Third Eye Retroscope Randomized Clinical Evaluation (TERRACE)

This study has been completed.
Information provided by (Responsible Party):
Avantis Medical Systems Identifier:
First received: January 6, 2010
Last updated: January 22, 2013
Last verified: January 2013

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.

Condition Intervention
Colorectal Neoplasms
Device: Third Eye Retroscope

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Diagnostic
Official Title: Third Eye Retroscope Randomized Clinical Evaluation (The "TERRACE" Study)

Further study details as provided by Avantis Medical Systems:

Primary Outcome Measures:
  • Detection rates for adenomas and for total polyps [ Time Frame: Acute - during procedure ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Times for withdrawal phase and for complete colonoscopy procedure [ Time Frame: Acute - during procedure ] [ Designated as safety issue: No ]

Enrollment: 448
Study Start Date: March 2009
Study Completion Date: February 2010
Primary Completion Date: February 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Group A - COLO, then TER
Complete examination with standard colonoscope ("COLO") followed by complete examination with Third Eye Retroscope ("TER") used in conjunction with standard colonoscope
Device: Third Eye Retroscope
Device used with colonoscope to provide second, retrograde view of the colon
Active Comparator: Group B - TER, then COLO
Complete examination with Third Eye Retroscope ("TER") used in conjunction with standard colonoscope, followed by complete examination with standard colonoscope ("COLO") alone
Device: Third Eye Retroscope
Device used with colonoscope to provide second, retrograde view of the colon


Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes

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.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01044732

United States, Maryland
Johns Hopkins Hospital
Baltimore, Maryland, United States, 21231
United States, Missouri
Kansas City Veterans Administration Medical Center
Kansas City, Missouri, United States, 64128
United States, New Hampshire
Dartmouth-Hitchcock Medical Center
Lebanon, New Hampshire, United States, 03756
United States, Rhode Island
Bayside Endoscopy Center
Providence, Rhode Island, United States, 02905
United States, Texas
Baylor University Medical Center
Dallas, Texas, United States, 75246
Cliniques Universitaires Saint-Luc
Brussels, Belgium, B-1200
Istituto Clinico Humanitas
Milan, Italy, 20089 Rozzano
University Medical Center Utrecht
Utrecht, Netherlands, 3584 CX
United Kingdom
St. Mark's Hospital
London, United Kingdom, HA1 3UJ
Sponsors and Collaborators
Avantis Medical Systems
Principal Investigator: Peter D. Siersema, MD, PhD UMC Utrecht
  More Information

Responsible Party: Avantis Medical Systems Identifier: NCT01044732     History of Changes
Other Study ID Numbers: Avantis TER-08-06
Study First Received: January 6, 2010
Last Updated: January 22, 2013
Health Authority: United States: Food and Drug Administration

Keywords provided by Avantis Medical Systems:
Miss rates
Detection rates
Third Eye Retroscope

Additional relevant MeSH terms:
Colorectal Neoplasms
Colonic Diseases
Digestive System Diseases
Digestive System Neoplasms
Gastrointestinal Diseases
Gastrointestinal Neoplasms
Intestinal Diseases
Intestinal Neoplasms
Neoplasms by Site
Rectal Diseases processed this record on August 27, 2015