Technical considerations in coronary bypass operations
The first operations for coronary bypass in our hospital were performed more than 13 years ago when congenital anomalies were repaired using small caliber Dacron fabric tubes to create a two-coronary system. In the ensuing years the autologous saphenous vein (for special situations, the cephalic vein) has replaced the fabric graft and is used almost exclusively for all types of myocardial revascularization. The pedicled internal mammary artery was used occasionally in the past, but only rarely at the present since results with the saphenous vein appear more satisfactory to us. We believe that careful harvesting and preparation of the saphenous vein is important to provide for the best survival of the free graft. Usually only the vein from one leg is necessary to perform triple, quadruple, or even quintuple procedures, if he vein is removed from ankle to groin. The vein in the other leg is thus preserved for possible future use. After careful ligation of the venous tributaries, the vein is gently distended using heparinized blood drawn from the patient. Electrolyte solutions tend to diffuse through the vein wall and this may lead to subsequent fibrosis and premature graft occlusion.
Most operations are performed using temporary cardiopulmonary bypass with a priming volume of Ringer’s lactate and glucose solution, and the patient is maintained normothermic. In complicated cases with anticipated valve repair or replacement, general body hypothermia to 30 C is employed. For patients with depressed left ventricular function, left main coronary lesions or concomitant carotid and renal arterial lesions . . .