Suspicious-Appearing Glands On Volumetric Laser Endomicroscopy Are Concentrated In The Distal Esophagus Following Endoscopic Ablation Of Long-Segment Barrett'S Esophagus

Introduction: Volumetric laser endomicroscopy (VLE) is an intraluminal imaging modality based on optical coherence tomography. Each scan generates 6 cm of cross-sectional images with resolution down to 7 microns. In Barrett's Esophagus (BE), VLE can identify features concerning for dysplasia such as suspicious-appearing glands (SG). Our aim was to identify any difference in VLE SG distribution prior to and after BE ablation. Methods: All patients undergoing endoscopy with VLE at a single high volume center from May 2014 to May 2015 were considered for analysis. Patients were included if VLE was performed before or after visually complete BE ablation and both VLE SG locations and pathology results were known. Demographic, historical, endoscopic and histologic data were de-identified and aggregated prior to analysis. Results: A total of 139 VLE procedures were performed on 116 patients (69% male, mean age 62 years). Endoscopy was performed prior to (54) and following (85) BE ablation. Mean Prague scores were C 3.71 cm/M 5.56 cm pre-ablation and C 2.44 cm/M 4.94 cm for post-ablation cases. Original dysplasia grades included carcinoma or high-grade dysplasia (42.5%), low-grade dysplasia (17.9%) and non-dysplastic BE (39.6%). In the pre-ablation group, 25 patients had VLE performed for long segment BE (LSBE, 3+ cm) and 92 SG were identified. Only 23% of SG were found within 2 cm of the esophagogastric junction (EGJ), 45% were 2-5 cm from the EGJ and 32% were over 5 cm from the EGJ. For VLE after ablation of LSBE, 31 procedures had 23 SG. Nearly all SG (91%) were found within 2 cm of the EGJ, 4.3% were 2.1-5 cm from the EGJ and only 4.3% were over 5 cm from the EGJ. Findings on forceps biopsies paralleled VLE results. Prior to ablation, 36.5% of biopsies revealing dysplastic BE were within 2 cm of the EGJ, 33.8% were 2.1-5 cm from the EGJ and 29.7% were over 5 cm from the EGJ. In post-ablation biopsies, 85.7% of BE was identified within 2 cm from the EGJ, 14.3% was 2.1-5 cm from the EGJ, and none was over 5 cm from the EGJ. Conclusion: Following BE ablation, there is a marked shift in VLE SG locations from a relatively even distribution to a more focused presence within 2 cm of the EGJ. This finding parallels BE histology. Nearly all post-ablation SG were present within the distal 5 cm of esophagus, an area that can be imaged on a single VLE scan. Further studies are needed to confirm these results, which could lead to more focused optical and physical biopsies only in limited esophageal segments.