Video assisted thoracoscopic and cardioscopic radiofrequency Maze ablation

The authors examined the feasibility of transthoracic radio frequency Maze ablation of atrial fibrillation using video assisted thoracoscopy and cardioscopy in the experimental setting of a beating porcine heart. In six pigs under general anesthesia, the left atrium was viewed using a video assisted thoracoscopy system (VATS), and radiofrequency linear ablation of the left atrial wall was carried out using a radiofrequency ablation catheter (HAT200S:OSYPKA) inserted through a trocar port. The right atrium was also ablated in the same manner under VATS. In six other pigs, intravenous radiofrequency ablation by cardioscopic catheter device was carried out. Atrial fibrillation was provoked by acetylcholine injection plus rapid atrial pacing. The thoracoscopic visual field created for radiofrequency catheter ablation from a transthoracic approach and the cardioscopic visual field from an intravenous approach were sufficient, and safe positioning of the ablation catheter device on the atrial epicardium and endocardium, which enabled linear ablation of the atrium, was obtained. The Optimal setting for ablation was 70-80 degrees C/ 30 sec duration per each ablation. This process was monitored and documented by a video system through the thoracoscope and cardioscope, and results were confirmed by postmortem macrohistologic examination. In conclusion, the authors' results suggest the potential usefulness of the combination of transthoracic radiofrequency catheter ablation with video assisted thoracoscopic and cardioscopic linear ablation of atrial fibrillation, and the possibility that use of this system might eliminate the need for open heart Maze surgery.