The vascular system and stroke - Acute and chronic limb ischaemia Flashcards
What is peripheral arterial disease (PAD) ?
PAD is a term used to describe a narrowing or occlusion of the peripheral arteries, affecting the blood supply to the lower limbs
a) What is PAD most commonly caused by?
b) Which gender is it more common in?
c) How is the prevalence affected as you age?
d) What two diseases is it associated with?
a) Atherosclerosis
b) Males
c) Prevalence rises with age
d) Coronary artery disease and cerebrovascular disease
List 6 important modifiable risk factors of PAD
- Smoking (most important)
- Diabetes
- Hypertension
- Obesity
- Hyperlipidaemia
- Hypercholesterolemia
- Hyperhomocysteinemia
- C-reactive protein
What classification is used to classify the clinical presentation of PAD?
Fontaine classification
Describe the different stages and symptoms of the Fontaine classification
Stage I - asymptomatic
Stage II - Claudication
Stage Iia - Pain-free, claudication walking > 200m
Stage Iib - Pain-free, claudication walking < 200m
State III - Rest/nocturnal pain
State IV - Necrosis/gangrene
a) What is the most common sign of PAD?
b) Why is this sign important?
a) Asymptomatic PAD
b) Detection of symptomatic PAD identifies patients at increased risk of atherosclerosis in other vascular territories
What factors will encourage you to investigate and asymptomatic patient with PAD
- Abnormal or absent pedal pulses
- Age =/> 70 years
- Age 50-69 years and history of smoking or diabetes
Describe the investigation process for asymptomatic PAD
What is the most common symptom of PAD?
Intermittent claudication
Explain and describe what intermittent claudication is
- Exercise-induced muscle pain due to a lack of oxygen when you exercise
- Most commonly affects the calf, thighs and buttocks
- Relieved by rest
What is the distribution of disease of the following intermittent claudication site:
a) Buttock and hip
b) Thigh
c) Upper 2/3 of calf
d) Lower 1/3 of calf
e) Feet
a) Aortoiliac disease (Leiriche syndrome triad - laudication, erectile dysfunction, and decreased distal pulses)
b) Aortoiliac or common femoral artery
c) Superficial femoral artery
d) Popliteal artery
e) Tibial or peroneal artery
Where is the intermittent claudication found in the follow distribution of disease:
a) Aortoiliac
b) Aortoiliac or common femoral artery
c) Superficial femoral artery
d) Popliteal artery
e) Tibial or peroneal artery
a) Buttock and hip
b) Thigh
c) Upper 2/3 of calf
d) Lower 1/3 of calf
e) Feet
What are the atypical symptoms of PAD?
- Pain similar to classic claudication, but does not cause the patient to stop walking
- Pain similar to classic claudication, but does not involve calves or does not resolve within 10 minutes of rest
- Leg pain on both excretion and rest
What is chronic limb threatening ischaemia (CLTI)/critical limb ischaemia
A decrease in limb perfusion that causes a potential threat to limb viability in patients who present > 2 weeks after onset of symptoms
What are the 4 symptoms of chronic limb threatening ischaemia
- Ischaemic rest pain
- Tissue loss
- Ischaemic ulcer
- Gangrene
What are the two types of gangrene?
Dry (ischaemic) gangrene
Wet (infectious) gangrene
a) What is dry (gangrene)
b) What are the common causes of dry (ischaemic) gangrene
c) Is infection usually present?
d) Describe the management of dry (ischaemic) gangrene
a) Dry gangrene is ischaemic gangrene. It is necrosis that is secondary/develops due to cholerically reduced blood flow
b) Diabetes and tobacco smoking
c) No
d) Can be left to auto-amputate or can be amputated after revascularisation
a) What is (infectious) gangrene occur?
b) Why is wet gangrene a very serious and life threatening condition if not treated quickly?
c) Describe the management of wet (infectious) gangrene
a) Liquefactive necrosis due to infection. The tissue swells and blisters and is called “wet” because of pus
b) Infection from wet gangrene can spread quickly throughout the body
c) broad-spectrum IV high dose Abx
Revascularisation, debridement +/= amputation
Describe the difference between dry (ischaemic) gangrene and wet (infectious) gangrene
Dry (ischaemic) gangrene - patients do not show sign of infection
Wet (infectious) gangrene - Patients are pyrexial/septic
What investigation would you do to investigate PAD?
