Management of Incidental Peripheral Pulmonary Arterial Aneurysm by Interventional Radiology.

A peripheral pulmonary arterial aneurysm (PAA) is an abnormal dilatation of the distal pulmonary artery consisting of all three vessel wall layers (the intima, media, and adventitia). It is a rare, potentially life-threatening entity. There is no defined standard for an abnormal amount of dilation of the distal pulmonary vasculature, however, the most common criteria used is a diameter greater than 1.5 times the upper limit of a normal or proximal portion. Despite the rarity of peripheral PAAs, the ability to recognize and diagnose them is important for both radiologists and clinicians. Early recognition is needed because of the high mortality associated with rupture. Consistent guidelines still need to be developed to help clinicians determine when intervention is appropriate. In the interim, endovascular coil embolization has become a mainstay of treatment due to its minimally invasive nature and lower risk of complications when compared to open surgical approaches.