Efficacy and tolerance of botulinum toxin injections after sacral nerve stimulation failure for idiopathic overactive bladder

Introduction Management of idiopathic overactive bladder (iOAB) after the failure of sacral nerve modulation (SNM) is very challenging. To the best of our knowledge, no study has evaluated the use of botulinum toxin A (BoNT-A) after SNM failure for iOAB. The aim of this study is to evaluate the tolerance and efficacy of BoNT-A injection after the failure of SNM for iOAB. Methods We conducted a retrospective multicentric analysis of all patients who had received either onabotulinumtoxinA or abobotulinumtoxinA intradetrusor injection for iOAB after SNM failure, between January 2004 and December 2017. The primary outcome was the percentage of success of first BoNT-A injection (either resolution of their urinary incontinence or their frequency or more than 50% reduction in frequency). Secondary outcomes were results of urodynamic studies, complications, total number of injections, causes of withdrawal, and subsequent treatment. Results Seventy-six patients (62 female) were included. The percentage of success of first BoNT-A injection was 43.4% (n = 33). All overactive bladder symptoms were significantly improved on the 3-day bladder diary. Twenty-eight patients (36.8%) were put under clean intermittent self-catheterization transitory. After a mean follow-up of 57.7 (+/- 38.5) months, median number of injections was 2 (1-15). Overall, 42 patients (55.2%) stopped injections during follow-up. The estimated 36-months discontinuation-free rate was 48.1%. Mean cause of discontinuation was a primary failure (n = 32; 42.1%). Conclusion BoNT-A can be used in SNM nonresponders with a success rate of 43.4% but is associated with a high long-term discontinuation rate.