Barrett’s Epithelial Thickness, Assessed by Volumetric Laser Endomicroscopy, Is Associated With Response to Radiofrequency Ablation

Abstract

Radiofrequency ablation (RFA) is the most common treatment for flat Barrett's esophagus (BE), but reasons for varying outcomes are poorly understood. A recently developed contrast-enhancement algorithm allows reliable measurement of Barrett's epithelial thickness (BET) from volumetric laser endomicroscopy (VLE) images and correlation with response to RFA. Using this algorithm, we investigated whether patients with thicker Barrett's mucosa are less likely to respond to RFA. In the future, this algorithm may guide choice of RFA dosing or endoscopic resection. We performed a retrospective analysis on all patients with BE who received a baseline VLE scan between May 2015 and October 2016, followed by RFA and 1 follow-up exam, from 14 institutions participating in the United States VLE registry. We measured BET on equidistant locations by estimating the distance between the esophageal surface and the superficial edge of the deepest lamina propria. The primary outcome variable was the percentage reduction in Prague length; secondary outcome variables were complete remission of intestinal metaplasia (CRIM) and presence of strictures after 12 months. Images from 61 patients were included in our final analysis. Mean BET per patient ranged from 224 μm to 705 μm. A 100 μm thicker mean BET per patient resulted in a 12% lower response to treatment, measured by a reduction of Prague length (P = .03), after adjustment for confounders. We found an association between mean BET and CRIM, but not with stricture formation. Based on measurements on contrast-enhanced VLE images, we found that BET correlates with response to RFA. For clinical implementation, larger studies with a standardized follow-up and development of computer-aided image analysis systems are needed.