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.

Cost-effectiveness of urethral bulking polydimethylsiloxane-Urolastic® compared with mid-urethral sling surgery for stress urinary incontinence: A two-arm cohort study.

OBJECTIVE: To investigate the cost-effectiveness of urethral bulking polydimethylsiloxane-Urolastic® (PDMS-U) compared with mid-urethral sling (MUS) surgery for stress urinary incontinence (SUI) at 1-year follow-up. DESIGN: Prospective, two-arm cohort study with 2-year follow-up. SETTING: International multicentre. POPULATION: Women with moderate to severe SUI. MAIN OUTCOME MEASURES: Primary outcome was subjective cure (Patient Global Impression of Improvement). SECONDARY OUTCOMES: objective cure (negative cough stress test), Urogenital Distress Inventory (UDI-6), complications and re-interventions. Cost-effectiveness outcomes: total costs, quality-adjusted life year (QALY) using IIQ7-scores (Incontinence Impact Questionnaire) and EQ-5D-5L, incremental cost-effectiveness ratio (ICER) and monetary benefit (adjusted for baseline confounders). RESULTS: In all, 131 PDMS-U and 153 MUS surgery patients were treated. Subjective cure rates for MUS surgery and PDMS-U were, respectively: 101/112 (90%) versus 40/87 (46%), adjusted odds ratio (aOR; for age, body mass index [BMI], severity, type of urinary incontinence and previous SUI procedure) was 4.9. Objective cure rates for MUS surgery and PDMS-U were respectively: 98/109 (90%) versus 58/92 (63%), aOR 5.4. Average total costs for PDMS-U and MUS surgery were €3567 and €6688. ICER for MUS surgery cost €15 598 per IIQ QALY and €37 408 per EQ-5D-5L QALY. With a willingness to pay (WTP) of €25 000, MUS has a 84% chance of being cost-effective using IIQ, whereas PDMS-U has a 99% chance of being cost-effective using EQ-5D-5L. CONCLUSION: MUS surgery is more cost-effective in realising improved disease-specific quality of life (QoL), while PDMS-U is more cost-effective in realising improved generic QoL.

Sexual Function Following Treatment for Stress Urinary Incontinence With Bulk Injection Therapy and Mid-Urethral Sling Surgery.

BACKGROUND: Peri-urethral bulking injections (PBI) gain popularity for the treatment of stress urinary incontinence (SUI), but - in contrast to mid-urethral sling (MUS) surgery - little is known about its impact on sexual function. METHODS: This was a secondary analysis of a prospective cohort study that included patients with moderate to severe SUI undergoing either MUS surgery or PBI with polydimethylsiloxane Urolastic (PDMS-U). The validated Dutch and English version of the 'Pelvic Organ Prolapse and/or Urinary Incontinence Sexual Function Questionnaire - IUGA Revised' (PISQ-IR) was used to assess sexual function at baseline, at 6 and 12 months of follow-up. For between-group analysis, differences in baseline characteristics were corrected using multivariate analysis of covariance. OUTCOMES: The primary outcome was the PISQ-IR single summary score of sexually active (SA) women following both procedures, calculated by mean calculation. Secondary outcomes were the PISQ-IR subscale scores of SA and non-sexually active (NSA) women, the proportions of sexual activity and subjective improvement ('Patient Global Impression of Improvement' (PGI-I)). RESULTS: A total of 259 women (MUS: n = 146, PBI: n = 113) were included in this study. The PISQ-IR single summary score of SA women improved following both interventions (in the MUS group from 3.2 to 3.4 and in the PBI group from 3.0 to 3.3 after 12 months). After correcting for differences in baseline characteristics, the PISQ-IR summary score at 6 and 12 months was similar for both treatment groups. For SA women, condition-specific and condition-impact subscale scores significantly improved following both procedures. CLINICAL IMPLICATIONS: In treating SUI, PBI is inferior to MUS surgery. However, there is a need for less invasive strategies, especially for women who are unfit for surgery or have contraindications. Sexual function improves after PBI using PDMS-U, which is relevant for the counselling of women with SUI about available treatment options. STRENGTHS & LIMITATIONS: Strength: until this study, there was a lack of knowledge about the effects of PBI on sexual function. LIMITATION: there may be indication bias as we did not perform a randomized controlled trial. CONCLUSION: PBI using PMDS-U and MUS surgery for the treatment of SUI improve sexual function equally in SA women, mainly by decreasing the condition's impact on sexual activity and quality. Latul YP, Casteleijn FM, Zwolsman SE, et al. Sexual Function Following Treatment for Stress Urinary Incontinence With Bulk Injection Therapy and Mid-Urethral Sling Surgery. J Sex Med 2022;19:1116-1123.

Imaging findings of vinyl dimethyl polydimethylsiloxane used as a paraurethral injectable for female stress urinary incontinence.

