Aortic aneurysm and dissection Flashcards
what does the artery have if it has an aneurysm
dilatation >50% of its original diameter
what is a true aneurysm
abnormal dilatations involving all layers of the arterial wall
what is a false aneurysm
collection of blood in outer layer only (adventitia), communicated with the lumen
what are the typical causes of an AA
atheroma, trauma, infection, CT disorders, inflammatory
where are the common sites of an AA
aorta (infra renal most common), iliac, femoral, popliteal
complications of AA
rupture, thrombosis, embolism, fistulae, pressure on other structures
what age and gender does screening take place AA
all men at 65 years
symptoms + signs of ruptured AAA
intermittent or continuous abdo pain radiating to the back, iliac fossae or groins. collapse; expansile abdo mass; shock
what is the definition of an unruptured AAA
> 3cm across
what is the cause of unruptured AAA
degeneration elastic lamellae and smooth muscle loss
what are the signs of unruptured AAA
often none, may cause abdo/back pain
when is rupture more likely AA
increased bp, smoker, female, strong family history
when is elective surgery done for AA
aneurysms> 5.5cm ; or expanding at 1cm/yr
what are the complications from elective surgery AA
spinal or visceral ischaemia, distal trash from dislodged thrombus debris
what other than surgery can be used for AA
stenting- EVAR (endovascular repair) but higher graft complications
what is a thoracic aortic dissection
blood splits the aortic media with sudden tearing chest pain +/- radiation to the back
what happens as the dissection extends
branches of aorta occlude sequentially leading to hemiplegia (carotid artery), unequal arm pulses and BP or acute limb ischaemia, paraplegia (anterior spinal artery) and anuria (renal arteries)
what is hemiplegia due to (AD)
carotid artery
what is paraplegia due to (AD)
anterior spinal artery
what is anuria due to (AD)
renal arteries
what would happen if the dissection moved proximally
aortic valve incompetence, anterior MI, cardiac arrest
what is a Type A aortic dissection and what % of dissections are A
involve ascending aorta irrespective of site of tear. 70%
what is a Type B aortic dissection and what % of dissections are B
not involving the ascending aorta. 30%
which type should definitely be considered for surgery AD
type A
investigations in aortic dissection
ECG and CXR- expanded mediastinum rare; CT/MRI/TOE.
management aortic dissection
take to ITU; hypotensives keep systolic at 100-110; labetol or esmotol by IVI (calcium channel blockers if B blocker contraindications)
what is the acute operative mortality of AD
<25%
