Techniques and outcomes of pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension

Abstract

Cardiopulmonary function in patients with chronic thromboembolic pulmonary hypertension can almost be normalized by pulmonary endarterectomy. The procedure involves the removal of organized and incorporated fibrous obstructive tissue from the pulmonary arteries during circulatory arrest under deep hypothermia. Mortality rates reported for patients who have undergone pulmonary endarterectomy range from 4 to 24%. The operation is not an embolectomy but a true endarterectomy. After proximal intrapericardial pulmonary artery incision, the correct endarterectomy plane is established and circumferentially followed down to the lobar, segmental, and sometimes subsegmental pulmonary artery branches in each lobe. Completion of the endarterectomy procedure in one lung is usually possible within a 15-min period of circulatory arrest. This is followed by reperfusion and another period of circulatory arrest for the endarterectomy on the contralateral side. Additional cardiac procedures can be performed after arteriotomy closure, during the rewarming period, if necessary. The outcomes with regard to functional status, quality of life, hemodynamics, right-ventricular function, and gas exchange are very favorable. After surgery, significant and persistent decreases of pulmonary artery pressures and pulmonary vascular resistance are observed in a large majority of patients. Cardiac output is increased and right-heart function is persistently improved. Postoperative management of patients undergoing pulmonary endarterectomy can be challenging. Important complications are persistent pulmonary arterial hypertension due to inadequate endarterectomy or significant secondary vasculopathy, and reperfusion edema in the endarterectomized parts of the lung. Adequate postoperative care is therefore essential. Preoperative hemodynamic severity and the site of anatomic obstruction are believed to be key predictors of postoperative outcome.