Coronary artery bypass surgery is a cardiac surgery performed to supply blocked arteries with atheroma plaques.

It consists in making vascular bridges over partial or total obstructions of the arteries of the heart, because bridges help us cross obstacles.


To better understand

To understand, we must review the functioning of the heart and its oxygenation.


A muscular pump

The heart is a muscular pump the size of your fist.

Located in the center of the chest, between the two lungs, it is the motor of circulation. It beats on average more than 100,000 times a day.


Oxygen is its fuel

Its normal functioning is closely linked to its oxygenation, which is brought to it by the blood.


Coronary arteries

The delivery of its precious fuel is provided by the coronary arteries. Any reduction in oxygen supply can have serious and sometimes irreversible effects on the heart.


Left and right coronaries

The two coronary arteries, the left and the right, are located directly on the heart.


The size of a nail

They are easily visible and accessible by the surgeon. They measure on average from 1 to 3 mm.


Cholesterol plaques

When the atherosclerotic coronary disease, or the disease of the arteries of the heart, progresses, the presence of atheroma plaques, or commonly called cholesterol plaques, narrows the arteries of the heart.

These plaques are the accumulation of fat and calcium. When these plaques become large enough to slow the flow of blood, the heart is out of oxygen and the symptoms of angina (or chest pain) during effort appear.



When the artery is very severely narrowed or even completely blocked, the blood can no longer pass, the heart muscle suffers and it is painful!

When this pain persists for 20 to 30 minutes, the heart may stop contracting in this area or even die.


The Stroke

This portion of the dead heart is then replaced by a scar: it is a stroke. This scar can be compared to the very tough whitish fillet in a piece of meat.

A scar on a portion of the heart muscle may make the heart less efficient at pumping blood.



In order to treat angina or a stroke, it is necessary to restore good circulation in the arteries of the heart.


A surgery with a rich history

For more than half a century, coronary bypass surgery has been used to bypass a narrowed or obstructed coronary artery by putting another vessel on top of it.


We build bridges

As the name says, this surgery places bridges over the narrowed arteries. It is like building a bridge over a river.


Two types of bridges

There are two kinds of bridging, which depend on the conduct used to pass over the blockage.

• Venous bypasses

• Arterial bypasses


Venous bypasses

Coronary artery bypasses are done with sections of veins taken from the leg and then used to build a bridge over the narrowed heart artery.

The blood in the leg that used these veins to return to the heart borrows other veins close by to continue their journey to the heart.


Arterial bypass

Arterial bypasses are made with sections of arteries.

The most commonly used artery is the left internal mammary artery, which is attached to the left inner side of the thorax below the breast.

The blood that used the artery is redirected to other arteries without any consequence.


Number of bypasses

The number of bypasses to be done depends on the number of arteries blocked on the heart. Blockages in the arteries are visualized during an examination that aims to "color" the arteries of the heart; coronary angiography.

From 1 to 3 bypasses are commonly done, but it may rise to 6 or more.


The surgery

Bypass surgery is performed under general anesthesia. The surgeon accesses your heart through an opening in the chest.

To reach the heart, an opening of the rib cage is made. This opening must allow the surgeon to do the necessary work.



We see the heart beat

Once this opening is done, we see the heart moving between the two lungs. We see it slip into its pocket, the pericardium.

The pericardium is open and the arteries of the heart are accessible.


The arteries to be repaired are identified

The surgeon can then identify the bypasses to be performed and proceed to the sampling of the vascular conducts (vein and artery) for the bypasses.


We prepare the conducts for the bridges

In the vast majority of cases, a vein in one leg and the left internal mammary artery are used to make the bridge over narrowed arteries in the heart.

It is possible, in some cases, to use other veins from the thigh or back of the leg, or other arteries such as the right internal mammary artery on the right edge of the right chest or a radial artery that is found in the forearm towards the wrist. It is this artery on which one feels the pulse in the wrist.


Two possible operative techniques

Currently, there are two ways to do bypass surgeries.

