Women’s Health
Overactive bladder 5 years after the Mid-Urethral Sling Tensioning (MUST) Trial : prospective cohort study following a multi-centre randomized control trial in Alberta, Canada Taylor Hughes* Taylor Hughes Amy Metcalfe Miranda Fidler-Benaoudia Kirsten Fiest Erin Brennand
Background: Mid-urethral slings (MUS) are the preferred surgical treatment for female stress urinary incontinence, yet a small subset of MUS patients experiences overactive bladder (OAB) sometimes needing further treatment. The Mid-Urethral Sling Tensioning (MUST) Trial provides an opportunity to gage OAB after MUS through follow-up of a randomized clinical trial which used patient reported and administrative health data.
Objective: To holistically assess the burden of OAB 5 years after MUS insertion using medication, surgical intervention and patient-reported OAB outcomes, and to compare OAB outcomes by MUS tensioning technique.
Methods: MUST Trial participants provided 5-year post-MUS data via patient-reported questionnaires linked to administrative health data. OAB burden was assessed by analyzing changes in pre- and 5-year post-op scores on validated OAB questionnaires, post-op OAB medication use and incidence of bladder Botox procedures.
Results: Of the 318 MUST Trial participants, 259 had complete questionnaire data; among them, 211 (81.5%) had OAB 5 years post-MUS. 225 (86.9%) had OAB pre-MUS. Few experienced clinically significant worsening in OAB symptoms; 19.0% in daily urination, 22.5% in urgency, 18.1% in urine leakage. Conversely, 38.7%, 40.3% and 47.6% showed significant improvement in the respective symptoms. 1/5 of total participants used OAB medication (all were naïve) with median start at 151 days post-op for a median duration of 319 days. 7 underwent a Botox procedure. The Babcock Clamp tensioning technique provided less frequent nightly urination and less leakage than the Mayo Scissor.
Conclusion: After MUS, some patients experienced improved OAB symptoms, while a minority report worsening. 20% of patients will trial OAB medications after MUS, but not all continue. Despite this rarity, medication is a crucial point of discussion for MUS candidates. Surgeons can freely choose tensioning techniques, expecting no significant difference in OAB outcomes.