A balloon-assisted colonoscope does not increase the adenoma miss rate: Outcomes of a single-center tandem randomized clinical trial

Background: Colorectal cancer is the third leading cause of cancer death worldwide. Colonoscopy can prevent this complication but is imperfect because of missed adenoma. A device involving a variable-rigidity balloon has been developed: G-EYE colonoscopy (GEYEC). Only a few prospective studies on GEYEC are available. We compared GEYEC to standard colonoscopy (SC) during screening colonoscopy. Methods: We performed a single-center back-to-back colonoscopy tandem randomized clinical trial. Patients older than 50 years were referred for screening colonoscopy, among whom 1/3 with a positive fecal immunochemical test (FIT) were included. In Arm A, patients underwent SC followed by GEYEC; in Arm B, the opposite occurred. The primary objective was to assess and compare adenoma miss rate (AMR) between arms. The secondary objectives were to compare advanced AMRs (aAMRs), adverse events for each colonoscope and withdrawal stability rates for GEYEC. Results: One hundred ninety-five patients were included between January 2020 and June 2023. A total of 164 patients (83 women, 51%) completed the 2 procedures, performed by six experienced operators. The mean AMRs were 0.438 in Arm A and 0.393 in Arm B (p=0.713). The mean aAMRs were 0.176 in Arm A and 0.036 in Arm B (p=0.76). The rate of significant adverse events ( AGREE II) was 1.8%, and none were attributed to the GEYEC balloon. In 79% of cases, operators felt that GEYEC provided more stability during withdrawal. Conclusion: Although it is reliable and safe, compared with SC, GEYEC does not reduce AMR or aAMR. However, it increases the comfort of scope withdrawal during screening.