- Duplex ultrasound
- CT angiography
- MR angiography
- Contrast angiography
a) Why is contrast angiography avoided?
b) When would you do a contrast angiography in a patient being investigated for pad?
a) it is an invasive procedure and so has more complications
b) If the running investigations do not give sufficient information
Describe the management of PAD in asymptomatic patients or patients with mild claudication
Conservative - lifestyle modifications
- Smoking cessation
- Supervised exercise classes - 2 hrs weekly for 3 months
- Diet control
Pharmacological therapy - manage CVD risk
- Risk factor modification (control DM, BP with antihypertensives, cholesterol)
- Anti-platelet therapy (clopidogrel 75mg)
- Anti-cholesterol therapy with statins (80mg atorvastatin nightly)
Describe the management of PAD causing short distance claudication
Conservative - lifestyle modification
- Supervised exercise classes - 2 hrs weekly for 3 months
Pharmacological therapy - manage CVD risk
- BP/DM/Cholesterol control
- Antiplatelets (Clopidogrel 75mg, aspirin if contraindicate) and statins (atorvastatin 80mg nightly)
- Naftidrofyrl oxalate (vasodilator which alleviates pain in PAD)) / Cilostazol ( improves symptoms of claudication)
Endovascular
- Angioplasty +/- stent placement
Surgical revascularisation
- Endarterectomy
- Peripheral bypass graft (autologous graft/prosthetic)
Describe the management of chronic limb threatening ischaemia
- Lifestyle modification and wound care
- Pharmacological therapy
- Revascularization via angioplasty/endarterectomy/bypass (to relieve rest pain or for management of tissue loss/gangrene to avoid amputation)
- Amputation
a) What is angioplasty?
b) How does excessive calcification effect angioplasty
c) What are the complications?
a) Angioplasty is pressure controlled balloon inflation to fracture arterial plaque and remodel the artery
b) Excessive calcification is resistant to angioplasty
c)
- Arterial puncture site haemorrhage
- Arterial rupture
- Dissection
- Distal embolisation
- Contrast induced nephropathy
Stents is an endovascular surgical option to treat PAD causing short distance claudication.
a) What are stents
b) What are the two types of stents?
a) Stents are supportive frameworks that apply radial force to diseased arteries and promote vessel remodelling
b) Balloon expandable and self-expanding stents
What is the indication to use endarterectomy to treat PAD?
When PAD causes short distance claudication and the lesion is in a readily accessible site such as the common femoral artery
What type of bypass can be used to treat PAD and include what they can be constructed from
- Infra-inguinal bypass (can be constructed from autologous or prosthetic graft)
- Aorto-iliac, femoral-femoral crossover and axillo-bifemoral bypass -(constructed using prosthetics graft)
Describe the prognosis of intermittent claudication
- Over a 5-year period most people continue to have stable claudication
- 10-10% develop worsening symptoms
- 5-10% develop critical limb ischaemia
-Amputation is eventually required in roughly 1-2% of people with intermittent claudication - This increases to 5% in people with diabetes
Of people with critical lim ischaemia, how many are estimated to need a:
a) revascularisation procedure?
b) lower limb amputation within a year of diagnosis without revascularisation
a) 50-90%
b) 1/3
What is acute limb ischaemia (ALI)?
A sudden decrease in limb perfusion that causes a potential threat to limb viability in patients who present within 2 weeks of the acute event
Describe the aetiology of ALI
Mainly caused by thrombosis or embolisation
Embolus - cardiac source
- AF
- MI
- Endocarditis
- Atrial myxoma
- Prosthetic valves
Embolus - arterial source
- Aneurysm
- Atherosclerotic plaque
Thrombosis
- Vascular grafts
- Atherosclerosis
- Thrombosis of aneurysm
- Entrapment
- Hypercoaguable state
Trauma
- Blunt
- Penetrating
- Iatrogenic