combination with "stress incontinence" or "stress urinary incontinence" between January 1, 1990 and January 1, 2020. Extracted information included trial date, demographic information, defendant profession, procedure performed, procedure complications, alleged malpractice, trial outcome, and monetary award. Data were analyzed using descriptive statistics.

RESULTS

The Westlaw search yielded 79 case results. Of the cases, 70.4% (n = 38/54) had a defense verdict, 22.2% (n = 12/54) had a plaintiff verdict, and 7.4% (n = 4/54) were settled. The most commonly implicated procedure was mid-urethral sling (63.2%, n = 36/57). Among the plaintiffs, 48.4% (n = 61/126) claimed negligence in preoperative care, 33.3% (n = 42/126) claimed negligence in surgical performance, and 18.3% (n = 23/126) claimed negligence in postoperative care. Lack of informed consent was the most common complaint related to negligence in preoperative care (42.6%, n = 26/61). The average indemnity payment was $1,253,644 for preoperative care negligence, $1,254,491 for surgical performance negligence, and $2,239,198 for postoperative care negligence. Of the defendants, 63.4% (n = 52) were gynecologists and 36.6% (n = 30) were urologists.

CONCLUSIONS

Negligent preoperative care, with a particular emphasis on failure to obtain informed consent, and negligent surgical performance are the leading causes of malpractice claims during SUI management. Mid-urethral sling was the most commonly litigated procedure. This study highlights key factors to consider in minimizing malpractice risk during SUI management.

Stress Urinary Incontinence: Slings, Single-Incision Slings, and Nonmesh Approaches

Synthetic midurethral slings offer optimal cure rates for the minimally invasive treatment of stress urinary incontinence in women. Performed via a retropubic or transobturator technique, midurethral sling approaches demonstrate comparable efficacy, with unique adverse event profiles. Single incision slings were introduced to minimize the complication of groin pain with full-length transobturator slings and enhance operative recovery. The earliest therapies for stress urinary incontinence including urethral bulking, retropubic colposuspension, and autologous sling offer alternative methods of surgical management without using synthetic mesh. These methods boast satisfactory efficacy with low rates of complications, and may be ideal for appropriately selected patients.

Effectiveness and safety of bulking agents versus surgical methods in women with stress urinary incontinence: a systematic review and meta-analysis

INTRODUCTION AND HYPOTHESIS

The objective was to evaluate the efficacy and safety of bulking agents compared with surgical methods for female stress urinary incontinence.

METHODS

Inclusion and exclusion criteria: women with stress urinary incontinence. Bulking agents versus any surgical treatment as a comparison. Patients with other types of incontinence and treatment were excluded. Electronic databases (PubMed, MEDLINE, and the Cochrane Library) were searched from 2000 until 2021 to identify articles evaluating the effectiveness and safety of urethral bulking agents versus surgical methods. Risk-of-bias assessment tools recommended by the Cochrane Society were used to evaluate the risk of bias in the studies included.

RESULTS

Six studies were included in the quantitative synthesis for a total of 710 patients. Our systematic review and meta-analysis showed that bulking agents are less effective than surgical procedures according to subjective improvement after treatment (RR = 0.70, 95% CI: 0.53 to 0.92, p = 0.01). There was no statistically significant difference between these two methods with regard to complications after the intervention (RR = 1.30, 95% CI: 0.30 to 5.66, p = 0.73).

CONCLUSION

The main limitation of this systematic review and meta-analysis was the absence of a common objective outcome measure to evaluate effectiveness. However, it shows that bulking agents are less effective than surgical procedures in subjective improvement. Safety analysis showed no significant difference between these methods. Hence, we believe that the first and final surgery is considered to be the best.

Clinical presentation and treatment of Macroplastique® urethral exposures: a retrospective case series

INTRODUCTION AND HYPOTHESIS

Manufacturers of Macroplastique® for urethral bulking have not previously reported exposures as potential complications. This study was aimed at identifying presenting symptoms, management, and outcomes in patients experiencing urethral or bladder exposures.

