Botulinum neurotoxin A (BoNT/A) appears to be one of the best intravesical treatments for interstitial cystitis/bladder painful syndrome (IC/BPS). We aimed to point out what the evidence is regarding the effects of BoNT/A intravesically injected in patients with IC/BPS. We performed a systematic review of all randomized controlled trials (RCTs) assessing BoNT/A for IC/BPS by using Medline, EMBASE, CINAHL, CENTRAL and MetaRegister of Controlled Trials. Standardized mean differences (SMD) were extracted from the available trials and combined in a meta-analysis applying a random effect model, including heterogeneity of effects. Twelve trials were identified. Significant benefits from BoNT/A injections were detected in: Interstitial Cystitis Symptom Index and Problem Index (ICSI, ICPI) (small to medium effect size: SMD = -0.302; p = 0.007 and -0.430, p = 0.004, respectively); Visual Analog Scale (VAS) for pain and day-time urinary frequency (medium effect size: SMD = -0.576, p < 0.0001 and -0.546, p = 0.013, respectively). A great effect size was detected for post-void residual volume (PVR, SMD = 0.728; p =0.002) although no clinically relevant in most cases. Great heterogeneity was observed in treatments’ methodologies and symptoms assessment. Overall, BoNT/A intravesical injections significantly improve some of the most relevant symptoms affecting IC/BPS patients.

Toxins. 2019 Aug 30*** epublish ***

Antonella Giannantoni, Marilena Gubbiotti, Vittorio Bini

Department of Medical and Surgical Sciences and Neurosciences, Functional and Surgical Urology Unit, University of Siena, 53100 Siena, Italy. ., Department of Urology, San Donato Hospital, 52100 Arezzo, Italy., Department of Medicine, University of Perugia, 06123 Perugia, Italy.