[Intraoperative visualization of coronary arteries using two-dimensional echocardiography].

We attempted intraoperative ultrasonic visualization of the coronary arteries of animal models and of patients who underwent coronary artery bypass surgery. Ultrasonic visualization of coronary vessels using a high frequency wide band micro-transducer (3.5-9.0 MHz) was first attempted in three open-chest dogs. The coronary arteries were well visualized from the epicardium with and without contrast perfusion, and the experimentally-occluded portion was well imaged. Subsequently, this technique was clinically applied in two patients undergoing cardiac surgery for valvular and congenital heart diseases, and in nine patients undergoing coronary artery bypass surgery. Gas-sterilized probes were placed directly over the cardiac surface. Ultrasonic imaging of the coronary artery was performed to detect the coronary arteries beneath the fat tissue; image the lesions in coronary vessels, especially those not visualized by angiography; determine the site of bypass grafting and evaluate the graft-ability to the distal branch (the latter was poorly visualized via collateral circulation or not visualized angiographically because of total occlusion at a proximal site); and observe the effects of bypass grafting and intraoperative angioplasty of coronary arteries after these procedures. This ultrasonic technique was found to be useful for the intraoperative evaluation of coronary vessels for coronary artery bypass surgery.