Variable stiffness colonoscope versus regular adult colonoscope: meta-analysis of randomized controlled trials

Background and study aims: The variable stiffness colonoscope (VSC) may have theoretical advantages over standard adult colonoscopes (SACs), though data are conflicting. We conducted a meta-analysis to compare the efficacies of the VSC and SAC. Study design: We searched Medline (1966-2008) and abstracts of gastroenterology scientific meetings in the 5 years to February 2008, only for randomized clinical trials (RCTs) of adult patients. Trial quality was assessed using the Delphi list. In a meta-analysis with a fixed effects model, cecal intubation rates, cecal intubation times, abdominal pain scores, sedation used, and use of ancillary maneuvers, were compared in separate analyses, using weighted mean differences (WMDs), standardized mean differences (SMDs), or odds ratios (ORs). Results: Seven RCTs satisfied the inclusion criteria (1923 patients), four comparing VSC with SAC procedures in adults, and three evaluating the pediatric VSC. There was no significant heterogeneity among the studies. The overall trial quality was adequate. Cecal intubation rate was higher with the use of VSC (OR = 2.08, 95% confidence interval [CI] 1.29 to 3.36). The VSC was associated with lower abdominal pain scores and a decreased need for sedation during colonoscopy. Cecal intubation time was similar for the two colonscope types (WMD = -0.21 minutes, 95% CI - 0.85 to 0.43). Because of the nature of the intervention no studies were blinded. There was no universal method for using the VSC. Conclusions: Compared with the SAC, VSC use was associated with a higher cecal intubation rate, less abdominal pain, and decreased need for sedation. However, cecal intubation times were similar for the two colonoscope types.