Botulinum Toxin A (BTXA) versus Hydrodistension for Refractory Interstitial Cystitis/Painful Bladder Syndrome (IC/PBS)- a Multicentre, Prospective, Randomized, Double Blind Study

Background IC/PBS requires effective treatment options. Objective Is BTXA effective for the treatment of IC/PBS? Design, Setting and Participants: 2003-2009, 55 severe, refractory female subjects from 3 referral centres invited. UTI, malignancy, steroid use excluded. Intervention Double blind design, random allocation to treatment with hydrodistension and bladder wall injection of normal saline, or else hydrodistension with injection of BTXA. Outcome measures and statistical Analysis O’Leary Sant (OLS) problem (PI) and Symptom (SI), UIIQ, compared between BTXA and controls. Repeated measures ANOVA tested whether BTXA subjects performed better than control subjects (group effect) for changes from baseline to 3 months (time effect) by assessing significance of group by time interaction. Multivariate modelling analyzed effect over time of other possible confounders. Measurements made beyond 3 months, but no further randomized comparisons possible, as majority subjects then chose active BTXA injection. Withdrawal; 4 subjects completed questionnaires too poorly, 1 withdrawn pre treatment with bladder cancer, leaving 50. Results and limitations: In both groups, the OLS, bladder diary, UIIQ scores showed improvement over 3 months. But no difference detected during initial analysis between the BTXA and control subjects for any outcome measure except OLS PI, where improvement noted at 3 months (P=0.04). 12 had UTI treated during the study. This significantly confounded, with greater improvement seen in the control group treated for UTI. Multivariate modelling accounted for effect of UTI showing improvement in the total OLS score (P=0.02), the OLS SI for the BTXA (P=0.008) group, pain (Q4 of OLS PI) (P=0.015) for the BTXA group at 3 months. 24% request continuing periodic BTXA treatment. Conclusions BTXA treatment improves OLS score at 3 months when compared to hydrodistension and saline injection alone, for a minority women. Consideration of the significant confounding effect of UTI, strengthened this improvement.