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On-Pump CABG

Coronary Artery Bypass Surgery

CABG is a surgical procedure in which one or more blocked coronary arteries are bypassed by a blood vessel graft to restore normal blood flow to the heart. These grafts usually come from the patient’s own arteries and veins located in the chest (thoracic), leg (saphenous) or arm (radial). The graft goes around the blocked artery (or arteries) to create new pathways for oxygen-rich blood to flow to the heart. The goals of the procedure are to relieve symptoms of coronary artery disease (including angina), enable the patient to resume a normal lifestyle and to lower the risk of a heart attack or other heart problems. At Cleveland Clinic, bypass surgery may be performed in combination with other heart surgeries, when necessary, such as valve surgery, aortic aneurysm surgery or surgery to treat atrial fibrillation (an irregular heart beat).


Who is eligible to receive coronary artery bypass graft surgery?

Diagnostic tests have helped your heart doctor identify the location, type and extent of your coronary artery disease. The results of these tests, the structure of your heart, your age, the severity of your symptoms, the presence of other medical conditions, and your lifestyle will help your cardiologist, surgeon and you determine what type of treatment is best.


What happens during the cardiac bypass surgery?

After general anesthesia is administered, the surgeon removes the veins or prepares the arteries for grafting. There are several types of bypass grafts. The surgeon decides which graft(s) to use, depending on the location of the blockage, the amount of the blockage and the size of the coronary arteries.


IMA Grafts

Internal mammary arteries also called IMA grafts or internal thoracic arteries (ITA) are the most common bypass grafts used, as they have shown the best long-term results. In most cases, these arteries can be kept intact at their origin because they have their own oxygen-rich blood supply, and then sewn to the coronary artery below the site of the blockage. If the surgeon removes the mammary artery from its origin, it is called a “free” mammary artery. Over the last decade, more than 90% of all patients received at least one internal artery graft.


Radial (arm) Artery

The radial artery is another common type of arterial graft. There are two arteries in the arm, the ulnar and radial arteries. Most people receive blood to their arm from the ulnar artery and will not have any side effects if the radial artery is used. Careful preoperative and intraoperative tests determine if the radial artery can be used. If the radial artery is used as the graft, the patient may be required to take a calcium channel blocker medication for several months after surgery. This medication helps keep the artery open. Some people report numbness in the wrist after surgery. However, long-term sensory loss or numbness is uncommon.


Saphenous veins

Saphenous veins can be used as bypass grafts. Minimally invasive saphenous vein removal does not require a long incision. One to two incisions are made at the knee and a small incision is made at the groin. This results in less scarring and a faster recovery. Your surgeon will decide if this method cardiac bypass surgery is a good option for you. The gastroepiploic artery to the stomach and the inferior epigastric artery to the abdominal wall are less commonly used for grafting.


What are the risks?

As with any surgery, there are risks involved. Your surgical risks are related to your age, the presence of other medical conditions and the number of procedures you undergo during a single operation. Your cardiologist will discuss these risks with you before surgery; please ask questions to make sure you understand why the procedure is recommended and what all of the potential risks are


• Surgical Procedure To bypass the blockage, the surgeon makes a small opening just below the blockage in the diseased coronary artery. If a saphenous (leg) or radial (arm) vein is used, one end is connected to the coronary artery and the other to the aorta. If a mammary artery is used, one end is connected to the coronary artery while the other remains attached to the aorta. The graft is sewn into the opening, redirecting the blood flow around this blockage. The procedure is repeated until all affected coronary arteries are treated. It is common for three or four coronary arteries to be bypassed during surgery. Before the patient leaves the hospital, the doctor or nurse will explain the specific bypass procedure that was performed.

• Heart Lung Machine During surgery, the heart-lung bypass machine (called “on-pump” surgery) is used to take over for the heart and lungs, allowing the circulation of blood throughout the rest of the body. The heart’s beating is stopped so the surgeon can perform the bypass procedure on a “still” heart. Off-pump or beating heart bypass surgery allows surgeons to perform surgery on the heart while it is still beating. The heart-lung machine is not used. The surgeon uses advanced operating equipment to stabilize (hold) portions of the heart and bypass the blocked artery in a highly controlled operative environment. Meanwhile, the rest of the heart keeps pumping and circulating blood to the body.


