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.