Pulmonary thromboendarterectomy is a complex open-heart operation used to treat chronic thromboembolic pulmonary hypertension (CTEPH), a rare but serious condition in which blood clots form in the pulmonary (lung) arteries, restricting or blocking blood flow, thereby leading to high blood pressure in these arteries. CTEPH can cause severe shortness of breath and fatigue. Without treatment, the condition can lead to heart failure and death, making a timely diagnosis and treatment extremely important.

Pulmonary thromboendarterectomy, an operation performed at only a few centers across the United States, involves the surgical removal of those blood clots. In most cases, the procedure results in an immediate, long-lasting stabilization of blood pressure in the pulmonary arteries, as well as improved blood flow from the heart to the lungs. The procedure relieves symptoms and improves quality of life for most people who undergo it. It is the only treatment that can cure CTEPH.

CTEPH is a rare condition in which long-term—or chronic—blood clots form in the lungs’ arteries. It starts with an acute pulmonary embolism, which is a blockage in a pulmonary artery, usually from a blood clot. Although these blood clots often break apart on their own, in some cases an acute pulmonary embolism requires treatment, such as blood thinners or clot-busting drugs, to dissolve the clots and restore normal blood flow.

In rare cases, the blood clots from pulmonary embolisms remain intact in the pulmonary arteries for a long time. The chronic blood clots cause scarring and narrowing of the pulmonary arteries, resulting in a reduction of blood flow through—and an increase in blood pressure in—these blood vessels. This is known as CTEPH.

The pulmonary arteries play an essential role in blood circulation. In a healthy individual, they deliver blood from the heart to the lungs, picking up oxygen along the way. The oxygenated blood then returns to the heart, which pumps it to the rest of the body.

In a person with CTEPH, the narrowing of the pulmonary arteries causes the blood pressure in them to rise—called pulmonary hypertension. (Note that pulmonary hypertension refers only to the blood pressure in the pulmonary arteries; it is different than the blood pressure that health care providers measure with a blood pressure cuff around your upper arm.)

The increased blood pressure makes it harder for the heart to pump blood to the lungs. As a result, the heart—specifically its right side—must pump harder than usual to keep up with the body’s needs. Over time, this can lead to right-sided heart failure.

Pulmonary thromboendarterectomy, sometimes called pulmonary endarterectomy, is an open-heart surgical procedure in which chronic blood clots and scar tissue are removed from the pulmonary arteries to restore normal blood flow.

At the start of the procedure, the patient, who is under general anesthesia, is connected to a ventilator for breathing support. The surgeon makes an incision along the patient’s chest and then divides the breastbone to gain access to the heart and lungs. The patient is then connected to a heart-lung bypass machine, which takes over the function of the heart and lungs during the procedure. Next, the surgical team stops the heart and cools the body to stop blood circulation.

At this point, the surgeon opens the affected arteries in the lungs and surgically removes the blood clots and scar tissue. Throughout the procedure, circulation is restarted every 20 minutes, then stopped while the surgeon removes blood clots and scar tissue.

After the blood clots and scar tissue have been removed, the arteries are sutured back together. The patient’s body is then gradually warmed to a normal temperature, and the patient is weaned off the heart-lung bypass machine.

After the procedure, patients stay in the intensive care unit (ICU) for two to three days, where they are closely monitored. For the first day or two after surgery, they remain connected to a ventilator. Patients will also have tubes in their chests to help drain fluids for a few days.

Following the surgery, patients resume taking the blood thinners they were on before the operation, which they must continue for the rest of their lives to prevent recurrent blood clots.

After getting discharged from the ICU, patients typically spend another 7 to 10 days recovering in the hospital. During that time, several tests will be done to check heart and lung function and assess oxygen levels. For the first several months after surgery, regular doctor visits are vital to monitor recovery and heart and lung function.

All patients who are diagnosed with CTEPH—even those with mild symptoms—are evaluated by a multidisciplinary team of cardiac surgeons, pulmonologists, and cardiologists to determine whether pulmonary thromboendarterectomy is the appropriate treatment for them.

Tests will be done to locate the blood clots in the arteries to ensure they are accessible and can be safely removed during surgery. Doctors will also evaluate how likely the surgery is to reduce symptoms and improve blood flow. Patients will need to be healthy enough to undergo the procedure.

While pulmonary thromboendarterectomy is the most effective treatment for CTEPH, other treatments are available for those who cannot have the surgery. These other treatments include:

• Blood thinners

• Medications to relax the blood vessels to improve blood flow (called pulmonary arterial vasodilators)

• Pulmonary rehabilitation, a guided program designed to improve breathing and reduce symptoms

• Balloon pulmonary angioplasty (BPA), a procedure that uses balloons to open narrowed blood vessels

Like all surgical procedures, pulmonary thromboendarterectomy comes with certain risks. While rare, they may include:

• Heart arrhythmia

• Bleeding

• Infection of the surgical wound

• Pneumonia

• Pulmonary edema (fluid buildup in the lungs)

• Collapsed lung

• Ongoing pulmonary hypertension

Most people who undergo pulmonary thromboendarterectomy have good outcomes. Symptoms typically improve immediately after surgery. The procedure can improve blood flow and help the heart pump more blood. Studies have found that these benefits are long-lasting and that following the procedure, new pulmonary blood clots are rare, especially among patients who continue taking their blood thinning medications as directed.

Still, it’s important for people who have had pulmonary thromboendarterectomy to see their doctor regularly to monitor symptoms and the health of their heart and lungs.

“At Yale, it is our privilege to provide this surgical option for patients with CTEPH, as we are the only center in the state of Connecticut providing this surgery,” says Prashanth Vallabhajosyula, MD, MS, director of the Yale Pulmonary Thromboendarterectomy Program.

“Previously, patients were leaving the state to find care elsewhere. Pulmonary thromboendarterectomy is one of the most complex cardiopulmonary operations we perform. We have a multidisciplinary team, comprising cardiothoracic surgeons, pulmonologists, and cardiologists, together making decisions on optimal care for CTEPH patients. This approach has enabled us to maintain excellent outcomes and provide comprehensive care to our patients.”