Left Ventricular Bypass in the Dog: A Technique Employing Transthoracic Cannulation and a Paracorporeal Roller Pump

Ten dogs underwent temporary left ventricular bypass for four hours. Cannulation of the left atrium was performed by the closed-chest transthoracic method, and the output of a small air-driven paracorporeal roller pump was delivered into the left carotid artery. Bypass flow rates ranged from 19 to 55 ml/kg/min. Hemodynamics, blood gases, pH, and serum electrolyte levels remained normal throughout the entire bypass period. No pneumothorax or hemothorax was observed at autopsy one week later. The punctured wall of the left atrium healed well. Transthoracic left atrial cannulation is a safe and reliable method if proper precautions are observed. This technique may have clinical application in circulatory support following cardiac operation.