Impact of botulinum toxin injections into the external urethral sphincter on urodynamic parameters in neurogenic lower urinary tract dysfunction

Detrusor–sphincter dyssynergia, characterized by impaired voiding, is a common condition in patients with neurogenic lower urinary tract dysfunction, including those with spinal cord injury. The elevated intravesical pressure associated with detrusor–sphincter dyssynergia is considered a predictor of upper urinary tract deterioration, development of autonomic dysreflexia, recurrent urinary tract infections, and urinary incontinence. Current treatment approaches for detrusor–sphincter dyssynergia have notable limitations and demonstrate high rates of complications. Over the past decades, a number of studies have investigated the management of voiding disorders in detrusor–sphincter dyssynergia using injections of botulinum toxin type A. This review evaluates the efficacy of chemical denervation of the external urethral sphincter in patients with neurogenic lower urinary tract dysfunction, with particular emphasis on urodynamic parameters as the primary objective criteria for treatment effectiveness. Studies conducted to date have shown that injection of botulinum toxin type A into the external urethral sphincter reduces urethral pressure and postvoid residual urine volume and increases voiding efficiency in patients with neurogenic lower urinary tract dysfunction. However, the need for well-designed randomized studies in larger patient populations with long-term urodynamic follow-up is emphasized.