AAA

Question 1

what is a true aneurysm?

Answer 1

dilation of artery >50 percent original diameter, which is bound by all 3 walls of the vessel (intima, media, adventitia)

Question 2

what is a dissection?

Answer 2

when an aneurysm leads to intima tearing and blood entering, seperating it from the media and forming a false lumen

Question 3

where are saccular/berry aneurysms found

Answer 3

Circle of Willis

Question 4

where on the aorta is AAA normally?

Answer 4

below level of the renal arteries (infrarenal)

Question 5

risk factors for AAA?

Answer 5

• Atherosclerosis (smoking, HT, cholesterol)
• Demographic: male, increased age
• FHx
• Behcet’s
• Marfan’s

Question 6

Ex of a stable aneurysm (one found as an incidental finding/screening)?

Answer 6

• expansile (expands and contracts) mass (visible or palpable)
• if pain on palpation ↑ risk rupture

Question 7

Sx - patient presents with intermittent or continuous abdominal/flank/groin/back pain, shock, and syncope?

Answer 7

ruptured AAA

if Sx is collapse, consider in men >55, women >70

Question 8

Ix AAA?

Answer 8

Bedside:
• ECG

Bloods:
• FBC, coag, U+E, LFT, cross-match

Imaging:
• *diagnostic US
• CXR
• CT contrast or MRI angio provide more info, used if US not clear or before planned surgery

Question 9

who is one off screening for AAA offered to?

Answer 9

men >65

Question 10

“high attenuating crescent” on CT?

Answer 10

bleed within the aneurysmal wall suggesting imminent rupture

Question 11

Tx stable AAA?

Answer 11

Conservative:
• Regular US monitoring if small/Asx
• Manage risk factors
• DVLA if >6cm

Surgical
• If >5.5cm, expanding >1cm/yr, or Sx (risk of rupture>risk of surgery)
• Open repair - clamping artery + sewing graft inside aneurysm sac to replace it
• Endovascular aneurysm/aortic repair (EVAR) is less invasive, involving stents via femoral artery (✓ recovery, short-term mortality)

Question 12

Tx ruptured AAA?

Answer 12

• Resuscitation, transfuse, keep BP <100
• ECG, amylase, Hb, crossmatch, catheterise
• Emergency open repair
• 80 percent mortality risk

Question 13

risk factors for THORACIC aneurysm/dissection?

Answer 13

basically same as AAA (CVD, familial, Marfan’s, Ehler’s Danlos)

also  - mycotic aneurysm (infection eg endocarditis)
syphilitic aortitis (tertiary)
inflammatory (Behcets, Takayasu's, GCA, RA)

Question 14

Sx - patient presents with tearing/sharp pain maximal at onset, radiating to back?

Ex - hypotension, pulse deficit (unequal BP between arms in 15 percent), new murmur of aortic regurgitation?

Answer 14

thoracic aneurysm dissection

Question 15

Ix thoracic aneurysm dissection?

Answer 15

Bedside:
• ECG (ΔΔ MI)

Bloods:
• Crossmatch

Imaging:
• CXR (may show widened mediastinum)
• *diagnosis CT

Question 16

Tx thoracic aneurysm?

Tx thoracic dissection?

Answer 16

ANEURYSM:
Surgical (if unstable, >5.5cm, Sx)
• Open repair
• EVAR

DISSECTION
Medical
• IV labetalol
• Type A (70p) Ascending needs Surgery
• Type B (30p) descending only needs surgery if rupture
• Chronic, stable dissections can be managed with anti-hypertensives

Question 17

what is a pseudoaneurysm?

Answer 17

collection of blood in adventitia layer of vessel (after trauma)

Question 18

complication of thoracic dissection?

Answer 18

branches of the aorta occlude sequentially leading to hemiplegia (carotid) or paraplegia (anterior spinal artery) or anuria (renal arteries)

MI +/- arrest if proximal dissection