Active Cooling
Use of active cooling of the esophagus with ice water was unsuccessful28. In a more recent study, IMPACT, patients were randomized to either LET monitoring or to active cooling using the ensoETM device, which is used in critical care to alter body temperature29. The device is a silicone tube that is inserted into the esophagus, increased to an outer diameter of 12mm with 14.9 pounds per square inch, and has a closed loop system that pumps distilled water at 40C (Figure 1). Additionally, a heated air blanket was used to maintain a body temperature >350C. Endoscopy was performed at 7 days post ablation. Esophageal thermal injury was significantly greater in the control group in comparison to the protected group (12/60 vs 2/60, p < 0.01). There was no difference in duration of RF, procedure and fluoroscopy. This is the only randomized study assessing esophageal protection utilizing endoscopy results of esophageal injury as the primary endpoint.