Clinical effects of suburothelial injection of botulinum a toxin on patients with nonneurogenic detrusor overactivity refractory to anticholinergics

Objectives. To investigate the clinical and urodynamic effects of suburothelial injection of botulinum A toxin on patients with nonneurogenic detrusor overactivity. Intradetrusor injection of botulinum A toxin has been used to treat patients with detrusor overactivity. Suburothelial injection of botulinum A toxin might effectively inhibit the occurrence of detrusor overactivity mediated by sensory nerves. Methods. Twenty patients with nonneurogenic detrusor overactivity refractory to anticholinergics were enrolled and treated with injection of 200 U botulinum A toxin into the suburothelial space. The clinical effects on the lower urinary tract symptoms and urodynamic parameters were assessed. Results. At 3 months after treatment, 9 patients had regained continence (45%), 8 had improvement (40%), and treatment had failed in 3 (15%). At 6 months after treatment, 7 patients remained continent, but treatment had failed in 5. Hematuria developed in 1 patient, urinary tract infection in 7 (35%), and a large postvoid residual urine volume requiring catheterization in 6 (30%). Hesitancy in initiation and difficult urination was also noted in 15 patients (75%). The volume of the first sensation of bladder filling and bladder capacity increased about two times; however, the voiding efficiency was reduced by 50% at 2 weeks after treatment. The postvoid residual urine volume was increased by seven times the baseline value at 2 weeks and had decreased to three times greater at 3 and 6 months after treatment. Conclusions. The results of this study have shown that suburothelial injection of 200 U botulinum A toxin impairs bladder sensation and voiding efficiency, but is effective in the treatment of nonneurogenic detrusor overactivity. Transient urinary retention and the development of urinary tract infection should be carefully monitored.