Comparison of colon adenoma detection rate using transparent cap-assisted and conventional colonoscopy: result from an international trial in Asia

Introduction: Controversy remains regarding transparent cap-assisted technique improves adenoma detection rate (ADR) in colonoscopy. We aimed to investigate the effect of transparent cap-assisted colonoscopy on ADR and other colonoscopy performance. Methods: We performed sub-analysis of an international, multicenter, open-label database containing colonoscopy data from 11 centers in 4 Asian countries/regions on patients who underwent colonoscopy. The patient characteristics, procedure related characteristics, and pathological findings of all detected lesions were prospectively recorded. The patients were divided into 2 groups as receiving colonoscopy with or without transparent cap attachment. The ADR and procedure time were compared between the 2 groups. Other procedural factors related to ADR were also investigated. Results: Between November 2020 and January 2022, 3,029 who underwent colonoscopy (transparent cap-assisted colonoscopy, n=1,796; standard colonoscopy, n=1,233) were enrolled in this study. The transparent cap-assisted colonoscopy group ADR was significantly higher than the conventional colonoscopy (55.1% vs 50.0%, p<0.01). Transparent cap-assisted colonoscopy detected a higher proportion of patients with adenoma (odd ratio (OR): 1.59, 95%CI: 1.13-2.24, p<0.01) and any polypoid lesion (OR: 1.49, 95%CI: 1.04-2.16, p=0.03). Transparent cap-assisted colonoscopy also reduced cecal intubation time (mean difference: -0.35 min) and total colonoscopy time (mean difference -3.4 min). In the other procedural factors, using linked color imaging (OR: 1.75, 95%CI: 1.49-2.06, p<0.01), patient body rotation (OR: 1.54, 95%CI, 1.12-2.13, p<0.01), longer withdrawal time (OR:1.12, 95%CI: 1.09-1.15, p<0.01) were also significantly associated to adenoma detection. Conclusion: In real-world practice, transparent cap-assisted colonoscopy is a safe and inexpensive technology that could improve adenoma and polyp detection.