Factors affecting the success of intravesical onabotulinum toxin A injection in the treatment of refractory idiopathic overactive bladder.

BACKGROUND

Onabotulinum toxin A injection is recommended for overactive bladder (OAB) resistant to medical treatments. However, success is not universal, and factors influencing outcomes remain unclear. This study evaluates the factors affecting the success of onabotulinum toxin A injection in refractory idiopathic OAB.

METHODS

Data from patients with resistant idiopathic OAB treated with 100 IU onabotulinum toxin A (BOTOX®, Allergan, Dublin, Ireland) between January 2019 and August 2023 were analyzed. Demographic data and symptom duration were recorded. Patients were evaluated pre- and post-procedure using the overactive bladder symptom score (OABSS) and 3-day bladder diaries. A ⩾50% improvement in OABSS was considered treatment success. Botox was injected at 20 sites (5 IU per site) via 22 Fr rigid cystoscope under sedoanalgesia.

RESULTS

A total of 210 patients (80.5% female, n = 169) with a mean age of 53.76 ± 14.90 years were included. Symptom duration averaged 39.82 ± 22.28 months. Wet OAB was diagnosed in 83.3% (n = 175), while 16.7% (n = 35) had dry OAB. Pre-procedure mean OABSS was 9.18 ± 1.31, daily micturition 8.67 ± 1.52, urge incontinence 2.57 ± 1.28, nocturia 1.87 ± 0.75, and pad use 2.44 ± 1.24/day. Treatment success was achieved in 82.4% (n = 173).

CONCLUSION

The degree of patient complaints, particularly daily micturition frequency, significantly affects treatment success. Patients with higher daily micturition may require advanced interventions beyond Botox.