Coronary–Coronary Bypass

Abstract

There is increased risk of systemic embolism during cardiopulmonary bypass in patients with a severely atherosclerotic ascending aorta. We report a coronary–coronary bypass in a 74-year-old man with a porcelain aorta. He underwent a proximal right coronary–distal right coronary artery bypass with a saphenous vein graft, combined with a pedicled arterial graft (left internal mammary artery) to the left anterior descending artery, in the presence of a beating heart without cardiopulmonary bypass. The patient survived without evidence of perioperative myocardial infarction or cerebrovascular accident. One year later, follow-up angiography showed graft patency with good distal runoff. Coronary–coronary bypass on a beating heart without cardiopulmonary bypass can be performed safely in a patient with porcelain aorta. (Tex Heart Inst J 2002;29:54–5)

Severe atherosclerosis of the ascending aorta is associated with increased morbidity and mortality during coronary artery bypass grafting (CABG) because of the increased risk of perioperative atheroembolism. ^1–3 Moderate or severe atherosclerosis of the ascending aorta is present in as many as 13% of the patients undergoing CABG. ⁴ If atherosclerosis of the ascending aorta is severe, standard coronary bypass surgery should not be used. We present a case in which a patient with coronary artery disease and porcelain aorta underwent coronary–coronary bypass grafting on a beating heart without cardiopulmonary bypass (CPB), in order to avoid manipulation of the heavily calcified ascending aorta.

Case Report

In February 2000, a 74-year-old man was admitted to our hospital's cardiovascular clinic with unstable angina. After coronary angiography was performed, lesions were detected in the proximal left anterior descending coronary artery (LAD) and in the mid right coronary artery (RCA). Elective coronary artery bypass grafting was planned.

Left internal mammary artery (LIMA) and saphenous vein grafts were prepared. As we approached cannulation, we discovered that we could not place an aortic cannula because the ascending aorta was completely atherosclerotic. We decided to perform the operation in the presence of a beating heart, to avoid the complications of cardiopulmonary bypass. Because the RCA lesion was in the middle of the vessel and solitary, we decided that proximal-to-distal right coronary bypass grafting would be feasible for a beating-heart procedure. Distal anastomosis of the saphenous vein graft to the RCA was performed with the aid of 1 epicardial traction suture placed on the margin of the RCA and the other placed deeply on the proximal segment of the RCA, in order to immobilize the artery and expose a good anastomotic site. After the distal anastomosis was complete, we performed the proximal anastomosis to the RCA in the atrioventricular groove, with the help of Silastic bands (Fig. 1). We then performed a LIMA–LAD anastomosis.

Fig. 1 Coronary–coronary bypass with saphenous vein graft for right coronary artery lesion in a patient with porcelain aorta.

After the operation, the patient had no need of inotropic or intra-aortic balloon pump support. During his 20-hour stay in the intensive care unit, he showed no electrocardiographic changes or enzyme elevation. There was no evidence of cerebrovascular accident during the postoperative period, and he was discharged from the hospital on the 6th postoperative day on nothing but aspirin therapy (300 mg/day). When follow-up coronary angiography was performed 1 year later, both the RCA and LAD anastomoses were patent.

Discussion

Stroke is one of the major causes of morbidity following cardiac surgery, especially in patients with atherosclerotic ascending aorta. ¹ Although severe aortic atherosclerosis and calcific degeneration of the aorta are encountered occasionally in younger patients, this condition is of course found most often in elderly patients; and a third of patients undergoing CABG in recent years have been age 70 or older, according to the national database maintained by the Society of Thoracic Surgeons. ⁵

There are different methods of avoiding manipulation of a heavily calcified ascending aorta and aortic arch (porcelain aorta). These methods can be summarized as axillary or femoral cannulation with induction of cardiac fibrillation and avoidance of aortic clamping; use of anastomotic sites other than the calcified ascending aorta; aortic arch reconstruction; beating heart bypass without cardiopulmonary bypass; or a combination of these techniques. In addition to these methods, coronary–coronary bypass is an alternative technique that may be used to bypass isolated atherosclerotic coronary lesions, when the patient has a porcelain aorta. ⁶

Coronary–coronary bypass can be performed either between 2 segments of the same coronary artery, as in our case, or from 1 branch of a coronary artery to another (usually involving the right coronary tree). The coronary–coronary bypass method, either with saphenous vein grafts or free arterial grafts, should be considered a workable option for off-pump coronary artery bypass grafting when the aortic “no-touch” technique is called for and other indications are in place.

A surgeon who encounters a porcelain aorta at operation must quickly choose a safe and suitable revascularization method. The coronary–coronary bypass technique, with beating heart, should be borne in mind.