Abdominal aortic aneurysm Flashcards
aneurysm
permanent localised dilation of the artery to twice the normal diameter
true aneurysm
vessel walls are still intact just heavily dilated
aetiology
- present in 5% in population over 60% of age
- more frequent in men
- occur secondary to atherosclerosis
- genetic links
- hypertension
pathophysiology 1
- usually results from the degeneration of the media of the arterial wall
- abnormal regulation of elastin and collagen proteins in the aortic wall by enzymatic agents
- occur below renal arteries
pathophysiology 2
- in a ruptured AAA the wall of aorta completely fails and blood escapes freely into a body cavity
- continuous expansion of AAA until rupture
- decision to fix AAA is a balance between risk of rupture vs risks of surgery
asymptomatic
75% asymptomatic - incidental finding - until rupture occurs
symptomatic
can have epigastric/central pain with no rupture or dissection
a ruptured AAA will present as sudden onset abdominal pain radiating to back with an expansile abdominal mass
other signs
- dusky discolouration of digits
- collapse
- tachycardia
monitoring - USS
- check if asymptomatic patient has aneurysm
- shows if there is an AAA
- when a small aneurysm is detected patients enter a surveillance programme with regular ultrasound scans
ruptured AAA
- diagnosis must be made quickly an surgeon contacted
- are briefly contained by retroperitoneum
- CT is the only scan that can identify a ruptured AAA
medical managemetn
control of risk factors - antihypertensives, smoking cessation, lipid lowering medication
surgical medication
no intervention vs EVAR vs Open repair
EVAR
- EVAR not possible in 25% of patients
- Less mortality risk
- Faster recovery
- Needs life long follow-up appointments to check the stent graft
- The iliacs need to be disease free to insert the stent to the aorta
open repair
- possible in everyone
- Greater mortality risk
- Slower recovery
- Further appointments are rare
surgery on asymptomatic
- Elective surgery only performed if the AAA is > 5.5 cm in diameter - before this risk of surgery outweighs the risk of rupture
- Prophylactic operation
- Balances risk of rupture vs risk of procedure
surgery for symptomatic
- Graft - EVAR or open lap
- Therapeutic operation
- Balances expectation of death vs risk of procedure
outcome of repair for ruptured AAA
50-75% of patients will not make it to hospital
outcome of repair for asymptomatic AAA
3% of patients will die
fitness for intervention tests
- Cardiac assessment → Echo/ejection fraction
- Respiratory assessment → PFT
- Cardiopulmonary exercise test → CPX testing
- Renal assessment → U&Es
- Vascular assessment → Peripheral pulses/ABPI
- Anaesthetic assesment
- EBT → End of bed test
method of open repair
- General anaesthetic
- Laparotomy
- Clamp the aorta above and below the aneurysm
- Dacron graft
methods of EVAR
- Needs imaging+contrast
- Local/regional anaesthetic
- Majority are performed via percutaneous access in groin with he stent inserted up through the femoral artery
