Aortic
Aneurysm
Epidemiology and
Etiology:
- >50
years (except rarely)
- M >
F
- Causes:
- 2
most important:
- Atherosclerosis
(destruction of media by plaque)
- Cystic
medial degeneration of the arterial media
·
may be caused by a connection tissue abnormality (ex. Marfan’s)
·
younger patients
·
idiopathic
·
hypertension
·
bicuspid aortic valve
- Trauma
- Congenital
defects
- Infections
(mycotic aneurysm)
- Embolism
from infective endocarditis
- Direct
extension from adjacent process
- Syphilis
- Salmonella
Common sites:
- Atherosclerotic
aneurysms:
- Abdominal
aorta (AAA) – most common
- Usually
below renals and above bifurcation
- Common
iliac
- Arch
- Descending
thoracic aorta
Gross features:
- Granular
mural thrombi often
- Saccular:
- Spherical
- 5-20cm
- often
partially or completely filled with thrombus
- fusiform:
- involving
a long segment of the artery
- up to
20cm diameter
Histologic features:
- inflammatory
aortic aneurysm:
- dense
periaortic fibrosis with abundant inflammatory reaction
- lymphocytes
- plasma
cells
- many
macrophages
- giant
cells often
Immunophenotype:
Marker:
|
Sensitivity:
|
Specificity:
|
|
|
|
Molecular features:
Other features:
- risk
of rupture (peritoneal, retroperitoneal, pleural, retropleural)
- <4cm
– zero risk
- 5-6cm
– 10% / year risk
- >6cm
– 25% / year risk
- may
affect origins of renal arteries and SMA / IMA,
vertebral branches supplying the spinal cord
- may
become infected from bacteremia
- Salmonella gastroenteritis
- may
embolize
- may
compress adjacent structures (ureter,
vertebrae)
References: