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.