• A first way allows to operate the heart while the contractions are stopped.

• A second possibility is to operate the heart while it is still beating.


Technique without cardiac contraction

The first way requires the use of a pump to ensure extracorporeal circulation (artificial heart and lungs).

The heart is cooled to decrease oxygen requirements. Once cooled, it stops beating. He is like a hibernating bear.

The blood short-circuits the heart through pipes connected between it and the pump.

This device allows the blood to be oxygenated, substituting the lungs during the operation. Once the blood is oxygenated, the pump returns to the aorta. The circulation is maintained by the pump instead of the heart.


Beating heart technique

The second way allows the surgeon to perform bypass surgery while the heart continues de beat.

The circulation pump is not necessary.

However, as the heart constantly moves, the area where the bypass is done is immobilized with an instrument to stabilize the region of the heart to operate.


Small pipes sewn by a very fine thread

To stitch the bypasses, the surgeon uses an operating microscope (magnifying glasses) placed on his glasses in order to clearly see the bypasses to be made as they are small and the thread used is as thin as human hair.


Verification of the blood passage in the bypasses

When the bypass is completed, the surgeon uses a special device to check if the bypass fonctions and concludes if the operation was successful.


If it has cooled, warm the heart

In the event that the surgery is done with the heart-lung pump, it is time to put the heart back to work. The pre-cooled heart is "warmed up" to about 22 degrees, and it gradually resumes its work under the meticulous eye of the surgeon and the assistance of the health professional controlling the pump.


Temporary heart stimulator

Before closing the chest, temporary pacemaker wires will be placed on the heart to speed up the rhythm as needed. Chest drains (pipes) will be installed around the heart and lungs to drain air and blood.


And we close it all

The wounds will then be closed with steel pins to solidify the sternum (thorax) and resorbable sutures (melting stitches) or metal staples will be placed on the skin.


Intensive care surveillance

The patient is then transferred to a bed in the intensive care unit and wakes up a few hours later.


Recovery begins

A certain euphoria accompanies the first hours after the surgery. Human nature being what it is, the patient is happy to be alive and the surgery is behind him ...

The next day is often very different. The energy level is low. A certain depression can settle for one or two days ... then, the energy returns and the postoperative progress follows.


Before the operation:

Several tests must be done before having coronary bypass surgery.

Your family doctor and cardiologist will be able to inform you.

There must be a medical examination, an electrocardiogram, an X-ray of the lungs and different blood tests.

The decision on the need for a bypass operation is based on the results of a coronary angiography. This examination consists of coloring the arteries of the heart, see the blockages and consequently those to be repaired.

Your doctor may ask for further tests.

The hospital or cardiac surgery secretary will contact you to arrange the details, and schedule a day for the operation.

Most hospitals that offer cardiac surgery have a pre-admission service. You may have to go for a few exams and forms.

Do not forget to bring a list of your medications. The surgical team must check this list because some of these will have to be stopped before the operation.


Admission and last preparations:

Admissions for the operation are usually done the day before the operation.

Again bring all your medications.


With an empty stomach

The patient must fast as of midnight the night before the surgery. A little water is allowed for taking medication as directed by the medical team.


On the way to the operating room

Before entering the operating room, the patient must wear a hospital gown and remove underwear, socks, jewelry, watch and nail polish.

It is best to leave any valuables at home. Personal items normally follow the patient to the different areas of the hospital during his or her stay. It is therefore safer to keep them at home.


Advice before leaving home

A tip: bring only the bare minimum to the hospital. You will therefore eliminate the risk of losing your cellphone, a computer, a radio or other electronic device.


Duration and operating risks:

It takes an average of 30 to 60 minutes for the anesthesia team to prepare the patient, and the coronary bypass surgery lasts on average between 2 and 4 hours.

When the surgery is over, the patient is transferred to intensive care for usually one night.


The risks of surgery

The most serious risks associated with coronary artery bypass surgery occur on average from 1 to 2% of the cases.


A commonly performed surgery

It is one of the most practiced surgeries in the world. It is very safe and the operating techniques are constantly evolving.


