BACKGROUND & AIMS: Tethered capsule endomicroscopy (TCE) involves swallowing a small tethered pill that implements optical coherence tomography (OCT) imaging, procuring high resolution images of the whole esophagus. Here, we demonstrate and evaluate the feasibility and safety of TCE and a portable OCT imaging system in patients with Barrett's esophagus (BE) in a multi-center (5-site) clinical study. METHODS: Untreated patients with BE as per endoscopic biopsy diagnosis were eligible to participate in the study. TCE procedures were performed in unsedated patients by either doctors or nurses. After the capsule was swallowed, the device continuously obtained 10-µm-resolution cross-sectional images as it traversed the esophagus. Following imaging, the device was withdrawn through mouth, and disinfected for subsequent reuse. BE lengths were compared to endoscopy findings when available. OCT-TCE images were compared to volumetric laser endomicroscopy (VLE) images from a patient who had undergone VLE on the same day as TCE. RESULTS: 147 patients with BE were enrolled across all sites. 116 swallowed the capsule (79%), 95/114 (83.3%) men and 21/33 (63.6%) women (P = .01). High-quality OCT images were obtained in 104/111 swallowers (93.7%) who completed the procedure. The average imaging duration was 5.55 ± 1.92 minutes. The mean length of esophagus imaged per patient was 21.69 ± 5.90 cm. A blinded comparison of maximum extent of BE measured by OCT-TCE and EGD showed a strong correlation (r = 0.77-0.79). OCT-TCE images were of similar quality to those obtained by OCT-VLE. CONCLUSIONS: The capabilities of TCE to be used across multiple sites, be administered to unsedated patients by either physicians or nurses who are not expert in OCT-TCE, and to rapidly and safely evaluate the microscopic structure of the esophagus make it an emerging tool for screening and surveillance of BE patients. Clinical trial registry website and trial number: NCT02994693 and NCT03459339.
Barrett Esophagus , Esophageal Neoplasms , Barrett Esophagus/diagnostic imaging , Barrett Esophagus/pathology , Biopsy , Esophageal Neoplasms/pathology , Esophagoscopy/methods , Feasibility Studies , Female , Humans , Male , Tomography, Optical Coherence/methods
OCT tethered capsule endomicroscopy (TCE) is an emerging noninvasive diagnostic imaging technology for gastrointestinal (GI) tract disorders. OCT measures tissue reflectivity that provides morphologic image contrast, and thus is incapable of ascertaining molecular information that can be useful for improving diagnostic accuracy. Here, we introduce an extension to OCT TCE that includes a fluorescence (FL) imaging channel for attaining complementary, co-registered molecular contrast. We present the development of an OCT-FL TCE capsule and a portable, plug-and-play OCT-FL imaging system. The technology is validated in phantom experiments and feasibility is demonstrated in a methylene blue (MB)-stained swine esophageal injury model, ex vivo and in vivo.
