Clinical alternative bypass conduits and methods for surgical coronary revascularization.

Poor quality or inadequate length of venous and mammary conduits, or both, a severely calcified or atherosclerotic aorta, or diffuse coronary atherosclerosis are situations cardiovascular surgeons will be facing with increasing frequency. These conditions are more common to the increasing number of patients requiring reoperation for advancing disease and to the growing number of older patients requiring operation. Decisions will be made preoperatively or intraoperatively about the technique to be used. Extensive use of the internal mammary arterial graft, such as bilateral internal mammary artery bypass, sequential use of the mammary artery and use of a free internal mammary artery graft, are excellent choices. These methods can overcome some of the difficult situations of the severely calcified atherosclerotic aorta or the absence of adequate venous conduits. Coronary arterial bypass using the inverted internal mammary conduit has too low a flow to be considered. Composite conduits will help gain the length needed to solve both the inadequate length problem and the severely diseased aorta. Little clinical experience is reported to date. These methods should only be used when nothing else is available. The innominate to coronary arterial bypass and the left subclavian to coronary arterial bypass can help solve the problem of the severely atherosclerotic aorta. The coronary to coronary arterial bypass has been used to solve both the severely diseased aorta and the short conduit situation. These methods, while ingenious, are supported only by occasional isolated clinical experiences. A large number of researchers have done extensive work on the selective retrograde coronary venous bypass grafting, but the last published article of any clinical importance dates back to 1979 and this suggests that other alternatives may be better. This technique should be used as a last resort. The surgical arteriovenous fistula has been clinically applied during the coronary artery bypass procedure. The nonconduit revascularization technique of coronary artery endarterectomy is needed in the armamentarium of the surgeon. This technique is not ideal but presently has better results than intraoperative transluminal coronary angioplasty and far better results than laser angioplasty. These methods may be useful to solve the diffuse coronary arterial problem, but sequential grafting techniques should be considered first.