Images in Cardiovascular Medicine Long-Term Survivor With Pulmonary Veno-Occlusive Disease

A 51-year-old woman was admitted to our hospital because of shortness of breath. Her mean pulmonary artery pressure was 52 mm Hg, and idiopathic pulmonary artery hypertension was diagnosed. She received beraprost sodium, imidapril, warfarin, and home-based oxygen therapy. At 67 years of age, dyspnea on effort worsened to New York Heart Association functional class III. The plasma level of brain natriuretic peptide was 57 pg/mL. Transthoracic echocardiography showed an enlarged right ventricle, severe tricuspid regurgitation, and a large pericardial effusion. At 68 years of age, she was urgently admitted to our hospital because of severe dyspnea at rest. A chest x-ray showed bilateral pulmonary artery enlargement (Figure 1). Computed tomography of the chest revealed that both main bronchi were compressed by the pulmonary artery aneurysms, with no mural thrombus in the pulmonary arteries (Figure 2). The diameters of the right and left main pulmonary arteries were 69.8 and 55.5 mm, respectively. Bronchoscopy during mechanical ventilation confirmed nearly complete extrinsic compression of the left and right main stem bronchi without positive airway pressure (Figure 3). On hospital day 3, continuous administration of epoprostenol was begun. She received continuous positive airway pressure by mechanical ventilation. Because the pulmonary hypertension had been worsening, treatment with imatinib (50 mg/d) was started on hospital day 69. However, the patient died of recurrent obstructive pneumonia 12 months after admission, and autopsy was conducted. Histopathologically, pulmonary arteries/arterioles revealed dilatation, and alveolar walls were thickened with increased capillaries, deposition of hemosiderin, and loose fibrosis (Figure 4a and 4b). However, severe concentric medial hypertrophy, intimal fibrous thickening, and plexiform lesion, which are characteristic findings of idiopathic pulmonary artery hypertension, were not found in the pulmonary arteries/ arterioles (Figure 4a and 4b). Normal pulmonary veins in the thickened interlobular septa mostly disappeared, and capillaries increased instead (Figure 4c and 4d). The pulmonary veins might have been destroyed during the prolonged disease course. Enlarged bronchial veins (Figure 5) probably served as collateral vessels of the occluded pulmonary veins. On reviewing the computed tomography scans obtained at the patient’s initial admission, we found groundglass opacities and smooth thickened intralobular septa, which are characteristic features of pulmonary venoocclusive disease (PVOD; Figure 6).