Peripheral Arterial Disease Flashcards
Where are the normal palpable pulses?
Aorta
Common femoral artery
Popliteal artery
Posterior tibial pulse
Dorsalis pedis pulse
Explain pathophysiology for critical limb ischaemia?
Same disease process as coronary and carotid atherosclerotic disease - systemic disease
What is critical limb ischaemia?
Atheromatous disease of the arteries supplying the lower limb
Less commonly - vasculitis, Buerger’s disease (inflamed and swollen arteries collect blood clots)
What are the risk factors of critical limb ischaemia?
Male, age, smoking, hypercholesterolaemia , hypertension and diabetes
Explain Fontaine classification?
Stage I - asymptomatic, incomplete blood vessel obstruction
Stage II - mild claudication pain in the limb
Stage III - rest pain, mostly in feet
Stage IV- Necrosis and or gangrene of the limb
What stages are critical limb ischaemia/
3 and 4
Need max. attention
What is involved in history of critical limb ischamia?
Claudication - exercise tolerance, change over time, leg, type of pain, bilateral
Rest pain - relieving factors
Tissue loss - duration, trauma and peripheral sensation
Risk factors, PMH, Drug history, Surgical history
What can be seen on clinical examination of critical limb ischaemia?
Signs of chronic ischaemia
-ulceration, pallor and hair loss
What can you feel and auscultate on clinical examination of CLI?
Feel - Temp., capillary refill time, peripheral sensation, pulses
Auscultate - hand held doppler. Check dorsalis pedia and posterior tibial pulses
Explain ankle brachial pressure index?
Ankle pressure (mmHg/ Brachial pressure
Symptom free is 1 or more
Intermittent claudication is 0.95-0.5
Rest pain is 0.5-0.3
Gangrene and ulceration is <0.2
Explain the Buerger’s test
Elevate legs - pallor shows ischaemia at buergers angle < 20 which is severe ischaemia
Hang feet over edge of bed and slow regain of colour then dark red as more capillaries are open if ischaemia
What are benefits and negatives of Duplex imaging?
Dynamic and no radiation or contrast
Not good in abdomen, operator dependant and time consuming
What are the benefits and negatives of CTA/MRA - angiogram?
Detailed and first line according to NICE
Contrast and radiation, can overestimate calcification and difficulty in low flow states
What investigations are used for CLI?
Duplex
CTA/MRA
Digital subtraction angioplasty
What medical therapy is given for CLI?
Antiplatelet - reduces risk of revascularisation and cardiovascular mortality
Statins - inhibit platelet activation and thrombosis
What are the risk factor controls for CLI?
BP control - target 140/85
Smoking cessation
Diabetic control
Exercise
What are the options for management for CLI?
Medical treatment
Primary amputation
Revascularisation
What are the open surgery options for CLI?
Bypass and/or endarterectomy
What are the endovascular intervention options for CLI?
Balloon angioplasty
Stent replacement
Atherectomy
What does surgical bypass require?
Inflow, a conduit (autologous or synthetic) and outflow
What are the risks of complications for surgical bypass/
Bleeding, wound infection, pain, scar, DVT, PE, MI, CVA, LRTI and death
Can also have damage to nearby vein, artery, nerve, distal emboli, graft failure - stenosis or occlusion
What are the 2 types of surgical bypass graft?
Reversed saphenous vein graft
In situ saphenous vein graft
Is surgical bypass or angioplasty better?
In short term where results matter then angioplasty is likely preferred
In patients with suitable anatomy, vein availability and reasonable life expectancy - surgery may be better
What is the pathophysiology for acute limb ischaemia?
Arterial embolus, thrombosis, trauma, dissection and acute aneurysm thrombosis i.e. popliteal
What is the clinical presentation of acute limb ischaemia?
6 Ps - Pain, pallor, pulselessness, paraesthesia, paresis/paralysis and poikilothermic (cold)
Remember to compare to contralateral limb to index limb
Explain compartment syndrome
Muscle ischaemia leads to inflammation, oedema and venous obstruction
Then get tense and tender calf
Then rise in creatine kinase and risk of renal failure due to myoglobulinaemia
When is muscle ischaemia irreversible?
After 6-8 hours
What happens if there is irreversible ischaemia?
Major tissue loss or permanent loss damage, paralysis and profound
No pulse over artery or vein
What are the options if the limb salvageable?
Suspicion of embolus then embolectomy
Suspicion of thrombus in situ - thrombolysis, thrombectomy or embolectomy and maybe bypass
What happens when the limb is not salvageable?
Palliate or amputation
Describe an embolectomy
Catheter passes through clot and balloon collects clot
Is acute limb ischaemia a medical emergency?
Yes
30% embolic and 60% thrombosis in situ
How many diabetic patients will develop ulcer?
25%
What is the pathophysiology of diabetic foot disease?
Microvascular peripheral artery disease, peripheral neuropathy, mechanical imbalance, foot deformity, minor trauma and susceptibility to infection
Describe foot care for diabetics in DFU prevention?
Always wear shoes
Check fit of footwear
Check pressure points/plantar surface of foot
Wound care of skin breaches
Effective glycaemic control
Explain management of DFU
Prevention, Diligent wound care, infection and investigate for osteomyelitis, gas gangrene or necrotizing fasciitis (air between bones)
Explain surgical management of DFU
Revascularization - attempt distal crural angioplasty/stent and distal bypass
Amputation
What are adjunctive measures for DFU?
Dressings, debridement- larval therapy, negative pressure wound closure and skin grafts
What are major amputations?
Below knee and above knee as energy energy requirements are much more
