Therapeutic Effects of Urethral Sphincter Botulinum Toxin A Injection on Dysfunctional Voiding with Different Videourodynamic Characteristics in Non-Neurogenic Women

Clinical Application of Botulinum Neurotoxin in Lower-Urinary-Tract Diseases and Dysfunctions: Where Are We Now and What More Can We Do?

Botulinum toxin A (Botox) had been considered a promising drug that has an effect on functional disorders of the lower urinary tract. Because Botox exhibits anti-inflammatory and antispasmodic effects, Botox injection into the bladder can decrease detrusor contractility, reduce bladder hypersensitivity, and eliminate painful sensations. Injecting Botox into the bladder outlet can relax the hyperactivity of the bladder neck, and of the urethral smooth and striated muscles. Based on these therapeutic effects, Botox has been widely applied to treat lower-urinary-tract dysfunctions (LUTDs) such as overactive bladder and neurogenic detrusor overactivity. However, this treatment has not been licensed for use in other LUTDs such as interstitial cystitis, voiding dysfunction due to benign prostatic hyperplasia in men, and dysfunctional voiding in women. Botox has also not been approved for the treatment of children with overactive bladder and dysfunctional voiding; in patients with spinal cord injuries with detrusor sphincter dyssynergia and autonomic dysreflexia; or for poorly relaxed external sphincter in non-neurogenic patients. This article reviews the current knowledge regarding Botox treatment for LUTDs and discusses the potential clinical applications of Botox, as well as work that can be conducted in the future.

Effect of videourodynamic subtypes on treatment outcomes of female dysfunctional voiding

INTRODUCTION AND HYPOTHESIS

Dysfunctional voiding (DV) is not uncommon in women and is typically challenging to treat. This study retrospectively investigated the long-term treatment outcomes of DV women with different videourodynamics (VUDS) characteristics.

METHODS

Data of women with VUDS-proven DV (n = 302) were retrospectively analyzed. All patients at first received biofeedback pelvic floor muscle training and medications; urethral sphincter botulinum toxin A injection was administered after treatment failure. Long-term follow-up outcomes were graded by global response assessment (GRA) and objective responses of decrease of detrusor pressure (Pdet), increase in maximum flow rate (Qmax) and voiding efficiency (VE). The treatment outcomes were investigated among different VUDS subgroups.

RESULTS

Of 302 women, 165 (54.6%) had mid-urethral DV, 117 (38.7%) had distal urethral DV, and 20 (6.6%) had both bladder neck dysfunction (BND) and mid-urethral DV. A total of 170 (56.3%) patients were available for follow-up VUDS after treatment. Pdet was decreased in all three subgroups, but increase in Qmax and VE was only noted in the BND plus DV subgroup. Overall, 120 (70.6%) patients showed improvement (GRA ≥ 1), including 14 with BND plus DV (93.3%), 50 with mid-urethral DV (60.8%) and 56 with distal urethral DV (77.8%) (p = 0.044). All three subgroups showed significant reduction in bladder outlet obstruction index after treatment, with BND plus DV subgroup showing the greatest reduction.

CONCLUSIONS

Women with DV have different VUDS characteristics resulting from different pathophysiological mechanisms and treatment results. The VUDS characteristics may help predict treatment outcomes of female DV.