Modified Botulinum Toxin Type A Injections Improve Symptoms Associated With Interstitial Cystitis/Bladder Pain Syndrome in Women: A Retrospective Cohort Study.

[OBJECTIVE] To investigate the efficacy and safety of modified botulinum toxin type A (BoNT-A) injections (with additional periurethral injection [PUI] of BoNT-A) for the treatment of interstitial cystitis/bladder pain syndrome (IC/BPS).

[METHODS] This single-center, retrospective cohort study included 52 adult female patients with IC/BPS, with 24 patients receiving conventional BoNT-A injections and 28 receiving modified BoNT-A injections. The primary outcome measure was patient-reported global response assessment. Secondary outcomes included daytime frequency, nocturia, number of urinary urgency episodes in the voiding diary, pain visual analog score, O'Leary-Sant interstitial cystitis symptom index and interstitial cystitis problem index, pelvic pain and urgency/frequency scores, risk factors for recurrence, and postoperative recurrence-free time.

[RESULTS] The median duration of follow-up was 16.0 months (interquartile range 11.75-21 months). Patients who underwent modified BoNT-A injections showed significant improvement in postoperative global response assessment, symptom questionnaires, and pain assessment compared with those who underwent conventional surgery. A statistically significant difference was observed between the 2 groups in terms of recurrence-free time (12.5 vs 18.0 months, P = .02). Subgroup analysis suggested that additional PUI of BoNT-A was more effective in patients with combined severe periurethral pain. No serious complications occurred in both groups, and all minor postoperative complications were temporary.

[CONCLUSION] Modified BoNT-A injection is an effective treatment for IC/BPS that significantly reduces pain and improves voiding symptoms. It is particularly effective in patients with combined periurethral pain. In such patients, PUI of BoNT-A should be added to the routine intravesical injection of BoNT-A.