Coronary artery bypass surgery

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Image:Coronary artery bypass surgery Image 657C-PH.jpg

Image:Coronary artery bypass surgery Image 657B-PH.jpg

A coronary artery bypass graft (CABG) or heart bypass. it was invented in Argentina by René Favaloro and it is a surgical procedure performed in patients with coronary artery disease (see atherosclerosis) for the relief of angina and possible improved heart muscle function. Veins or arteries from elsewhere in the patient's body are grafted from the aorta to the coronary arteries, bypassing coronary artery narrowings caused by atherosclerosis and improving the blood supply to the myocardium (heart muscle).

First, the sternum is cut down the middle with a special bone saw and the chest opened (a procedure known as "cracking the chest" or a median sternotomy). Depending on a number of factors, the surgeon may decide to place the patient on cardiopulmonary bypass ("on-pump") or use suction-stabilizing devices to hold the heart still while sewing the anastamoses ("off-pump"). Blood vessels are harvested from elsewhere in the body for grafting. Sometimes artery end branches supplying tissues near the heart are rerouted to create the bypass.

Typically, the great saphenous vein from the leg and the left internal thoracic artery (LITA) (previously referred to as left internal mammary artery or LIMA) are used for the bypass. Veins used either have their valves removed or are turned around so that the valves in them do not occlude blood flow in the graft. LITA grafts are longer-lasting than vein grafts, both because the artery is more robust than a vein and because, being already connected to the aorta, the LITA need only be grafted at one end. The LITA is usually grafted to the left anterior descending coronary artery (LAD) because of it superior long-term patency when compared to saphenous vein grafts.^[1]^[2] The LAD supplies the left ventricle, the part of the heart that pumps oxygenated blood around the body, and is the most important for survival. Alternatively, an artery such as the radial artery from the arm, may be used in place of a vein.

Prognosis following CABG depends on a variety of factors, but successful grafts typically last around 10-15 years.

References

^ Kitamura S, Kawachi K, Kawata T, Kobayashi S, Mizuguchi K, Kameda Y, Nishioka H, Hamada Y, Yoshida Y. [Ten-year survival and cardiac event-free rates in Japanese patients with the left anterior descending artery revascularized with internal thoracic artery or saphenous vein graft: a comparative study] Nippon Geka Gakkai Zasshi. 1996 Mar;97(3):202-9. PMID 8649330
^ Arima M, Kanoh T, Suzuki T, Kuremoto K, Tanimoto K, Oigawa T, Matsuda S. Serial Angiographic Follow-up Beyond 10 Years After Coronary Artery Bypass Grafting. Circ J. 2005 Aug;69(8):896-902. PMID 16041156 Full Text