Randomized tandem clinical trial comparing the efficacy of a standard colonoscope and a colonoscope equipped with the G-EYE system during a screening colonoscopy

Aims Colorectal cancer is the third leading cause of cancer deaths worldwide. In recent decades, colonoscopy has proven its effectiveness in screening for colorectal cancer in large series. However, colonoscopy screening is unperfect and the interval cancer rate is not zero. SMART MEDICAL has developped a system (G-EYE) equipped with a distal balloon to improve adenoma detection particularly behind the folds. A few studies are in favor of G-EYE system. We aim to confirm these results bu assessing efficacy and safety of the G-EYE colonoscope [1] [2].

Methods We conducted a tandem randomized clinical trial of patients over 50 years with indication for screening colonoscopy, including a minimum rate of one-third with FIT+test. The number of patients was calculated to show a 20% difference in the adenoma miss rate with a power of 90%. Arm A corresponded to standard colonoscopy by one operator followed by G-EYE colonoscopy by a second operator, arm B corresponding to the opposite. All visible adenomas were resected during each colonoscopy. Follow-up was at 1 month post-colonoscopy, with collection of pathology and any complications. The primary objective of our study was to compare the adenoma miss rate by the standard colonoscope and by the G-EYE colonoscope after colonoscopy performed respectively with the G-EYE colonoscope and the standard colonoscope in patients aged over 50, including a proportion of FIT+patients. Secondary objectives were to compare the rate of advanced adenomas missed by the 2 colonoscopes, compare the adenoma detection rate (ADR) of each colonoscope, adverse events and assess the stability of the colonoscope during the withdrawal.

Results 195 patients were included between January 2020 and June 2023. 29 were excluded (non-optimal preparation, material not available, patient's wishes, etc.). A total of 164 patients (83 women, 51%) completed the 2 procedures. Regarding the primary endpoint, the adenoma miss rate was equivalent in arms A and B: 24/56 adenomas (30%) and 24/60 (29%) respectively (p=0.427). In the FIT+subgroup, there was no significant difference between arms A and B. The rate of advanced missed adenomas was comparable in both arms: 6/74 (7%) in arm A versus 3/81 (4%) in arm B (p=0.3201). The ADR of each colonoscope (at first procedure) was 51% for the standard colonoscope (60% in the FIT+subgroup) and 54% for the G-EYE colonoscope (59% in the FIT+subgroup). This difference was not significant. The rate of diagnostic perforation was null in both arms. In 73% of cases, the operator judged that inspection on removal of the coloscope was improved by the G-EYE coloscope (better stability).

Conclusions The G-EYE colonoscope is equivalent but not superior to a standard high-definition colonoscope of the same generation for colorectal cancer screening, even in a FIT+population. Nevertheless, the study confirms that G-EYE colonoscopy is no more morbid than a standard colonoscope, and could improve stability during withdrawal.

Publication History

Article published online:
27 March 2025

• References

• 1 Halpern Z, Gross SA, Gralnek IM, Shpak B, Pochapin M, Hoffman A, Mizrahi M, Rochberger YS, Moshkowitz M, Santo E, Melhem A, Grinshpon R, Pfefer J, Kiesslich R.. Comparison of adenoma detection and miss rates between a novel balloon colonoscope and standard colonoscopy: a randomized tandem study. Endoscopy 2015; 47 (03): 238-44 Epub 2015 Feb 17. Erratum in: Endoscopy. 2015 Apr;47(4):301. 10.1055/s-0034-1391894. PMID: 25704662.
• 2 Shirin H, Shpak B, Epshtein J, Karstensen JG, Hoffman A, de Ridder R, Testoni PA, Ishaq S, Reddy DN, Gross SA, Neumann H, Goetz M, Abramowich D, Moshkowitz M, Mizrahi M, Vilmann P, Rey JW, Sanduleanu-Dascalescu S, Viale E, Chaudhari H, Pochapin MB, Yair M, Shnell M, Yaari S, Hendel JW, Teubner D, Bogie RMM, Notaristefano C, Simantov R, Gluck N, Israeli E, Stigaard T, Matalon S, Vilkin A, Benson A, Sloth S, Maliar A, Waizbard A, Jacob H, Thielsen P, Shachar E, Rochberger S, Hershcovici T, Plougmann JI, Braverman M, Tsvang E, Abedi AA, Brachman Y, Siersema PD, Kiesslich R.. G-EYE colonoscopy is superior to standard colonoscopy for increasing adenoma detection rate: an international randomized controlled trial (with videos). Gastrointest Endosc 2019; 89 (03): 545-553 Epub 2018 Sep 28. PMID: 30273591.