Trigonal Injection of Botulinum Toxin A in Patients with Refractory Bladder Pain Syndrome/Interstitial Cystitis

BackgroundBladder pain syndrome/interstitial cystitis (BPS/IC) is a chronic disease without an effective treatment, characterized by pain during bladder filling. Most nociceptive bladder afferents course in the trigone.ObjectiveTo evaluate efficacy and tolerability of trigonal injection of botulinum toxin A (BoNTA) in patients with BPS/IC. Urine concentration of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) were also evaluated.Design, setting, and participantsWomen with refractory BPS/IC were included in an open, exploratory study.InterventionUnder sedation, 100 U of BoNTA (Botox) were injected in 10 trigonal sites (10 U per 1 ml saline). Retreatment was allowed 3 mo after injection.MeasurementsPain, urinary frequency, O’Leary-Sant score (OSS), quality of life, (QoL), and urodynamic testing at 1 and 3 mo and every 3 mo thereafter. Urine NGF and BDNF were assessed at the same points. Patients who were retreated were evaluated every 3 mo.Results and limitationsAll patients reported subjective improvement at 1- and 3-mo follow-up. Pain, daytime and nighttime voiding frequency, OSS, and QoL improved significantly. Bladder volume to first pain and maximal cystometric capacity more than doubled. Treatment remained effective in >50% of the patients for 9 mo. Retreatment was also effective in all cases, with similar duration. A significant, transient reduction in urinary NGF and BDNF was observed. No cases of voiding dysfunction occurred.The low number of patients and the lack of a placebo arm are obvious limitations of this study.ConclusionsTrigonal injection of BoNTA is a safe and effective treatment for refractory BPS/IC.