Structural and pathologic changes in the lung vasculature in chronic liver disease

The abnormal vascular pathways found in the hepatopulmonary syndrome are portapulmonary, shunting passage around alveoli through pleural and hilar blood vessels and intrapulmonary vascular dilatations. Although there is evidence for each of these, dilatation of alveolar capillaries appears to be the most likely cause of arterial hypoxemia. Pulmonary hypertension may occur in chronic liver diseases even without arterial hypoxemia, but this is rare. The hypertensive pulmonary vascular disease is pulmonary arteriopathy with plexiform lesions.