Third Eye Retroscope Randomized Clinical Evaluation (TERRACE)

The Third Eye® Retroscope® is a device that can be inserted through the instrument channel of a standard colonoscope to provide an additional, retrograde (or backward) view that reveals areas behind folds and flexures in the colon, and might detect additional polyps that cannot be seen with the colonoscope alone. Patients who participate as subjects in the study will undergo two complete colonoscopy procedures, a standard colonoscopy and a colonoscopy in which a Third Eye Retroscope is used along with the same colonoscope. Half of the patients will have the standard colonoscopy first followed by the Third Eye colonoscopy, and the other half will have the Third Eye procedure first. Results from the two groups will be analyzed and compared to determine the effectiveness of the Third Eye Retroscope for detecting additional adenomas and other polyps compared with the standard colonoscope alone.

Colonoscopy is generally agreed to be the best method for detecting and removing pre-cancerous polyps, but some lesions can be missed, especially if they are located behind folds in the lining of the colon or behind flexures (sharp bends) in the colon. The Third Eye® Retroscope® is a device that can be inserted through the instrument channel of a standard colonoscope to provide an additional, retrograde (or backward) view that reveals areas behind folds and flexures in the colon. Previous studies have shown the device to be effective for detecting additional polyps that could not have been seen with the colonoscope alone. The purpose of this research is to compare the additional diagnostic yield obtained by using the Third Eye® Retroscope® vs. the diagnostic yield for the standard colonoscope alone in the context of a randomized, controlled study design. Patients who are scheduled for colonoscopy will be recruited to the study and randomized to one of two groups. Each patient will undergo two "back-to-back" procedures. Patients in Group A (study group) will undergo a standard colonoscopy followed immediately by a Third Eye colonoscopy. Patients in Group B (control group) will undergo a Third Eye colonoscopy followed immediately by a standard colonoscopy. Results from the two groups will be analyzed and compared to determine the effectiveness of the Third Eye Retroscope for detecting additional adenomas and other polyps compared with the standard colonoscope alone.

Colorectal, Neoplasms, Adenomas, Polyps, Miss rates, Detection rates, Colonoscope, Third Eye Retroscope

Complete examination with standard colonoscope ("COLO") followed by complete examination with Third Eye Retroscope ("TER") used in conjunction with standard colonoscope

Complete examination with Third Eye Retroscope ("TER") used in conjunction with standard colonoscope, followed by complete examination with standard colonoscope ("COLO") alone

For all examinations with each method (SC or TEC), mean time for withdrawal phase and mean time for total procedure

Inclusion Criteria: The patient is undergoing colonoscopy for screening, for surveillance in follow-up of previous polypectomy or for diagnostic workup; The patient must understand and provide written consent for the procedure. Exclusion Criteria: Patients with a history of colonic resection; Patients with inflammatory bowel disease; Patients with a personal history of polyposis syndrome; Patients with suspected chronic stricture potentially precluding complete colonoscopy; Patients with diverticulitis or toxic megacolon; Patients with a history of radiation therapy to abdomen or pelvis; Patients who are currently enrolled in another clinical investigation in which the intervention might compromise the safety of the patient's participation in this study.

Leufkens AM, DeMarco DC, Rastogi A, Akerman PA, Azzouzi K, Rothstein RI, Vleggaar FP, Repici A, Rando G, Okolo PI, Dewit O, Ignjatovic A, Odstrcil E, East J, Deprez PH, Saunders BP, Kalloo AN, Creel B, Singh V, Lennon AM, Siersema PD; Third Eye Retroscope Randomized Clinical Evaluation [TERRACE] Study Group. Effect of a retrograde-viewing device on adenoma detection rate during colonoscopy: the TERRACE study. Gastrointest Endosc. 2011 Mar;73(3):480-9. doi: 10.1016/j.gie.2010.09.004. Epub 2010 Nov 10.

Siersema PD, Rastogi A, Leufkens AM, Akerman PA, Azzouzi K, Rothstein RI, Vleggaar FP, Repici A, Rando G, Okolo PI, Dewit O, Ignjatovic A, Odstrcil E, East J, Deprez PH, Saunders BP, Kalloo AN, Creel B, Singh V, Lennon AM, DeMarco DC. Retrograde-viewing device improves adenoma detection rate in colonoscopies for surveillance and diagnostic workup. World J Gastroenterol. 2012 Jul 14;18(26):3400-8. doi: 10.3748/wjg.v18.i26.3400.