FULL-FIELD OPTICAL COHERENCE TOMOGRAPHY OF THE NORMAL DIGESTIVE MUCOSA: A PROMISING TOOL FOR THE STUDY OF THE DIGESTIVE BARRIER

Aims:

Full-field optical coherence tomography (FF-OCT) is a non-invasive imaging technique, based on interferometry, allowing dynamic acquisition of images of ex vivo specimens on a microscopic scale. The aim of this study was to demonstrate the feasibility of imaging normal digestive biopsies using FF-OCT.

Methods:

We enrolled adult subjects scheduled for an endoscopy with biopsies, who had no history of digestive disease. We a posteriori excluded patients, whose biopsies showed abnormal aspects at pathological examination. Four biopsies were sampled in each patient, 2 for pathological examination, 2 for immediate FF-OCT analysis, from 5 different locations: esophagus, gastric antrum, gastric fundus, duodenum or colon. Fresh biopsies were scanned using the LL-Tech benchtop scanner in order to performanoptical slicing beneath the tissue surface at selected depths (static mode) and a measurement of intracellular activity data (dynamic mode). Biopsies were then fixed in formaldehyde, sliced in a longitudinal plane parallel to the surface and stained using hematoxylin-eosin. FF-OCT images and pathological slides were then reviewed with the assistance of a senior pathologist.

Results:

We enrolled 25 patients with normal biopsies of the esophagus (n = 5), gastric fundus (n = 10), gastric antrum (n = 10), duodenum (n = 7) and colon (n = 6). Specific histological structures of each organ were clearly identified in 100% of FF-OCT images. For instance, the cellular structure of esophageal squamous epithelium with papillae, gastric crypts and glands, duodenal villi and colonic crypts was clearly seen at a 1 µm resolution.

Conclusions:

FF-OCT allows a morphological and functional analysis of digestive tissues on fresh routine endoscopic biopsies, at a subcellular scale. It is a promising tool for the study of the digestive barrier.