Vascular Path Robbins Part 2

Question 1

aneurysm

Answer 1

localized abnormal dilation of a BV

-may be congenital or acquired

Question 2

true aneurysm vs false aneurysm

Answer 2

• true- intact (but thinned) muscular wall

- false- defect thru the vessel wall or heart, communicating with an extravascular hematoma (“pulsating hematoma”)

Question 3

saccular vs fusiform aneurysms

Answer 3

• saccular- spherical

- fusiform- diffuse, circumferential dilations of a long vascular segment

Question 4

aneurysm- caused by?

Answer 4

• defective vascular wall CT
• net degradation of vascular wall CT
• weakening of vascular wall by ischemia (atherosclerosis, HTN, tertiary syphilis)

Question 5

defective vascular wall CT- causes

Answer 5

• 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

Question 6

net degradation of vascular wall CT- causes

Answer 6

• inflammation and assoc proteases
• matrix metalloprotease (MMP)- degrade extracellular matrix in aretrial wall
• dec expression of TIMPs (tissue inhibitors of MMP)

Question 7

weakening of vascular wall by ischemia- causes

Answer 7

• 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

Question 8

aneurysm - loss of vascular wall elastic tissue or ineffective elastin syn- leads to final common result of diff conditions??

Answer 8

-cystic medial degeneration- with disorganized elastin filaments and increased ground substance (proteoglycans)

Question 9

2 most important causes of aortic aneurysms

Answer 9

• atherosclerosis (abdominal aorta)

- HTN (thoracic aorta)

Question 10

abdominal aortic aneurysm- due to? occurs where? more frequent in?

Answer 10

• atherosclerosis!
• usually below renal a’s; often involve common iliac a’s
• men, smokers, 6th decade of life

Question 11

abdominal aortic aneurysm- characterized by? complications?

Answer 11

severe atherosclerosis of aorta, covered with mural thrombus

• pulsating mass in abdomen!
• rupture, hemorrhage
• occlusion of branching a’s, downstream ischemia
• embolism
• impingement on another structure

Question 12

abdominal aortic aneurysm- rupture risk related to?

Answer 12

aneurysm size!

->5 cm- managed surgically! (11% risk)

Question 13

3 AAA variants

Answer 13

• 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

Question 14

thoracic aortic aneurysm- caused by? clinical presentation?

Answer 14

• HTN or less commonly Marfan syndrome!
• impingement- lower resp tree, esophagus, recurrent laryngeal n’s (cough)
• aortic valvular insuff
• pain- erosion of bone
• rupture

Question 15

aortic dissection- occurs when? occurs in who? primary risk factor? classic presentation?

Answer 15

blood enters a defect in the intima- travels within layers of aortic media

• HTN males (40-60); Marfan’s syndrome, rarely in pregnancy
• HTN!!
• severe chest pain, radiating to back b/w scapulae

Question 16

major risk factor for aortic dissection

Answer 16

HTN

-medial hypertrophy of vasa vasorum with degenerative changes

Question 17

aortic dissection pathogenesis, most occur where?

Answer 17

• 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

Question 18

aortic dissection- type A and B

Answer 18

• A- more common, higher morbidity and mortality- adj to aortic root!- treat with antiHTN therapy, surgical repair (deBakey types 1 and II)
• B- distal not involving the ascending part (deBakey type III