Aortic aneurysms and carotid artery disease Flashcards
What is an aneurysm?
- localised swelling in the wall of an artery
- can rupture
What is an aneurysm?
- localised enlargement of an artery caused by weakening of the vessel wal
- can rupture
State risk factors for degenerative AAA disease
- male
- age (>65)
- smoking
- hypertension
- FMX
Causes of aneurysm disease
Anything that causes weakness of BV wall
- degenerative disease
- connective tissue disease ( Marfan’s)
- Infection
- atherosclerosis
What is abdominal aortic aneurysm screening
- detects dangerous swelling of aorta. Mainly in men the year they turn 65
Criteria for screening
REMOVE
State possible outcome of screening
Normal aorta : discharged
Small AAA(3-4.4cm) : annual USS scans
Medium AAA(4.5-5.5cm): 3 monthly USS scans Large AAA : (>5.5cm)
Presentation: symptomatic + unusual symptoms of an aneurysm
Asymptomatic
Symptomatic
- dyspnoea/stridor
- HF ( due to dilation of cardiac skeleton
- hoarseness ( compressing on laryngeal nerve; ascending aorta)
- abdominal/back/flank pain
- painful pulsatile mass
- haemodynamic instability( single episode/progressive)
- hypopoperfusion
Unusual presentations
- distal embolisation
- aortocaval fistula
- aortoenetric fistula
- ureteric occlusion
- duodenal obstruction
Aneurysm size and risk of rupture
e
Investigation of aneurysm
USS(ultrasound)
- no radiation/contrast
- but operatory dependent
- not used in surgical planning
CTA/MRA
- quick + not operatory dependent
- surgical planning (detailed anatomy)
- but uses contrast/radiation
-Bloods ECG ECHO PFTs MPS CPEX
Types of aneurysm
True and false aneurysms
True vs false aneurysms
True aneurysms
- walls of artery (t.intima) form walls of aneurysm
- can be fusiform(equal dilation) + saccular(unequal dilation)
False aneurysms
- hole in wall causes blood to pool(haemorrhage) but contained within T.advettia/surrounding tissue
- haematoma can go on to form a clot
What is a dissecting aneurysm !
- tear in t.intima causing bleeding in t.media. It seperates the 3 layers and doesn’t forma balloon unlike a pseudoaneurysm
- Type A = ascending aorta
- Type B = dissection that occurs anywhere but the ascending aorta
Causes of true aneurysms
- atherosclerosis
- hypertension
- smoking
- collagen abnormalities ( marfan’s syndrome)
- trauma
- infection( mycotic; detaches and embolises and causes weakness to vessel eall)
Causes of false aneurysms
- inflammation(endocarditis
- trauma
- iatrogenic(catheters)
Symptoms of an aneurysm
remove
Clinical presentation of aneurysm
- if rupture, tachycardia/hypotension
- pulsatile mass in abdomen
Investigations of aneuryssm
- ultrasound screening for men >60yrs
- MRI/CT scan
Treatment of aneurysms
Surgery>5.5cm(if less does not benefit)
-Surgery= open repair/EVAR (Endovascular aneurysm repair)
Sizes of aneurysm classification ( small, medium, large)
REMOVE
Describe Open +endovascular repair (fixx)
Open
-invasive, surgically open abdomen to gain access to AA
and a stent is placed.
EVAR
- Cut into femoral artery in groin and a guided wire introduced in AA via femoral artery then a sheathed stent graft ( with use of flurosopy which is a movie X-Ray).
- upper portion of device immediately below renal arteries
- 2nd guide wire contralateral iliac artery placed into open lumen of stent
- sheath is withdrawn leaving the stent in place.
- This will expand to fit against the wall of the artery
Endovascular repair complications
- infection, bleeding/haematoma
- scarring
- contrast reaction
- kidney injury, radiation
Technical
- endoleak
- femoral artery dissection/pseudoaneurysm(false)
- rupture
- distal emboli/ischaemia/colonic isachemia
- damage to femoral vein/nerve
What is an endoleak?
An endoleak is defined as persistent blood flow in the aneurysm sac external to the endograft
Open vs EVAR
- Open AAA repair better than stenting as it can deal with short necks/poor iliac anatomy
- Wheras EVAR need to have good neck/illiac anatomy so that stent can be placed well
Describe what happens in an emergency open repair
- theatre
- transfusion protocol. Prep abdomen, rapid anaesthetic
- laprotomy xiphersternum to pubic symphysis
- 30-50% morbiditity
What can atherosclerosis of carotid ateries lead to?
- transient isachemic attacks
- isachaemic stroke
What is a transient ischaemic attack?
- focal CNS disturbance caused by microemboli + occlusion > cerebral ischaemia
- symptoms last LESS than 24 hours + no permanent neurological damage
What is a stroke?
- syndrome consisting of signs of focal/global disturvance of cerebral function
- lasts LONGER than 24 hours/can cause death
Causes of stroke/TIA
- cerebral infarction(mainly)
- AF, carotid atherosclerotic plaque rupture/thrombus
- endocarditis
- MI
- carotid artery trauma/dissection
- drug abuse
- haemotological disorder ( sickle cell disease)
- primary intracerebral haemorrhage
- subarachnoid haemorrhage
What does virchow’s triad state?
3 categories that contribute to thrombosis: BF, coagulability, vessel wall
State the symptoms of TIA/troke
-paralysis/paresis/visuospatial neglect, dysphasia, ipsilateral amaurosis fagux symptoms
Investigation of TIA/stroke
- cardiac
- ascultation of carotids
- CT
- carotid USS
- doppler
What does poisuille’s law state?
- as radius of vessel decreases, velocity increases
- used to measure severity of stenosis
Velocity and its stenosis
Velocity <125cm/s = <50% stenosis
Velocity >125cm/s = 50-69% stenosis
Velocity >270cm/s = 70-79% stenosis
What is the end diastolic velocity?
> 140cm/s = 80-99% stenosis
Treatment of TIA/stroke
- smoking cessation
- control of hypertension
- antiplatelet
- statin
- diabetic control
- carotid endarectomy ( if high stenosis)
- stenting ( if atherosclerosis/plaque)
Describe carotid endartectomy
- incision on neck to open the carotid artery + plaque is removed
- closed
complications of carotid enarectomy
- wound infection, bleeding scar, anaesthetic risks
- vagus/hypoglossal nerve damage
- perioperative stroke due to plaqe rupture/hypoperfusion/virchow’s traid ( raw intimal surface + thrombosis)
