[Surgical treatment in patients with chronic thromboembolic pulmonary hypertension]

Chronic thromboembolic pulmonary hypertension (CTEPH), which has a natural history with low long-term survival, is increasingly being diagnosed. Pulmonary endarterectomy (PE) is the treatment of choice, which can be curative. This technique consists of a true endarterectomy through a midline sternotomy with extracorporeal circulation and periods of hypothermic circulatory arrest. The following procedures should be performed before surgery: transesophageal echocardiogram, ventilation-perfusion pulmonary scintigraphy, right cardiac catheterism, pulmonary angiography and helicoidal computed tomography. Surgery should be indicated in CTEPH as soon as the diagnosis is made, before arteriopathy develops in the non-obstructed regions and CTEPH becomes severe. The only absolute contraindication to PE is the presence of obstructive or restrictive, severe underlying pulmonary disease. There are no inaccessible grades of embolic obstruction, or grade of right ventricular failure or level of pulmonary vascular resistance (PVR) that are inoperable. However, prognosis worsens with greater preoperative pulmonary pressure and greater postoperative PVR. Mortality in PE is 4-10% and the main cause of postoperative death is the persistence of high pulmonary pressures and PVR, followed by reperfusion edema, which requires prolongation of mechanical ventilation, the use of pulmonary vasodilators and, sometimes, extracorporeal respiratory support. In the long-term, 75% of patients undergoing PE show good functional results and half recover adequate exercise tolerance. Pulmonary transplantation is an alternative for patients unsuitable for PE, although with worse results and greater mortality.