Brief Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Jul 14, 2012; 18(26): 3400-3408
Published online Jul 14, 2012. doi: 10.3748/wjg.v18.i26.3400
Retrograde-viewing device improves adenoma detection rate in colonoscopies for surveillance and diagnostic workup
Peter D Siersema, Amit Rastogi, Anke M Leufkens, Paul A Akerman, Kassem Azzouzi, Richard I Rothstein, Frank P Vleggaar, Alessandro Repici, Giacomo Rando, Patrick I Okolo, Olivier Dewit, Ana Ignjatovic, Elizabeth Odstrcil, James East, Pierre H Deprez, Brian P Saunders, Anthony N Kalloo, Bradley Creel, Vikas Singh, Anne Marie Lennon, Daniel C DeMarco
Peter D Siersema, Anke M Leufkens, Frank P Vleggaar, Department of Gastroenterology and Hepatology, University Medical Center Utrecht, 3508 GA Utrecht, The Netherlands
Amit Rastogi, Vikas Singh, Division of Gastroenterology and Hepatology, Kansas City Veterans Administration Medical Center, Kansas City, MO 64128, United States
Paul A Akerman, Department of Gastroenterology, Bayside Endoscopy Center, 33 Staniford Street, Providence, RI 02905, United States
Kassem Azzouzi, Olivier Dewit, Pierre H Deprez, Department of Gastroenterology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, B-1200 Brussels, Belgium
Richard I Rothstein, Department of Gastroenterology and Hepatology, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756, United States
Alessandro Repici, Giacomo Rando, Department of Gastroenterology, Istituto Clinico Humanitas, 20089 Rozzano, Italy
Patrick I Okolo, Anthony N Kalloo, Anne Marie Lennon, Department of Internal Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins Hospital, Baltimore, MD 21205, United States
Ana Ignjatovic, James East, Brian P Saunders, Wolfson Unit for Endoscopy, St. Mark’s Hospital, Harrow HA1 3UJ, United Kingdom
Elizabeth Odstrcil, Bradley Creel, Daniel C DeMarco, Department of Internal Medicine, Division of Gastroenterology, Baylor University Medical Center, Dallas, TX 75246, United States
Author contributions: Siersema PD, Rastogi A, Akerman PA, Azzouzi K, Rothstein RI, Vleggaar FP, Repici A, Rando G, Okolo PI, Dewit O, Ignjatovic A, Odstrcil E, East J, Saunders BP, Kalloo AN, Lennon AM and DeMarco DC performed the endoscopy procedures; Leufkens AM, Ignjatovic A, Deprez PH, Creel B, Singh V and Lennon AM coordinated and collected the data; Rastogi A, Akerman PA, Vleggaar FP, Repici A, Dewit O, Ignjatovic A, Odstrcil E, East J, Deprez PH, Creel B, Singh V, Lennon AM and DeMarco DC were involved in editing the manuscript; Siersema PD and Leufkens AM designed the study, analyzed the data and wrote the paper.
Supported by A grant from Avantis Medical Systems, in part
Correspondence to: Peter D Siersema, MD, PhD, Director, Department of Gastroenterology and Hepatology, University Medical Center Utrecht, PO Box 85500, 3508 GA Utrecht, The Netherlands.
Telephone: +31-30-2506274 Fax: +31-30-2505533
Received: September 28, 2011
Revised: March 23, 2012
Accepted: April 2, 2012
Published online: July 14, 2012

AIM: To determine which patients might benefit most from retrograde viewing during colonoscopy through subset analysis of randomized, controlled trial data.

METHODS: The Third Eye® Retroscope® Randomized Clinical Evaluation (TERRACE) was a randomized, controlled, multicenter trial designed to evaluate the efficacy of a retrograde-viewing auxiliary imaging device that is used during colonoscopy to provide a second video image which allows viewing of areas on the proximal aspect of haustral folds and flexures that are difficult to see with the colonoscope’s forward view. We performed a post-hoc analysis of the TERRACE data to determine whether certain subsets of the patient population would gain more benefit than others from use of the device. Subjects were patients scheduled for colonoscopy for screening, surveillance or diagnostic workup, and each underwent same-day tandem examinations with standard colonoscopy (SC) and Third Eye colonoscopy (TEC), randomized to SC followed by TEC or vice versa.

RESULTS: Indication for colonoscopy was screening in 176/345 subjects (51.0%), surveillance after previous polypectomy in 87 (25.2%) and diagnostic workup in 82 (23.8%). In 4 subjects no indication was specified. Previously reported overall results had shown a net additional adenoma detection rate (ADR) with TEC of 23.2% compared to SC. Relative risk (RR) of missing adenomas with SC vs TEC as the initial procedure was 1.92 (P = 0.029). Post-hoc subset analysis shows additional ADRs for TEC compared to SC were 4.4% for screening, 35.7% for surveillance, 55.4% for diagnostic and 40.7% for surveillance and diagnostic combined. The RR of missing adenomas with SC vs TEC was 1.11 (P = 0.815) for screening, 3.15 (P = 0.014) for surveillance, 8.64 (P = 0.039) for diagnostic and 3.34 (P = 0.003) for surveillance and diagnostic combined. Although a multivariate Poisson regression suggested gender as a possibly significant factor, subset analysis showed that the difference between genders was not statistically significant. Age, bowel prep quality and withdrawal time did not significantly affect the RR of missing adenomas with SC vs TEC. Mean sizes of adenomas detected with TEC and SC were similar at 0.59 cm and 0.56 cm, respectively (P = NS).

CONCLUSION: TEC allows detection of significantly more adenomas compared to SC in patients undergoing surveillance or diagnostic workup, but not in screening patients ( Identifier: NCT01044732).

Keywords: Colonoscopy, Colorectal cancer, Adenomas, Miss rates, Retrograde-viewing