METHODS

A retrospective case series from 2010 to 2019 was performed in an academic affiliated hospital system. Participants were 18-89 years old and received Macroplastique® urethral bulking for treatment of stress urinary incontinence. Charts were identified through diagnosis and procedure codes relating to injections of urethral bulking agents and foreign bodies in the bladder or urethra. Factors evaluated were patient history and presenting symptoms, diagnostic evaluation, treatment, and outcomes using frequency tables for categorical values and statistical distribution with median and interquartile ranges (IQR) for continuous variables.

RESULTS

After review of 1,269 charts, 580 cases met the inclusion criteria and 14 Macroplastique® urethral exposures were identified. The median age at first presentation was 73.5 years (IQR57.5-79.7 years) with 48 months (IQR 22-78 months) as the median time to first presentation after last Macroplastique® injection. The median number of injection sessions was 2 (IQR 1-2.75 sessions) with a medium volume of 4.5 ml (IQR 2.75-9.0 ml). Presenting symptoms included urge incontinence (64.3%), stress urinary incontinence (57.1%), recurrent urinary tract infection (42.9%), urinary urgency (28.9%), urinary frequency (28.9%), urinary retention (14.3%), and interrupted flow (7.1%). Macroplastique® urethral exposures were extracted in 10 patients using blunt, sharp, or electrocautery excision. No complications after excision were identified and improvement in urinary symptoms was observed.

CONCLUSION

Urethral bulking with Macroplastique® can lead to symptomatic urethral exposures.

Periurethral injection with polyacrylamide after previous TVT surgery

INTRODUCTION AND HYPOTHESIS

The aim of this registry study was to assess the clinical utility of using periurethral bulking with polyacrylamide hydrogel in women with stress urinary incontinence (SUI) after previous midurethral sling surgery.

METHODS

The study period was 2007 through 2019. Using data from the Norwegian Female Incontinence Registry we included 57 women who had received Bulkamid® because of insufficient improvement or recurrent SUI after previous retropubic TVT surgery. The primary outcome was cure of SUI, and secondary outcomes were patient satisfaction, degree of leakage, change in urgency incontinence (UUI), free flow rate, postvoid residual volume, and complications. Descriptive statistics were used to characterize data and Wilcoxon signed-rank test to compare pre- and postoperative results for pairs, with level of significance at p < 0.05.

RESULTS

Pure SUI was seen in 19 (33.3%) while 38 (66.7%) had mixed incontinence. Postoperatively 72.9% had a negative stress test and 73.7% were satisfied with treatment. There was only 1 complication in 67 injections (1.5%). De novo UUI occurred in five patients, corresponding to 8.8% of the whole study group, but 26.3% among those with no preoperative UUI problems. Among the patients with preoperative UUI, 39.5% were cured of this problem and a further 36.8% were improved.

CONCLUSIONS

The cure rate and satisfaction rate of periurethral bulking with polyacrylamide after previous MUS are favorable and complications are rare. There seems to be a risk of overactive bladder symptoms developing in women with no such symptoms preoperatively.

Urethral bulking agent found in a urethral caruncle which did not respond to topical oestrogens: A case report

Background

Urethral caruncles are lesions occurring at the urethral orifice, around the posterior lip of the urethra. They are the most common benign growth of the female urethra. They are often asymptomatic and found incidentally on clinical examination. When symptomatic they commonly present with bleeding. Treatment includes vaginal oestrogens or, failing that, surgical excision. We present an unusual finding after excision of a urethral caruncle.

Case

A patient with a background of stress urinary incontinence had numerous pelvic surgeries, including colposuspension, tension-free vaginal tape (TVT) and Macroplastique (a urethral bulking agent). She developed bleeding from a 3 cm urethral caruncle, which did not improve with vaginal oestrogens. She proceeded to have a surgical excision of the caruncle. Histology revealed a foreign material with surrounding foreign-body-type multinucleate giant cell reaction. The material was compatible with Macroplastique.

