Pulmonary Angiography: Arteriovenous Malformation and Pseudoaneurysm

Pulmonary arteriovenous malformations (PAVMs) are direct vascular communications between pulmonary arteries and veins which bypass capillary beds to create low-resistance, high-flow continuous intrapulmonary right-to-left shunts. These structural abnormalities are frequently congenital and commonly associated with hereditary hemorrhagic telangiectasia (HHT). PAVMs are often asymptomatic but can result in serious complications if left untreated. Physiologic consequences correlate with size of PAVM and degree of right-to-left shunting which can limit oxygenation and natural filtration by the lung. Patients may present with dyspnea, cyanosis, clubbing, or chest pain. Serious complications include paradoxical embolism resulting in brain abscess, stroke or transient ischemic attack (TIA), hemoptysis, or intrapulmonary hemorrhage. Current indications for endovascular treatment of PAVM include any (solitary or multiple) PAVM with feeding artery diameter ≥ 2–3 mm particularly if associated with paradoxical emboli, symptomatic hypoxemia, or other serious complications. Pulmonary artery pseudoaneurysms are rare acquired vascular dilatations in which at least one of the three layers of the vessel wall is damaged. Manifestations are related to rupture, local mass effect, or peripheral emboli which may be identified incidentally on imaging. Symptoms include hemoptysis, dyspnea, chest pain, cough, and bruit. All pseudoaneurysms should be considered for interventional therapy, especially those who have already had hemoptysis.