Results of cardiac bypass graft surgery have improved over the past 30 years

due to improved techniques. 

 In the beginning veins were removed from the

legs and used to replace the clogged arteries of the heart ,but now that has changed , resulting in longer survival.

The heart is supplied with oxygen and nutrients by small feeding arteries which travel around the outside surface of the heart. With the passage of time these arteries become clogged with cholesterol plaques, and clots form on these plaques leading to narrowing and blockage of the vital coronary arteries.  As these vessels block, the area of heart muscle which is fed by the vessels becomes damaged and dies due to lack of oxygen.  When 3 or more coronary arteries were found to have a build-up of cholesterol deposits causing a lack of adequate blood supply to the heart, coronary arteries are removed and replaced in an effort to prolong life. In the early days, veins were used. Now arteries are used to replace arteries(a logical progression in the scheme of things). The arteries which are used  are located in the chest, and studies are showing that 80-90% of grafts taken from the internal thoracic artery  and used to replace coronary arteries are still open and flowing 20 years later. This is much longer than the 5-10years expected 20 years ago using saphenous veins from the legs, which had a strong tendency to develop cholesterol plaque and hence block up much more quickly.

 Radial arteries from the wrists are also used to supplement the internal thoracic arteries of the chest.

 Experience with caring for grafts has also improved greatly. Careful preparation,storage and harvesting have all contributed to the increase in survival.

 In addition, control of the tendency for cholesterol deposits to form generally, by reducing blood pressure, treating diabetes, avoiding cigarettes and lowering of cholesterol using statins has led to a marked improvement in graft outcome.

References:

1.Buxton BF,Raman JS and others “Radial artery patency and clinical outcomes-5-Year interim results of a randomized trial. Journal Thoracic Cardiovascular Surgery 2003;125(6):1363-70

2. SoS Investigators Coronary artery bypass surgery versus percutaneous coronary intervention with stent implantation in patients with multivessel coronary artery disease Lancet 2002 Sept 28 360(9338) 965-70

3. Holmes DR and others Bypass Angioplasty Revascularization Investigation (BAR)Thoracic Cardiovascular Sugery 2007:134(1)38-46