Outpatient periurethral injections of polyacrylamide hydrogel for the treatment of female stress urinary incontinence: effectiveness and safety

Reconstruction of Urethral Sphincter With Polyacrylamide Hydrogel

IMPORTANCE

Urethral bulking is an alternative to synthetic midurethral sling for the treatment of stress urinary incontinence (SUI) in women. Urethral bulking agents, which are injected in the submucosal tissues of the proximal urethra/bladder neck, have demonstrated less adverse effects with similar satisfaction rates but lower subjective and objective cure rates when compared with midurethral sling. Cystoscopic Reconstruction of External Sphincter Technique (CREST) is a novel technique, which reinforces the natural closure mechanism of the external urinary sphincter (EUS).

OBJECTIVE

The aim of the study was to provide safety and efficacy data for injecting polyacrylamide hydrogel (PAHG) in the components of the female EUS.

STUDY DESIGN

This was a retrospective chart review of patients using CREST with PAHG as initial treatment for SUI by a single surgeon from January 2022 to October 2022. Exclusion criteria are as follows: younger than 18 years, prior SUI surgery, concomitant pelvic organ prolapse or reconstructive procedure, neurological conditions, or history of radiation. Subjective and objective cure rates were measured by patient-reported symptoms and cough stress test. Urinary retention, postoperative urinary infection, and de novo urinary urgency were assessed.

RESULTS

One hundred and thirteen consecutive patients met inclusion criteria with median follow-up of 3 months. Eighty-five percent of participants reported subjective improvement, 69% reported subjective cure, and 69% demonstrated objective cure. Nine patients reported transient postoperative retention, 8 reported postoperative urinary tract infections, and 5 reported de novo urgency. There were no serious adverse events.

CONCLUSIONS

CREST is a novel technique for injection of PAHG, into the EUS to treat SUI. Our data suggest that this technique could improve urethral injection outcomes with minimal complications.

Up-to-Date Procedures in Female Stress Urinary Incontinence Surgery: A Concise Review on Bulking Agents Procedures

To avoid complications related to mid-urethral slings (MUS), alternative procedures to treat stress urinary incontinence (SUI), such as urethral bulking agents (UBAs) have been adopted. The aim of this review is to narratively report the efficacy and safety of UBAs for SUI treatment. For this review, research from PubMed and EMBASE was performed to evaluate relevant studies that were undertaken from January 2012 to January 2022. Nineteen prospective studies were included. Several definitions of subjective and objective success were adopted. At a follow-up of <24 months, significant improvement was widely observed, even if with a heterogeneous rate of success between 32.7−90%, and a reinjection rate of 8.3−77.3%. Compared with other procedures, MUS resulted as significantly superior to UBAs but was balanced by a higher complication rate. Acute urinary retention, urinary tract infection and de novo urgency, and other complications, such as injection site rupture, urethral erosion and particle migration have been described after UBAs. SUI after UBAs treatment resulted in improvements in all studies and can be considered a safe and effective option to treat SUI. However, homogenous and longer-term data lack, limiting general recommendations. Thus, larger RCTs evaluating long-term effects are required.

Urethral bulking agents for the treatment of stress urinary incontinence in women: A systematic review

AIMS

To perform a systematic review to assess and compare the efficacy and safety of all urethral bulking agents (UBAs) available for the treatment of stress urinary incontinence (SUI) in women.

METHODS

This systematic review was conducted in accordance with the PRISMA guideline. A systematic search was conducted using the Ovid Medline, Embase and PubMed databases. Studies were included if they involved women who underwent either Bulkamid®, Macroplastique®, Durasphere®, Coaptite®, or Urolastic® injections for the treatment of SUI. A total of 583 articles were screened with 56 articles included. A qualitative analysis was performed.

RESULTS

The newer synthetic UBAs are not inferior to Contigen®, with variable mean success rates of 30%-80% in the short-term. Better long-term success rates were found with Bulkamid® (42%-70%), Coaptite® (60%-75%), and Macroplastique® (21%-80%) on qualitative review. Urinary tract infection rates were similar between bulking agents (4%-10.6%) although temporary acute urinary retention was more commonly associated with Coaptite® (mean: 34.2%), and de novo urgency in Durasphere® (mean: 24.7%). Significant complications such as migration into lymph nodes was reported with Durasphere®. Erosion was reported with Macroplastique®, Coaptite®, and Urolastic®, with a rate as high as 24.6% in one study of Urolastic®.

