Variation in the histopathological features of patients with ascending aortic aneurysms: a study of 111 surgically excised cases.
BACKGROUND
Ascending aortic aneurysms (AA) are a common, though poorly understood medical condition.


OBJECTIVE
To document the histological changes in a large series of human ascending AA, and to correlate these changes with clinical variables.


METHODS
111 ascending AA were excised at surgery over a 3 year period. Each aneurysm was received as a continuous ring of tissue. Sections were taken from the anterior, posterior, greater and lesser curvature of the aorta and graded in a semi-quantitative fashion for the degree of elastin fragmentation, elastin loss, smooth muscle cell (SMC) loss, intimal changes and inflammation.


RESULTS
Mean patient age at surgery was 58.7 (15.6) years; there were 70 men and 41 women. 12 patients had Marfan syndrome, 34 (30.6%) had a bicuspid aortic valve (BAV), while 71 (64.0%) had a tricuspid aortic valve (TAV). Inflammatory cells were present in 28 cases (25.2%) and were confined to the adventitia. No particular region of the aortic circumference was more severely affected, however a BAV was associated with significantly less intimal change, and less fragmentation and loss of elastic tissue compared with patients with a TAV. Advanced age (>65 years), female gender and Marfan syndrome were all associated with more severe elastin degeneration and smooth muscle cell loss (p<0.05 for all).


CONCLUSIONS
Results indicate a wide variation in the histological appearance in ascending AA, depending on patient characteristics. They suggest that the underlying aneurysm pathogenesis may also be highly variable; this warrants further investigation.
Collins
M J
MJ
Department of Pathology, Toronto General Hospital, Toronto, Ontario, Canada.
Dev
V
V
Strauss
B H
BH
Fedak
P W M
PW
Butany
J
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001014:Aortic Aneurysm / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D001021:Aortic Valve / Q000002:abnormalities; D004547:Elastic Tissue / Q000473:pathology; D004549:Elastin / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D008382:Marfan Syndrome / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000473:pathology; D012737:Sex Factors; D017539:Tunica Intima / Q000473:pathology
D004549:Elastin