BOTULINUM TOXIN TYPE A: A NOVEL APPROACH TO THE TREATMENT OF RECURRENT URETHRAL STRICTURES

Abstract

Recently, investigators have demonstrated that botulinum toxin type A (BTX-A) can be used to prevent scar formation in facial wounds.1 This concept led us to investigate the treatment of recurrent urethral stricture scars using a combination of direct visual internal urethrotomy (DVIU) and BTX-A. MATERIALS AND METHODS Three patients with a history of posterior urethral stricture disease who had undergone failed DVIU were treated with repeat DVIU in combination with BTX-A injection. Etiologies for urethral strictures included radical retropubic prostatectomy in 2 patients with prostate cancer, and Targis microwave procedure (Urologix, Inc., Minneapolis, Minnesota) for benign prostatic hyperplasia in 1. All patients had a combination of stress urinary incontinence and recurrent urethral strictures diagnosed by videourodynamics and cystoscopy, respectively. Intraoperatively, each stricture was radially incised through the fibrous tissue in 4 quadrants until bleeding tissue was reached and a 21Fr or greater cystoscope could be easily passed into the bladder. Using a 25 gauge Williams needle 100 units BTX-A diluted in 2 ml preservative-free saline was injected circumferentially at the base of the scar into the intervening areas between the incisions (fig. 1). All patients had a catheter placed at the end of the procedure that was left indwelling for 2 to 5 days. Patients returned at approximately 4 to 6 weeks for repeat cystoscopy. On repeat cystoscopy a 21Fr cystoscope easily passed through the previous stricture site in 2 of 3 patients, each of whom later underwent successful placement of an artificial urinary sphincter (AUS) to treat the stress urinary incontinence. Nine months following DVIU plus BTX-A injection cystoscopy revealed continued patency of the posterior urethra in 1 patient who had undergone implantation of an AUS (fig. 2). Long-term urethral patency of the other AUS implant was confirmed during operative revision of the AUS 12 months after DVIU plus BTX-A injection. The third patient, who previously had undergone radical retropubic prostatectomy complicated by an anastomotic urinary stricture, had a moderate recurrence of the scar following DVIU plus BTX-A treatment. Repeat cystoscopy 6 weeks postoperatively showed an approximately 10Fr to 12Fr caliber urethral lumen. An 18-week followup cystoscopy demonstrated no further diminution in urethral caliber. Nine months after stricture incision and BTX-A injection the patient continues to void to completion without straining or the need to catheterize.