Published online Feb 16, 2019. doi: 10.4253/wjge.v11.i2.145
Peer-review started: November 5, 2018
First decision: November 28, 2018
Revised: January 9, 2019
Accepted: January 26, 2019
Article in press: January 26, 2019
Published online: February 16, 2019
Duodenal biopsies are commonly obtained during esophagogastroduodenoscopy (EGD) but are very often histopathologically normal. Therefore, a more strategic method for evaluating the duodenal mucosa and avoiding unnecessary biopsies is needed.
To examine the clinical utility of narrow band imaging (NBI) for evaluating duodenal villous morphology.
We performed a prospective cohort study of adult patients at Mayo Clinic Rochester from 2013-2014 who were referred for EGD with duodenal biopsies. A staff endoscopist scored, in real-time, the NBI-based appearance of duodenal villi into one of three categories (normal, partial villous atrophy, or complete villous atrophy), captured ≥ 2 representative duodenal NBI images, and obtained mucosal biopsies therein. Images were then scored by an advanced endoscopist and gastroenterology fellow, and biopsies (gold standard) by a pathologist, in a masked fashion using the same three-category classification. Performing endoscopist, advanced endoscopist, and fellow NBI scores were compared to histopathology to calculate performance characteristics [sensitivity, specificity, positive and negative, negative predictive value (NPV), and accuracy]. Inter-rater agreement was assessed with Cohen’s kappa.
112 patients were included. The most common referring indications were dyspepsia (47%), nausea (23%), and suspected celiac disease (14%). Duodenal histopathology scores were: 84% normal, 11% partial atrophy, and 5% complete atrophy. Performing endoscopist NBI scores were 79% normal, 14% partial atrophy, and 6% complete atrophy compared to 91%, 5%, and 4% and 70%, 24%, and 6% for advanced endoscopist and fellow, respectively. NBI performed favorably for all raters, with a notably high (92%-100%) NPV. NBI score agreement was best between performing endoscopist and fellow (κ = 0.65).
NBI facilitates accurate, non-invasive evaluation of duodenal villi. Its high NPV renders it especially useful for foregoing biopsies of histopathologically normal duodenal mucosa.
Core tip: Duodenal mucosal biopsies are frequently obtained during upper endoscopy to assess villous architecture but are largely negative (i.e., histopathologically normal); thus, a method to better evaluate the duodenal mucosa and avoid unnecessary biopsies is needed. Narrow band imaging (NBI) permits superior inspection of mucosal surfaces via filter separation of conventional white light into only green and blue components. Based on the findings of this prospective study, NBI appears to have excellent diagnostic performance in evaluating duodenal villous morphology and can facilitate targeting of biopsies; its high negative predictive value renders it particularly useful in avoiding biopsies that are likely to reveal histopathologically normal mucosa.