Conclusion

This case report describes an unusual and unexpected histological finding. Macroplastique is injected in the urethra, 10–15 mm from the bladder neck. We suspect the caruncle dragged the Macroplastique material out through the urethral meatus. If urethral caruncles are not adequately treated with vaginal oestrogens, surgery should be considered.

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Urethral caruncles are lesions occurring at the urethral orifice, around the posterior lip of the urethra

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They are the most common benign growths of the female urethra

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When symptomatic they commonly present with bleeding.

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Treatment includes topical oestrogens or failing that, surgical excision.

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The presence of a urethral bulking agent in a caruncle, which did not respond to topical oestrogen, is reported.

Bladder neck and urethral erosions after Macroplastique injections

AIMS

To evaluate the presentation, risk factors, diagnostic workup, management, and outcomes of Macroplastique (MPQ) erosions.

METHODS

We performed a retrospective chart review of women experiencing MPQ erosion at two tertiary care centers (United States and United Kingdom). Data collected included age, presenting symptoms, parity, comorbidities, hormone replacement therapy, sexual activity, and smoking status. Previous surgical history, time from MPQ injection, urine culture results, and cystoscopic and imaging findings were also reviewed. Development of stress urinary incontinence (SUI) after MPQ removal and subsequent SUI treatments were recorded.

RESULTS

From 2012 to 2018, 18 patients were identified with a median follow-up time of 24 months (interquartile range [IQR] 8-33). All patients presented with recurrent urinary tract infections (rUTI) and had cystoscopic evidence of MPQ erosion. The most common location of erosion was the bladder neck area (72%). Median time to presentation since MPQ injection was 14 months (IQR 11-35). The majority of patients (72%) had a previous history of anti-incontinence surgery. The overall success rate of endoscopic management defined as resolution of presenting symptoms including rUTI was 80%. The majority of patients (80%) developed recurrent SUI following MPQ resection with 33% requiring a subsequent autologous fascial sling placement.

CONCLUSION

MPQ erosions present predominantly with UTI, sometimes years after the original injection, and may necessitate endoscopic management with satisfactory results in most patients. Following excision of MPQ, these patients are highly likely to experience SUI recurrence and need to be appropriately counseled. Some may require additional subsequent autologous fascial sling placement for treatment of their SUI symptoms.

Polydimethylsiloxane Erosion as a Cause for Recurrent Urinary Tract Infections

Background: Urethral bulking agents are commonly used for the management of stress urinary incontinence (SUI). Little long-term data exist for these agents, with few reports of migration or urethral erosion. Case Presentation: We describe a unique case of a woman who received a midurethral sling 3 years after receiving an injection of the urethral bulking agent, polydimethylsiloxane, because of persistent SUI. Her subsequent recurrent urinary tract infections led to the identification of a bladder neck erosion of the urethral bulking agent with a concomitant calcification. Conclusion: When irritative voiding symptoms are experienced in patients who have received urethral bulking agents, erosion must be considered. Furthermore, little is known regarding the definitive management of SUI in patients that have previously received an injection of a urethral bulking agent.

Patients' satisfaction and safety of bulk injection therapy Urolastic for treatment of stress urinary incontinence: A cross-sectional study

Aims

Primary outcome was to evaluate patients' satisfaction after being treated with bulk injection therapy polydimethylsiloxane Urolastic (PDMS‐U) for stress urinary incontinence (SUI). Secondary outcomes were: subjective cure, objective cure, severity of SUI symptoms, complications, reintervention rate, and disease‐specific quality of life. Furthermore, to determine if outcomes worsened during time‐after‐treatment (time‐frames: 0‐12, 13‐24, and ≥25 months).

