Pulmonary Artery Pseudoaneurysm: A Case Report and Review of the Literature

Purpose: We aim to illustrate a rare case of a peripheral artery pseudoaneurysm secondary to pulmonary infection that underwent successful treatment with coil embolization. We will discuss the prevalence, risk factors, and physiopathogenesis of pulmonary artery pseudoaneurysm. We will also review the current state-of-the art treatment and complications for embolization of pulmonary artery pseudoaneurysms.

Materials and Methods: A 86-year-old man with a history of dementia was admitted to the hospital with productive cough and chills for 5 days with development of hemoptysis few hours before arrival. The patient underwent computed tomography (CT) examination, which demonstrated a 6-cm cavitary pneumonia in the left lower lobe with a central globular outpouching lesion with equal enhancement to the pulmonary vasculature measuring 14 mm. The patient underwent emergent angiography, which demonstrated a pseudoaneurysm arising from the left lower lobe basal segmental pulmonary artery. After the diagnostic angiography, embolization of the vessel supplying the pseudoaneurysm was performed with four 3 ´ 3 Vortex diamond microcoils and one 4 ´ 14 micro-Nester coil. The patient tolerated the procedure well. Blood and sputum cultures were negative, and suspicion was for a chronic anaerobic pulmonary infection in the setting of chronic aspiration. Follow-up imaging demonstrated resolution of the cavitary pneumonia after antibiotic treatment.

Results: Pulmonary artery pseudoaneurysms are rare with prevalence ranging from 5% to 11% in patients presenting with hemoptysis. It is important to recognize them promptly because they have up to a 50% mortality rate attributed to aspiration and asphyxia. Pulmonary artery pseudoaneurysms are more common at the peripheral pulmonary artery branches and tend to be solitary. The most common cause of acquired pulmonary artery pseudoaneurysm is infection. Other less common causes are malignancy, trauma and iatrogenic. Pathogenesis of PAPs secondary to infectious pneumonia includes destruction of vessel wall from outer wall to inner lumen caused by contiguous spread and invasion from the lung.

Conclusions: Pulmonary artery pseudoaneurysms are rare entities with a high mortality rate. Pulmonary CT angiography is useful in guiding selective angiography and subsequent intervention. Endovascular treatment by direct coil embolization, stent placement, or embolization of the feeding vessel is effective in occluding pseudoaneurysms and is considered the treatment of choice.