C2 CryoBalloon™ 180 Ablation System Dose De-escalation Study.

The procedure will be performed on an outpatient basis, and the CryoBalloon 180 Ablation system will be used for all ablations following the instructions for use provided with the product. Patients who meet the eligibility criteria will be assigned to one of the treatment groups and doses, depending on the order of their enrollment: In phase I, the first 62 patients will be treated with Dose 1 (lowest), in one application to ablate 50% of the esophageal circumference. All patients will undergo 10 week (±2 weeks) follow-up EGD to evaluate efficacy of the dose before the study continues. If follow-up shows that Dose 1 eradicates ≤60% of the treated BE (by median percentage) and no SAE's are reported, the treatment phase will continue but at the next incremental higher dose (Second Dose) after approval from the IRB. If the Dose 1 median BE surface regression percentage is ≥60%, the dose is defined as the therapeutic dose. In that case, the study will be prematurely terminated without the consecutive treatment of an additional 62 patients with a higher dose. \--------------------------------------------------------------- Dose-related SAEs include pain in the treatment area greater than 6 (0-10 NRS score) at 24 hours AND seven (7) days post-treatment; symptomatic stricture requiring an additional EGD with endoscopic dilation before the first follow-up EGD; symptomatic stricture at follow-up EGD; or any stricture (symptomatic or asymptomatic) preventing passage of the therapeutic endoscope at follow-up EGD. Any other serious adverse events within 30 days after treatment will also be evaluated by the Data and Safety Monitoring Board (DSMB) for relationship to the dose and severity.