[The effect of botulinum toxin injection into the bladder for overactive bladder: two case].

Two cases of intractable overactive bladder which were treated by intradetrusor botulinum-A toxin (BTX-A) are presented. Case 1: A 53-year-old woman suffered from adhesive arachinoiditis. She had severe detrusor hyperreflexia and urge urinary incontinence despite a high dose of anticholinergic medication. Under cystoscopic control, a total of 300 units of BTX-A were injected into the detrusor muscle at 30 sites (10 units per ml per site), sparing the trigone area using a 27G flexible injection needle. This procedure was done under both caudal anesthesia with 10 ml 1% lidocaine and bladder mucosa anesthesia by instilling 40 ml 2% lidocaine. At a 12-week followup she was completely continent. Case 2: A 63-year-old man with intractable detrusor overactivity of idiopathic origin was treated using the above technique. Urge urinary incontinence decreased 4 weeks after the BTX-A injections. However, postvoid residual urine volume was increased, and intermittent self-catheterization was needed. Intradetrusor BTX-A dramatically increases the bladder capacity and decreases the frequency of urge urinary incontinence. However, this treatment caused urinary retention in Case 2. We believe that the dosage amount of BTX-A should be changed case by case.