Probe-based Volumetric Laser Endomicroscopy (pVLE) of Endoscopic Mucosal Resection (EMR) Tissue in Patients With Barrett's Dysplasia

Inclusion Criteria: 1. Males and females over the age of 18 years. 2. Patients with either suspected or confirmed Barrett's-associated high grade dysplasia (HGD) or intramucosal cancer (IMC) presenting for endoscopy possibly requiring EMR. 3. Ability to provide written, informed consent. 4. Females must be willing to take a pregnancy test if still capable of bearing a child. Exclusion Criteria: 1. Patients on anticoagulation undergoing high risk procedures in accordance to ASGE guideline for the management of antithrombotic agents for endoscopic procedures (2009)\*. 2. Patients with esophageal varices that preclude biopsies. 3. Presence of an esophageal mass/cancer that precludes full distention of the balloon from the Nvision balloon guide sheath. 4. Patients with esophageal strictures that would prevent adequate expansion of the balloon from the Nvision guide sheath. 5. Patients with known inflammatory disease, esophageal tears or ulcers, which prohibit full distention of the balloon from the Nvision balloon guide sheath. 6. Patients with known eosinophilic esophagitis. 7. Patients who are pregnant. 8. Patients with a history of hemostasis disorders\*. * Patients on anticoagulation undergoing low risk procedures are not excluded. \*\* Hemostasis disorders will include, but will not be limited to: patients with hemophilia or other congenitally acquired clotting factor deficiencies, patients with cirrhosis with coagulopathy, patients known to have thrombocytopenia (\<100,000 plt/ul) and individuals with von Willebrand's disease or other known platelet malfunction disorders.