Aneurysms of the Pulmonary Artery

Pulmonary artery (PA) aneurysms (PAAs) are rare and infrequently diagnosed. Deterling and Clagett1 discovered 8 cases of PAAs in 109 571 consecutive postmortem examinations. PAAs generally occurred in a younger age group than aortic aneurysms with an equal sex incidence.2 Eighty-nine percent of all PAAs were located in the main PA, whereas only 11% were located in the pulmonary branches.3 When affecting the PA branches, PAAs in the left PA were more common than in the right PA.1An aneurysm is defined as a focal dilatation of a blood vessel involving all 3 layers of the vessel wall. Pseudoaneurysms, on the other hand, do not involve all layers of the arterial wall but possess a higher risk of rupture. In computed tomography, the upper limit for adults of the main PA diameter is 29 mm, and the upper limit of the interlobar PA is 17 mm.4 Therefore, Nguyen et al5 describe a PAA as a focal dilatation of the PA beyond its maximal normal caliber. In contrast, Brown and Plotnick6 define a PAA as a PA with a diameter exceeding 40 mm, distinguishing between an ectasia of the PA and a true PAA. However, both definitions do not relate the PAA threshold to body dimensions or to the diameters of other vessels.In our center, the upper limit of the main PA diameter (29 mm) was defined as a PAA. In case of a PAA in children, the PAA size was compared with the normal values according to the method of Kampmann et al.7 In high-risk patients, the diameter of the PAA was indexed to the body weight according to patients presenting with an aneurysm of the aorta.Various origins of PAA have been described, allowing us to differentiate among congenital causes, …