Stent or bypass surgery?

This decision is made by a heart team in which a cardiologist and a heart surgeon work together. The anatomy of your arteries and how complex the narrowings are, other conditions such as diabetes, and your general health are all considered together. Guidelines generally regard bypass surgery as the preferred option for patients at low surgical risk, because the chance of a later heart attack or another procedure is lower. For patients whose artery anatomy is not very complex, a stent can be considered instead of bypass as a less invasive option. The options are explained to you with their possible benefits and risks, and the decision is made together with you.

Why is intravascular imaging used?

An angiogram shows the inside of the artery only as a dye-filled outline, like a shadow. Intravascular imaging, by contrast, views the artery from the inside. This allows the true size of the left main artery to be measured, a stent of the right size to be chosen, and a check that the stent is fully expanded and sits well against the artery wall. Current guidelines recommend that stenting in complex areas such as the left main artery is guided by intravascular imaging.

In case of sudden chest pain, shortness of breath or fainting, call 112.

Stenting for left main coronary artery narrowing

The left main coronary artery is the short main trunk that supplies most of the heart's left ventricle. A narrowing here can be treated with bypass surgery or, in suitable patients, with a balloon and a stent; a heart team decides which is more suitable for you.

What is it?

The left main coronary artery is a short main trunk that arises from the aorta, the body's main artery. After a short distance it divides into two large branches: the left anterior descending artery (LAD) and the circumflex artery (the branch that runs around the side and back of the heart). Together these branches supply most of the left ventricle, the heart's main pumping chamber. This is why a narrowing in the left main artery, unlike a narrowing in a single branch, affects the blood flow to a large area of the heart. It can cause chest pain or breathlessness on exertion; sometimes it is found on tests done for another reason. When there is a significant narrowing in the left main artery, treating the narrowing, in addition to medication, is usually recommended. The narrowing can be treated in two ways: opening the artery with a balloon and a stent (percutaneous coronary intervention, PCI) or bypass surgery. Which one is more suitable depends on how complex your artery anatomy is, whether other arteries are also narrowed, other conditions such as diabetes, and your general health. This decision is made by a heart team in which a cardiologist and a heart surgeon work together, and your own preference is also taken into account. Prof. Dr. Barış Kılıçaslan performs left main coronary stenting in his clinical practice.

Who is it for?

Patients found to have a significant narrowing in the left main artery; these patients often have symptoms such as chest pain or breathlessness, or signs on tests that the heart muscle is short of blood (ischaemia)
In patients whose artery anatomy is of low or intermediate complexity, a stent can be an alternative to bypass surgery
Diabetes, widespread narrowings in several arteries or complex artery anatomy are factors that favour bypass surgery, while a high surgical risk can favour a stent. The decision is made by a heart team that includes a heart surgeon

Before the procedure

A left main narrowing is usually found with coronary angiography (often simply called an angiogram). If the importance of the narrowing is not clear on the angiogram, its effect on blood flow can be measured with a thin pressure wire passed into the artery. If needed, intravascular imaging, usually intravascular ultrasound (IVUS), is used to measure the size of the artery and the extent of the narrowing. These findings are used by the heart team when weighing up stenting and bypass surgery. Before the procedure you will have an examination, an ECG and blood tests. Your kidney function is checked with a blood test, because the dye used in the procedure (contrast agent) is cleared by the kidneys. Tell your doctor beforehand if you have ever had an allergy to contrast dye, or if you have kidney disease or diabetes. Your medications, especially blood thinners, are reviewed with your doctor and adjusted if needed; do not stop any medication on your own.

How is it done?

Access site: The wrist or groin is numbed with local anaesthetic and a thin sheath is placed in the artery. Which access site is used depends on the anatomy of your arteries and the planned technique. Under X-ray guidance, the catheter is advanced to the opening of the left main artery.
Intravascular imaging: A fine wire is passed beyond the narrowing. A small imaging catheter is advanced over this wire to view the artery from the inside. The size of the artery and the length and structure of the narrowing are measured, so that a stent of the right size can be chosen.
Balloon and stent: The narrowed segment is prepared with a balloon and a stent is placed. Because the left main artery divides into two branches, either a single-stent or a two-stent technique is chosen for this branching point, depending on the anatomy. With the single-stent technique, the side branch is treated further only if needed.
Optimising the stent: Because the left main artery is wider than the branches it divides into, the part of the stent that lies in the left main is expanded with a larger balloon so that it fits the artery. Intravascular imaging is repeated to check that the stent is fully expanded and sits well against the artery wall.
Check and closure: Dye is injected to image the result and to check that blood flows well into both branches. The catheters are removed and the access site is closed or compressed with a pressure band.

Recovery

After a stent is placed, two medicines that prevent blood clots (dual antiplatelet therapy) are taken together for a period. After a planned procedure this is usually six months; depending on your bleeding and clotting risk, your doctor may recommend a shorter or longer period. After a procedure done during a heart attack, this period is usually longer. Once this period is over, most patients continue long term with a single medicine. It is very important to take these medicines without missing doses; do not stop them without talking to your doctor, even before another treatment or a dental procedure. Regular check-ups after the procedure are important; your symptoms and medicines are reviewed at these visits. Contact your doctor if chest pain or breathlessness comes back. A stent opens the narrowing, but it does not remove the underlying artery disease. Keeping cholesterol, blood pressure and blood sugar under control, stopping smoking, regular activity and a healthy diet help slow the disease down.

Risks

Like every interventional procedure, left main stenting has risks. These include bleeding or bruising at the access site, an allergic reaction to the contrast dye, a decline in kidney function and heart rhythm disturbances. Because the left main artery divides into two large branches, the opening of one branch can become narrowed while the stent is placed; that branch may then also need a balloon or a second stent. Rarely, a clot can form inside the stent, and over time the artery can also narrow again inside the stent. Because the left main artery supplies a large area of the heart, the effect of these problems can be greater. Less commonly, serious complications such as a heart attack, a stroke or the need for emergency surgery can occur. This is why the procedure and the follow-up afterwards are planned carefully. Your possible benefits and risks are explained in detail by your doctor, according to your personal situation, at the consultation before the procedure.

Frequently asked questions

Stent or bypass surgery? This decision is made by a heart team in which a cardiologist and a heart surgeon work together. The anatomy of your arteries and how complex the narrowings are, other conditions such as diabetes, and your general health are all considered together. Guidelines generally regard bypass surgery as the preferred option for patients at low surgical risk, because the chance of a later heart attack or another procedure is lower. For patients whose artery anatomy is not very complex, a stent can be considered instead of bypass as a less invasive option. The options are explained to you with their possible benefits and risks, and the decision is made together with you.
Why is intravascular imaging used? An angiogram shows the inside of the artery only as a dye-filled outline, like a shadow. Intravascular imaging, by contrast, views the artery from the inside. This allows the true size of the left main artery to be measured, a stent of the right size to be chosen, and a check that the stent is fully expanded and sits well against the artery wall. Current guidelines recommend that stenting in complex areas such as the left main artery is guided by intravascular imaging.
How long will I need to take medicines after the procedure? After a planned procedure, two anti-clotting medicines are usually taken together for six months. After a procedure done during a heart attack, this period is usually longer. Once this period is over, most patients continue long term with a single medicine. Your doctor decides how long, based on your bleeding and clotting risk; do not stop your medicines without talking to your doctor.

Medical content reviewed and approved by Prof. Dr. Barış Kılıçaslan. Last updated: 4 October 2026. Editor: Baran Zeydan (info@clinixcrm.app).