High-definition colonoscopy for improving adenoma detection: a systematic review and meta-analysis of randomized controlled studies

Background and Aims: Previous meta-analysis showed marginal benefit of high-definition white-light endoscopy (HD-WLE) over standard-definition colonoscopy (SDC) for adenoma detection, but with residual uncertainty due to inclusion of nonrandomized studies. We aimed to further assess the effect of HD-WLE on adenoma detection by including only randomized controlled trials (RCTs). Methods: A literature search was performed for RCTs evaluating HD-WLE versus SDC in terms of adenoma, advanced adenoma, and serrated sessile adenoma detection rates as well as the mean number of adenomas per colonoscopy (MAC), the mean number of advanced adenomas per colonoscopy (MAAC), and the mean number of sessile serrated adenomas per colonoscopy (MSSAC). The effect size on study outcomes is presented as the risk ratio (RR; 95% confidence interval [CI]) or mean difference (MD; 95% CI). We assessed the strength of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Results: Six RCTs involving 4594 individuals (HD-WLE, 2323; SDC, 2271) were included. Clinical indications were screening (1 study), positive result for fecal occult blood test, personal/family history of colorectal cancer (1 study), and mixed indications (4 studies). Withdrawal time was similar between the 2 arms (MD, -0.06; 95% CI, -0.25 to 0.12; P = .50). The adenoma detection rate was significantly higher in the HD-WLE arm compared with the SDC arm (40% vs 35%; RR, 1.13; 95% CI, 1.05-1.22; P = .001; I-2 = 0%; GRADE, low). This effect was consistent for advanced and sessile serrated adenoma detection rates (RR, 1.33; 95% CI, 1.03-1.72; P = .03; I-2 = 0%; GRADE, low; and RR, 1.55; 95% CI, 1.05-2.28; P = .03; I-2 = 0%; GRADE, low, respectively). In contrast, the difference was not significant for MAC, MAAC, and MSSAC. Conclusions: Meta-analyses of RCT data support the use of HD-WLE in clinical practice, although the additional benefit is limited.