**Abstract**

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare consequence of acute or chronic pulmonary embolism. Pulmonary endarterectomy (PEA) is the gold standard treatment: expert centers are able to offer this challenging procedure with low in-hospital mortality, excellent hemodynamic results, and significant improvement in exercise tolerance and quality of life. Despite careful preoperative selection and increasing technical experience in PEA, some patients may suffer from life-threatening complications requiring extracorporeal life support (ECLS). ECLS is necessary in case of heart failure, respiratory failure, or both. According to different indications and timing, cardiopulmonary failure after PEA should be managed with a tailored approach: veno-venous or veno-arterial support, and central or peripheral cannulation. In the present chapter, causes, management strategies, and outcomes of perioperative ECLS for PEA are discussed.

**Keywords:** extracorporeal life support (ECLS), pulmonary endarterectomy (PEA), chronic thromboembolic pulmonary hypertension (CTEPH), surgical strategies, outcomes of perioperative ECLS

## **1. Introduction**

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare consequence of acute or chronic pulmonary embolism (PE). It has been estimated that it occurs in about 3% of acute PE survivors [1]. CTEPH has unique pathogenesis and a potentially curative surgical treatment other than pulmonary transplantation: for these reasons it represents the 4th group of pulmonary hypertensions (PH), according to the Nice classification [2]. CTEPH has been defined as "dual compartments vascular disease" because the occlusive disease due to fibrotic organization of thromboembolic lesions is associated with arterial wall hypertrophy and vasospasm

of non-occluded segments, which leads to progressive development of PH and to right ventricular (RV) dysfunction [3–5]. Diagnosis and clinical management of CTEPH requires a dedicated multidisciplinary high-skilled team that could offer the entire range of therapeutical options: from medical therapy to balloon pulmonary angioplasty (BPA) and pulmonary endarterectomy (PEA) [6]. PEA is the treatment of choice in CTEPH [7]: technically, the operation is performed through full median sternotomy, cardiopulmonary bypass, myocardial arrest and myocardial protection, intermittent deep hypothermic circulatory arrest (DHCA). Patients should be carefully selected in order to balance surgical risk and optimal outcomes. Preoperative anatomical and hemodynamic information are crucial for preoperative risk stratification and surgical feasibility assessment. Nowadays, expert centers are able to offer this challenging procedure with low in-hospital mortality (<5%), excellent hemodynamic results, and significant improvement in exercise tolerance and quality of life [8].

Nevertheless, despite careful selection, some patients may suffer from life-threatening perioperative cardiorespiratory decompensation requiring extracorporeal life support (ECLS): in the present chapter, we are going to discuss causes, management strategies, and outcomes of perioperative ECLS for PEA.
