Production of narrow but deep lesions suitable for ablation of atrial fibrillation using a saline-cooled narrow beam Nd:YAG laser catheter

• Published in: Lasers in surgery and medicine Vol. 28; no. 4; pp. 375 - 380
• Main Authors: Thomas, Stuart P., Guy, Duncan J.R., Rees, Arianwun, Collins, Lee, Ross, David L.
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 01.04.2001; Wiley-Liss
• Subjects: Animals; arrhythmia; Atrial Fibrillation - surgery; Biological and medical sciences; canine; Cardiac dysrhythmias; Cardiology. Vascular system; Catheter Ablation - methods; Diseases of the cardiovascular system; Dogs; Heart; Laser Therapy; Medical sciences; myocardium; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Animal model; Arrhythmia; Cardiovascular disease; Vascular disease; Prevention; Heart disease; Complication; Dog; Cerebrovascular disease; Ungulata; Fissipedia; Evaluation; Carnivora; Nervous system diseases; Stroke; Bovine; Treatment efficiency; Atrial fibrillation; YAG laser; Instrumentation therapy; Experimental study; Radiofrequency; Ablation; Excitability disorder; Cerebral disorder; Vertebrata; Mammalia; Animal; Central nervous system disease; Myocardium; Artiodactyla
• ISSN: 0196-8092; 1096-9101
• DOI: 10.1002/lsm.1065

Background and Objective Lines of radiofrequency ablation for cure of atrial fibrillation are broad, and the consequent loss of atrial mass may impair atrial function and contribute to the risk of stroke. We studied whether Nd:YAG laser could produce deep but narrower lesions. Study Design/Materials and Methods Laser lesions were made in ventricular myocardium of nonperfused ovine hearts and at thoracotomy in dogs. Results Lesions were well demarcated, deep, and narrow. Saline irrigation prevented crater formation for energy levels below 200 J. Lesion depth increased with increasing duration of ablation (maximum 5.3 ± 0.8mm, P < 0.01). The depth to width ratio was >1 in all cases (maximum 2.5 ± 1.6). The narrowest lesions were made by using high power, short duration of exposure, and intermittent delivery. Conclusions Irrigated Nd:YAG laser can be used to make deep narrow myocardial lesions without crater formation. Laser ablation may be more suitable than radiofrequency ablation for intraoperative or catheter‐based cure of atrial fibrillation. Lasers Surg. Med. 28:375–380, 2001. © 2001 Wiley‐Liss, Inc.