Surgery - Vascular Flashcards
What is carotid artery disease? (pathophys)
Build up of atherosclerotic plaque in one or both common and internal carotid arteries.
- Starts off as a fatty streak
- accumualtes a lipid core and fibrous cap
- turbulent flow at bifurcation of carotid artery predisposes to this process
What are the classifications of carotid artery disease?
Mild stenosis is <50% reduction in diameter
Moderate = 50-69% reduction
Severe = 70-99% reduction
Total = 100% reduction
What are some risk factors for carotid artery disease?
The usual = over 65, smoking, htn, hyperhcolesterolaemia, obesity, DM, CVS disease, fhx of cvs disease
how does carotid artery disease present?
Typically asymptomatic (especially if unialteral) due to collateral supply from contralateral internal carotid artery and also vertebral arteries via circle of willis.
Otherwise can be a focal neuro deficit eg stroke or tia
Stroke from ICA = anterior circulation infarct
How would you investigate and manage carotid artery disease?
Investigate
- urgent non contrast CT head
- CT head contrast angiography
- bloods (fbc, u&es, clotting, lipids, glucose)
- Afterwards, screen carotids for disease precipitating the presentation eg. Carotid artery duplex US scan and CT angiography
Acute Management
- high flow o2, ensure blood glucose optimised
- Ischaemic stroke = IV alteplase in 4.5 hours, 300mg aspirin, thrombectomy, etc
- Haemorrhagic stroke = correct htn, correct coagulopathy, neurosurgery etc
Long term management
- dual antiplatelets = aspirin and clopidogrel
- statins = high dose atorvastatin
- htn and dm control
- stop smoking!!!!
- exercise and weight loss plan
- refer to SALT for dysphagia or dysphasia
- physio and OT input
- Carotid endarterectomy if carotid stenosis 50-99%
What is the spectrum of peripheral vascular disease?
Intermittent claudication –> critical limb ischaemia
What are risk factors for peripheral vascular disease?
- smoking!!!!
- hypercholesterolaemia/ hyperlipidaemia
- HTN
- DM
- FHx of cardiovascular disease
- cardiac disease
- cerebrovascular disease
What is intermittent claudication?
- pain in the lower limb muscles elicited by walking
- typically calf muscles as the superficial femoral artery (add canal region) is most often affected
- pain relieved rapidly by rest (even while standing)
- The pain is due to the build up of anaerobic metabolites and pain producing chemicals (Substance P) in the muscle due to inadequate arterial supply
How would you investigate Peripheral Vascular disease?
Investigate:
- bloods
- routine, lactate for level of ischaemia, etc
- Thrombophilia screen if <50y/o with no risk factors
- Group and save
-
Ankle Brachial Pressure Index (arterial disease <0.9, normal is >1.1)
- this may be falsely high in people with calcified vessels like in dm, renal failure, elderly
- Exercise test for claudication + palpable peripheral pulses
- resting and post exercise ABPI
- a drop after exercise indicates PVD
- Arterial duplex scan
- Doppler US for Critical Limb Ischaemia
- CT Angiogram
How would you manage intermittent claudication?
- risk factors = smoking cessation, reduce cholesterols (statin), treat htn, treat DM
- Regular exercise
- antiplatelet therapy = 75mg clopidogrel
- Angioplasty if significantly affecting QOL
- Surgical bypass if angioplasty unsuccessful
What is acute limb ischaemia?
A sudden decrease in limb perfusion resuting in a threat to viability of the limb.
Presents as 6Ps = pain, pallor, pulseless, paraesthesia, perishly cold, paralysis
Common causes = embolisation, thrombus in situ, trauma eg compartment syndrome
How would you manage acute limb ischaemia?
in >6 hours this can result in irreversible tissue damage!! a surgical emergency
- high flow o2 and IV access
- Emergency assessment by a vascular specialist!!!
- heparin bolus dose then heparin infusion asap
- paracetamol + opioid for analgesia
- Scoring system = Rutherford score for limb ischaemia
- 1st line = Surgery
- viable limb and a thrombotic cause = percutaneous catheter directed thrombolysis
- viable limb and an embolic cuase = embolectomy with balloon catheter
- Non viable limb = amputation
Long term management
- smoking cessation
- diet and exercise
- statin therapy
- manage dm and htn
- antiplatelet therapy = clopidogrel 75mg daily
What is chronic limb ischaemia?
Chronic limb ischaemia is a peripheral artery disease that results in symptomatic reduced blood supply to limbs.
What are the stages of chronic limb ischaemia?
what is critical limb ishaemia?
Fontaine classification of CLI
- asymptomatic
- intermittent claudication
- ischaemic rest pain (critical limb ischaemia)
- ulceration or gangrene
Critical limb ischaemia is advanced chronic limb ischaemia.
- ischaemic rest pain >2 weeks duration
- presence of ischaemic lesions or gangrene
- abpi<0.5
- limbs are pale, cold, weak or absent pulses
What is leriche syndrome?
PAD affects aortic bifurcation, resulting in buttock/thigh pain and Erectile Dysfunction
What is Buerger’s test?
Pt lies supine and raises legs until they go pale or lowers them until colour returns.
angle of paleness = buerger’s angle
<20 degrees is severe ischaemia