If my artery is completely blocked, how does my heart get blood?

Side branches (collateral vessels) that develop over time carry some blood to the area beyond the blockage. This may be enough at rest, but it is often not enough during exertion, and symptoms can appear.

Does every blocked artery need to be opened?

No. The decision depends on your symptoms, whether the heart muscle supplied by the blocked artery is alive, and signs of reduced blood supply on tests. Some patients who have no symptoms, or whose symptoms are relieved by medication, may continue with medication.

Can a blocked artery always be opened?

No. Some blockages cannot be crossed with a wire. In that case options such as medication, bypass surgery or another attempt at a later date are discussed with your doctor.

Why does the procedure take longer?

Finding a safe path through a hardened blockage takes care and time. Sometimes imaging from both sides and different wire techniques are needed. For this reason the procedure can take longer than a standard stent procedure.

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

Opening a chronically blocked heart artery (CTO)

A heart artery that has been completely blocked for a long time is reopened, where possible, using special wires and catheters. The aim is to reduce symptoms such as chest pain and breathlessness.

What is it?

A chronic total occlusion (CTO) is when a coronary artery has been completely blocked for a long time, usually for more than 3 months. Over time the blocked segment hardens and can turn into fibrous, calcified tissue. Even though the artery is blocked, the heart muscle often does not lose its blood supply completely. Over time, small side branches (collateral vessels) can develop around the heart and carry blood from neighbouring arteries to the area beyond the blockage. However, these side branches often cannot carry enough blood during exertion, which can cause chest pain or breathlessness. In a CTO procedure, the blocked segment is crossed with special thin wires and microcatheters. The wire is usually advanced in the normal direction of blood flow, from the front (antegrade). If this route is not suitable, the far side of the blockage may be reached through the side branches and crossed from behind (retrograde). Once the wire is across, the artery is widened with a balloon and kept open with a stent. Prof. Dr. Barış Kılıçaslan's areas of work include complex coronary interventions, among them chronic total occlusions (CTO).

Who is it for?

Patients with a long-standing blocked heart artery whose symptoms, such as chest pain or breathlessness, continue despite medication
Patients whose tests show that the heart muscle supplied by the blocked artery is still alive (viable) and short of blood (ischaemia)
The decision is made by looking together at your symptoms, viability and ischaemia tests, the anatomy of your arteries and your general health. For some patients medication or bypass surgery may be more appropriate

Before the procedure

Before the procedure is planned, your symptoms are assessed in detail. Whether the heart muscle supplied by the blocked artery is alive, and how short of blood it is, may be investigated with tests such as an exercise test, stress echocardiography, a nuclear scan or cardiac MRI. Your previous angiogram images are studied in detail to plan the procedure. Your kidney function is checked with a blood test. 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; do not stop any medication on your own.

How is it done?

Access sites: Thin sheaths are placed in the artery at the wrist or groin. Two access sites may be needed so that both sides of the blockage can be seen at the same time.
Imaging: Dye is injected to show the length and structure of the blockage and the artery beyond it.
Crossing the blockage: Special thin wires, supported by a microcatheter, are advanced through the blockage from the front (antegrade). If this route is not suitable, the blockage may be crossed from behind (retrograde) through the side branches.
Balloon and stent: Once the wire is across the blockage, the artery is widened with a balloon and kept open with a stent.
Check and closure: The result is checked with imaging. The catheters are removed and the access sites are closed or compressed with a pressure band.

Recovery

After the procedure you stay under observation for a while, and the access sites and your heart rhythm are monitored. If the groin was used, you may be asked to stay in bed for a few hours. The timing of discharge depends on your general condition. If a stent was placed, it is very important to take the anti-clotting medicines without missing doses for as long as your doctor recommends. Do not stop them without talking to your doctor. Changes in your symptoms and the condition of the artery are followed with regular check-ups. Keeping cholesterol, blood pressure and blood sugar under control, stopping smoking and regular activity help slow the progression of artery disease.

Risks

Like every interventional procedure, a CTO procedure has risks. These include bleeding or bruising at the access sites, an allergic reaction to the contrast dye, a decline in kidney function, injury to the artery and heart rhythm disturbances. Because the procedure can take longer and may need more dye and X-ray, the effects on the kidneys and skin are given extra attention. Rarely, serious complications can occur, such as a tear in the heart artery, blood collecting around the heart, a heart attack or a stroke. Your doctor will explain the possible benefits and risks for you in detail, based on your personal situation, before the procedure.

Frequently asked questions

If my artery is completely blocked, how does my heart get blood? Side branches (collateral vessels) that develop over time carry some blood to the area beyond the blockage. This may be enough at rest, but it is often not enough during exertion, and symptoms can appear.
Does every blocked artery need to be opened? No. The decision depends on your symptoms, whether the heart muscle supplied by the blocked artery is alive, and signs of reduced blood supply on tests. Some patients who have no symptoms, or whose symptoms are relieved by medication, may continue with medication.
Can a blocked artery always be opened? No. Some blockages cannot be crossed with a wire. In that case options such as medication, bypass surgery or another attempt at a later date are discussed with your doctor.
Why does the procedure take longer? Finding a safe path through a hardened blockage takes care and time. Sometimes imaging from both sides and different wire techniques are needed. For this reason the procedure can take longer than a standard stent procedure.

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