ATRIAL ABLATION WITH AN IRK-151 INFRARED COAGULATOR

Background. The purpose of this study was to develop a method of atria l ablation. In the IRK-151 infrared coagulator, light from a tungsten- halogen lamp is focused into a quartz rod. The distal exit plane is co nnected to a tip made of sapphire to allow linear ablation. Methods. T hirty-six lesions were created in 9 mongrel dogs. The beating ventricu lar myocardium was ablated from the epicardium. In each dog, 4 lesions were created by using the following durations of application: 3, 9, 1 5, and 21 seconds. After the ablation, the myocardium was fixed and st ained. A linear lesion on the beating right atrial free wall was creat ed. Before and after the ablation, epicardial plaque-electrode mapping was performed. Three months after ablation, remapping was performed. Results. The ablated myocardium had well-demarcated necrosis without c arbonization or vaporization. The maximum depth was 10.3 +/- 0.8 mm. T he conducting pathway was blocked. The block, once made, continued for 3 months. Conclusions. The IRK-151 produces well-demarcated lesions t hat were deep enough for atrial ablation to block the conducting pathw ay. (Ann Thorac Surg 1998;66:95-100) (C) 1998 by The Society of Thorac ic Surgeons.