Comparison of Standard Versus High Definition Colonoscopy for Polyp Detection: A Randomized Controlled Trial

Abstract

Background and Aims: Colonoscopy is the most commonly performed gastrointestinal procedure due to its utility in colorectal cancer screening. Detection of polyps is an important goal of colonoscopy; therefore it's of great interest to find out endoscopic techniques associated with the highest polyps' detection rate. In the present study, we sought to compare the performance of colonoscopy using a high definition, wide-angle colonoscope versus a standard colonoscope for the detection of polyps. The literature data regarding this issue is limited. Patients and Methods: A total of 390 patients, aged 50 years or older with intact colons, submitted to routine colonoscopy, were prospectively randomized between high definition colonoscopy (HD group, n = 193) and standard colonoscopy (SC group, n = 197). Times required to reach and withdraw from the cecum were measured. All the examinations were performed by a single experienced endoscopist with a known high polyps' detection rate. Sample size calculation showed that at least 182 patients on each group were needed in order to achieve a statistical power of 80% to detect a 15% increase in the number of detected polyps between the two groups at the 5% level of significance. Results: The per-patient basis analyses demonstrated that there were no significant differences between the 2 groups, as far as the overall detection rate of polyps (SC, 1.31 ± 1.90; HD, 1.68 ± 2.31; P=0.085), of large polyps (size≥10 mm; SC, 0.39 ± 0.89; HD, 0.48 ± 0.80; P=0.29) and of medium polyps (10mm>size≥5 mm; SC, 0.60 ± 1.46; HD, 0.58 ± 1.25; P=0.83). In contrast, a significant difference was observed in the detection rates of small polyps (size<5mm; SC, 0.32 ± 0.86; HD, 0.71 ± 1.65; P=0.004). Moreover, no significant differences between the 2 groups were observed, in the overall detection rates of adenomas, large adenomas, medium adenomas, large hyperplastic polyps and medium hyperplastic polyps. On the other hand, the detection rates of small hyperplastic polyps (SC, 0.11 ± 0.38; HD, 0.27 ± 0.63; P=0.003) and small adenomas (SC, 0.21 ± 0.63; HD, 0.44 ± 1.17; P=0.018), as well as the overall detection rate of hyperplastic polyps (SC, 0.20 ± 0.48; HD, 0.35 ± 0.69; P=0.011) were significantly increased with high definition colonoscopes. Conclusion: High definition colonoscopy led to a significant increase in the detection of small polyps including adenomas and hyperplastic polyps.