Coronary Artery Bypass Graft (CABG) Surgery

What is Coronary Artery Bypass Graft (CABG)?

Coronary Artery Bypass Graft (CABG) is a surgical procedure done when a coronary artery is blocked and other methods of treatment are ineffective. As a part of this procedure, a small segment of a blood vessel from either the arm, leg or chest is taken and is fixed to the coronary arteries so that the blood bypasses the blocked portion and reaches the heart muscles. Coronary arteries arise from the aorta and supply blood to the heart muscles. Heart attacks happen due to blockage of coronary arteries.

Alternate names

• Bypass Surgery
• Heart Bypass Surgery

Is Coronary Artery Bypass Graft (CABG) Surgery an emergency procedure?

Mostly, a Coronary Artery Bypass Graft (CABG) is performed as an elective procedure. However, under certain circumstances, a CABG may be performed as an emergency surgery which includes:

• Narrowing of the main stem of the left coronary artery
• 3 vessel diseases i.e the left coronary artery, the right coronary artery and the circumflex artery are blocked
• When PCI (percutaneous coronary intervention) has been attempted in the past but has failed
• When the structure of the coronary arteries is such that a PCI cannot be performed
• The heart muscle continuing to be damaged despite maximum medications
• When a person is brought to the hospital with a cardiogenic shock. This is a condition wherein the heart fails to pump blood and this has resulted in damage of vital organs due to poor blood supply to them

Variations in this procedure

The graft used in a CABG could be of several types:

• Arterial grafts:

• Internal thoracic artery graft
• The radial artery graft
• The gastroepiploic artery grafts
• The inferior epigastric artery grafts

• Vein grafts: Saphenous vein grafts

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The technique of CABG could be of the following types:

• On-pump CABG: The heart is stopped, the blood vessels are connected to a heart-lung machine and the surgery is done.
• Off-pump CABG or Beating heart CABG: Only the portion of the heart the surgeon is working on will be stopped while the rest of the heart continues to beat.
• Minimally invasive CABG: The cuts (incisions) made on the chest are very small and the surgeon performs the operation with robotic equipment and video imaging.

Indications

Coronary Artery Bypass Graft (CABG) is performed when:

• The blood vessels supplying the heart muscle are narrowed
• When angioplasty is not an appropriate procedure in a person
• When a stent was placed in the past but the artery has narrowed down again
• When medications are not effective in clearing the blockage in the Coronary Arteries

Contraindications

Coronary Artery Bypass Graft (CABG) is considered inappropriate when a person does not have any symptoms and is not found to be at risk of a heart attack (Myocardial Infarction). Sometimes, when a person is above 85 years of age, a CABG may be performed but it needs careful consideration. This is because the older and more fragile a person is the higher the risk of complications.

Preparing for this procedure

Prior to the surgery:

• One must discuss with the doctor in detail about the medications currently being taken
• All the existing medical conditions in the person
• Any allergies to medications, chemicals, or food
• Surgeries in the past

Details of the procedure

The important steps in Coronary Artery Bypass Graft (CABG) are:

• General anesthesia is given
• Most of the bypass surgeries are performed after bringing the heart to a standstill. But, even when the heart is not beating, the blood circulation and lung activity must continue
• This is achieved by connecting the major blood vessels of the heart to a special machine called the Heart-Lung Bypass machine. This keeps the blood flowing and the lungs functioning even when the blood vessels are disconnected from the heart
• This method is called on-pump coronary bypass surgery
• A long cut is made on the breast bone (sternum) in the chest
• The chest is opened up and the heart is stopped. Once the blood vessels are connected to the Heart-Lung bypass machine, it continues the circulation
• A segment of another healthy blood vessel is taken
• It is fixed to the coronary arteries such that the blood can take this bypass route thereby avoiding the blocked portion of the coronary artery
• Once the surgery is done, the blood vessels are reconnected to the heart, the heart once again starts beating and the chest is closed. The breast bone is fixed with special wires

Hospitalization

Immediately after surgery, the person will be moved to an intensive care unit (ICU). The person will be carefully monitored for 1 or 2 days. Once the individual is able to breathe without the help of a ventilator he/she will be moved out of the ICU. Most people are discharged within 1 week, provided, there are no complications after surgery.

Complications

Possible complications are:

• Bleeding
• Infection of the operation site
• Disturbance of heart rhythm
• Brain Stroke
• Heart Attack
• Kidney problems

Prognosis

The long-term outcome of Coronary Artery Bypass Graft (CABG) Surgery is mostly favorable. People have a good quality of life for as long as 10 to 15 years after the surgery. However, as time passes, some might develop another block in the graft (segment of healthy blood vessel transferred to the heart). Some might develop a blockage of other coronary arteries. That is when another CABG or an Angioplasty might be needed.

The results depend on several factors like:

• Regular intake of prescribed medications
• Maintaining normal blood pressure, blood sugar, blood cholesterol
• Taking blood-thinning medications without fail
• Staying away from smoking and alcohol
• Maintaining a healthy diet and thereby an optimum weight
• Regular exercise as advised by the doctors

When to contact the doctor?

Whenever a person develops symptoms suggestive of heart disease such as breathlessness, chest pain, unable to perform daily activities, immediate medical attention has to be sought.

Suggested clinical specialist to consult for this procedure

• Cardiology
• CT surgery