Anomalies and Aneurysms

Question 1

What is an AVM?

Answer 1

atrioventricular abnormality

• connection between arteries and veins w/o capillaries
• typically pulsatile mass

Cause:

• congenital
• arterial aneurysm rupture into adjacent vein
• surgically generated -> hemodialysis or chemotherapy

Question 2

What is a complication of AVMs?

Answer 2

w/ large or multiple -> shunt blood -> high-output cardiac failure

Question 3

What is a berry aneurysm?

Answer 3

dilation in an artery due to defect in tunica media

Question 4

What are risk factors for berry aneurysms?

Answer 4

• HTN
• smoking

Genetic:

• polycystic kideny disease
• Marfan syndrome
• Ehlers Danlos syndrome

Question 5

Where do berry aneurysms most commonly occur?

Answer 5

branch points of Circle of Willis:

-particularly junction of anterior cerebral A. and anterior communicating A.

Question 6

What is complication of berry aneurysms?

Answer 6

most common cause of subarachnoid hemorrhage -> “worst headache of my life”

Question 7

What is a mycotic aneurysm?

Answer 7

dilation of an artery due to an infection in the wall

Causes:

• septic emboli
• infection in adjacent tissue
• circulating bacteria

Question 8

What is fibromuscular dysplasia?

Answer 8

focal, irregular thickening of arteries with intervening normal segments -> beads on a string

Question 9

Where does fibromuscular dysplasia most commonly occur and what is an associated complication?

Answer 9

renal arteries most common -> renovascular HTN

-50% have epigastric abdominal bruit

Question 10

What is the difference between a true aneurysm, false aneurysm, and arterial dissection?

Answer 10

True aneurysm:

-muscular wall is intact but thinned -> dilation of vessel

False aneurysm:

-defect through muscular wall -> extravascular hematoma (dilation)

Dissection:

-defect in tunica intima -> blood accumulates within muscular wall -> causes further seperation between layer

Question 11

What is Marfan syndrome?

Answer 11

defect in fibrillin gene (FBN1)

fibrillin normally sequesters TGF-β:

Marfan -> increased free TGF-β -> increased metalloprotease activity -> fragmentation of elastin

Question 12

How does Marfan syndrome present?

Answer 12

• tall, thin build
• long arms
• long fingers
• pectus excavatum

Question 13

What complications occur with Marfan syndrome?

Answer 13

• lens dislocation
• aortic aneurysm/dissection
• mitral valve prolapse

Question 14

What is Ehlers-Danlos syndrome?

Answer 14

various mutations affecting collagen synthesis

Question 15

How does Elhers-Danlos syndrome present?

Answer 15

• fragile, hyperextensible skin
• hypermobile joints
• poor wound healing

Question 16

What complications occur with Ehlers-Danlos syndrome?

Answer 16

• mitral valve prolapse
• rupture of cornea, colon, or arteries

Question 17

How does tertiary syphilis present?

Answer 17

Gumma - granulomatous lesions

Cardiovascular:

• aortitis -> aortic aneurysm (“tree bark appearance”)
• aortic valve regurgitation

Neurosyphilis:

Question 18

What is the primary risk factor of throacic aortic aneurysm?

What are other risk factors?

Answer 18

• HTN
• smoking

Other:

• age
• tertiary syphilis
• connective tissue disorders (Marfan/Elhers-Danlos)
• aortic valve defects
• giant cell/Takayasu arteritis

Question 19

How do thoracic aortic aneurysms present?

Answer 19

typically asymptomatic

symptoms, if present, related to compression of surrounding structures:

• dyspnea
• dysphagia
• cough (recurrent laryngeal nerve)
• upper back pain

Question 20

What are the primary risk factor of abdominal aortic aneurysm?

Answer 20

-atherosclerosis

-smoking

Other:

-age

Question 21

Where are throacic aortic aneurysms most commonly seen?

Answer 21

-ascending aorta

Question 22

How do abdominal aortic aneurysms present?

Answer 22

Most are asymptomatic and discovered via exam or incidentally on radiology:

• pusatile abdominal mass
• abdominal bruit

If symptomatic

-low back pain (severe and acute when ruptured)

Question 23

What subtypes of AAA are not related to atherosclerosis?

Answer 23

Inflammatory AAA:

• lymphoplasmacytic and macrophage (giant cells) infiltration
• can be treated with corticosteroids

IgG4 AAA:

• subtype of inflammatory AAA with high IgG4
• similar lymphoplasmacytic infiltration
• can be treated with corticosteroids

Mycotic AAA:

-caused by infection of tissue surrounding aorta causing weaking of its walls

Question 24

Where are abdominal aortic aneurysms most commonly seen?

Answer 24

-below renal arteries, above aoritc bifurcation

Question 25

How are AAAs treated?

Answer 25

Less than 5cm and <1cm of growth/yr:

• conserative treatment
• monitor with US, frequency increases with size

Greater than 5cm OR greater than 1cm of growth/yr:

-surgery (stenting)

Question 26

What are the major risk factors of aortic disection?

Answer 26

• HTN
• trauma (particularly deceleration injuries)

Other:

-connective tissue disorders (Marfan/Ehlers-Danlos)

Question 27

How does aortic dissection present?

Answer 27

Triad:

• “tearing” thoracic pain
• pulse abnormalities (absent or >20mmHg difference)

-mediastinal widening on XR

Question 28

Where is aortic dissection most commonly seen?

Answer 28

ascending aorta (proximal to brachiocephalic A.)

greatest risk factor is high blood pressure so area of highest pressure -> highest risk