Aneurysms - Presentation, Investigation & Therapy Flashcards
What is the definition of an aneurysm?
enlargement of an artery caused by weakness in the arterial wall
What is an abdominal aortic aneuruysm (AAA)?
localized enlargement of the abdominal aorta such that the diameter is greater than 3 cm or more than 50% larger than normal.
It involves rupture of all three layers of the artery.
What are presenting symptoms of a ruptured AAA?
5
- sudden, intense and persistent chest or back pain.
- painful pulsatile mass
- hypoperfusion (shock)
- hypotensive
- syncope
What is a false aneurysm?
A pseudoaneurysm, also known as a false aneurysm, is a collection of blood that forms between the two outer layers of an artery, the tunica media and the tunica adventitia.
A dissecting aneurysm forms between which layers in the arteries?
intima and tunica media
What is arteriomegaly and subaneurysmal dilatation?
dilatation of an artery less than the required size for aneurysm (i.e. <3cm in abdominal aorta).
Where do the majority of AAA’s occur?
between the renal arteries and the bifurcation of the abdominal aorta
What are some causes of AAA’s?
3
- degenerative (e.g. atheroma)
- connective tissue damage (e.g. Marfan’s)
- infection (e.g. mycotic aneurysm)
What are some risk factors associated with AAA’s?
5
male age smoking alcohol hypertension Fx
How do unruptured aneurysms often present?
asymptomatic
How are AAA’s often diagnosed?
3
- imaging (ultrasound, CTA)
- Hx/Fx
- clinical examination
Are AAAs screened for?
yes, men over 65 are screened
How is patient fitness for elective repair assessed?
6
- full Hx/examination
- exercise tolerance
- CPEX
- aortic morphology
- Bloods (U+E)
- ECHO
What is the outcome if screening for AAA shows aorta is 3 to 4.4 cm (small aneurysm)?
annual surveillance (e.g. US)
What is the outcome if screening for AAA shows aorta is 4.5-5.5 cm (medium aneurysm)?
3-monthly surveillance
What is the outcome if screening for AAA shows aorta is >5.5cm (large aneurysm)?
treatment offered
What is the first step in determining the best surgical intervention for AAA repair?
What information can we gather from this?
CT angiography
aortic morphology, is it good or bad
If the CTA reveals a patient has good anatomy/aortic morphology. what would be the best treatment option?
EVAR (endovascular aneurysm repair)
Outline what an EVAR is?
- endovascular procedure, accessed via femoral artery
- inputs stent into abdominal aorta to provide an alternative route for blood flow
What type of stent is usually used in EVAR?
- nitinol (nickel and titanium)
- with covering fabric
What are the contraindications to an EVAR?
- patient preference
- predictable lack of follow up
- other CIs
If a patient has unsuitable anatomy/aortic morphology, what would be their treatment path?
- laparotomy/open repair
- only if they are a fit candidate for surgery
If a patient was unfit for open repair surgery, what treatment options would be considered?
(3)
- EVAR
- snorkel
- balloon expandable stent
Why is an EVAR procedure preferred over open repair surgery?
4
- less invasive
- faster recovery
- lower risk of complications
- less risk of infection
What are the patient factors for complications in EVAR/open repair of AAAs?
DVT/PE
MI
Stroke
Death
What are the general complications for endovascular repair of AAA’s?
(5)
- Wound infection
- Bleeding/haematoma
- Pain
- contrast renal impact
- Radiation
what are the technical complications of endovascular repair of AAAs?
(5)
- Endoleak
- Femoral artery dissection/pseudoaneurysm
- Rupture
- Distal emboli / ischaemia
- Damage to femoral vein/nerve
What is a type I AAA?
inadequate circumferential seal (proximal, distal, common iliac)
What is a type II AAA?
backflow from collaterals into aneurysmal sac.
What is a type III AAA?
endograft/structural failure
What is a type IV AAA?
leak from graft fabric (porosity)
If a patient was unfit for an EVAR due to the proximity of the aneurysm to renal arteries, what treatment might be offered?
FEVAR (fenestrated EVAR)
What scoring system is used to assess severity/mortality of a ruptured AAA?
ERAS (Edinburgh ruptured aneurysm score)
What are the symptoms of an impending AAA rupture?
2
increasing back pain
tender AAA
What is the role of vascular surgeons in strokes?
management of carotid disease to prevent further events, secondary prevention
What are the causes of stroke?
9
- AF
- carotid atherosclerosis (15%)
- IE
- MI
- Carotid artery trauma/dissection
- Drug abuse
- Haematological disorder e.g. sickle cell disease
- Primary intracerebral haemorrhage (10%)
- Subarachnoid haemorrhage (6%)
How is stroke diagnosed?
- Hx
- Exam (neuro, cardio, auscultate carotids)
- CT
- Carotid USS
What are neurological symptoms of stroke?
contralateral symptoms of paralysis/paresis/visuospatial neglect, dysphasia
What happens to the velocity of flow in a vessel as radius decreases?
it increases
What are the primary prevention techniques for stroke in terms of medical therapy?
- antiplatelets
- statin
- diabetic control
- antihypertensives
If a carotid artery is fully occluded and there are no (stroke/TIA) symptoms is surgery performed?
no, only when there is risk of high speed distal embolism. i.e. partially occluded <70%
What are the interventional procedures for carotid atheroma causing >70% stenosis?
- carotid endarterectomy
- stenting
What are the complications of carotid endarterectomy?
6
- wound infection
- bleeding
- anaesthetic risks
- nerve damage
- plaque rupture
- hypoperfusion
