Peripheral Vascular Disease Flashcards
What causes peripheral vascular disease (PVD)?
Who does it affect?
PVD is caused by atherosclerosis causing stenosis commonly affecting the:
=> aorto-iliac arteries
=> infra-inguinal arteries
Commonly affects the middle aged ; men > women
Mortality is often assoc. with co-existing CVS or cerebrovascular disease, not PVD
PVD = umbrella term for many different conditions/manifestations
What are the clinical symptoms of chronic lower limb ishcaemia?
Fontaine classification:
Stage I: asymptomatic
Stage II: intermittent claudication
Stage III: Rest pain / nocturnal pain
Stage IV: necrosis / gangrene
=> intermittent claudication: patients complain of exertional discomfort/cramping pain in the calf, thigh, buttock. Relieved by rest.
Patients with aorto-iliac disease => pain in bum, hip, thigh ± erectile dysfunction
=> Rest pain: severe, burning, unremitting pain in foot - stops patient from sleeping. Relieved by dangling foot over the edge of the bed or standing on a cold floor = cardinal feature of critical ischaemia
=> Severe PVD / lower limb ischaemia = ulceration or necrosis of tissue (gangrene)
What are the signs of chronic lower limb ischaemia ?
Cold, white lower limbs with dry skin + lack of hair
Atrophic skin ; punched out ulcers (painful)
Pulses femoral, popliteal, foot absent
Ulceration ± dark discolouration of toes / gangrene
Capillary filling time >15s - severe ischaemia
What is the differential diagnosis for chronic lower limb ischaemia ?
Spinal canal claudication (all pulses present)
Osteoarthritis of the hip/knee (knee pain at rest)
Peripheral neuropathy
Popliteal artery entrapment
Venous claudication (bursting pain with walking with past hx of DVT)
Fibromuscular dysplasia
Buerger’s disease
What are the investigations for [acute & chronic] lower limb ischaemia?
- Ankle/Brachial pressure index (ABPI) - severity of chronic limb ischaemia
=> ABPI 0.5 - 0.9 = intermittent claudication
=> ABPI <0.5 = critical limb ischaemia - Colour duplex ultrasound = first line investigation
- Contrast-enhanced MR angiography
- CT angiography
- Digital subtraction angiography
- Exclude diabetes, arteritis (ESR, CRP), FBC (anaemia, polycythaemia), U&E (renal disease), lipids (dyslipidaemia), ECG (cardiac ischaemia), thrombophililia screen
What is the medical management of chronic lower limb ischaemia?
- Risk factor management because PVD patients at increased risk of IHD and cerebrovascular disease. Diabetes managed + regular chiropodist review.
Quit smoking. - Supervised exercise programme to all with intermittent claudication
- Naftidrofuryl oxalate => vasodilator agent, inhibits vascular and platelet 5HT2 receptors => lowers lactic acid
=> Improves quality of life + increase walking distance
What is the surgical management of chronic lower limb ischaemia?
Percutaneous trans-luminal angioplasty = first line
=> carried out via a catheter inserted into femoral artery
Arterial stents may be used in recurrent iliac disease
Bypass procedures
Amputation in severe ischaemia with unreconstructable arterial disease
What are the symptoms of acute lower limb ischaemia?
5 P's => Pain => Pallor => Paraesthesia => Paralysis => Perishingly cold
What are the signs of acute lower limb ischaemia?
Cold skin with molting / marbling => irreversible
Pulses diminished/ absence
Sensation and movement of the leg reduced in severe ischaemia
Patients may deliver compartment syndrome with pain in the calf on compression
What is the underlying aetiology of acute lower limb ischaemia?
Acute limb ischaemia may occur due to an embolic or thrombotic disease.
Embolic disease:
=> commonly due to cardiac thrombus / arrhythmia i.e. AF
=> also due to 2nd to aneurysm thrombus or thrombus from an atherosclerotic plaque
Thrombotic disease:
=> more common than emboli
=> acute thrombus forms on a chronic atheroscleroctic stenosis in patients with symptoms of claudication
=> thrombus in normal vessels if hypercoagulable due to malignancy or thrombophilia
=> Prosthetic or venous graft can thrombose
=> Popliteal aneurysm can thrombose or embolise distally
What is the management for acute lower limb ischaemia?
Surgical emergency requiring revascularisation within 4-6h to save the limb !!
- Surgical management: urgent open surgery/angioplasty
=> Occluded grafts = graft thrombolysis
=> Underlying stenosis within a graft or vessel = angioplasty
=> Surgical removal (embolectomy)
=> Bypass graft after occlusion of popliteal aneurysm or acute-on-chronic lower limb arterial disease
=> Amputation for unreconstructable / severe ischaemia
- Medical management:
=> Patients improving can be managed on heparin + treatment of underlying cause
=> Emboli following MI or AF need long term warfarin
What are the complications of treating acute lower limb ischaemia?
Sudden improvement from ischaemic limb revascularisation => reperfusion syndrome => release of toxic metabolites into circulation
Oedema => compartment syndrome => requires fasciotomies
Acute aortic syndromes:
Acute aortic syndromes include
=> aortic dissection
=> intramural haematoma
=> penetrating aortic ulcers
INFO CARD
Acute aortic syndromes:
What is aortic dissection?
Aortic dissection starts with a tear in the intima. Blood penetrates the diseased medial layer, through the intimal layer => aortic dissection
Aortic dissection is classified according to the timing of diagnosis from the origin of symptoms:
i. Acute : <2 weeks
ii. Sub-acute : 2-8 weeks
iii. Chronic : >8 weeks
*mortality decreases with time
Aortic dissection can also be classified anatomically:
i. Type A : aortic arch and aortic valve proximal to left subclavian artery origin
=> this includes De Bakey type 1 (extends to abdominal aorta)
=> De Bakey type 2 (localised to ascending aorta)
ii. Type B : descending thoracic aorta distal to the left subclavian artery origin
=> this includes De Bakey type 3
What are the clinical features of acute aortic syndromes?
Symptoms:
=> sudden onset of severe, central chest pain
=> often radiates to the back and down the arm
=> mimics MI
=> pain = tearing in nature
=> pain may be migratory
Signs: => Shock => Neurological symptoms secondary to loss of blood supply to spinal cord => Aortic regurgitation => Coronary ischaemia => Cardiac tamponade
=> Acute kidney failure, acute lower limb ischaemia, visceral ischaemia in distal extension
=> peripheral pulses absent