Coronary artery bypass grafting (CABG) is a procedure to improve poor blood flow to the heart. It may be needed when the arteries supplying blood to heart tissue, called coronary arteries, are narrowed or blocked. This surgery may lower the risk of serious complications for people who have obstructive coronary artery disease, a type of ischemic heart disease. CABG may also be used in an emergency, such as a severe heart attack.
CABG uses blood vessels from another part of the body and connects them to blood vessels above and below the narrowed artery, bypassing the narrowed or blocked coronary arteries. One or more blood vessels may be used, depending on the severity and number of blockages. The blood vessels are usually arteries from the arm or chest, or veins from the legs. Risks and possible complications may occur with this procedure. After CABG, your doctor may recommend medicines and heart-healthy lifestyle changes to further reduce your symptoms, treat your disease, and help prevent complications such as blood clots.
There two types of CABG procedures:
- Traditional Method (Open heart surgery)
- Minimally Invasive Method
Traditional CABG Surgery
Traditional CABG is the most common type of CABG surgery. This surgery takes about three to six hours, depending on how many arteries need to be bypassed.
You will be given an intravenous (IV) line for fluids and medicines that will make you sleep before the surgery. You will be connected to a ventilator to support your breathing. The surgeon makes a cut down the middle of the chest, through the breastbone. The bone is split and the rib cage separated so the surgeon can reach the heart.
You will receive medicines to temporarily stop your heart from beating. This makes it easier for the surgeon to connect the healthy blood vessels, called grafts, into the coronary arteries. This requires a heart-lung bypass machine, which adds oxygen to your blood and pumps it throughout your body during surgery while your heart is not beating.
How a heart-lung bypass machine works during surgery?
The heart-lung bypass machine adds oxygen and pumps blood throughout the body while the heart is stopped during surgery. The blood supply is connected to the machine through tubes. First, blood that needs oxygen leaves the heart and goes into the machine, bypassing the lungs. Oxygen is added to the blood in the machine. Then the machine pumps the oxygen-rich blood to the rest of the body.
The surgeon will then take an artery or a vein from your leg, arm, stomach, or chest. The graft is connected to the blocked coronary artery. The new blood vessel bypasses the blocked portion to create a new path for blood flow to the heart muscle. The number of grafts depends on how many coronary arteries need to be bypassed.
When the grafting is finished, the surgeon will restart the heart and restore blood flow. The heart usually starts beating on its own, but sometimes mild shocks are used to start it. Surgeons will sew the breastbone back together with a wire.
Sometimes CABG can be done without stopping the heart and using a heart-lung bypass machine. This is called off-pump CABG because the heart-lung bypass machine, or pump, is not used. The heart is steadied with a mechanical device. It is more difficult for surgeons because the heart is beating, and surgeons do not have easy access to blood vessels. However, it may be safer for certain people, such as those who have a higher risk of complications from using a heart-lung bypass machine. These include older adults and people who have ventricular dysfunction, diabetes, kidney disease, and chronic lung disease. This type of surgery is also sometimes called beating-heart bypass grafting.
Minimally Invasive CABG
Sometimes, CABG surgery may not be done as open heart surgery. There are less-invasive methods, including:
- Minimally invasive direct coronary artery bypass (MIDCAB). MIDCAB is a modified version of CABG where the chest bone is not cut open. Instead, the surgeon makes a smaller cut on the left side of the chest over the artery that needs to be bypassed and enters in between the ribs. It is also usually an off-pump procedure.
- Robotic. Sometimes CABG surgery can be done using a robot to surgically place the graft. This is called robotic-assisted or robotic surgery. The surgeon controls the robot instead of doing the work by hand, and the machinery only needs small openings in the chest. A heart-lung bypass machine is sometimes used.
- Hybrid. During a hybrid bypass surgery, the robotic bypass is done for one of the main arteries, but a stent is used for other blocked arteries. The stent is a rolled-up mesh tube-like structure that goes inside the blocked artery to hold it open. This procedure is typically used only if your doctor is unable to perform the traditional bypass procedure.
You will stay in Intensive Care Unit (ICU) for 24-48hours for close monitoring and nursing care. Expect to be discharged from the hospital for about one week unless you had other procedures done as well or if you have a complication.
After you leave the hospital, you will need about six to 12 weeks to recover completely. People who undergo minimally invasive CABG need less time to recover than for traditional CABG.