Aneurysms of the pulmonary arteries.

HISTORIC PERSPECTIVE AND OVERVIEW D escriptions of pulmonary artery aneurysm(s) (PAA) date back to the 1700s, but the history is fragmented and difficult to follow. Deterling and Clagett’ noted that in a 1785 review of530 intrathoracic aneurysms, two involved the pulmonary arteries. The early historians of PAA indicate that individual reports of PAA began to accrue during the early 1800s.’ The first reviews of PAA as a separate topic appeared in the late 1800s and early 1900s38 and were fueled by two ancient diseases ofman, tuberculosis and syphilis. Both diseases, when unchecked, have a significant capacity to cause PAA, and in the preantibiotic era the two together appear to have caused the majority of cases. While both are infectious diseases, they cause PAA by different mechanisms, and syphilitic aneurysms almost always occur in the large pulmonary arteries, while tuberculous aneurysms almost always involve small intraparenchymal arteries. These differences spawned two literatures, one dealing with proximal PAA’35 and the other with peripheral PAA, ’ A third subset of PAA was created when Charlton and DuPlessis9 and subsequent authors wrote only on aneurysms of the “large mntrapulmonary “910 Finally, arteriovenous aneurysms, including those associated with hereditary hemorrhagic telangiectasia (HHT), have followed yet another pathway in the hl As (1) awareness of PAA has increased, (2) the use ofantimicrobials has diminished the incidence of PAA caused by syphilis and tuberculosis, and (3) the differential diagnosis of PAA has expanded, the historical subdivisions of PAA have become less clinically useful.