Upper extremity vein graft for aortocoronary bypass

Saphenous Vein Grafts: To Use or Not to Use?

The choice of the graft conduit is crucial to the success of coronary artery bypass grafting (CABG) because the patency of a coronary conduit is closely associated with an uneventful postoperative course and better long-term patient survival. From the beginning of coronary bypass surgery venous conduits particularly the great saphenous veins (GSV) have been the most frequently used coronary conduit from the beginning of the coronary bypass surgery. However, over the last decade or so, coronary bypass graft surgery with arterial revascularization of all diseased coronaries has shown to be efficient because arterial grafts have better long-term patency, especially left internal mammary artery (LIMA), compared with venous grafts. Early vein graft failure coupled with occlusion is the most important limitation of saphenous vein grafts. Nevertheless, vein grafting is still an integral part of cardiac surgical practice. This review provides a summary of the patency rates, technical features and certain characteristics of the venous conduits. It also examines the current understanding and knowledge of venous histology, vein graft pathology and the associated endothelial and smooth muscle cell physiology and pharmacology. In addition, the existing and the emerging strategies to combat and control vein graft intimal hyperplasia and accelerated atherosclerosis are reviewed in detail.

Saphenous Vein Grafts: to Use or Not to Use?

The choice of the graft conduit is crucial to the success of coronary artery bypass grafting (CABG) because the patency of a coronary conduit is closely associated with an uneventful postoperative course and better long-term patient survival. From the beginning of coronary bypass surgery venous conduits particularly the great saphenous vein (GSV) has been the most frequently used coronary conduit. However, over the last decade or so, coronary bypass graft surgery with arterial revascularization of all diseased coronaries has shown to be efficient because arterial grafts have better long-term patency, especially left internal mammary artery (LIMA), compared with venous grafts. Early vein graft failure coupled with occlusion is the most important limitation of saphenous vein grafts. Nevertheless, vein grafting is still an integral part of cardiac surgical practice. This review provides a summary of the patency rates, technical features and certain characteristics of the venous conduits. It also examines the current understanding and knowledge of venous histology, vein graft pathology and the associated endothelial and smooth muscle cell physiology and pharmacology. In addition, the existing and the emerging strategies to combat and control vein graft intimal hyperplasia and accelerated atherosclerosis are reviewed in detail.

MRI of pseudoaneurysm of a brachial venous coronary bypass graft

Coronary artery bypass grafting (CABG) is being performed all over the world, with major success in the management of ischemic heart disease and angina pectoris. Complications of bypass grafting include partial or total graft reocclusion, and less common entities such as aneurysm or pseudoaneurysm formation. Noninvasive imaging procedures exist which can help include or exclude the presence of these unusual types of complications when mass-like abnormalities are seen on a chest X-ray following coronary artery bypass grafting. This case specifically illustrates the usefulness of ultrafast magnetic resonance imaging techniques in the evaluation and diagnosis of pseudoaneurysm formation at the site of coronary artery bypass graft.

Right gastroepiploic-to-coronary artery bypass. The first decade of use

BACKGROUND

The right gastroepiploic artery was first used by us as a coronary artery bypass graft (CABG) in June 1984 and has become an accepted alternative conduit for myocardial revascularization.

METHODS AND RESULTS

We have now performed this operation in 126 patients (111 of whom were men) aged 32 to 78 years. The right gastroepiploic artery was used as a pedicle graft to the right main coronary artery in 25 patients, to its posterior descending branch in 90, to a left ventricular branch in 2, to branches of the circumflex system in 6, and to the left anterior descending artery in 1. Free (aortocoronary) gastroepiploic grafts were placed to circumflex branches in 2 patients. There were 2 hospital deaths (stroke, arrhythmia), and mean +/- SD postoperative stay was 7.5 +/- 2.0 days. All survivors were symptomatically improved and are functionally in New York Heart Association functional class I or II. There have been 3 late deaths (at 34, 50, and 84 months) in 2 to 120 months of follow-up (mean, 41.4 months). Angiography of bypass grafts and coronary arteries was performed in 44 patients at 7 days to 80 months postoperatively, providing direct evidence of gastroepiploic graft patency in 34 patients and strong indirect evidence in another 6; adequate data could not be obtained in 3 patients for technical reasons, and 1 graft was occluded.

CONCLUSIONS

These short-term, intermediate, and long-term results demonstrate the suitability of the right gastroepiploic artery as a CABG. The use of the right gastroepiploic artery as a graft to coronary arteries on the posterior wall of the heart, in conjunction with one or both internal mammary arteries, has the potential to allow complete myocardial revascularization with viable arterial grafts.

