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Pulmonary Artery Pseudoaneuyrsm/Aneurysm:


Pulmonary artery pseudoaneurysms (PAPs) can occur as a result of erosion of the artery by an adjacent tuberculous cavity (Rasmussen aneurysm), infection, blunt or penetrating thoracic trauma, neoplasms, improper placement of flow directed pulmonary arterial (Swan-Ganz) catheters, and septic emboli (endocarditis). Hemoptysis is common. Causes of pulmonary artery aneurysms include Behcet's disease [4], Hughes-Stovins syndrome, and Marfans syndrome. [3]

In one study, PAPs showed a strong predilection for the peripheral pulmonary artery branches with 83% located in the segmental or subsegmental branches [5]. The lesion tends to be solitary, but multiple lesions can be seen in association with endocarditis (septic emboli) and metastatic disease to the lung [5]. Massive hemoptysis may occur after rupture of a pulmonary artery pseudoaneurysm and is associated with a mortality rate as high as 50% [5]. Endovascular treatment by direct coil embolization, stent placement, or embolization of the feeding vessel are considered the treatment of choice [5].

i) Rasmussen (Tuberculous) Pseudoaneurysm:

Pseudoaneurysms are found in about 4% of patients with chronic cavitary tuberculosis at autopsy. Patients typically present with massive hemoptysis (over 300 mL/24 hr), but it is most commonly secondary to bronchial artery pseudoaneursym. Treatment is coil or balloon embolization [1].

ii) Complications of Swan-Ganz catheterization:

A false aneurysm of the pulmonary artery may rarely occur as a result of peripheral placement of the catheter (about 0.15% of cases). The pseudoaneurysm typically forms following rupture of the vessel by the catheter. Generally, the right pulmonary artery is involved (93% of cases)- and typically the lesion occurs in a lower or middle artery. The rate of hemorrhage associated with a false aneurysm is between 30-40% and mortality is between 40-100% (mortality is increased following rupture of the pseudoaneurysm). Risk factors associated with pulmonary artery rupture include technical errors, anticoagulation, pulmonary arterial hypertension, long-term steroid therapy (fragile vessels), age greater than 60 years, and female sex. Technical errors can be avoided by inflating the balloon in a large pulmonary artery before pushing it distally and deflating the balloon before withdrawing it. Hemoptysis is the typical presenting symptom.


Following pulmonary artery rupture chest radiographs typically demonstrate an infiltrate which represents an area of hemorrhage. A false aneurysm may be detected as the infiltrate (hemorrhage) clears- leaving a rounded nodule or mass. CT with contrast will demonstrate the false aneurysm as an enhancing mass with an adjacent vessel and sometimes a partially thrombosed lumen. Percutaneous transcatheter embolization is the treatment of choice for a pulmonary artery false aneurysm. [2] However, the procedure can be complicated by pulmonary infarction following improper coil placement [3].


(1) Radiology 1994; 193: 396-98

(2) AJR 1996, 167:941-945

(3) AJR 1997; Hubler B, et al. Traumatic pulmonary arterial and venous pseudoaneurysms. 169: 1354 (No abstract available)

(4) AJR 1999; Tunaci M, et al. CT findings of pulmonary artery aneurysms during treatment for Behcet's disease. 172: 729-733

(5) AJR 2017; Chen Y, et al. Pulmonary artery pseudoaneurysms: clinical features and CT findings. 208: 84-91

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