Efficacy of combination therapy of mid-urethral sling and low-dose Abobotulinumtoxin-A injection in mixed urinary incontinence

Objectives: To determine the outcome of combined transobturator tape sling (TOT) and low dose intradetrusor injection of Abobotulinumtoxin-A (Abobot-A, Dysport®) in women with mixed urinary incontinence (MUI).

Methods: This randomized, active comparator-controlled, parallel-group, two-part clinical trial was conducted on women who had positive Valsalva leak point pressure (VLPP) + detrusor overactivity (DO), cough-associated DO. In Part 1, 20 women with MUI who had a failure of medical and behavioral therapies to cure MUI, randomized in two groups receiving TOT surgery alone, or in combination with Dysport® injection (n = 10 in each group), and then Part 2 was initiated as a prospective open-label on 40 more patients. We performed cystoscopy and injected 300 U of Dysport®in 20-30 intradetrusor injection sites in each patient.

Results: The patient's symptoms in both groups decreased significantly after treatment. The symptoms were improved significantly in the combination therapy group according to the International Consultation on Incontinence Questionnaire-overactive bladder (ICIQ-OAB) questionnaire (p < .001), and International Consultation on Incontinence Questionnaire-urinary Incontinence-short form (ICIQ-UI-SF) (p = .041) in comparing with the TOT group. In Part 2, the mean score was 17.10 (4.75) for ICIQ-UI-SF and 9.22 (2.89) for ICIQ-OAB before the treatment. Twelve weeks after the intervention, the median (interquartile range: IQR) of ICIQ-OAB symptoms (2.0 [3.0]; p < .001) and ICIQ-UI-SF decreased, too (1. 0 [2.0]; p < .001). Considering improvement using Patient Global Impression of Improvement scale, 46 (92.0%) stated that they had significant subjective improvement of their symptoms.

Conclusions: Combination therapy was accompanied with a promising effect in the patients with MUI according to the results of standardized questionnaires. However, further studies with controlled arms are recommended.