Neurogenic and non-neurogenic urethral sphincter dysfunction are common causes of voiding dysfunction. Injections of botulinum toxin A (BoNT-A) into the urethral sphincter have been used to treat urethral sphincter dysfunction (USD) refractory to conventional treatment. Since its first use for patients with detrusor sphincter dyssynergia in 1988, BoNT-A has been applied to various causes of USD, including dysfunctional voiding, Fowler's syndrome, and poor relaxation of the external urethral sphincter. BoNT-A is believed to decrease urethral resistance via paralysis of the striated sphincter muscle through inhibition of acetylcholine release in the neuromuscular junction. Recovery of detrusor function in patients with detrusor underactivity combined with a hyperactive sphincter also suggested the potential neuromodulation effect of sphincteric BoNT-A injection. A large proportion of patients with different causes of USD report significant improvement in voiding after sphincteric BoNT-A injections. However, patient satisfaction might not increase with an improvement in the symptoms because of concomitant side effects including exacerbated incontinence, urinary urgency, and over-expectation. Nonetheless, in terms of efficacy and safety, BoNT-A is still a reasonable option for refractory voiding function. To date, studies focusing on urethral sphincter BoNT-A injections have been limited to the heterogeneous etiologies of USD. Further well-designed studies are thus needed. Key Contribution:This article summarized the effects of sphincteric BoNT-A injections among various USDs in view of pathophysiology, urodynamic outcome, and subjective patient reports.

BackgroundTo explore the feasibility and long-term outcomes of renal preservation in a retrospective cohort of patients with ureteral urothelial carcinoma undergoing total ureterectomy with ileal-ureteral substitution.MethodsA retrospective review of the data from patients treated with total ureterectomy with ileal-ureteral substitution from 1988 to 2016 was performed. The pre-operative oncological status, long-term oncological outcome, long-term renal functional outcome, early and late complications were analyzed.ResultsA total of eight patients with a median age of 70 years were included. The median follow-up time was 109 months. Six patients had multi-focal tumor involvement over the target ureter, and six patients had bilateral upper tract involvement. Only one patient encountered the upper-tract recurrence. The 2 and 5-year cancer-specific survival rates were 87.5 and 75.0%, respectively. The renal function was well-preserved in most patients, with only one patient needed life-long postoperative hemodialysis. Five patients experienced early complications and four patients experienced late complications. No perioperative mortality happened.ConclusionsA total ureterectomy with an ileal-ureteral substitution is feasible for treating ureteral urothelial carcinoma when a renal-sparing procedure is indicated. It provides good long-term oncological outcomes over the upper tract, and it also preserves the renal function.

External urethral sphincter (EUS) dysfunction is a common, bothersome female voiding dysfunction. This study aims to analyze the characteristics of different types of female EUS dysfunction, as well as to determine the outcome predictors of sphincteric botulinum toxin A (BoNT-A) injection. Women receiving sphincteric BoNT-A injections for refractory EUS dysfunction were retrospectively reviewed. A comparison of the baseline clinical, urodynamic parameters and the treatment responses were made for patients with different EUS dysfunctions. A total of 106 females were included. Significantly increased detrusor overactivity, detrusor contracting pressure and the bladder outlet obstruction index with decreased urge sensation were noted in patients diagnosed with dysfunctional voiding or detrusor sphincter dyssynergia comparing to those diagnosed with poor relaxation of the external urethral sphincter. The average subjective improvement rate was 67% for the injection. The therapeutic effect was not affected by the type of EUS dysfunction. The multivariate analysis revealed that bladder neck narrowing and catheterization history were predictive of negative outcomes. There is a distinct urodynamic presentation for each type of female EUS dysfunction. Sphincteric BoNT-A injection provides a good therapeutic outcome for refractory EUS dysfunction. A narrowing bladder neck and a history of catheterization suggest poor therapeutic outcomes.