The efficacy of cap-assisted colonoscopy in polyp detection and cecal intubation: a meta-analysis of randomized controlled trials

Am J Gastroenterol. 2012 Aug;107(8):1165-73. doi: 10.1038/ajg.2012.135. Epub 2012 Jun 5.


Objectives: The role of cap-assisted colonoscopy (CAC) in polyp detection and cecal intubation is unclear. We conducted a meta-analysis to compare the efficacy of CAC vs. standard colonoscopy (SC).

Methods: Publications in English and non-English literatures (OVID, MEDLINE, and EMBASE) and abstracts in major international conferences were searched for controlled trials comparing CAC and SC. Outcome measures included the proportion of patients with polyps or adenomas detected, cecal intubation rate, cecal intubation time, and total colonoscopy time. The statistical heterogeneity of trials was examined and the effects were pooled by random-effects model. The risk of bias was evaluated by the assessment tool from the Cochrane Handbook. Subgroup analyses were performed for possible clinical and methodological heterogeneities.

Results: From 2,358 citations, 16 randomized controlled clinical trials were included consisting of 8,991 subjects (CAC: 4,501; SC: 4,490). Mean age of subjects was 61.0 years old and 60% were males. CAC detected a higher proportion of patients with polyp(s) (relative risk (RR): 1.08; 95% confidence interval (CI): 1.00-1.17) and reduced the cecal intubation time (mean difference: -0.64 min; 95% CI: -1.19 to -0.10). Cecal intubation rate (RR: 1.00; 95% CI: 0.99-1.02) and total colonoscopy time (mean difference: -0.97 min; 95% CI: -2.33 to 0.40) were comparable between the two groups. In subgroup analyses, a short cap (≤4 mm) was associated with improved polyp detection, whereas a long cap (≥7 mm) was associated with a shorter cecal intubation time.

Conclusions: CAC demonstrated marginal benefit over SC for polyp detection and shortened the cecal intubation time.

Publication types

  • Comparative Study
  • Meta-Analysis
  • Review

MeSH terms

  • Adenoma / diagnosis*
  • Cecum / pathology*
  • Colonic Neoplasms / diagnosis*
  • Colonic Polyps / diagnosis*
  • Colonoscopes
  • Colonoscopy / instrumentation
  • Colonoscopy / methods*
  • Humans
  • Intubation
  • Randomized Controlled Trials as Topic