Diagnosis, Treatment, and Management of Orthotopic Liver Transplant Candidates With Portopulmonary Hypertension

摘要

Portopulmonary hypertension (POPH) is seen in 5-8% of orthotopic liver transplantation (OLT) candidates and has significant implications for clinical outcomes. POPH is characterized by vasoconstriction and remodeling of the pulmonary vasculature. It is exacerbated by the hyperdynamic circulation that is common in advanced liver disease. Screening all OLT candidates with transthoracic echocardiography to assess pulmonary pressures and right ventricular function is crucial, as clinical symptoms alone are not reliable. Any significant right ventricular dysfunction or dilatation along with an elevation in estimated pulmonary pressures usually triggers further investigation with right heart catheterization. The mainstays of therapy of POPH are vasodilators that are used in pulmonary arterial hypertension. They include monotherapy or combination therapy with prostanoids, endothelin receptor antagonists, and phosphodiesterase-5 inhibitors/guanylate cyclase stimulator. Limited evidence from smaller studies and case series suggests that a timely diagnosis of POPH and the early initiation of treatment improve patient outcomes, whether or not OLT is ultimately undertaken. Given the historically high perioperative mortality rate of more than 35%, POPH remains a contraindication to OLT unless it is treated and responsive to vasodilator therapy. We review the current literature and International Liver Transplant Society practice guidelines (2016) for the latest in understanding POPH, its pathogenesis, diagnosis, modern pharmacological treatment, indications, and contraindications for OLT, as well as perioperative management.