CONCLUSION

Available data support the use of Bulkamid® and Macroplastique®, which has shown a short-term efficacy of 30%-90% and 40%-85% respectively, and long-term efficacy of 42%-70%, and 21%-80%, respectively. Bulkamid® appears to have a more favorable safety profile, with no cases of erosion or migration of product associated with its use. Direct comparisons of UBAs have not been performed.

Seven-year efficacy and safety outcomes of Bulkamid for the treatment of stress urinary incontinence

AIMS

Bulking agents are a minimally invasive treatment option for women with stress urinary incontinence (SUI) or stress-predominant mixed urinary incontinence (MUI). The aim of this study was to evaluate long-term efficacy and safety following treatment with Bulkamid as a primary procedure for SUI or stress-predominant MUI.

METHODS

This was an Institutional Review Board-approved single-center retrospective study of female patients with SUI or stress-predominant MUI who had undergone injection with Bulkamid since 2005 and had completed 7 years of follow up. The primary endpoint was patient satisfaction measured on a four-point scale as cured, improved, unchanged, or worse. Secondary outcomes included the number of incontinence pads used, International Consultation on Incontinence Questionnaire-Short Form (ICIQ-UI SF) scores, Visual Analog Scale Quality of Life (VAS QoL), reinjection rates, and perioperative and postoperative complications.

RESULTS

A total of 1,200 patients were treated with Bulkamid since 2005 and of these, 388 (32.3%) had completed 7 years of follow-up. A total of 67.1% of the patients reported feeling cured or improved if Bulkamid was a primary procedure, 11.1% reported no change, and 2.3% reported worsening of incontinence. A total of 19.5% of patients received a subsequent other incontinence procedure. The ICIQ-UI SF was reduced by 8.6 points. VAS QoL improved by a mean of 4.3 points. Postoperative complications were transient. Prolonged bladder emptying time was reported in 15.3% of patients and urinary tract infection in 3.5%.

CONCLUSIONS

Bulkamid injections are an effective and safe first-line treatment option for women with SUI or stress-predominant MUI providing durable outcomes at 7 years.

Quality of life and sexual function after TVT surgery versus Bulkamid injection for primary stress urinary incontinence: 1 year results from a randomized clinical trial

Introduction and hypothesis

To assess changes in quality of life (QoL) and sexual function outcomes at 1 year after tension-free vaginal tape (TVT) versus polyacrylamide hydrogel injection (PAHG).

Methods

In a randomized trial comparing TVT (n = 111) and PAHG (n = 113) treatments of stress urinary incontinence (SUI), we compared urinary incontinence and health-related QoL using the Urogenital Distress Inventory (UDI-6), Incontinence Impact Questionnaire, Short Form (IIQ-7), Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12) and RAND-36 Item Health Survey (RAND-36) at baseline and 1 year.

Results

UDI-6 and IIQ-7 showed improved incontinence-related QoL (p = 0.001) from baseline in both groups except for difficulty emptying the bladder and pain/discomfort. At 1 year, TVT patients experienced less urinary symptom-related distress compared to PAHG (p < 0.001). Sexual function improved in both groups (p < 0.001 for TVT and p = 0.01 for PAHG) with higher scores for the physical section subscale (p < 0.001) for TVT. Health-related QoL (RAND-36) improved from baseline in both groups in physical and social functioning (p < 0.001) with better outcome in the TVT group for physical functioning (p < 0.001). Increase in pain from baseline (p = 0.02) was detected for TVT, but not for PAHG. However, there was no difference between the groups (p = 0.78).

Conclusions

In primary SUI, TVT and PAHG treatments both improved QoL and sexual function at 1 year. However, incontinence and health-related QoL scores were better in the TVT group. More pain compared to the baseline was reported after TVT, although there was no difference between groups. Clinical significance needs to be evaluated in long-term follow-up.