Methods

In a cross‐sectional design, patients treated with PDMS‐U were recruited for hospital revisit. The primary outcome, patients' satisfaction, was assessed by the surgical satisfaction questionnaire. Subjective cure, objective cure, and severity of symptoms were assessed by the patients global impression of improvement, standardized cough stress test, and Sandvik severity scale, respectively. Medical charts and face‐to‐face interviews were used to determine complications and reinterventions.

Results

About 110 patients participated, 87 revisited the hospital. Median follow‐up was 25 months (interquartile range: 14;35 months). Patients' satisfaction rate was 51%. Subjective and objective cure were respectively 46% and 47%. Most prevalent complications were: urinary retention (22%), pain (15%), and dyspareunia (15%). Exposure and erosion occurred in 7% and 5%, respectively. Reintervention rate of reinjection and excision of bulk material was 6% and 18.0%, respectively. Objective cure significantly worsened during time‐after‐treatment (P = < .05).

Conclusions

About half of the patients being treated with PDMS‐U were satisfied and subjectively cured 2 years after treatment, although the majority still experienced symptoms of SUI. Most complications were mild and transient, however, in 18% excision of bulk material was indicated for severe or persistent complications such as pain, exposure, or erosion.

Particulate Versus Non-Particulate Bulking Agents In The Treatment Of Stress Urinary Incontinence

Stress urinary incontinence (SUI) has been treated surgically with the midurethral sling but in recent years, this option has come under scrutiny and the risk-benefit balance continues to be reviewed. The low-risk alternative for women with uncomplicated SUI is the bulking agent, which aims to achieve continence through coaptation of the urethra. Two classes of bulking agents can be identified: those made from solid microparticles in an absorbable liquid or gel carrier (particulate agents) and those comprising a homogenous gel (non-particulates) that resists absorption. Polydimethylsiloxane®, carbon-coated zirconium oxide®, calcium hydroxyapatite® and polyacrylate polyalcohol copolymer® are currently marketed particulate agents. With the exception of calcium hydroxyapatite, the particles are non-degradable. Each agent achieves its long-term bulking effect through reactive changes around the persisting particles while the carrier volume is lost. Bulkamid® is a non-particulate agent with the bulking effect resulting from the volume of gel injected. The lasting network of fine fibers formed by the host tissue anchors the gel in situ. Foreign-body granulomas, erosion and migration/material extrusion and loss of bulk have been observed in connection with the particle-based products. Bulkamid may be mechanistically less liable to these events; however, there are minimal data directly comparing the two types of bulking agent. The question of durability is inevitable based on their differing modes of action.

Complications of urethral bulking therapy for female stress urinary incontinence

AIMS

To review, report, and discuss the complications associated with urethral bulking therapy in female stress urinary incontinence.

METHODS

An extensive nonsystematic literature review on complications associated with injectable bulking agents used in the clinical practice was conducted. We reviewed articles published in English and indexed in the PubMed, Embase, and Google Scholar databases. Original articles, case reports, and case series were taken into consideration. Data regarding the safety of injectable bulking agents and the complications associated with their utility within the context of urethral bulking therapy for female stress urinary incontinence were extracted and discussed.

RESULTS

Approximately, 1/3 of the patients experience some type of a complication after urethral bulking therapy. The majority of these complications are of low grade, transient, do not necessitate additional surgical intervention, and amenable to treatment with conservative measures such as clean intermittent catheterization and antibiotics. However, more serious complications such as abscess formation, delayed hypersensitivity reactions, and vaginal erosion have been reported. Some of the injectable bulking agents have been withdrawn from the market because of their unfavorable adverse effect profile.

CONCLUSIONS

Urethral bulking therapy can be considered as a low-risk procedure. However, it is not without complications which can be severe in rare instances. The search for the ideal urethral bulking agent is ongoing and future comparative studies assessing the safety and efficacy of these compounds in randomized controlled settings are warranted.

