Pathology of the thoracic aorta: a morphologic review of 338 surgical specimens over a 7-year period.

A total of 338 surgical specimens of the thoracic aorta were studied morphologically. These were obtained from patients (238 males, 100 females) operated on for aortic aneurysm or dissection at the Careggi Hospital, Florence, Italy, between January 1999 and June 2005. Medial degeneration was diagnosed in 299 cases (138 aneurysms, 161 dissections), atherosclerosis with extensive medial destruction was seen in 32 cases (26 aneurysms, 6 dissections), and giant cell arteritis (GCA) was found in 7 cases (all aneurysms). These data show that medial degeneration was a common nonspecific histologic diagnosis in aortic resection after the occurrence of aneurysm or dissection. Considering that this diagnosis was made in as many as 118 patients over 70 years of age and in 175 patients over 65, normal advancing age would appear as the most frequent correlation with these aortic events. Ageing is also associated with the increasing number of cases of GCA with aortic involvement. Angiogenesis, always observed next to areas of medial damage whatever the underlying pathology, may contribute to the pathogenesis of aortic dissection and aneurysm.