[Urodynamic evaluation of the efficacy of botulin toxin in refractory neurogenic hyperactive detrusor muscle].

OBJECTIVES

Proper treatment of neurogenic hyperactive detrusor muscle is responsible for several features essential for life such as renal function, and quality of life relevant issues such as urinary incontinence. Anticholinergic drugs allow treatment in most cases, but their failure in cases of refractory neurogenic hyperactive detrusor is a challenge. To evaluate the efficacy of detrusor injection of type A botulin toxin in patients with refractory neurogenic hyperactive detrusor, on the following urodynamic parameters: maximum cystomanometric capacity, detrusor compliance, reflex volume, maximum detrusor pressure and post void residual.

METHODS

Prospective study in 16 patients with the diagnosis of neurogenic hyperactive detrusor refractory to anticholinergic therapy. Urodynamic studies were performed 30 and 60 days before the procedure and after at least two weeks from stopping anticholinergic therapy. 300 units of type A botulin toxin (BTX-A) were endoscopically injected in 30 punction sites, 10 units per ml each punction. Urodynamic control was performed 30 to 45 days after injection.

RESULTS

Six of the 16 patients in the study where females and 11 males; mean age was 39.5 years (22 to 63 years). Urodynamic results: mean maximum capacity on cystomanometry before BTXA was 204.73 ml and after BTX-A 381.87 ml. Maximum detrusor capacity before was 91.46 H2O cm whereas post-treatment was 41.2 H2O cm. Mean final filling pressure was 68 H2O cm before treatment and 34 H2O cm after. Mean reflex volume was 111.33 ml before and 310.8 ml after. Finally, mean post void residual before BTX-A was 129.6 ml whereas post-BTX-A was 345.9 ml.

CONCLUSIONS

The injection of 300 U of type A botulin toxin in the detrusor muscle has demonstrated to be effective and safe for the treatment of refractory neurogenic hyperactive detrusor. There were statistically significant differences in the urodynamic parameters before and after the injection. There were no significant adverse events.