Visualization of the esophagus during ablation
Visualization of the esophagus and LA during the ablation procedure can contribute to a reduced risk of esophagus damage. Several techniques have been used to locate the esophagus either before or during AF ablation, but they all have certain limitations. Since the esophagus is mobile structure, preprocedural imaging of the esophagus by CT does not always reflect the position of the esophagus during procedure.11,12 Beside, contrast esophagography by asking the patient to swallow the contrast medium just before the procedure can outline the esophageal lumen clearly on fluoroscopy,7,8 but it cannot display the distance between the esophagus and LA endocardium at the site of ablation. An esophageal temperature probe to monitor esophageal temperature is widely used.5,6 However, esophageal temperature prove cannot cover the whole esophagus lumen, so that it may not accurately reflect the esophageal intramural tissue temperature because of the variable and unpredictable distance between the temperature probe and the ablation catheter tip.
In the present study, we created the 3D esophagus image adjacent to the LAPW by inserting the Carto SoundStar® catheter into the LA cavity and with the assist of the CartoMergeTMmodule. This method allowed us to visualize the 3D esophagus image clearly during PV isolation, and therefore we could adjust safely AI value while confirming the distance between the ablation catheter tip and the esophagus.