Low dose intradetrusor injections of onabotulinumtoxinA in women with overactive bladder symptoms or the painful bladder syndrome: unfavorable balance between clinical efficacy and the need for catheterization

We evaluated our results with low dose intradetrusor injections of onabotulinu - mtoxinA in women with overactive bladder symptoms and the painful bladder syndrome in terms of clinically successful outcomes and the need for clean intermittent self-catheterization (CISC) and in relation to urodynamic aspects. The files of patients treated with 100 U of onabotulinumtoxinA injected at 20 sites with sparing of the trigone were retrospectively analyzed. Nearly all patients completed voiding- incontinence diaries and the King’s Health Questionnaire (KHQ) pre- and post-operatively. Cystometric and pressure-flow studies were done in the majority of patients. Success was defined as the patient’s and clinician’s joint choice for re-treatment with the same dose of onabotulinumtoxinA after a period of at least six months of clinical satisfaction. Twenty-six women were treated. On average, the improvement in most voiding diary parameters and in most KHQ categories lasted less than six and three months, respectively. Eight patients (31%) were scheduled for re-treatment with 100 U again after at least six months. No prognostic cystometric parameters were found. Six patients (23%) needed CISC. None of the bladder contraction strength parameters derived from the pressure-flow studies appeared predictive of the need of CISC. We obtained a success rate of 31% after six months with 100 U of onabotulinumtoxinA, while 23% of the patients applied CISC. We consider this success rate low and find the balance between the success rate and the rate of patients needing CISC inadequate.