OnabotulinumtoxinA and Midurethral Sling have Comparable Outcomes for Mixed Urinary Incontinence Treatment: JAMA

Mixed urinary incontinence, a condition marked by the simultaneous presence of stress and urgency urinary leakage, significantly impacts quality of life and poses considerable treatment challenges. Despite its prevalence, there remains a lack of comparative data on procedural interventions specifically targeting this dual-symptom profile.

In light of this gap, Heidi S. Harvie, Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, and colleagues set out to evaluate whether intradetrusor onabotulinumtoxinA injections offer greater therapeutic benefit compared to midurethral sling surgery in managing mixed urinary incontinence among women.

For this purpose, the researchers conducted a randomized superiority trial across seven U.S. centers, enrolling women aged 21 and above with moderate to severe mixed urinary incontinence unresponsive to conservative or oral treatments. Participants received either a 100-unit intradetrusor injection of onabotulinumtoxinA targeting urgency or a midurethral sling surgery targeting stress incontinence. Follow-up allowed additional or crossover treatments within 6–12 months.

The main outcome measured was the 6-month change in the Urogenital Distress Inventory (UDI) total score, with secondary assessments focusing on stress and irritative symptom subscores.

The study revealed the following findings:

• Out of 150 women enrolled, 137 were treated and included in the main analysis, with an average age of 59.
• Both treatment groups showed improvement in urinary symptoms after 6 months, but there was no major difference between them.
• Women who received onabotulinumtoxinA had an average symptom score improvement of 66.8 points, while those who had the sling surgery improved by 84.9 points.
• The sling group had better results for stress-related symptoms compared to the onabotulinumtoxinA group.
• For urgency-related symptoms, both groups showed similar improvements.
• In the onabotulinumtoxinA group, about 13% received a second injection by 6 months and 28% by 12 months.
• By 12 months, nearly 30% of those in the sling group received onabotulinumtoxinA, while 15% in the injection group switched to sling surgery.
• The number of side effects was similar in both groups.

“In women with moderate to severe mixed urinary incontinence who did not respond to earlier conservative measures, both onabotulinumtoxinA injections and midurethral sling surgery showed comparable improvement in symptoms at 6 months,” the researchers concluded. They further noted that since a notable proportion of participants ultimately needed both treatments, “a single therapy may not be sufficient to manage all symptoms effectively.”

According to the study team, these findings highlight the importance of considering patient preferences and clinical judgment when deciding treatment strategies.

Reference:

Harvie HS, Menefee SA, Richter HE, et al. Midurethral Sling vs OnabotulinumtoxinA in Females With Urinary Incontinence: The MUSA Randomized Clinical Trial. JAMA. Published online May 05, 2025. doi:10.1001/jama.2025.4682