Overactive Bladder 5 Years After the Mid-Urethral Sling Tensioning (MUST) Trial

The midurethral sling (MUS) procedure is the gold standard surgical treatment for stress urinary incontinence; however, it can significantly affect symptoms of overactive bladder (OAB).

This study aimed to evaluate the burden of OAB 5 years after MUS insertion by analyzing medication prescriptions, surgical intervention and patient-reported data, with comparisons by sling tensioning technique.

This prospective cohort study followed participants of the Mid-Urethral Sling Tensioning trial for 5 years post-MUS surgery. Participants completed validated OAB questionnaires before and 5 years post-MUS surgery. Linked administrative health data measured postoperative OAB medication use, and incidence of bladder onabotulinumtoxinA (Botox) procedures.

Of the 318 participants, 260 had complete questionnaire data; among them, 225 (86.9%) had baseline OAB symptoms and at 5 years post-MUS surgery, 211 (81.5%) had symptoms. Approximately 1 in 5 reported clinically significant worsening in OAB symptoms; 19.0% in daily urination, 22.5% in urgency, and 18.1% in urine leakage. Conversely, 38.7%, 40.3%, and 47.6% showed significant improvement in these respective symptoms. In the 5 years after MUS surgery, 21.4% trialed OAB medication with 5.3% persisting at study end, and 2.2% (n=7) underwent a Botox procedure. The Babcock clamp tensioning technique provided less OAB burden compared with Mayo Scissor; however, the study was underpowered to detect statistical significance.

After MUS surgery, twice the proportion of patients experienced improved OAB symptoms than the proportion reporting worsening. Trials of OAB medications after MUS surgery were common, but most patients discontinued use long term. This study advises surgeons and patients of realistic OAB expectations after MUS surgery.