The bypass part of the surgery
When using a vessel from the forearm or leg a surgeon connects, or grafts, one end of the harvested vessel to the aorta- which allows blood to flow into the graft. The other end is attached to the coronary artery that has a blockage, bypassing the blocked portion of coronary artery to restore blood flow to the heart muscle.
It is not uncommon for a surgeon to perform one or more of these grafts during an operation — Depending upon how many bypass grafts the surgeon performs, this can be referred to as double (2), triple (3), quadruple (4) or more bypasses.
Heart with bypass
During the bypass procedure, your surgeon has two options:
- Stop the heart and use a heart-lung machine (On-pump)
- Keep your heart beating during the operation (Off-pump)
Bypass procedures became routine in the 1960s, following the invention of the heart-lung machine. The heart-lung machine is a device that temporarily does the job of the heart and lungs. This allow the heart to be stopped during CABG surgery. The heart-lung machine supplies oxygen to the blood and keeps blood circulating while a surgeon is sewing the grafts.
Once the operation is complete, the heart is returned to its normal rhythm and the heart-lung machine is no longer needed.
The heart-lung machine made it possible for surgeons to save the lives of millions of patients. However, there are potential risks involved in its use, especially for high-risk patients and those with diabetes or kidney disease. These patients are more likely to experience complications due to coronary surgery.
With off-pump bypass the heart continues to beat and supply oxygenatd blood throughout the body while the surgeon performs the bypass grafts. For some patients, the use of the heart-lung machine can add increased risk to their operation, or their surgeon may prefer to keep the heart beating during the operation to minimize the risk of certain complications.