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.

The efficacy and safety of urethral injection therapy for urinary incontinence in women: a systematic review

To evaluate the efficacy and safety of different bulking agents for treating urinary incontinence in women, a systematic review including only randomized controlled trials was performed. The subjects were women with urinary incontinence. The primary outcomes were clinical and urodynamic parameters. The results were presented as a weighted mean difference for non-continuous variables and as relative risk for continuous variables, both with 95% confidence intervals. Initially, 942 studies were identified. However, only fourteen eligible trials fulfilled the prerequisites. Altogether, the review included 1814 patients in trials of eight different types of bulking agents, and all studies were described and analyzed. The measured outcomes were evaluated using a large variety of instruments. The most common complications of the bulking agents were urinary retention and urinary tract infection. Additionally, there were certain major complications, such as one case of death after use of autologous fat. However, the lack of adequate studies, the heterogeneous populations studied, the wide variety of materials used and the lack of long-term follow-up limit guidance of practice. To determine which substance is the most suitable, there is a need for more randomized clinical trials that compare existing bulking agents based on standardized clinical outcomes.

Efficacy and safety of polyacrylamide hydrogel for the treatment of female stress incontinence: a randomized, prospective, multicenter North American study

PURPOSE

Bulkamid® is a new polyacrylamide hydrogel bulking agent for stress urinary incontinence that is injected in the urethral submucosa using a specifically designed device. We evaluated the safety and efficacy of Bulkamid vs Contigen® collagen gel for stress urinary incontinence or stress predominant mixed urinary incontinence.

MATERIALS AND METHODS

This was a single-blind, randomized, prospective, 33-center, 2-arm parallel study of hydrogel vs collagen gel with followup to 1 year. At baseline patients underwent physical examination and bladder testing, and completed quality of life questionnaires and bladder diaries. After randomization patients could receive up to 3 injections at 1-month intervals. Patients were assessed 3, 6, 9 and 12 months after bulking. They completed bladder diaries and quality of life questionnaires, and pad weight was tested. At the last visit Valsalva leak point pressure was measured. Subjective and objective incontinence outcomes and adverse events were compared.

RESULTS

Of the 345 women 229 were randomized to hydrogel and 116 were randomized to collagen gel. At 12 months a 50% or greater decrease in leakage and incontinence episodes was seen in 53.2% and 55.4% of patients who received hydrogel and collagen gel, respectively. At 12 months 47.2% of patients with hydrogel and 50% with collagen gel reported zero stress incontinence episodes, and 77.1% and 70%, respectively, considered themselves cured or improved. Major adverse events were rare in each group.

CONCLUSIONS

Bulkamid is not inferior to Contigen. It has a favorable, persistent effect on stress urinary incontinence with a low risk of serious adverse events. Bulkamid is a new, simple, office based bulking system that shows promise as a treatment in women with stress urinary incontinence, particularly since Contigen is no longer commercially available.

Use of periurethral injections of polyacrylamide hydrogel for treating post-vesicovaginal fistula closure urinary stress incontinence

AIMS

Following successful closure of obstetric genitourinary fistula, stress urinary incontinence (SUI) is a common and challenging problem. Despite many decades of various treatment options, the effective management of post-fistula SUI remains unresolved. This study aims to assess the feasibility of periurethral injections of polyacrylamide hydrogel, commonly used for urinary stress incontinence in non-fistula women, in women with post-fistula closure SUI.

MATERIAL AND METHODS

Women with urinary incontinence following successful fistula closure were assessed to exclude detrusor overactivity and urinary residual volumes of more than 100 mL. The urethrovesical junction was identified and polyacrylamide hydrogel was injected through the periurethral skin and vaginal epithelium at three sites.

RESULTS

Four women with post-fistula SUI were treated with polyacrylamide hydrogel injections. Three of the four women were dry post-operatively and remained continent at discharge.

CONCLUSION

In the short-term, periurethral injections of polyacrylamide hydrogel appears to be a promising method to treat post-obstetric fistula urinary stress incontinence.