Review of combined intravesical and urethral botulinum neurotoxin type A injection in patients with neurogenic lower urinary tract dysfunction

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BSTRACT

Neurogenic lower urinary tract dysfunction (NLUTD) is frequently characterized by coexisting storage and voiding abnormalities, particularly in patients with spinal cord injury (SCI) and concomitant detrusor overactivity (DO) and detrusor sphincter dyssynergia (DSD). Conventional therapies often improve either storage or voiding function at the expense of the other, creating a significant therapeutic challenge. Combined intradetrusor and urethral botulinum neurotoxin type A (BoNT-A) injection has emerged as a potential dual-target strategy aimed at simultaneously improving bladder storage and facilitating bladder emptying. This review summarizes the current evidence regarding concomitant detrusor and urethral BoNT-A injection in patients with NLUTD. Available clinical data are limited and are derived predominantly from male patients with SCI, DO, and DSD. Preliminary studies have demonstrated improvements in urodynamic parameters, urinary continence, spontaneous voided volume, bladder compliance, and quality of life without significantly increasing clean intermittent catheterization frequency or post-void residual ratio. These findings suggest that combined injection may provide a therapeutic balance between storage and emptying functions while preserving spontaneous voiding. However, current evidence remains limited by small sample sizes, heterogeneous study designs, and the absence of randomized controlled trials. Important questions regarding optimal patient selection, long-term efficacy, and generalizability to other neurogenic conditions remain unanswered. Although future application in selected nonneurogenic patients may be possible, further prospective studies are required to establish the role of combined detrusor and urethral BoNT-A injection in the management of NLUTD.