Transmyocardial revascularization with CO2 laser

A new cardiac surgical procedure called transmyocardial revascularization (TMR), using a high-power CO₂ laser, is currently being studied in the United States under an FDA investigational device exemption (IDE) and under other protocols outside the U.S. These studies are being undertaken to determine if TMR may solve some of the problems inherent in the currently used procedures or if it could be used instead of or in conjunction with these procedures. Currently, in the U.S., it is being investigated on patients who are not eligible for any other intervention. TMR involves using THE HEART LASER, a 1000-watt, fast-axial-flow, rf-excited CO₂ laser, which is used to deliver 8 to 80 joule pulses of 10 to 99 msec. in width. The laser energy is delivered through a seven mirror articulated arm to various types of hand pieces designed specifically for TMR. Approximately 15 to 30 channels, 1 mm in diameter, are drilled through the ischemic region of the heart muscle into the left ventricle of the beating heart. Oxygenated blood from the ventricle is given a direct pathway to the oxygen starved tissue