1. What is a coronary artery?
The coronary artery is the vessel that supplies blood to the heart musculature and its effective functioning is mandatory for an active lifestyle. The artery starts from the coronary sinus at the base of the great artery, the aorta. The main trunk divides itself into two main branches namely the left and the right coronary arteries. From there onwards multiple branching arteries will supply the heart musculature.
The blood flow through the coronary arteries is dependant on the pressure generated by the heart in its 'systolic' contraction as well as the un-obstructive nature of the blood vessel lumen.
2. How does the coronary flow get compromised?
Due to various causes, the coronary arteries can get blocked. The process is initiated by the deposit of fats or cholesterol plaques in the arterial wall. These plaques can narrow the arterial lumen to an extent where the blood supplies to the heart muscles are deficient. This deficiency can be precipitated by exertion and in severe cases even at rest.
These patients will complain about chest pain either on exertion or at rest. It might be associated with difficulty in breathing as well. A coronary angiogram will be able to diagnose and pinpoint the area of narrowing and assess the blood flow towards a certain area of the heart.
In certain instances a spasm in the coronary artery can give rise to a temporary narrowing of the blood vessel and is known as 'Coronary artery spasm'.
3. How are blocks in the coronary artery relieved?
In most instances, the narrowing can be reduced by the introduction of a balloon device and a permanent 'stent' to support the arterial wall. But, if the narrowing is too much or in other words, the narrowing is closer to 99-100%, as well as the presence of multiple occlusion, the 'Stenting' might not be the best option. In these instances, the doctors will consider a surgical correction called the 'Coronary Artery Bypass Grafting' or CABG.
4. How is the coronary bypass performed?
In this surgery the blocked section of the coronary artery is bypassed through a transplanted vein connecting the most proximal as well as the distal end of the narrowed lumen. The surgery will permanently restore the perfusion of the heart musculature that was deprived by the blocked artery. The transplanted venous graft will accommodate itself to the new role with time.
5. From where is the bypass graft obtained?
The venous graft used for the coronary artery bypass is obtained either from the forearm or most commonly from the lower limb. The forearm vein that is harvested for the bypass grafting is the 'radial vein' whereas the lower limb vessel used in the process is the saphenous vein.
6. Will the blood flow be affected after removal of veins from arm and legs?
These veins are mostly superficial veins and its removal would not compromise the blood flowing back to the heart. This is because the collateral veins as well as the deep veins will accommodate the loss of superficial veins.