Tethered confocal endomicroscopy capsule for diagnosis and monitoring of eosinophilic esophagitis.
Eosinophilic esophagitis (EoE) is an allergic condition that is characterized by eosinophils infiltrating the esophageal wall. The treatment of the disease may require multiple follow up sedated endoscopies and biopsies to confirm elimination of eosinophils. These procedures are expensive, time consuming, and may be difficult for patients to tolerate. Here we report on the development of a confocal microscopy capsule for diagnosis and monitoring of EoE. The swallowable capsule implements a high-speed fiber-based reflectance confocal microscopy technique termed Spectrally Encoded Confocal Microscopy (SECM). SECM scans the sample in one dimension without moving parts by using wavelength swept source illumination and a diffraction grating at the back plane of the objective lens. As the wavelength of the source is tuned, the SECM optics within the 7 x 30 mm capsule are rotated using a driveshaft enclosed in a 0.8 mm flexible tether. A single rotation of the optics covered a field of view of 22 mm x 223 µm. The lateral and axial resolutions of the device were measured to be 2.1 and 14 µm, respectively. Images of Acetic Acid stained swine esophagus obtained with the capsule ex vivo and in vivo clearly showed squamous epithelial nuclei, which are smaller and less reflective than eosinophils. Imaging of esophageal biopsies from EoE patients ex vivo demonstrated the capability of this technology to visualize individual eosinophils. Based on the results of this study, we believe that this capsule will be a simpler and more effective device for diagnosing EoE and monitoring the therapeutic response of this disease.
Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
Nima
N
Tabatabaei
Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
Dongkyun
D
Kang
Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
Tao
T
Wu
Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA ; School of Engineering, The University of Tokyo, Yayoi 2-11-16 Bunkyo, Tokyo 113-8656, Japan.
Minkyu
M
Kim
Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
Robert W
RW
Carruth
Food Allergy Center and Pediatric Allergy & Immunology, Harvard Medical School/Massachusetts General Hospital, Boston, MA 02114, USA.
John
J
Leung
Department of Gastroenterology, Massachusetts General Hospital, Boston, MA 02114, USA.
Jenny S
JS
Sauk
Food Allergy Center and Pediatric Allergy & Immunology, Harvard Medical School/Massachusetts General Hospital, Boston, MA 02114, USA.
Wayne
W
Shreffler
Department of Pediatrics, Harvard Medical School/Massachusetts General Hospital, Boston, MA 02114, USA.
Qian
Q
Yuan
Department of Pediatrics, Harvard Medical School/Massachusetts General Hospital, Boston, MA 02114, USA.
Aubrey
A
Katz
Department of Gastroenterology, Massachusetts General Hospital, Boston, MA 02114, USA.
Norman S
NS
Nishioka
Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA ; Harvard-MIT Division of Health Sciences and Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA ; Department of Pathology, Harvard Medical School/Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
Guillermo J
GJ
Tearney
(170.1790) Confocal microscopy; (170.2150) Endoscopic imaging; (170.2680) Gastrointestinal; (170.4730) Optical pathology