Focal Ablation of Barrett’s Esophagus Using a Novel Endoscopic Device Kenneth J. Chang Introduction: Several ablative modalities have been evaluated for focal ablation of BE (APC, MPEC, laser) and wide-field ablation of BE (PDT and balloon-based circumferential RF ablation). An ideal focal ablative device would improve results of both primary and adjunctive (‘‘touch-up’’) BE ablation if the device was capable of the following: 1) ablating to a controlled depth without risk for stricture formation, 2) delivery of a fixed amount of energy per unit surface area, and 3) treatment area large enough area to avoid the technical issues related to point-and-shoot coagulation methods (i.e., APC, MPEC, laser), yet avoiding the necessity of treating the entire circumference of the esophageal lumen. Aims: Develop and assess an endoscopic device for focal mucosal ablation that can be used for: 1) primary treatment of short segment Barrett’s esophagus (BE), and 2) adjunctive treatment of residual BE following a primary ablation therapy. Methods: We assessed a novel endoscopic device (BÂRRX Medical, Sunnyvale, CA) that fits on the distal tip of a standard gastroscope, preserving visualization (similar to EMR cap). The upper surface is a 20 15 mm curved, articulated platform (adjusts for variability in scope angulation, thus optimizing apposition to the esophageal mucosa) with a bipolar electrode array identical to that of the HALO Ablation System (BÂRRX Medical). The design uses high power RF energy (300 W) and controlled delivery of a fixed energy density (J/cm), and thus controls ablation depth. The electrode is apposed to the targeted epithelium under direct visualization. Results: In the acute porcine model, 115 ablations zones were created. Treatment variables: electrode surface area (1-4 cm), power density (20-50 W/cm), and energy density (8-20 J/cm). A device width of up to 15 mm was easy to introduce/manueuver. Settings of 20-30 W/cm and 10-15 J/cm resulted in uniform ablation effects with immediate epithelium slough and no exposure of submucosa. There was no evidence of transmural injury. Confluent vertical and horizontal ablations (including circumferential) were easily performed. Conclusions: This is the first report of a focal ablation device that incorporates the HALO Ablation technology and is capable of treating focal areas more efficiently and uniformly than point-and-shoot techniques. This device should complement the HALO balloon device by providing effective adjunct (‘‘touch-up’’) focal ablations, thus optimizing complete BE ablation. Clinical evaluations in patients with BE, as well as in selected patients with other indications (ex. vascular lesions) in the GI tract, are underway.