Epicardial beating heart cryoablation using a novel argon-based cryoclamp and linear probe

Area of Science:

• Cardiology
• Medical Devices
• Surgical Innovation

Background:

• Epicardial cryoablation for atrial fibrillation can be limited by blood flow.
• A new argon-based cryoclamp device aims to overcome these limitations by occluding blood flow.

Purpose of the Study:

• To evaluate the efficacy of an argon-based cryoclamp device in creating transmural cryolesions on a beating heart.
• To assess the safety and durability of these lesions in a preclinical model.

Main Methods:

• Six mongrel dogs underwent epicardial application of a 10-cm argon-based cryoclamp device to isolate pulmonary veins and left atrial appendage.
• Pulmonary vein stenosis, left atrial function, and pulmonary venous flow were assessed using MRI and echocardiography.
• Lesion transmurality was confirmed electrically and histologically post-procedure, with 30-day follow-up.

Main Results:

• All cryoclamp lesions achieved conduction block, with 93% demonstrating transmurality.
• No significant changes were observed in pulmonary vein diameter or left atrial function.
• Cryoclamp lesions were more consistently transmural (93%) compared to linear ablations (84%).

Conclusions:

• The epicardial cryoclamp device successfully created persistent transmural lesions on a beating heart.
• This device offers a potentially effective alternative for atrial fibrillation treatment without cardiopulmonary bypass.
• The cryoclamp shows superior performance in achieving transmurality compared to linear epicardial cryoablation.