Su1018 Higher Polyp Detection Rate and Shorter Cecal Intubation Time With Cap-Assisted Colonoscopy (CAC): A Systematic Review and Meta-Analysis

Abstract

Background: CAC has been shown to improve detection of polyps, adenomas, cecal intubation rates and decrease cecal intubation times. However, conflicting results have been reported with regards to these endpoints. Aims:To compare CAC with standard colonoscopy (SC) with respect to:(i) proportion of subjects detected with polyps, (ii) proportion of subjects detected with adenoma and advanced adenoma, and (iii)cecal intubation time. Methods:Studies were identified by searching Ovid MEDLINE, PubMed, and Cochrane Library database for studies published in English language between 1966 to October 2011 using a reproducible search strategy. References from retrieved articles and national meeting abstracts for past 3yrs were manually reviewed. Only prospective studies comparing CAC with SC in adult subjects were included. 2 reviewers independently scored identified studies for methodology and abstracted pertinent data. Pooling was conducted by random-effects model using MantelHaenszel method for dichotomous outcomes and inverse variance method for continuous outcomes. Cochran's Q-test with inverse variance weights and I2 test were used to assess heterogeneity. Outcomes measured were:(i)prevalence of polyps (number of subjects with polyps),(ii)prevalence of adenoma and advanced adenoma, and (iii)cecal intubation time. Results:14 studies met defined inclusion criteria (CAC-3172 and SC-3233 subjects). CAC detected a higher proportion of subjects with polyps [40% vs. 36%, OR 1.23 (95% CI 1.021.49), p=0.03]; with low heterogeneity (p=0.4, I2=2%) across 6 studies (CAC-970, SC1012) (Figure 1). There was no difference between the two groups with regards to proportion of subjects detected with adenomas [32% vs. 34%, OR 1.08 (95% CI 0.81-1.45), p=0.59], but significant heterogeneity (p<0.01, I2=72%) noted among the five studies with 3771 subjects (CAC-1972, SC-1799). Similarly, there was no difference between the two groups with regards to detection rates of advanced adenomas [10.7% vs. 12.4%, OR 0.9 (95% CI 0.57-1.4), p=0.63], with significant heterogeneity (p=0.04, I2=69%) noted across 3 studies with 2647 subjects (CAC-1316, SC-1331). CACwas associated with a shorter cecal intubation time [7.63 vs. 8.98 min, mean difference 0.88 (95% CI 0.35-1.42), p=0.001]; with significant heterogeneity (p<0.001, I2=84%) across the 13 studies included with 4984 subjects (CAC2473, SC-2511) (Figure 2). No complications attributable to CAC were noted in any of the studies. Conclusions:CAC is associated with improved polyp detection rate as well as shorter cecal intubation times. Although the adenoma detection rates were not different with CAC; given the heterogeneity of studies, more data are needed to make definite conclusions. CAC is a simple and efficient technique that has the potential to decrease the risk of interval colon cancer by improving the detection of polyps.