Comparing Single-Incision Midurethral Sling with Bulking Agents for Female Stress Urinary Incontinence: Rationale for a Non-Randomized Controlled Trial.

Objectives: Midurethral slings are considered the gold standard for the surgical treatment of stress urinary incontinence (SUI), with an efficacy up to 80%. Another therapeutic option is the use of bulking agents, which create an artificial mass in the urethral submucosa, with an efficacy varying from 64% to 74%. Although bulking agents have a lower risk of complications than midurethral sling surgery, they are mainly used in case a midurethral sling is not an option or if midurethral sling surgery failed to cure stress urinary incontinence. In this study, we offer all patients with SUI in secondary care a choice between a single-incision midurethral sling procedure and treatment with a bulking agent. We want to examine patient preference and patient satisfaction for both procedures. We expect that offering both interventions in combination with standardized counselling will result in high patient satisfaction.

Design: In this non-randomized controlled trial, 266 patients will be objectively counselled for both interventions, after which all patients will choose between single-incision midurethral slings and polyacrylamide hydrogel (PAHG), followed by the standard care procedure for women with SUI.

Participants/materials, setting, methods: From January 1, 2021, onward, all consecutive adult patients (between 18 and 80 years of age) attending the outpatient gynaecology department with objectively confirmed, moderate to severe SUI will be eligible for enrolment in this non-randomized study. The primary outcome is patient satisfaction at 1 year, measured by the Patient Global Impression of Improvement; secondary outcomes are patient satisfaction at 3 months, objective and subjective cure at 3 months and 1 year, adverse events, post-operative pain, and cost-effectiveness. Differences in outcome measures will be assessed through logistic and linear regression analyses, both unadjusted and adjusted with covariate adjustment using the propensity score.

Results: No results are available yet.

Limitations: The major disadvantage of this study design is the potential confounding bias. We intend to eliminate this bias by applying propensity scoring.

Conclusion: By designing a non-randomized patient preference trial, we not only expect to demonstrate high patient satisfaction with both interventions but also provide insight into the possible role of PAHG-injections in the treatment of female SUI as a first-choice non-conservative treatment.