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A Detailed Guide to Coronary Artery Bypass Graft Surgery

Author: Nucleus Medical MediaTime: 2024-01-24 08:20:00

Table of Contents

What is Coronary Artery Bypass Graft (CABG) Surgery and Why is it Performed?

A coronary artery bypass graft (CABG) is a surgical procedure performed to improve blood flow to the heart muscle in people with severe coronary artery disease. In CABG surgery, a healthy artery or vein from another part of the body is grafted around the blocked portion of the coronary artery. This allows oxygen-rich blood to bypass the blockage and reach the heart muscle.

CABG surgery is typically performed when coronary artery disease has caused one or more of the heart's major blood vessels to become narrow or blocked. This limits oxygen-rich blood flow to the heart muscle and can cause chest pain or other symptoms.

When medication and lifestyle changes aren't enough, CABG surgery creates new routes for blood to flow around diseased vessels, improving blood flow and oxygen delivery to heart muscle tissue. This can help relieve chest pain and other coronary artery disease symptoms.

Why is CABG Performed?

There are a few key reasons why a doctor may recommend CABG surgery:

  • To improve blood flow to the heart muscle when coronary arteries are severely diseased
  • To help relieve persistent chest pain or discomfort (angina)
  • In some cases, to lower risk of heart attack
  • For certain patients, to improve chances of survival

How Does CABG Improve Blood Flow to the Heart?

During CABG surgery, the surgeon harvests a graft made from an artery or vein, often from another area of the body. The graft essentially creates a detour around the blocked part of the coronary artery. One end of the graft is usually connected to the aorta (the major artery leaving the heart), while the other end is attached beyond the blockage in the coronary artery. This bridges the blockage, providing a new path for oxygen-rich blood to flow around the diseased artery. Depending on the extent and location of coronary artery disease, one or more coronary arteries may be bypassed with grafted vessels during CABG surgery.

How is CABG Surgery Performed?

There are a few main steps involved in CABG surgery:

  1. General anesthesia is used to put the patient to sleep for the operation. Medications may also be given to help the patient relax beforehand.

  2. The chest cavity is opened by making an incision down the breastbone. The breastbone itself may be cut and the ribs pried open to access the heart.

  3. The patient is connected to a cardiopulmonary bypass machine, also called a heart-lung machine. This device temporarily takes over the functions of the heart and lungs during surgery.

  4. To create the bypass graft, an artery or vein is taken from another area of the body. Common sites include the chest wall or leg.

  5. While the heart is stopped, the grafted blood vessel is sewn around the blockage in the coronary artery. Bypass grafts may be created in multiple coronary arteries.

  6. Normal blood flow is restored once grafting is complete. Temporary pacemaker wires help control the heart rate afterward.

  7. The breastbone and surgical incision are closed up with stitches or staples.

What Happens During Conventional CABG Surgery?

Conventional CABG surgery, often called on-pump surgery, uses a cardiopulmonary bypass machine. This allows the surgeon to operate on a still heart after blood flow is rerouted through the bypass machine.

Harvesting the Grafts

To create the bypass graft, the surgeon detaches a blood vessel from elsewhere in the body while the patient is connected to the heart-lung machine. An artery in the chest or a vein in the leg are common sites. For an internal thoracic artery graft, one end stays connected to an artery branching from the aorta. The lower end is diverted from the chest wall to the coronary artery beyond its blockage. For a saphenous vein graft from the leg, one end is attached to the aorta while the other is sewn into the coronary artery after the blockage.

Attaching the Grafts

With the patient on the cardiopulmonary bypass pump, the heart is stopped temporarily. This allows the surgeon to accurately sew each graft in place, bypassing blockages in one or more coronary arteries. Once grafting is complete, the heart is restarted using electrical stimulation. Temporary pacemaker wires help control heart rate afterward.

Alternative CABG Procedures: Off-Pump and Minimally Invasive

Some newer, alternative CABG techniques have also been developed:

  • Off-pump CABG, also called beating heart bypass surgery, is performed while the heart is still beating. A special device stabilizes the area for grafting.

  • Minimally invasive CABG uses small incisions between ribs versus splitting the breastbone. Hybrid procedures may combine minimally invasive CABG on some arteries with stents in others.

Recovering from CABG Surgery

After surgery, patients are monitored closely in the intensive care unit. Heart rate and blood pressure are checked regularly.

Temporary drainage tubes, breathing tubes, pacemakers and catheters help recovery. These are gradually removed over the next several days as the patient’s condition stabilizes.

Post-surgery medications help manage pain and prevent complications like infection. With proper precautions and follow-up care, most people can return to their regular activities within 12 weeks.


In summary, a CABG or bypass surgery uses grafted vessels to reroute blood flow around severely blocked arteries feeding the heart muscle. This procedure helps improve oxygen delivery to heart tissue in patients with coronary artery disease not adequately treated by other methods.

Conventional, on-pump CABG requires stopping the heart temporarily while grafts are stitched in place. Newer off-pump and minimally invasive techniques allow grafting without complete suspension of heart function.


Q: How long does CABG surgery take?
A: CABG surgery generally takes 3 to 6 hours.

Q: What kinds of grafts are used in CABG?
A: The internal thoracic artery in the chest or the saphenous vein in the leg are typically used.

Q: Is CABG major surgery?
A: Yes, CABG is major open heart surgery done under general anesthesia.

Q: How long is recovery after CABG?
A: The hospital stay is typically 3 to 4 days, but full recovery takes several weeks.

Q: What are the risks of CABG surgery?
A: Risks include bleeding, infection, memory loss, stroke, and death in rare cases.

Q: When is CABG necessary?
A: CABG is done when medication and other treatments can't improve blood flow in severe coronary artery disease.

Q: Is CABG better than angioplasty?
A: For certain patients, CABG provides better long-term outcomes than angioplasty and stenting.

Q: How is the heart stopped during CABG?
A: A heart-lung bypass machine takes over the functions of the heart and lungs during surgery.

Q: Does CABG cure heart disease?
A: No, CABG doesn't cure the underlying disease. Lifestyle changes and medication are still needed.

Q: What is beating heart CABG surgery?
A: Beating heart or off-pump CABG is done without stopping the heart or using a heart-lung machine.