Prospective Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. May 16, 2015; 7(5): 555-562
Published online May 16, 2015. doi: 10.4253/wjge.v7.i5.555
Polyp detection rates using magnification with narrow band imaging and white light
Nooman Gilani, Sally Stipho, James D Panetta, Sorin Petre, Michele A Young, Francisco C Ramirez
Nooman Gilani, Sally Stipho, James D Panetta, Sorin Petre, Michele A Young, Francisco C Ramirez, Section of Gastroenterology, Department of Medicine and Research, Phoenix VA Healthcare System, Scottsdale, AZ 85254, United States
Author contributions: Gilani N and Ramirez FC designed and performed the research study; Stipho S, Panetta JD, Petre S and Young MA helped to collect the data; Gilani N and Ramirez FC performed statistical analysis and wrote the paper.
Ethics approval: This study was approved by Institutional Review Board at Phoenix VA Medical Center, Arizona, United States.
Clinical trial registration: Not applicable as this was a non-randomized study.
Informed consent: All patients in the study gave informed consent for the colonoscopy. Informed consent for the study was waived by the Institutional Review Board per request due to non-randomization.
Conflict-of-interest: None.
Data sharing: Technical appendix, statistical code, and dataset available from the corresponding author at (ngilani@hotmail.com). Consent for data sharing was not obtained from the participants but the presented data are anonymized and risk of identification is low.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Nooman Gilani, MD, FACG, FASGE, AGAF, Section of Gastroenterology, Department of Medicine and Research, Phoenix VA Healthcare System, 5529. E. Angela Drive, Scottsdale, AZ 85254, United States. ngilani@hotmail.com
Telephone: +1-602-3686008
Received: November 18, 2014
Peer-review started: November 19, 2014
First decision: December 29, 2014
Revised: January 28, 2015
Accepted: February 10, 2015
Article in press: February 12, 2015
Published online: May 16, 2015
Processing time: 180 Days and 21.9 Hours
Abstract

AIM: To compare the yield of adenomas between narrow band imaging and white light when using high definition/magnification.

METHODS: This prospective, non-randomized comparative study was performed at the endoscopy unit of veteran affairs medical center in Phoenix, Arizona. Consecutive patients undergoing first average risk colorectal cancer screening colonoscopy were selected. Two experienced gastroenterologists performed all the procedures that were blinded to each other’s findings. Demographic details were recorded. Data are presented as mean ± SEM. Proportional data were compared using the χ2 test and means were compared using the Student’s t test. Tandem colonoscopy was performed in a sequential and segmental fashion using one of 3 strategies: white light followed by narrow band imaging [Group A: white light (WL) → narrow band imaging (NBI)]; narrow band imaging followed by white light (Group B: NBI → WL) and, white light followed by white light (Group C: WL → WL). Detection rate of missed polyps and adenomas were evaluated in all three groups.

RESULTS: Three hundred patients were studied (100 in each Group). Although the total time for the colonoscopy was similar in the 3 groups (23.8 ± 0.7, 22.2 ± 0.5 and 24.1 ± 0.7 min for Groups A, B and C, respectively), it reached statistical significance between Groups B and C (P < 0.05). The cecal intubation time in Groups B and C was longer than for Group A (6.5 ± 0.4 min and 6.5 ± 0.4 min vs 4.9 ± 0.3 min; P < 0.05). The withdrawal time for Groups A and C was longer than Group B (18.9 ± 0.7 min and 17.6 ± 0.6 min vs 15.7 ± 0.4 min; P < 0.05). Overall miss rate for polyps and adenomas detected in three groups during the second look was 18% and 17%, respectively (P = NS). Detection rate for polyps and adenomas after first look with white light was similar irrespective of the light used during the second look (WL → WL: 13.7% for polyps, 12.6% for adenomas; WL → NBI: 14.2% for polyps, 11.3% for adenomas). Miss rate of polyps and adenomas however was significantly higher when NBI was used first (29.3% and 30.3%, respectively; P < 0.05). Most missed adenomas were ≤ 5 mm in size. There was only one advanced neoplasia (defined by size only) missed during the first look.

CONCLUSION: Our data suggest that the tandem nature of the procedure rather than the optical techniques was associated with the detection of additional polyps’ and adenomas.

Keywords: Colonoscopy; Narrow band imaging; High-definition; Magnification; Screening; Yield

Core tip: The role of narrow band imaging for polyp detection is controversial. We studied 3 groups of 100 patients each, undergoing tandem colonoscopy by (1) white light followed by narrow band imaging; (2) narrow band followed by white light; and (3) white light followed by white light. Detection rate for polyps with white light used first was similar irrespective of the light used afterwards. Miss rate of polyps and adenomas was higher when narrow band imaging was used first (29.3% and 30.3%, respectively; P < 0.05). Our study suggests that the tandem nature of colonoscopy rather than the optical techniques, detects missing pathology.