Outcomes of bladder neck Onabotulinumtoxin A injection in the treatment of men and women with primary bladder neck obstruction

Abstract

Objectives This study aims to determine the clinical outcomes of bladder neck injection of Onabotulinumtoxin A as treatment for adult men and women with primary bladder neck obstruction (PBNO). Methods Patients at participating institutions who underwent bladder neck injection of Onabotulinumtoxin A for PBNO between May 2011 and May 2018 were included in this retrospective case series study. All patients underwent cystoscopy to exclude anatomical causes and had video urodynamics to diagnose PBNO. Clinico-pathological data were collected from medical records. The primary outcome was subjective improvement in symptoms on clinical follow-up. Proportions were compared using Fisher’s exact test. Results This study had 13 patients with a median age of 40. There were five men and eight women. Nine patients had failed alpha-blocker therapy previously, and none had undergone prior surgery for PBNO. Of the 12 patients who attended at least one follow-up appointment, 75% reported improvement in symptoms. The response rate was significantly higher in men compared with women (100% vs 57.1%, p=0.034). There were no significant complications reported on follow-up. We have subsequently developed a novel practical management algorithm from our clinical experience. Conclusions Bladder neck injection of Onabotulinumtoxin A for the treatment of PBNO has a good response rate with minimal risk of complications and is a reasonable alternative or precursor to bladder neck incision surgery for patients wishing to avoid complications associated with surgery. Further prospective comparative studies on its use are warranted.