Conduit options in coronary artery bypass surgery

The choice of graft conduit is crucial to the success of coronary artery bypass grafting (CABG) because the patency of a coronary conduit is closely associated with an uneventful postoperative course and a better long-term patient survival. The standard conduits used for CABG are the greater saphenous vein (GSV) and the internal thoracic artery (ITA). An excellent substitute conduit for coronary bypass operations that can be taken "off the shelf" is certainly the dream of every practicing cardiac surgeon. However, virtually every synthetic and biologic alternative to arterial conduits or autologous fresh saphenous vein has proved disappointing. Fortunately, patients with absolutely no autologous conduit alternatives are uncommon. Circumstances exist, however, that often necessitate the use of alternative conduits such as young hyperlipemic patients, absent or unsuitable autologous ITAs and GSV as a result of previous myocardial revascularization, peripheral arterial reconstruction, and varicose vein ligation procedures. This review provides an update on the clinical work done with all coronary conduits available for myocardial surgical revascularization.

Patency of cryopreserved saphenous vein grafts as conduits for coronary artery bypass surgery

STUDY OBJECTIVE

To determine the angiographic patency of cryopreserved saphenous vein grafts used as conduits during coronary artery bypass surgery and whether this is affected by postoperative immunosuppressive therapy.

DESIGN AND SETTING

A retrospective review of medical records and coronary angiograms of patients at a university hospital.

PATIENTS

Eleven patients undergoing 12 coronary artery bypass operations during which a total of 26 distal coronary anastomoses were created using cryopreserved vein grafts.

MEASUREMENTS

Eight postoperative coronary angiograms were performed in 10 patients surviving longer than 1 week. All angiograms were performed on the basis of symptoms of suspected myocardial ischemia. Angiographic results, postoperative anticoagulation, and therapy with immunosuppressive agents were analyzed.

RESULTS

Seventeen cryopreserved vein grafts were studied; one (6%) was patent, 12 (71%) were occluded, and 4 (23%) were stenosed. In patients treated with azathioprine, seven of the eight cryopreserved vein grafts were occluded. In patients not receiving immunosuppression, five were occluded, three were stenosed, and one was patent. All internal mammary grafts were widely patent.

CONCLUSION

Cryopreserved vein grafts have a poor angiographic patency which did not appear to be affected by immunosuppressive therapy with azathioprine. The use of this graft should be restricted and alternative arterial conduits utilized.

Vascular prostheses for aortocoronary bypass grafting: a review

Alternative conduits must be chosen when autologous grafts are not available for coronary artery bypass grafting (CABG). Viable grafts do not always have perfect characteristics for CABG, and homologous venous conduits have been used with unsatisfactory results. Many small caliber vascular grafts used for coronary bypass conduits have been developed in the past, but most of them have failed except in rare instances. In this paper the current problems in available conduits, new technologies for improvement, animal models, and possibilities for the future for CABG conduits are discussed.

Angiography of right gastroepiploic artery for coronary artery bypass graft

We describe the angiographic technique of grafting the right gastroepiploic artery to the coronary artery. With the femoral approach, our specially devised catheter was placed in the common hepatic artery or gastroduodenal artery. The gastroepiploic artery and graft to the coronary artery were visualized satisfactorily by manual injection of contrast media.

The possibility of using celiac trunk branches as coronary artery bypass grafts

The internal mammary artery has proved to be superior to the saphenous vein for coronary artery bypass grafting, because of its arterial nature and closer approximation in size to the coronary arteries. But the internal mammary artery cannot reach the posterior surface of the heart as a pedicled graft. Two suitable intra-abdominal grafts can reach that surface, viz. the right gastroepiploic artery and the splenic artery. In experiments on eight dogs (weight 9-13.5 kg), the gastroepiploic artery was found to be too small for coronary artery anastomosis, and therefore the splenic artery was used. The size approximation with coronary artery (diameter less than 1 mm) was good. Four dogs survived the month of the study. In two of them the anastomosis was patent, in another the splenic artery was patent despite occlusion of the anastomosis, and in the fourth dog both anastomosis and graft were thrombosed. The possibility of using visceral arterial grafts in coronary surgery is discussed.

Biologic fate of valves in reversed and nonreversed arterial vein grafts

The cusps of valve-bearing segments of canine cephalic, femoral, and jugular veins were completely divided and were used in interposition grafts in the femoral and carotid arteries in the nonreversed position. Three control grafts had intact valves in the reversed position, and one control graft in the reversed position had division of the leaflets. Nine grafts were studied up to 2 months postoperatively with gross and microscopic observations. The cusp tissue, which shrinks immediately after complete division, disappears very early in the postoperative period in the reversed and nonreversed positions. Two reversed intact valves were still grossly microscopically normal 5 and 7 weeks postoperatively. The complete disappearance of the divided valve with a nonreversed coronary graft 101/2 months postoperatively has been documented at autopsy for the first time in a human subject. The significance of these findings and the superiority of the valveless nonreversed autogenous vein graft in clinical cardiovascular surgery has been discussed.