Sphincteric Injection of Botulinum Toxin for Urinary Retention due to Neurogenic Bladder

We summarized current available literature on botulinum toxin injections into the urethral sphincter for patients with neurogenic bladder, including procedural technique, clinical outcomes, predictors of success and failure, adverse effects, and alternative treatments.

After injection into the urethral sphincter, botulinum toxin can induce a temporary flaccid paralysis of the sphincter and facilitate bladder emptying. In men, this is performed via a cystoscopic or transperineal approach and in women, via a periurethral technique. Typically, doses of 100 units of onabotulinumtoxin A are administered, though alternative agents, primarily abobotulinumtoxin A, are being explored. Patients report 60–90% satisfaction following injection and are found to have improvements in urethral pressure, detrusor pressure, and post-void residual on urodynamic testing. In addition, decreased incidences of autonomic dysreflexia and urinary tract infections are reported. Following injection, patients with detrusor underactivity and an open bladder neck have been found to have better outcomes. Many patients report urinary incontinence or persistent need to perform self-catheterization following injection, which greatly affect patient satisfaction. Therefore, patient counseling and expectations are key.

In patients with neurogenic bladder, botulinum toxin injection into the urethral sphincter has been promising in terms of patient satisfaction and urodynamic improvements.