Pulmonary thromboendarterectomy (PTE) is an open heart surgery performed for chronic thromboembolic pulmonary hypertension (CTEPH). It is also sometimes called pulmonary endarterectomy (PEA). When blood clots in the lungs fail to resolve they can result in scarring in the blood vessels that leads to narrowing's and occlusions. This causes the blood pressure in the lungs to become elevated and can result in shortness of breath and heart failure. Surgery is performed to remove the scar causing these narrowing's and occlusions, restoring blood flow to the lungs. It can be helpful to alleviate the elevated blood pressure in the lungs and decrease symptoms of shortness of breath. The surgery is performed through a midline breastbone incision to gain access to the heart and with the assistance of the heart & lung bypass machine. With cooling of the body to protect the brain and other organs all blood flow is stopped for a brief period of time to allow complete removal of the scars deep into the lungs. This is called deep hypothermic circulatory arrest. Pulmonary thromboendarterectomy is the first line therapy for patients who are surgical candidates suffering from CTEPH. It is highly successful at improving debilitating symptoms and can reduce the risk of death related to heart failure from CTEPH.