G-EYE colonoscopy is superior to standard colonoscopy for increasing adenoma detection rate: an international randomized controlled trial (with videos)

Gastrointest Endosc. 2019 Mar;89(3):545-553. doi: 10.1016/j.gie.2018.09.028. Epub 2018 Sep 28.


Background and aims: Colorectal cancer (CRC) is largely preventable with routine screening and surveillance colonoscopy; however, interval cancers arising from precancerous lesions missed by standard colonoscopy still occur. An increased adenoma detection rate (ADR) has been found to be inversely associated with interval cancers. The G-EYE device includes a reusable balloon integrated at the distal tip of a standard colonoscope, which flattens haustral folds, centralizes the colonoscope's optics, and reduces bowel slippage. The insufflated balloon also aims to enhance visualization of the colon during withdrawal, thereby increasing the ADR.

Methods: In this randomized, controlled, international, multicenter study (11 centers), patients (aged ≥50 years) referred to colonoscopy for screening, surveillance, or changes in bowel habits were randomized to undergo either balloon-assisted colonoscopy by using an insufflated balloon during withdrawal or standard high-definition colonoscopy. The primary endpoint was the ADR.

Results: One thousand patients were enrolled between May 2014 and September 2016 to undergo colonoscopy by experienced endoscopists; 803 were finally analyzed (standard colonoscopy n = 396; balloon-assisted colonoscopy n = 407). Baseline parameters were similar in both groups. Balloon-assisted colonoscopy provided a 48.0% ADR compared with 37.5% in the standard colonoscopy group (28% increase; P = .0027). Additionally, balloon-assisted colonoscopy provided for a significant increase in detection of advanced (P = .0033) flat adenomas (P < .0001) and sessile serrated adenomas/polyps (P = .0026).

Conclusion: Balloon-assisted colonoscopy yielded a higher ADR and increased the detection of advanced, flat, and sessile serrated adenomas/polyps when compared with standard colonoscopy. Improved detection by the G-EYE device could impact the quality of CRC screening by reducing miss rates and consequently reducing interval cancer incidence. (Clinical trial registration number: NCT01917513.).

Publication types

  • Randomized Controlled Trial
  • Video-Audio Media

MeSH terms

  • Adenoma / diagnosis*
  • Adenomatous Polyps / diagnosis
  • Aftercare
  • Aged
  • Colonic Polyps / diagnosis*
  • Colonoscopes
  • Colonoscopy / instrumentation
  • Colonoscopy / methods*
  • Colorectal Neoplasms / diagnosis*
  • Early Detection of Cancer
  • Feces / chemistry
  • Female
  • Hemoglobins / analysis
  • Humans
  • Immunochemistry
  • Male
  • Middle Aged


  • Hemoglobins

Associated data

  • ClinicalTrials.gov/NCT01917513