Botulinum A toxin urethral injection for the treatment of lower urinary tract dysfunction.

PURPOSE: This study investigates the effectiveness of botulinum A toxin in the treatment of various types of lower urinary tract dysfunction and determines the predictive factors for a successful outcome.

MATERIALS AND METHODS: A total of 103 patients with chronic urinary retention (45) or severely difficult urination (58) received urethral injection of botulinum A toxin. The dose was 50 units in 48 patients and 100 units in 55. Clinical effects and urodynamic parameters were compared at baseline and after treatment.

RESULTS: The 48 men and 55 women (age range 14 to 86 years) had various types of lower urinary tract dysfunction including detrusor sphincter dyssynergia in 29, dysfunctional voiding in 20, nonrelaxing urethral sphincter in 19, cauda equina lesion in 8, peripheral neuropathy in 14 and idiopathic detrusor underactivity in 13. A total of 40 (39%) patients had an excellent result and 47 (46%) had significant improvement as assessed by the patients. The total success rate was 84.5%. Among these patients mean maximum voiding pressure decreased significantly (62 +/- 40 vs 43 +/- 31 cm H2O, p = 0.000), as did maximal urethral closure pressure (65 +/- 36 vs 48 +/- 31 cm H2O, p = 0.000) and post-void residual (226 +/- 165 vs 89 +/- 112 ml, p = 0.000) at 2 to 4 weeks after treatment. Among 45 patients with urinary retention the indwelling catheters were removed or clean intermittent catheterization was discontinued in 39 (87%).

CONCLUSIONS: Botulinum A toxin urethral injections at doses of 50 or 100 units were effective in decreasing urethral sphincter resistance in patients with various types of lower urinary tract dysfunction.