Extracorporeal Life Support May Be Needed After Pulmonary Endarterectomy for CTEPH

Pulmonary endarterectomy (PEA) is an ideal treatment for patients with chronic thromboembolic pulmonary hypertension (CTEPH) and extracorporeal life support (ECLS) may be needed postoperatively, according to a review published in the Annals of Cardiothoracic Surgery.

Researchers conducted a literature review and reported on their own experiences performing154 PEA procedures at their institution from December 2003 to July 2018. Patients selected for PEA were discussed among a multidisciplinary team that included cardiologists, radiologists, and a heart surgeon. Patients were often referred with an imprecise diagnosis of PH without underlying etiology.

Angiography was performed to evaluate operability when a definitive diagnosis of CTEPH was made. Researchers adopted their own protocol of cardiopulmonary bypass management to avoid circulatory arrest and deep hypothermia, which was successfully performed in 49 cases. PEA was performed with intermittent periods of deep hypothermic circulatory arrest after this initial experience. Indications of extracorporeal membrane oxygenation (ECMO) were respiratory failure and hypercapnia when pulse oximetry was <90%, difference between mean systemic and pulmonary pressure of <20 mm Hg, evident echocardiographic signs of severe right ventricular dysfunction, and biochemical and clinical negative data like lactic acidosis or oliguria.

In 12.3% of the 154 patients, ECLS was needed. In cases performed with moderate hypothermia (n=44), ECMO was needed in 18.2%, and in 10% of cases performed with deep hypothermia and circulatory arrest. Weaning from ECLS was achieved in 10 patients with a survival rate of 70%. Three patients died after ECLS removal due to septic shock, multiple organ failure, and cardiorespiratory failure.

Complications following PEA included persistent PH with right ventricular and respiratory failure; the postoperative period is crucial as PH might progressively increase hours later due to reperfusion edema. When conventional medical and respiratory support are insufficient to interrupt increasing pulmonary vascular resistance, hypoxia, right ventricular failure, and low cardiac output, ECLS is a good option.

The researchers also proposed a new radiologic score to identify patients with a higher risk for less favorable response to surgery and ECLS, which works by correlating the patient’s computed tomography scan and hemodynamic data. The researchers agreed with the literature stating that patients requiring ECLS can be grouped accordingly: those with proximal occlusion and very good surgical results that suffer massive parenchymal edema due to a large reperfused territory, patients with bad postoperative hemodynamic profile of right ventricular failure and distal occlusion, and patients with parenchymal bleeding secondary to technical problems and fragility of the denuded vessels and presence of areas of infarcted lung parenchyma.

The researchers agreed with previous findings that in patients with worse hemodynamic profiles and less accessible anatomy, newer techniques like balloon pulmonary angioplasty in tandem with medical management can be the therapeutic option with the best risk-benefit relationship.

Reference

Martin-Suarez S, Gliozzi G, Fiorentino M, et al. Role and management of extracorporeal life support after surgery of chronic thromboembolic pulmonary hypertension. Ann Cardiothorac Surg. 2019;8(1):84-92.