Peripheral arterial disease Flashcards
what is are the causes of chronic limg ischaemia?
atherosclerosi or the arteries supplying the lower limb
less commonly:
vasculitis and Buerger’s disease (Thromboangiitis obliterans)
what is Buerger’s disease?
rare disease of the arteries and veins in the arms and legs. In Buerger’s disease, your blood vessels become inflamed, swell and can become blocked with blood clots
what are the risk factors for chronic limb ischaemia?
male age smoking hypercholesterolaemia hypertension diabetes
what is the Fontaine class I chronic limg ischaemia?
Asymptomatic, incomplete blood vessel obstruction
what is the Fontaine class IIA chronic limg ischaemia?
Mild claudication pain in limb claudication when walking a distance of greater than 200 meters
what is the Fontaine class IIB chronic limg ischaemia?
mild claudication pain in limb claudication when walking a distance of less than 200 meters
what is the Fontaine class III chronic limg ischaemia?
Rest pain, mostly in the feet
what is the Fontaine class IV chronic limg ischaemia?
Necrosis and/or gangrene of the limb
what must be picked up in the history for chronic limb ischaemia?
claudication: exercise tolerance, effect of incline, change over time, relief from rest, where in leg, type of pain
rest pain: type and relieving factors
tissue loss: duration, history of trauma, peripheral sensation
risk factors
PMH- hypertension, DM, hypercholesterioaemia
DH- prothrombotic and antithrombotic factors
SH-smoking
OH- effect of claudication on job
what are the signs of chronic limb ischaemia?
ulceration pallor hair loss palpate- capillary refil reduced temperature reduced pulses reduced or absent peripheral sensation reduced auscultate with hand held doppler over dordalis pedis and posterior tibial pulses.
doppler auscultation over the dorsalis pedis will show what in healthy, more unhealthy and very unhealthy arteries?
healthy- triphasic nature
unhealthy- biphasib
very unhelathy- monophasic
what are the specialist tests caried out for chronic limg ischaemia?
Ankle Brachial Pressure Index
Buerger’s test
how do you calculate ankle brachial pressure index?
ankle pressure divides by brachial pressure. the lower it is the more severe the chronic limb ischaemia
what does a ABPI of 1 or more indicate?
symptom free I
what does a ABPI of 0.95-0.5 indicate?
CLI causing intermettent claudication
what does a ABPI of 0.5-0.3 indicate?
CLI causing pain at rest
what does a ABPI of <0.2 indicate?
gangrene and ulceration
describe BUerger’s test for CLI?
elevate legs if there is pallor with < 20 degrees elevation then there is severe ischaemia
fee are then hung over the edge of the bed. In CLI the feet are slow to regain colour and turn a dark red colour.
what is the best medical therapy for CLI?
antiplatelet statin BP control smoking cessation exercise biabetic control
what is the purpose of statins in the treatment of CLI?
stabilise plaque to prevent embolisation and thrombus formation
what is the BP target for CLI?
<140/85
why does exercise increase the symptoms of CLI?
increases collateral circulation and trains muscle to work in ischaemic conditions.
what is the treatment of moderate CLI?
best medical therapy only
what is the tretament of severe CLI?
BMT
anioplsty/stenting
surgical bypass
what is the treatment of critical CLI?
BMT
angioplasty/stent
endovascular reconstruction
surgical bypass/stent
what are the imaging investigations carried out for CLI?
duplex
CTA
magnetic resonance angiography
what are the pros and cons of duples on CLI?
pros
Dynamic
No radiation/contrast
cons
Not good in the abdomen
Operator dependent, time consuming
what are the pros and cons of CTA and MRA in CLI?
pros
Detailed – allows treatment planning
First line according to NICE
cons
Contrast and radiation
Can overestimate calcification, difficulty in low flow states
what is needed for a surgical bypass graft for CLI?
Inflow
A conduit: autologous (vein from legs, arm), synthetic (PTFE/Dacron)
Outflow
what are the risk and complications of surgical bypass for CLI?
bleeding wound infection pain scar DVT and PE (despite systemic heparin) MI CVA LRTI death damage to nearby: vein, artery, nerve distant emboli graft failure (stenosis, occlusion)
what are the sites of amputation if lower limb/foot cannot be saved by angioplasty/stenting or bypass?
above knee below knee transmetarsal digit hip disarticulation hindquarter through knee symes (ankle)
what is the aetiology of acute limb ischaemia?
arterial embolus from: MI, AF, proximal atherosclerosis (not DVT and PE)
thrombosis from previously diseased artery
trauma
dissection
acute aneurysm thrombosis
what must be found in the history of acute limb ischaemia?
history of chronic limb ischaemia risk factors cardiac histry onset/duration of symptoms functional status
what is teh presentation (signs) of acute limb ischaemia
pain pallor perishingly cold paraesthesia paralysis pulseless
compare with contralateral limb and is it reversible
what is compartment syndrome?
build up of pressure in muscle compartments
describe the pathophysiology of compartment syndrome?
- the build up of pressure in the compartment causes obstruction of venous flow
- this leads to oedema
- this leads to reduced arterial flow and muscle ischaemia
- ultimately this leads to renal failure (myogloulinaemia)
what are the signs of compartment syndrome?
tense, tender calf, rise in creatinine kinase
what is the management of compartment syndrome?
fasciotomy`
what is the management of ALI?
ECG bloods analgesia anticoagulate nil by mouth in case of surgery
what is the management of ALI caused by embolus?
embolectomy
what is the management of ALI caused by thrombosis in situ?
endovascular mechanical thrombectomy
thrombolysis
open embolectomy +/- bypass
what is the management of acute limb ischaemia if the limb is not slavagable?
palliation
amputation
what is the pathophysiology of diabetic foot disease?
Microvascular peripheral artery disease
Peripheral neuropathy
Mechanical imbalance
Susceptibility to infection
how can diabetic foot disease be prevented?
footcare glycaemic control (wear shoes, check fit of shoes, check presssure points regularly, prompt and regular woundcare)
what is the management of diabetic foor disease?
- prevention
- good wound care
- tracking infection- consider systemic antibiotics
- investigate for osteomyelitis, gas gangrene, necrotising fasciitis
- revascularisation ( distal crural angioplasty /stent, distal bypass
- amputation
what are the reascularising techniwues for diabetic fot disease?
attempt distal crurual angioplasty/stent (if disease very distal)
distal bypass
