Peripheral Vascular Disease (PVD) Flashcards
Define Peripheral Vascular Disease (PVD)
Obstruction of large arteries not within the coronary, aortic or brain vasculature.
What are the causes of PVD?
- Atherosclerosis
- Inflammation leading to stenosis
- Thrombosis
- Emboli
What are the risk factors for PVD?
- Sex: male
- Age : older
- Diabetes mellitus
- BP high
- Elevated cholesterol (hyperlipidaemia)
- Tobacco
- Renal disease
- Obesity
- Homocysteinaemia
What are the stages of Atherosclerosis?
- Fatty Streak
- Fibrous Plaque
- Atherosclerotic Plaque
- Plaque rupture/ fissure & thrombosis
What symptoms may an atherosclerotic plaque produce?
- Stable angina
- Intermittent claudication
What symptoms may a ruptured plaque/ fissure & thrombosis produce?
- Unstable angina
- MI Stroke/ TIA
- Critical leg ischaemia
- Cardiovascular death
What are symptoms of PVD?
- Intermittent claudication
- Rest pain (burning distally)
- Blueness or paleness
- Coolness
- Gangrene
- Sores, wounds or ulcers (slowly or not healing)
- Infection (between toes)
- Diminished hair & nail growth where affected
What is Leriche’s syndrome? What does it indicate?
- Buttock intermittent claudication
- Sexual impotence
- Absent femoral pulse
- Indicates bilateral aorto-iliac occlusion
Define gangrene
Tissue necrosis with putrefaction
Describe dry gangrene
- Necrosed tissue mummified following infarction
- Black (haemoglobin breakdown) and dry
- Cellulitis spreads
- Zone of demarcation
Describe wet gangrene
- Superadded infection with the spore- and gas- forming anaerobe Clostridium perfringens
- Severe pain, patient septic & unwell
- Gas collection in subcutaneous tissue results in crepitus
- Cellulitis does not spread
- No zone of demarcation
What examinations would you perfume on suspected PVD?
- Pulses in limbs (& evidence of AF)
- BP
- Temperature of both limbs
- Palpate for abdo, femoral & popliteal aneurysm
- Capillary refill of toes
- Ankle-brachial pressure index (ABPI)
- Doppler
What is Buerger’s angle/ sign?
The angle at which the foot becomes white when raised from lying flat
A normal leg should remain perfused at 90 degrees
What is an ABPI and what does it show?
Ankle-brachial pressure index
The difference between brachial and ankle
- BP 0.9-1.2 = normal
- 0.4-0.8 = moderate arterial disease, consistent with claudication
- <0.4 = severe ischaemia, consistent with rest pain
What investigations would you perfume in suspected PVD?
- Arterial ultrasound scan with duplex
- Angiography
- CT
- Magnetic resonance angiography
Describe arterial ultrasound scan with duplex
- Determines degree of blood flow (& extent of atherosclerosis)
- Waveform
- Triphasic = normal
- Biphasic = moderate disease
- Monophasic = significant disease
Describe angiography
- Goild standard anatomical definition of the arterial tree
- Intra-arterial contrast, CT or magnetic resonance
- Done when surgery of angioplasty/ stent considered
What are the risks of angiography?
- Bleeding
- False aneurysm
- Thrombosis
- Distal embolization
- Allergic reaction to contrast
- Nephrotoxicity
Describe Fontaine’s classification of PVD
- Stage 1 = Asymptomatic
- Stage 2 = Intermittent claudication
- Stage 3 = Rest pain
- Stage 4 = Ulceration and/or grangrene
Define critical limb ischaemia
Chronic or acute-on-chronic ischaemia that endangers the whole or part of a leg
What are signs of critical limb ischaemia?
- Rest pain
- Tissue loss
- Ankle pressure <50mmHg
- Toe pressure less than 30mmHg
What are indications for intervention in lower limb ischaemia?
- Critical limb ischaemia
- Disabling claudication
Detail risk factor modifications you would want to consider
- Smoking cessation
- Antiplatelet therapy
- Treatment of hyperlipidaemia
- Exercise programmes
- Diabetes management
- Hypertension management
Describe the effectiveness of smoking cessation
- Improvement in claudication in 3-6 months
- Reduced risk of critical ishaemia, MI and mortality
What are the aims of treating hyperlipidaemia?
LDL <5.0mmol/l
Describe the methods and indications for use of different antiplatelet therapys
- Aspirin
- Lowers MI, stroke and death risk
- Low dose as effective as high dose
- Clopidogrel
- Better than aspirin in lowering risks
- Costly, use for;
- Aspirin intolerance
- Ineffectiveness of aspirin
- High risk cases
Outline the TASC guidelines
- Type A - endovasc. treatment
- Single stenosis <10cm
- Single occlusion <5cm
- Type B - endovasc. treatment
- Single <15
- Multiple, each <5
- Heavily calcified <5
- Popliteal stenosis
- Type C - surgery
- Recurrent after 2 endovasc. interventions
- Mulitple totalling >15
- Type D - surgery
- Chronic >20
- Popliteal & prox. trifurcation vessels
What is the treatment for patients with stable claudication?
- Risk factor reduction
- Supervised exercise program
- +/- Cilostazol - phosphodiesterase 3 inhibitor
- Antagonise platelet aggregation
- Increase heart contractility
- Enhance vascular smooth muscle relaxation
What surgical options are available in the treatment of PVD?
- Angioplasty
- Plaque excision
- Bypass grafting
Describe angioplasty
- Mechanically widen narrowed/ obstructed arteries using water-inflated balloon
- Poor sustained benefits
Describe bypass grafting
- Needed to circumvent seriously stenosed areas
- Saphenous vein > short SV > aim veins OR synthetic (ePTFE) graft
- Synthetics & veins equal in larger arteries
- Synthetics perform poorly in smaller arteries
What is Buerger’s disease (thromboangiitis obliterans)?
Outline;
- Aetiology
- Presentation
- Diagnostic criteria
Chronic segmental inflammation & thrombosis of small-medium sized arteries & veins of peipheral upper & lower limbs (especially hands & feet).
Aetiology
- Young men
- Smoking
- Lower socio-economic groups
Presentation (mainly hands & feet)
- Claudication to severe rest pain
- Exactly the same but more aggressive than PVD
- Reynaud’s phenomenom
- Later: enlarged, red, tender cord-like veins
Diagnostic criteria
- Shionoya
- Smoking history
- Onset <50yrs
- Infrapopliteal arterial occlusions
- Either arm involvement or phebitis migrans
- Absence of atherosclerotic risk factors other than smoking
What is Subclavian Steal Syndrome?
- Definition
- Causes
- Presentation
Definition
- Subclavian steal phenomenon: Stenosis/ occlusion of subclavian artery proximal to vertebral artery origin ⇒ ipsilateral backflow in that vertebral artery
- Subclavian steal syndrome: Symptoms in upper limb, brain or heart.
Causes
- Artherosclerosis
- Surgical repair of coarctation or Fallot’s tetralogy
- Asia 36% due to Takayasu’s arteritis (early presentation, females)
Presentation (2% symptomatic)
- Arm claudication, pain, fatigue
- On exercising the upper limb ⇒ Cerebellar signs
- Vertigo
- Visual loss
- Ataxia, diplopia, dysphagia, dysarthria
- Tingling/ numbness of the face
- Sensory hemianaesthesia/ transient hemiparesis
- Syncope
- Signs
- BP decreased in affected arm (/ difference of 10mmHg)
- Collapsing pulse
What is Takayasu’s arterisis?
