Flashcards in Vascular Path Robbins Part 2 Deck (18)
localized abnormal dilation of a BV
-may be congenital or acquired
true aneurysm vs false aneurysm
-true- intact (but thinned) muscular wall
-false- defect thru the vessel wall or heart, communicating with an extravascular hematoma ("pulsating hematoma")
saccular vs fusiform aneurysms
-fusiform- diffuse, circumferential dilations of a long vascular segment
aneurysm- caused by?
-defective vascular wall CT
-net degradation of vascular wall CT
-weakening of vascular wall by ischemia (atherosclerosis, HTN, tertiary syphilis)
defective vascular wall CT- causes
-Marfan syndrome (fibrill def)
-Loeys-Dietz syndrome- mutations in TGF-B R's- def syn of elastin and collagens I, III
-Ehlers-Danlos syndrome- def type III collagen syn
-vit C def- altered collagen cross-linking
net degradation of vascular wall CT- causes
-inflammation and assoc proteases
-matrix metalloprotease (MMP)- degrade extracellular matrix in aretrial wall
-dec expression of TIMPs (tissue inhibitors of MMP)
weakening of vascular wall by ischemia- causes
-loss of smooth m or syn of noncollagenous or nonelastic ECM
-inner media ischemia- atherosclerosis
-outer media ischemia- HTN (vaso vasorum narrowed)
-tertiary syphilis- obliterative endarteritis of vaso vasorum of thoracic aorta
aneurysm - loss of vascular wall elastic tissue or ineffective elastin syn- leads to final common result of diff conditions??
-cystic medial degeneration- with disorganized elastin filaments and increased ground substance (proteoglycans)
2 most important causes of aortic aneurysms
-atherosclerosis (abdominal aorta)
-HTN (thoracic aorta)
abdominal aortic aneurysm- due to? occurs where? more frequent in?
-usually below renal a's; often involve common iliac a's
-men, smokers, 6th decade of life
abdominal aortic aneurysm- characterized by? complications?
severe atherosclerosis of aorta, covered with mural thrombus
-pulsating mass in abdomen!
-occlusion of branching a's, downstream ischemia
-impingement on another structure
abdominal aortic aneurysm- rupture risk related to?
->5 cm- managed surgically! (11% risk)
3 AAA variants
-infl AAA (5-10%)- younger pts, back pain, elevated infl markers- localized immune response to aortic wall
-IgG4-related disease- high plasma levels of IgG4 and tissue fibrosis
-mycotic AAA- lesions infected by the lodging of circulating microorganisms in the wall
thoracic aortic aneurysm- caused by? clinical presentation?
-HTN or less commonly Marfan syndrome!
-impingement- lower resp tree, esophagus, recurrent laryngeal n's (cough)
-aortic valvular insuff
-pain- erosion of bone
aortic dissection- occurs when? occurs in who? primary risk factor? classic presentation?
blood enters a defect in the intima- travels within layers of aortic media
-HTN males (40-60); Marfan's syndrome, rarely in pregnancy
-severe chest pain, radiating to back b/w scapulae
major risk factor for aortic dissection
-medial hypertrophy of vasa vasorum with degenerative changes
aortic dissection pathogenesis, most occur where?
-blood enters aortic wall via an intimal tear- forms an intramural hematoma
-in HTN pts- have some degree of cystic medial degeneration
-most in ascending aorta