Single-institution experience in 110 patients with botulinum toxin A injection into bladder or urethra

To detail, in a review, one institution's 6-year experience using botulinum toxin A (BTX-A) in the bladder and urethra in 110 patients for a variety of lower urinary tract disorders.

A total of 110 patients (35 men and 75 women, age range 19 to 82 years) received injections of BTX-A into the bladder (n = 42) or urethra (n = 68). Voiding dysfunction included neurogenic detrusor overactivity and/or detrusor sphincter dyssynergia, overactive bladder, bladder neck obstruction, and interstitial cystitis. Under light sedation in most cases, patients were treated with either 100 to 200 U of BTX-A in 4 mL divided in equal doses into the four quadrants of the external sphincter or by injection into the bladder base using 100 to 300 U of BTX-A diluted in approximately 10 to 30 mL of sterile saline. At last follow-up, 27 patients had received additional injections (up to six) at intervals of 6 months or longer.

All patients who underwent bladder BTX-A injection had preoperative evidence of involuntary detrusor contractions during urodynamic testing. Analysis of the 110 patients indicated that 67.3% reported a decrease or absence of incontinence. Diaries indicated a decrease in both daytime and nighttime voiding symptoms. Maximal efficacy occurred between 7 and 30 days and lasted for at least 6 months. Condition-specific quality-of-life symptom scores also demonstrated improvement. No long-term complications had occurred at last follow-up. Two women with multiple sclerosis and mild baseline stress urinary incontinence reported increased leakage with stress after BTX-A external sphincter injection, and one woman with multiple sclerosis noted new onset stress urinary incontinence after external sphincter injection. However, they all reported significant improvement in their detrusor sphincter dyssynergia with decreased postvoid residual urine volume, improved uroflow, decreased urge incontinence, and decreased daytime and nighttime frequency. One woman with multiple sclerosis who underwent bladder injection had increased postvoid residual urine volume from 78 to 155 mL. She did not have to perform intermittent catheterization.

BTX-A injection is a safe and promising treatment modality for a variety of lower urinary tract dysfunctions for both skeletal and smooth muscle dysfunction. In our series, BTX-A is equally effective in women as it is in men. When injected into the sphincter, the risk of stress incontinence is low. Bladder injections with BTX-A are effective for not only neurogenic detrusor overactivity, but also overactive bladder. BTX-A can even be considered for interstitial cystitis.