The lowest, most serious risks

Among the most serious risks are death, strokes (heart attack or paralysis), or coma. Fortunately, they are rare, but can occur during, immediately after surgery or even a few days later.


And the other risks

Other less serious risks include cardiac arrhythmias (heart beating too fast or too slow) that occur in one-third of these patients, the need for blood transfusions, infections and kidney problems to name the most important ones.

Depending on your age or the presence of other important diseases, the risks may be greater. There are never two identical patients, each having a different medical history: ask your doctor to explain as needed.

Once the presentation of these risks and benefits of bypass surgery is completed, a consent sheet must be signed by the patient.


Recovery and progressive return to everyday life:

When everything goes well, the average patient will spend one day in the intensive care unit and then transfer to the cardiac surgery department.


Departure for the house

After a few days, the patient will be transferred to his local hospital or sent home. He or she will have been in the hospital for approximately 5 to 7 days after the operation.


How to take care of the wounds

The indications for caring for the wounds will be given to the patient by the nurses, and the list of medications to be taken will be updated before departure.


Medication at home

It is therefore important to understand what medications to take because the doctor may have changed your list. As a matter of fact, some medications may have been added, modified or stopped.

In addition, pain killers are prescribed and help your recovery.

When you leave the hospital, go directly to your pharmacist with your new prescription.

It is normal to have a little pain in the wounds, especially the sternum, and to feel some fatigue for a few days.


Opinions and recommendations

If there is a significant change in your general condition or in a wound, such as redness, swelling or discharge of blood or pus, promptly notify the treatment team or even report to the closest emergency room.

You have to take your temperature to make sure it is normal, and follow the advice given by the team before you left.


Follow-up with your surgeon

An appointment with the cardiac surgeon is usually scheduled 3 months after the operation for a follow-up.

Once again, bring the list of your medications and all important documents with you such as notes from other health professionals, test results or any information deemed relevant.


Follow up with your doctors

A follow-up with your cardiologist, your internist or with your family doctor should be scheduled.

They will do the long-term follow-up and adjust the medication as needed.


Back to work

Your return to work usually happens 3 months after the operation. The surgeon must confirm this return at the appointment 3 months after the operation.


Driving a car

Driving is allowed 6 weeks after the operation.


Do not leave questions without answers

Do not hesitate to ask questions to your doctor and the treatment team. Write them on a sheet of paper as they come to your mind. This way, you will not forget them.

Related articles


13 January 2018


Most commonly, angina takes the form of chest pain that radiates towards the jaw and the left arm. It can also be felt in many other ways, especially as back pain, or only in the jaw or the left arm.

View more

06 January 2018


The heart is a muscle fuelled by oxygen, which is delivered by the coronary arteries. Any reduction in the oxygen supply can have serious and sometimes irreversible consequences for the heart.

View more


In the case where the clot partially obstructs the coronary artery or one of its branches, the cardiac muscle it feeds still receives oxygen, but in potentially limited quantity. This situation is unstable, this is unstable angina, now called NSTEMI.

View more


In the case where a clot completely obstructs a coronary artery, the underlying cardiac muscle suffers and it is painful. It is a “heart attack”. This is a medical emergency!

View more


Coronary angiography is an examination that allows the professional to visualize the arteries of the heart known as the coronaries. As a result, it is possible to demonstrate the presence of obstructions like the presence of atheromatous plaques in these arteries.

View more


The majority of chest pains often remain without identifiable causes. We must make sure that the heart is not the source of this pain. If you have thoracic discomfort, and it worries you, speak to a doctor.

View more


Everyone talks about cholesterol, the good one and the bad one that causes clogging of the arteries, but very few people know the vital role of cholesterol in the human body.

View more


The heart is a muscle that relies on oxygen to work properly. The delivery of this invaluable fuel is provided by the coronary arteries.

View more


Risk factors for the development of plaques include age, male gender, hypercholesterolemia, diabetes, high blood pressure, smoking and obesity.

View more