Meta-analysis of botulinum toxin A detrusor injections in the treatment of neurogenic detrusor overactivity after spinal cord injury.

OBJECTIVE

To examine the effectiveness of botulinum toxin type A (BTX-A) on neurogenic detrusor overactivity (NDO) in individuals with spinal cord injury (SCI).

DATA SOURCES

MEDLINE, CINAHL, EMBASE, and PsycINFO databases were searched for all relevant articles published from 1980 to June 2012.

STUDY SELECTION

Trials examining the use of BTX-A injections into the detrusor wall in the treatment of NDO after SCI were included if (1) ≥ 50% of study sample comprised subjects post-SCI; (2) outcomes of interest were assessed before and after treatment with a single injection of BTX-A; and (3) the sample size was ≥ 3.

DATA EXTRACTION

A standardized mean difference ± SE (95% confidence interval) was calculated for at least 1 of the following outcomes in every study: postvoid residual urine volume, reflex detrusor volume, bladder capacity, bladder compliance, catheterization frequency, and maximum flow rate. Results from all studies were then pooled using a random-effects model. Treatment effect sizes were interpreted as small, >0.2; moderate, >0.5; or large, >0.8.

DATA SYNTHESIS

Fourteen studies representing data from 734 subjects were included. After BTX-A injection, large treatment effects were observed in postvoid residual urine volume, reflex detrusor volume, bladder capacity, bladder compliance, and catheterization frequency (P<.01). Rate of incontinence episodes was reduced from 23% to 1.31% after BTX-A treatment. No significant decrease in max flow rate was observed (P=.403).

CONCLUSIONS

Results of the meta-analysis indicate BTX-A is effective in treating NDO after SCI. The use of BTX-A was associated with a decrease in incontinence episodes, catheter use, and bladder pressures.