Poster 45: Effectiveness of Botulinum Toxin Injections to the External Sphincter in Treating Incomplete Voiding Postspinal Cord Injury: A Meta-Analysis

Abstract

Objective: To examine effectiveness of botulinum toxin (BTX) on bladder emptying in individuals with spinal cord injury (SCI). Data Source: Medline, CINAHL, EMBASE, and PsycINFO databases were searched for all relevant articles published between 1980 to March 2010. Study Selection: All trials examining use of BTX injections into the detrusor sphincter in treatment of bladder emptying post-SCI were included if 50% or more of the study sample was comprised of subjects post-SCI and if the SCI sample size was 3 or more. Data Extraction: Studies involved injections of 100–150 units of BTX into 3–4 sites of the detrusor sphincter. A standardized mean difference (SMD) ± SE and 95% confidence interval (CI) was calculated for in each of the studies and the results pooled using a random effects model. Outcomes assessed included postvoid residual urine volume, detrusor pressure, and urethral pressure. Effect sizes were interpreted as: small=0.2, moderate=0.5, large=0.8. Data Synthesis: 5 studies (1 RCT, 4 uncontrolled trials) met inclusion criteria, whereby subjects (pooled total=86) were assessed before and after treatment. Dose of BTX varied among the studies from 300–600 units in total. Significant decrease in postvoid residual urine volume (SMD=1.152±0.261; 95% CI, 0.640–1.665; P=0.0001) and detrusor pressure (SMD=0.865±0.270; 95% CI, 0.336–1.394, P=0.001) was found post-BTX treatment; while no significant decrease in urethral pressure (SMD=1.166; 95% CI, 0.285–1.040, P=0.061) was seen. Conclusions: Results of the meta-analysis indicate BTX is effective in treating bladder voiding dysfunction post-SCI.