OBJECTIVES: Vinyl dimethyl polydimethylsiloxane (VDPDMS) is a urethral bulking agent used for female stress urinary incontinence (SUI), that is clearly visible on computed tomography (CT). Clinical effects are promising, but it remains difficult to identify factors predicting clinical success. Clinical outcome might depend on the shape and position of the implants after injection. Objective of this study is to analyze the appearance and position of bulk material on CT scans and to see whether it is delivered the intended circumferential and mid-urethral position. METHODS: A single-center retrospective study was performed in 20 women, treated with VDPDMS for SUI. A senior radiologist analyzed all CTs, using an assessment scheme. This scheme describes whether the bulk is scattered, mid-urethral, and/or circumferentially distributed. The imaging findings were subsequently correlated to the patient global impression of improvement (PGI-I) and the percentage of subjective improvement experienced 6 weeks post-operatively. RESULTS: The patient's mean age was 61 years, and they underwent median 2.0 previous surgical treatments for SUI. Three patients reported no improvement, 9 patients had 20-90% improvement and 8 reported >90% improvement of their SUI. In 17/74 (24%) positions, the implant was scattered rather than spherical. In 9/20 (45%), the implants were not located in the intended mid-urethral position. In 8/20 patients (40%), the material was distributed circumferentially. CONCLUSION: This is the first study describing the position and shape of VDPDMS in patients after treatment. The appearance and position of the implants appears to be variable, but optimal positioning or shape seems to be no absolute requisite for success.

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.

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.

Patients' perspectives on urethral bulk injection therapy and mid-urethral sling surgery for stress urinary incontinence.

INTRODUCTION AND HYPOTHESIS: The aim of this study was to identify all treatment decision factors that determined the preference for peri-urethral bulk injection therapy (PBI) or mid-urethral sling (MUS) surgery in patients with primary stress urinary incontinence (SUI). Second, we explored what patients expect from treatment for SUI and whether patients would consider PBI as a primary treatment option. METHODS: In a qualitative design, 20 semi-structured, face-to-face interviews were conducted in women with primary SUI. Exclusion criteria were: previous PBI or MUS surgery; predominating urgency. Interviews were guided by three open-ended questions and a topic list. PBI treatment and MUS surgery were described in detail, and the efficacy was stated as 70% and 90%, respectively. Data saturation was reached when no new treatment decision factors were identified in three consecutive interviews. Interviews were audiotaped and fully transcribed. Thematic analysis by a coding process was done independently by two researchers. RESULTS: Sixteen procedural, personal, professional, social and external treatment decision factors were identified. Regarding expectations about treatment for SUI, women believed 'becoming dry' was wishful thinking. The majority of patients accepted a small degree of persistent urinary incontinence after treatment. Regardless of their treatment preference, patients indicated that women should be informed about PBI as a primary treatment option. CONCLUSION: Patients with primary SUI are open to PBI as an alternative treatment option even with lower cure rates compared with MUS surgery performed under general or spinal anesthesia. Patients indicated that women with primary SUI seeking treatment should be informed about PBI as a treatment option.

Results of an innovative bulking agent in patients with stress urinary incontinence who are not optimal candidates for mid-urethral sling surgery.

AIMS: To assess the efficacy and safety of peri-urethral bulking injections (PBI) with an innovative bulking material (PDMS-U) in women with stress-urinary incontinence (SUI) who are not optimal candidates for mid-urethral sling surgery. METHODS: A prospective study was performed in women with SUI who, for several reasons, have a relative contraindication for a mid-urethral sling procedure. These reasons include: (i) recurrent SUI after a prior SUI surgical procedure; (ii) a history of oncologic gynaecological surgery; (iii) a history of neurologic disease resulting in voiding problems; (iv) a maximal flow rate of less than 15 mL per second or; (v) women with a contraindication for surgery with general or regional anaesthesia. All women were treated with PBI consisting of PDMS-U, a bulking agent that polymerizes in situ. The primary outcome was subjective improvement, defined as "a little better" to "very much better" on the PGI-I. Secondary outcomes included objective cure, disease specific quality of life and adverse events. RESULTS: Subjective improvement was reported by 18 (90%) of the 20 included patients. The subjective cure rate was 56% and the objective cure rate was 65%. There was a statistically significant improvement of all domain scores of the UDI-6, IIQ-7, and PISQ-12 at 6 months follow up. Abnormal post voiding residual volume (>150 mL) was the most common adverse event (40%), but persisted in only one patient, based on the patient's preference for a catheter. CONCLUSIONS: PBI with PDMS-U is a viable treatment option in women with a relative contra-indication for mid-urethral sling surgery.

Are patients willing to trade cure rate against less pain? Patients' preferences for single incision midurethral sling or transobturator standard midurethral sling.

AIMS: To quantify to what extent patients are willing to trade their chance of cure of stress urinary incontinence (SUI) against less postoperative groin pain. Randomized, controlled trials show less postoperative pain following single-incision mini-sling (SIMS), but slightly higher cure rates following a transobturator standard midurethral sling (SMUS). METHODS: A multi-center, interview-based trade-off experiment for treatment preference among 100 women with predominant SUI and undergoing SIMS. A hypothetical cure rate of SIMS was systematically varied from 10% to 70%, while keeping the cure rate of SMUS constant at 70%. The trade-off was assessed for two hypothetical durations of substantial postoperative pain after SMUS-2 days or 2 weeks-while simultaneously assuming the absence of substantial postoperative pain after SIMS. RESULTS: To prevent 2 days of substantial postoperative pain with SMUS, patients were willing to accept a 4.3% mean decrease in cure rate of SIMS, while a 7.1% mean decrease was acceptable to forego 2 weeks of substantial pain. Younger women (P = 0.04) and single women (P = 0.04) were associated with the trade-off limit for 2 days, respectively, 2 weeks of substantial postoperative pain. Single women were willing to accept lower cure rates. No correlations with trade-off limits were found for patients' actual severity, duration, and frequency of SUI. CONCLUSIONS: Patients are willing to accept a slightly lower probability of cure to prevent substantial post-operative pain by undergoing a less invasive procedure. These results are relevant for counselling of patients indicated for SUI surgery.