Pulmonary Thromboendarterectomy

I have CTEPH (chronic thromboembolic pulmonary hypertension) and have been told I may benefit from a pulmonary thromboendarterectomy. What is this?

A pulmonary thromboendarterectomy (PTE)* is a surgical procedure that removes chronic blood clots from the arteries in the lung. It is a highly specialized surgery that was developed at the University of California, San Diego and is now performed in select hospitals in the United States and other parts of the world.

Chronic blood clots can cause partial or complete blockage of arteries resulting in high blood pressure in the lungs, known as chronic thromboembolic pulmonary hypertension (CTEPH). Patients may develop CTEPH even without a history of blood clots or pulmonary embolism. These chronic blood clots form scars that adhere to the walls of the arteries. They cannot be dissolved with “clot busters” or suctioned out; they can only be removed surgically. For up to 2/3 of patients, removal of the blood clots through PTE surgery can potentially cure this type of pulmonary hypertension.

How do I know if I am a candidate for PTE surgery?

If you have pulmonary hypertension (high blood pressure in the pulmonary arteries) due to old, chronic blood clots in the lungs, you are a potential candidate for PTE surgery. Your doctors may run tests to determine if you could benefit from PTE surgery (visit the About CTEPH section to learn more). If you are a candidate for PTE, your expert CTEPH team may decide to insert an inferior vena cava (IVC) filter before surgery.

The IVC filter is a piece of wire mesh that is placed by a catheter through a vein in the neck or groin into the inferior vena cava, a large blood vessel in the abdomen that carries blood from the lower half of the body up to the heart and lungs. IVC filters are typically used to prevent new blood clots from reaching the lungs.

Please note: PTE surgery is a technically difficult procedure. Candidates should only be referred to centers where PTEs are performed by surgeons with extensive experience with this surgical technique.

What happens during PTE surgery?

Patients are generally taken to the operating room early in the morning. The anesthesia team puts the patient to sleep and then inserts an endotracheal tube into the lungs. This tube will connect the patient to the ventilator, the machine that will support the patient’s breathing during and after the surgery. Additional lines will be placed in the patient’s neck, wrist and groin for monitoring and administration of fluids and medications. This is also done while the patient is under general anesthesia.

Surgeons then make an incision in the center of the patient’s chest and the breast bone, the sternum, is divided so the surgeons can access the heart and lungs. The patient is placed on a heart-lung machine (cardiopulmonary bypass), a machine that will function as the patient’s heart and lungs during the surgery.

For a period of time during the surgery the cardiopulmonary bypass machine must be turned off so that the surgeons have an optimal view to remove the blood clots. To avoid organ damage to the patient when the heart-lung machine is paused and no blood is flowing through the patient’s body, patients are cooled down to 65 degrees Fahrenheit for this surgery. This is accomplished by cooling the blood as it passes through the bypass machine. Once the patient has been cooled appropriately, the surgeons carefully dissect the clots out of the pulmonary arteries.

Once the clots are removed, the patient is rewarmed to normal body temperature and then taken off the cardiopulmonary bypass machine. Several drains will be placed in the chest to allow drainage of extra fluid for several days following surgery. The chest is then closed and the patient is transported to the Intensive Care Unit (ICU). This procedure typically lasts all day with patients being brought to the ICU by mid to late afternoon.

What happens after surgery?

On arrival to the ICU patients are still sound asleep as a result of their anesthetic and will remain asleep that night. Patients will be assessed by their doctors each morning to see if they are medically ready to come off the ventilator (breathing machine). Once patients are ready to come off the ventilator, administration of sedatives is decreased and they will be asked to breathe on their own for a short period of time while receiving oxygen through their breathing tube. If they demonstrate they can do this successfully, the breathing tube is removed and the patient is placed on oxygen by mask or nasal cannula.

Patients will have drains in their chest for several days after surgery. Once the amount of drainage decreases, these drains will be removed. Patients typically get out of bed the day after they come off the ventilator and begin to walk with assistance the following day. Patients have a variable amount of pain following this procedure, but are provided pain medicine as needed. Blood thinners are resumed as soon as bleeding appears to be of minimal risk.

Once all tubes are removed, the patient is walking in the halls satisfactorily, and their oxygen needs are in an acceptable range, several post-operative studies are typically obtained. These include a V/Q scan, echocardiogram and an oxygen prescription study to determine supplemental oxygen needs. The V/Q scan will show the changes to the arteries after surgery and can be used as the patient’s new baseline to compare against follow-up tests. The echocardiogram will assess heart function after surgery and check that there are no significant fluid collections before patients go home.

What should I expect after discharge?

Most patients are well enough to travel home at the time of discharge from the hospital, although occasionally you may be asked to remain in the area near the hospital briefly for follow-up. Most people will require oxygen for several months following surgery, even if they did not need oxygen before surgery, while the lung recovers. Your local doctor can follow the oxygen levels and wean the oxygen as the lungs improve.

It takes several months to feel well again—it is, after all, a major operation!

Patients should walk, but they should not lift anything heavier than 5-10 pounds for eight weeks following surgery. This is to allow time for the sternum (breastbone) to heal.

Patients require lifelong anticoagulation (blood thinners) following surgery to prevent the blood clots from returning. Anticoagulation dosing is reviewed with patients prior to discharge. Most patients are treated with warfarin and will need their INR (international normalized ratio, or the rate at which your blood clots) monitored upon returning home.

A discharge summary describing the patient’s entire evaluation and surgery is generally sent to the patient’s referring doctor and to the patient. A copy of the post-operative V/Q scan will also be mailed to the referring doctor. Typically, patients should undergo repeat echocardiograms and V/Q scans at six and 12 months following surgery. These can be done at the patient’s local hospital.

What are the short-term and long-term outcomes of PTE?

The outcomes following PTE are quite favorable, and continue to improve. In-hospital mortality for experienced centers should not exceed 5-10%. Most patients feel better, have improved exercise capacity and significant improvement in their pulmonary artery pressures.

Despite surgery, approximately 10-15% of patients may exhibit persistent pulmonary hypertension, and may require PH-specific therapy. Even so, many of those patients also have improvement in symptoms and pulmonary artery pressures. A timely referral to an experienced center, prior to development of organ failure and weight loss, is critical in ensuring the best possible outcomes.

This article was originally written by Kim M. Kerr, MD, Professor of Clinical Medicine in the Division of Pulmonary & Critical Care Medicine at University of California, San Diego School of Medicine.

*Sometimes referred to as pulmonary endarterectomy (PEA)