Impact of cap-assisted colonoscopy on detection of proximal colon adenomas: systematic review and meta-analysis

Background and Aims: Proximal colon adenomas can be missed during routine colonoscopy. Use of a cap or hood on the tip of the colonoscope has been shown to improve overall adenoma detection with variable rates. However, it has not been systematically evaluated for detection of proximal colon or right-sided adenomas where the cap may have maximum impact on adenoma detection rate (ADR). Our aim was to perform a systematic review and meta-analysis to evaluate the impact of cap-assisted colonoscopy (CC) on right-sided ADRs (r-ADRs) compared with standard colonoscopy (SC). Methods: PubMed, EMBASE, SCOPUS, and Cochrane databases as well as secondary sources (bibliographic review of selected articles and major GI proceedings) were searched through October 1, 2016. Primary outcome was the pooled rate of r-ADR. Detection of flat adenoma, sessile serrated adenoma/polyp (SSA/P), and number of right-sided adenomas per patient were also assessed. Pooled odds ratio (OR) and 95% confidence intervals (CIs) were calculated using random-effect models. Results: Wescreened 686 records and analyzeddata from4 studies (CCgroup, 2546patients; SCgroup, 2547patients) that met criteria for determination of r-ADRs, whereas 6 studies (CC group, 3159 patients; SC group, 3137 patients) were analyzed to estimate right-sided adenomas per patient. r-ADR was significantly higher with CC compared with SC (23% vs 17%; OR, 1.49; 95% CI, 1.08-2.05; I-2 = 79%; P = .01). CC also improved detection rates of flat adenoma (OR, 2.08; 95% CI, 1.35-3.20; P < .01) and SSA/P (OR, 1.33; 95% CI, 1.01-1.74; P = .04). The total number of right-sided adenomas (CC: 1428 [60%] vs SC: 1127 [58%]) and number of right-sided adenomas per patient (CC, .71 +/- .5, vs SC, .65 +/- .62 [mean +/- standard deviation]) were numerically higher for CC but were not statistically significant (P = .43). Approximately 17 CCs would be required to detect an additional patient with right-sided adenoma. Conclusions: Use of CC significantly improves the proximal colon ADR. In addition, flat adenoma and serrated colonic lesion detection rates are also significantly higher as compared with SC.