Added value of a balloon-based mucosal exposure device in computer-aided detection-assisted colonoscopy: a randomized controlled trial (COMBAT study)

Abstract

Background

Both computer-aided detection (CADe) systems and mucosal exposure devices can enhance adenoma detection during colonoscopy. This research investigates whether combining a CADe system with a balloon-based mucosal exposure device increases the identification of individuals with high risk colonoscopy findings within a fecal immunochemical test (FIT)-based organized screening program.

Methods

We conducted a multicenter, open-label, parallel-arm randomized controlled trial. FIT-positive subjects were randomized 1:1 to either CADe-assisted colonoscopy with a balloon-based mucosal exposure device (CADe+balloon arm) or CADe-assisted colonoscopy alone (CADe arm). Randomization was performed using a computer-generated block sequence, with age and sex stratified. Participants, but not endoscopists, were masked to the random assignment. The primary end point was the rate of individuals with high risk colonoscopy findings according to ESGE criteria (≥5 low risk adenomas or ≥1 advanced adenoma or ≥1 advanced serrated lesion). The key secondary end point was the adenoma detection rate (ADR).

Results

644 subjects (51.5% women) were randomized in three centers. High risk findings were observed in 19.3% (95%CI 15.0% to 23.5%) of the CADe+balloon arm and 23.1% (95%CI 18.4% to 27.8%) of the CADe arm (P = 0.24). The ADR was 55.4% (95%CI 50.1% to 60.8%) versus 59.1% (95%CI 53.8% to 64.8%) in the CADe+balloon and CADe arms, respectively (P = 0.32). No adverse events were reported.

Conclusions

In a FIT-based screening program, adding a balloon-based mucosal exposure device to CADe-assisted colonoscopy did not enhance the detection of subjects with high risk features or of neoplastic lesions. A CADe-related ceiling effect may have limited the benefit of the additional device.

Publication History

Received: 02 February 2025

Accepted after revision: 02 June 2025

Article published online:
01 August 2025

• References

• 1 Cervantes A, Adam R, Roselló S. et al. Metastatic colorectal cancer: ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up. Ann Oncol 2023; 34: 10-32
• 2 Malvezzi M., Carioli G, Bertuccio P. et al. European cancer mortality predictions for the year 2018 with focus on colorectal cancer. Ann Oncol 2018; 29: 1016-1102
• 3 Zauber AG, Winawer SJ, O’Brien MJ. et al. Colonoscopic polypectomy and long-term prevention of colorectal-cancer deaths. NEJM 2012; 366: 687-696
• 4 Triantafyllou K, Gkolfakis P, Tziatzios G. et al. Effect of Endocuff use on colonoscopy outcomes: A systematic review and meta-analysis. World J Gastroenterol 2019; 25: 1158-1170
• 5 Kim SY, Park HJ, Kim HS. et al. Cap-assisted chromoendoscopy using a mounted cap versus standard colonoscopy for adenoma detection. Am J Gastroenterol 2020; 115: 465-472
• 6 Haghbin H, Zakirkhodjaev N, Azizullah B. et al. Efficacy and safety of thermal ablation after endoscopic mucosal resection: a systematic review and network meta-analysis. J Clin Med 2024; 13: 1298
• 7 Seager A, Sharp L, Neilson LJ. et al. Polyp detection with colonoscopy assisted by the GI Genius artificial intelligence endoscopy module compared with standard colonoscopy in routine colonoscopy practice (COLO-DETECT): a multicentre, open-label, parallel-arm, pragmatic randomised controlled trial. Lancet Gastroenterol Hepatol 2024; 9: 911-923
• 8 Bretthauer M, Ahmed J, Antonelli G. et al. Use of computer-assisted detection (CADe) colonoscopy in colorectal cancer screening and surveillance: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement. Endoscopy 2025; 57: 667-673
• 9 Spadaccini M, Hassan C, Rondonotti E. et al. Combination of mucosa-exposure device and computer-aided detection for adenoma detection during colonoscopy: a randomized trial. Gastroenterology 2023; 165: 244-251.e3
• 10 Aniwan S, Mekritthikrai K, Kerr SJ. et al. Computer-aided detection, mucosal exposure device, their combination, and standard colonoscopy for adenoma detection: a randomized controlled trial. Gastrointest Endosc 2023; 97: 507-516
• 11 Lui TK, Lam CP, To EW. et al. Endocuff with or without artificial intelligence-assisted colonoscopy in detection of colorectal adenoma: a randomized colonoscopy trial. Am J Gastroenterol 2024; 119: 1318-1325
• 12 Weight J, Repici A, Antonelli G. et al. Performance of a new integrated computer-assisted system (CADe/CADx) for detection and characterization of colorectal neoplasia. Endoscopy 2022; 54: 180-184
• 13 Calderwood AH, Jacobson BC. Comprehensive validation of the Boston Bowel Preparation Scale. Gastrointest Endosc 2010; 72: 686-692
• 14 Endoscopic Classification Review Group. Update on the Paris classification of superficial neoplastic lesions in the digestive tract. Endoscopy 2005; 37: 570-578
• 15 Radaelli F, Paggi S, Hassan C. et al. Split-dose preparation for colonoscopy increases adenoma detection rate: a randomised controlled trial in an organised screening programme. Gut 2017; 66: 270-277
• 16 Dixon MF. Gastrointestinal epithelial neoplasia: Vienna revisited. Gut 2002; 51: 130-131
• 17 Hassan C, Antonelli G, Dumonceau JM. et al. Post-polypectomy colonoscopy surveillance: European Society of Gastrointestinal Endoscopy (ESGE) Guideline – Update 2020. Endoscopy 2020; 52: 687-700
• 18 Rondonotti E, Di Paolo D, Rizzotto ER. et al. Efficacy of a computer-aided detection system in a fecal immunochemical test-based organized colorectal cancer screening program: a randomized controlled trial (AIFIT study). Endoscopy 2022; 54: 1171-1179
• 19 Shirin H, Shpak B, Epshtein J. et al. G-EYE colonoscopy is superior to standard colonoscopy for increasing adenoma detection rate: an international randomized controlled trial (with videos). Gastrointest Endosc 2019; 89: 545-553
• 20 Kiesslich R, Teubner D, Hoffman A. et al. Retrospective comparison of G-EYE balloon-colonoscopy with standard colonoscopy for increased adenoma detection rate and reduced polyp removal time. Endosc Int Open 2023; 11: E920-E927
• 21 Rex DK. Key quality indicators in colonoscopy. Gastroenterol Rep (Oxf) 2023; 11: goad009