Mo1521 Detection of Buried Barrett Glands After Radiofrequency Ablation (RFA) With Volumetric LASER Endomicroscopy (Vle)

Abstract

Mo1521 Detection of Buried Barrett Glands After Radiofrequency Ablation (RFA) With Volumetric LASER Endomicroscopy (Vle) Anne-Fre Swager*, David F. Boerwinkel, Daniel M. De Bruin, Dirk J. Faber, Ton G. Van Leeuwen, Bas L. Weusten, Sybren L. Meijer, Jacques J. Bergman, Wouter L. Curvers Gastroenterology and Hepatology, Academic Medical Centre, Amsterdam, Netherlands; Biomedical Engineering, Academic Medical Centre, Amsterdam, Netherlands; Pathology, Academic Medical Centre, Amsterdam, Netherlands Background: The prevalence and clinical relevance of Buried Barrett’s (BB) epithelium after radiofrequency ablation (RFA) in Barrett’s esophagus (BE) is questioned. Recent studies using small optical coherence tomography (OCT) catheters for scanning underneath the neosquamous epithelium demonstrated a high prevalence of tissue structures that might correspond to BB. Histological correlation, however, is lacking. Volumetric Laser Endomicroscopy (VLE) is a novel balloon-based OCT imaging technique that provides a 6-cm long circumferential volumetric scan of the esophageal wall layers to a depth of 3 mm with a resolution comparable to lowpower microscopy. Aim: To evaluate if post-RFA subsquamous structures, detected with VLE, actually correspond to BB and to pursue direct histological correlation of VLE images. Methods: In-vivo VLE was performed to detect subsquamous structures suspicious for BB in patients with 100% endoscopic regression of dysplastic Barrett’s epithelium after RFA. Areas with suspicious subsquamous VLE structures were marked with electrocoagulation after which in-vivo VLE was repeated to confirm that the correct area was demarcated. These areas were subsequently resected endoscopically, followed by immediate ex-vivo VLE scanning to reconfirm the presence of the subsquamous VLE structures. Extensive histological sectioning was then performed and all histopathology slides were evaluated by an expert BE pathologist (blinded for VLE images). Results: In 9 patients, 6 areas with suspicious subsqua-