Botulinum A Toxin Intravesical Injections in the Treatment of Painful Bladder Syndrome: A Pilot Study

ObjectiveWe evaluated the efficacy and tolerability of botulinum A toxin (BTX-A) intravesical injections in patients affected by painful bladder syndrome with increased urinary frequency, refractory to conventional treatment modalities.MethodsTwelve women and two men were prospectively included in the study. Under short general anaesthesia patients were given injections of 200 U of commercially available BTX-A diluted in 20 ml 0.9% NaCl. Injections were performed submucosally in the trigone and bladder floor under cystoscopic control. Voiding chart, the Visual Analog Scale (VAS) for pain, and urodynamics were performed before treatment and 1 and 3 mo afterward.ResultsOverall, 12 patients (85.7%) reported subjective improvement at 1 and 3 mo follow-up. The mean VAS score was significantly reduced at 1 and 3 mo after treatment (p < 0.05 for both); at the same time points daytime and nighttime urinary frequency significantly decreased (p < 0.01 and p < 0.05, respectively), and bladder cystometric capacity significantly increased (p < 0.01). Two patients reported incomplete bladder emptying. We did not detect any systemic side effects during or after treatment.ConclusionsThe results of this pilot study indicate that BTX-A intravesical injections are effective in the short-term management of painful bladder syndrome. By modulating afferent C-fiber activity within the bladder walls, BTX-A significantly improves urodynamic parameters and reduces bladder pain and urinary frequency.