• Minimally Invasive Technique Minimally invasive coronary artery bypass (MIDCAB) surgery is an option for some patients who require a left internal mammary artery (LIMA) bypass graft to the left anterior descending (LAD) artery. The benefits of minimally invasive surgery include a smaller incision (3 to 4 inches instead of the 6- to 8-inch incision with traditional surgery) and smaller scars. Other possible benefits may include a reduced risk of infection, less bleeding, less pain and trauma, decreased length of stay in the hospital (3 to 5 days) and decreased recovery time. The surgical team will carefully compare the advantages and disadvantages of minimally invasive CABG surgery versus traditional CABG surgery. Your surgeon will review the results of your diagnostic tests before your surgery to determine if you are a candidate for any of these minimally invasive techniques.


• Open Surgical Repair: The traditional treatment technique involves opening the chest and surgical removing the dissected aorta. A synthetic graft is sewn in its place for blood to flow freely to the rest of the arterial system. This procedure often requires a hospital stay of a week or more, and recuperation can take 6-8 weeks.


How long does the procedure last?

The surgery generally lasts from 3 to 5 hours, depending on the number of arteries being bypassed.


After Surgery

After the grafts have been completed during the “on pump” procedure, the heart-lung machine is turned off, the heart starts beating on its own, and the flow of blood returns to normal. Temporary pacing wires and a chest tube to drain fluid are placed before the sternum is closed with special sternal wires. Then the chest is closed with internal stitches or traditional external stitches. Sometimes a temporary pacemaker is attached to the pacing wires to regulate the heart rhythm until your condition improves. The patient is transferred to an intensive care unit for close monitoring for about one to two days after the surgery. The monitoring during recovery includes continuous heart, blood pressure and oxygen monitoring and frequent checks of vital signs and other parameters, such as heart sounds. Once the patient is transferred to the step-down nursing unit, the hospital stay is about 3 to 5 more days.


How will I feel after surgery?

For a while after the surgery, you may feel worse than you did before surgery. This is normal and is usually related to the trauma of surgery, not necessarily to the functioning of your heart valves. It may take you from 4 to 10 weeks to fully recover from surgery. How you feel after surgery depends on your overall health, the results of the surgery, and how well you take care of yourself after surgery. After recovering from surgery, most patients do feel better. To some extent, how you feel will depend on how you felt before surgery. Patients with more severe symptoms before surgery may experience a greater sense of relief after surgery. Call your doctor if you are concerned about your symptoms or rate of recovery.



Full recovery from coronary artery bypass graft surgery takes about 2 months, or may be sooner if minimally invasive surgery techniques were used. Most patients are able to drive in about 3 to 8 weeks after surgery. Your doctor will provide specific guidelines for your recovery and return to work, including specific instructions on activity and how to care for your incision and general health after the surgery.


Follow Up Care

During the first few months after surgery, you will probably need to visit a few times with the doctor who referred you for surgery. You will need to schedule regular appointments with your cardiologist (even if you have no symptoms). Your follow-up appointments may be scheduled every year, or more often, as recommended by your doctor. Your appointments should include a medical exam. Diagnostic studies (such as an echocardiogram) may be repeated at regular intervals. You should call your doctor if your symptoms become more severe or frequent. Don’t wait until your next appointment to discuss changes in your symptoms.


Importance of Making Lifestyle Changes

Coronary artery bypass graft surgery increases the blood supply to your heart, but it does not cure coronary artery disease. You will still need to decrease your risk factors by making lifestyle changes, taking medications as prescribed and following your doctor’s recommendations to prevention future disease. Lifestyle changes include:


• Quitting smoking

• Treating high cholesterol

• Managing high blood pressure and diabetes

• Exercising regularly

• Maintaining a healthy weight

• Eating a heart-healthy diet Controlling stress and anger

• Taking prescribed medications as directed

• Participating in a cardiac rehabilitation program, as recommended

• Following up with your doctor for regular visits