How cure rates drive patients' preference for urethral bulking agent or mid-urethral sling surgery as therapy for stress urinary incontinence

AIMS

To assess the patients' median-accepted threshold of cure rate for urethral bulking agent (UBA) treatment compared to mid-urethral sling (MUS) surgery for treatment of female stress urinary incontinence (SUI). Secondly, to determine the correlation between treatment trade-off point and patient characteristics.

METHODS

Women older than 18 years, with predominant SUI, seeking treatment, underwent a structured interview. The treatment trade-off point was determined in scenario one: UBA vs transobturator standard MUS surgery (SMUS) performed under general/spinal anesthesia with one-night hospital stay, and scenario 2: UBA compared to single-incision MUS surgery (SIMS) performed under local analgesia (with sedation) in a daycare setting. The treatment trade-off point was assessed by decreasing the cure rate of UBA from 85% to 10% with steps of 2% until the patient's treatment preference switched to SMUS/SIMS.

RESULTS

One hundred and five patients were interviewed. Mean age was 52 years (SD, ±13.4). The median trade-off point for scenarios 1 and 2 was 79% (interquartile range [IQR]: 69, 85) and 85% (IQR: 71, 85), respectively. Patients with longer duration of SUI symptoms were willing to trade more efficacy to prefer UBA treatment.

CONCLUSIONS

Patients with SUI are willing to trade a lower cure rate to prefer UBA over SMUS to avoid hospitalization and general anesthesia. When SIMS is performed in a daycare setting under local analgesia, the majority of patients with SUI are of the opinion that cure rates of UBA should be at least as high as SIMS to be worth considering. The treatment preference is not strongly correlated with the patients' characteristics.

Injection of Urethral Bulking Agents

Urethral injection is a safe and minimally invasive method of treating female stress urinary incontinence with multiple bulking agents currently commercially available. Although there are numerous studies that demonstrate efficacy, long-term success is not yet proven. This article aims to describe the mechanism of action and properties of various agents, patient selection factors, available techniques for injection, outcomes of urethral injections, and complications associated with the procedure.

A double-blind, randomized, placebo-controlled clinical trial evaluating the safety and efficacy of autologous muscle derived cells in female subjects with stress urinary incontinence

PURPOSE

The purpose of the study was to assess safety and efficacy of autologous muscle derived cells for urinary sphincter repair (AMDC-USR) in female subjects with predominant stress urinary incontinence.

METHODS

A randomized, double-blind, multicenter trial examined intra-sphincteric injection of 150 × 10⁶ AMDC-USR versus placebo in female subjects with stress or stress predominant, mixed urinary incontinence. AMDC-USR products were generated from vastus lateralis needle biopsies. Subjects were randomized 2:1 to receive AMDC-USR or placebo and 1:1 to receive 1 or 2 treatments (6 months after the first). Primary outcome was composite of ≥ 50% reduction in stress incontinence episode frequency (IEF), 24-h or in-office pad weight tests at 12 months. Other outcome data included validated subject-recorded questionnaires. Subjects randomized to placebo could elect to receive open-label AMDC-USR treatment after 12 months. Subject follow-up was up to 2 years.

RESULTS

AMDC-USR was safe and well-tolerated with no product-related serious adverse events or discontinuations due to adverse events. Interim analysis revealed an unexpectedly high placebo response rate (90%) using the composite primary outcome which prevented assessment of treatment effect as designed and thus enrollment was halted at 61% of planned subjects. Post hoc analyses suggested that more stringent endpoints lowered placebo response rates and revealed a possible treatment effect.

CONCLUSIONS

Although the primary efficacy finding was inconclusive, these results inform future trial design of AMDC-USR to identify clinically meaningful efficacy endpoints based on IEF reduction, understanding of placebo response rate, and refinement of subject selection criteria to more appropriately align with AMDC-USR's proposed mechanism of action.