28. Aneurysms + Carotid Artery Surgery Flashcards
Define aneurysm disease.
Dilatation of ALL layers of the aorta, leading to an increase in diameter of >50% (abdominal aorta >3cm)
What is the most common type of aortic aneurysm?
Infra-renal aortic abdominal aneurysm (abdominal aorta below the kidneys)
What layers of aortic wall do aneurysms affect?
Affect ALL 3 layers of the aortic wall: tunica intima, tunica media and tunica externa/ adventitia
What makes up tunica externa/adventita?
layer of collagen and connective tissue
What makes up tunica media?
layer of smooth muscle
What makes up tunica interna?
layer of epithelium (endothelium)
What are the main causes of aneurysm disease? (3)
- degenerative disease
- connective tissue disease (e.g. Marfan’s)
- Infection (mycotic aneurysm)
What are risk factors for degenerative abdominal aortic aneurysm disease? (5)
- male sex
- age
- smoking
- hypertension
- family history (prevalence of 30% in 1st degree male relatives)
What is the prevalence of abdominal aortic aneurysms in UK?
3%
Why are abdominal aortic aneurysms sometimes difficult to diagnose?
Appear asymptomatic; sometimes patients experience lower abdominal pain due to palpation, aneurysm will expand and move your hands sideways or lower back pain felt (often identified on scans incidentally)
Which family members on a family tree should be investigated for an abdominal aortic aneurysm if someone is suspected of having one?
the sons particularly (males)
Who can register for abdominal aortic aneurysm screening in UK?
Men who turned 65 years can have an ultrasound to identify possible aneurysms (swellings of the aorta)
What are the criteria that need to be met to perform a screening programme for a specific condition in the UK? (9)
- definable disease
- prevalence
- severity of disease
- natural history
- reliable detection (sensitivity and specificity needs to be reasonable)
- early detection confers advantage
- treatment options available
- cost effective
- feasibility and acceptability
What are the possible outcomes for abdominal aortic aneurysm screening (AAA)? (4)
- normal aorta, discharged
- small AAA
- medium AAA
- large AAA
What is a small AAA and what is the next step following screening?
- small AAA is 3-4.4cm
- will be invited for annual ultrasound scans to monitor
What is a medium AAA and what is the next step following screening?
- medium AAA is 4.5-5.5cm
- will be invited for 3 monthly ultrasound scans to monitor
What is a large AAA and what is the next step following screening?
- large AAA is >5.5 cm
- surgery is advised that replaces weakened section of aorta
How does AAA usually present?
without any symptoms
When do symptoms appear? (2)
- when aneurysm is impending rupture (nearly ruptured, at risk, inflammation around it)
- when aneurysm ruptures
What is the presentation of impending rupture AAA? (2)
- increasing back pain
2. tender abdominal aortic aneurysm (abdominal area/wall)
What is the presentation of ruptured AAA? (5)
- abdominal/ back/ flank pain
- painful pulsatile mass
- haemodynamic instability (single episode or progressive), bruising, unstable BP
- hyperfusion (patient cold, confused, urine output decreased)
- single episodes of collapse, loss of consciousness and recovery
What is the unusual presentation of AAA? (5)
- distal embolisation
- aortocaval fistula (AAA erodes into inferior VC)
- aortoenteric fistula(connection between aorta and small intestine)
- uretic occlusion
- duodenal obstruction
What questions should be asked for management of AAA in asymptomatic patients? (3)
- is the aneurysm a size to consider repair?
- is the patient a candidate for repair?
- is the aneurysm suitable for endovascular or open repair?
At what aneurysm size is treatment usually offered?
at 5.5cm
For aneurysms of which size does surgery have no benefit on?
aneurysms <5.5cm (need to be bigger to be considered for surgery)
How big does aneurysm have to be to have the greatest risk of rupture of 30-50%?
> 8cm in size
What is the risk of aneurysm rupture for aneurysms of <4cm?
<0.5% risk
What patient fitness tests need to be done on AAA patients to work out the right treatment method? (9)
- full history and examination
- bloods
- ECG
- ECHO (ultrasound of heart)
- PFTSs (pulmonary function tests)
- MPS (myocardial perfusion scan)
- CPEX (cardipulmonary exercise testing)
- end of best test
- patient preference
What is a myocardial perfusion scan? (MPS)
- radionuclide (radioactive chemical) travels through bloodstream into heart
- areas of heart that have a good blood flow will absorb the radionuclide and will emit more gamma rays
- areas with poor blood supply or damaged areas due to heart attack, stenosis, ischaemia etc will absorb less of the chemical and less gamma rays emitted
What imaging techniques can be used to detect AAA? (3)
- ultrasound scanning
2 CT angiography - MRA (magnetic resonance angiogram)
What are the pros of ultrasounds scanning? (3)
- no radiation
- no contrast
- cheap
What are the cons of ultrasound scanning? (2)
- operator dependent
2. inadequate for surgical planning