[13] Peripheral Arterial Disease Flashcards
What is peripheral arterial disease?
A condition where there is significant narrowing of the arteries distal to the arch of the aorta, most often due to atherosclerosis
What is the clinical relevance of PAD?
Patients diagnosed as having PAD, inclduing those who are asymptomatic, are at increased risk of mortality, myocardial infarction, and stroke
What is the most severe manifestation of PVD affecting a limb?
Critical limb ischaemia
What is critical limb ischaemia? q
A chronic condition defined as the presence of ischaemic rest pain, and ischaemic lesions or gangrene objectively attributable to arterial occusive disease
What are the risk factors for peripheral arterial disease?
- Smoking
- Diabetes mellitus
- Hypertension
- Hyperlipidaemia
- Physical inactivity
- Obesity
What are the symptoms of peripheral arterial disease?
- Intermittent claudication
- Leriche’s syndrome
- Ischaemic rest pain
What is intermittent claudication?
Muscle pain in the lower limbs on exercise
What are the features of intermittent claudication?
- Walking impairment
- Symptoms relieved by rest
- Pain comes on more rapidly when walking uphill than walking on flat
- Often worse in leg
What walking impairment may be present in intermittent claudication?
- Fatigue
- Aching
- Cramping
- Pain in buttock, thigh, calf, or foot
What is Leriche’s syndrome?
Pain similar to intermittent claudication in the buttocks and thighs, associated with absent femoral pulses and male impotence
What is ischaemic rest pain?
Severe, unremitting pain in the foot, particularly at night
How might ischaemic rest pain be partially relieved by the patient?
By hanging the foot out of the bed
Where does ischaemic rest pain occur?
In severe, extensive PVD
What are the examination signs of PVD?
- Affected leg may be pale and cold, with loss of hair and skin changes
- May be poorly healing wounds of the extremities
- May be ulceration or gangrene in severe cases
- Weak or absent femoral, popliteal, dorsalis pedis, and posterior tibial pulse
What are the differential diagnoses of PVD?
- Sciatica
- Spinal stenosis
- Deep vein thrombosis
- Entrapment syndromes
- Muscle/tendon injury
What assessment should any patient suspected as having PAD have?
A full cardiovascular risk assessment
What is included in a full cardiovascular risk assessment?
- BP
- FBC
- Fasting blood glucose
- Lipid levels
- ECG
What % of people with intermittent claudication are found to have ECG evidence of pre-existing CVD?
60%
What additional investigations should PVD patients under the age of 50 have?
- Thombophilia screen
- Serum homocysteine levels
What is the main method of confirmation of a diagnosis of PVD?
Doppler ultrasonography
What is the role of duplex ultrasonography in the investigation of PVD?
It can determine the site of disease, and indicate the degree of stenosis and length of occlusion
What is the ABPI?
The ratio of systolic blood pressure at the ankle and the arm
What does the ABPI provide a measure of?
Blood flow at the ankle
What is a normal ABPI?
1
What ABPI indicates claudication?
0.6-0.,9
What ABPI indicates impending gangrene?
>0.3
Other than ultrasound, what imaging methods can be used in the investigation of PVD?
- MR angiography
- CT angiography
What diseases are associated with PVD?
- Coronary heart disease
- Cerebrovascular disease
- Diabetes
What are the criteria for referral to secondary care in PVD?
Is invasive intervention always required in the management of PVD?
No, most patient’s symptoms improve with optimal medical treatment
Is the course of PVD variable?
Yes
What intervention is sufficient to improve symptoms for many patients?
- Lifestyle changes
- Medical management
What % of PVD patients will deteriorate and develop critical limb ischaemia?
Approximately 20%
How can cardiovascular risk factors be modified in PVD?
- Smoking cessation
- Regular exercise
- Lipid-lowering drugs
- Management of hypertension
- ACE inhibitors
- Management of diabetes mellitus
How can patients be helped to do regular exercise in the management of PVD?
A supervised exercise programme which comprises of 2 hours of exercise per week for a 3 month period should be offered to all patients with PVD
What is the trade-off with the management of hypertension in PVD?
It provides a long term benefit, but in the short term may worsen intermittent claudication
What effect have ACE inhibitors been shown to produce in PVD patients?
Shown to reduce cardiovascular morbidity and mortality
Why should caution be taken when using ACE inhibitors in PVD?
Over 25% of PVD patients have renal artery stenosis
When is antiplatelet therapy recommended in PVD?
For those with symptomatic PVD
What is recommended as the anti-platelet agent in PVD?
Clopidogrel
What is the purpose of clopidogrel in PVD?
- It prevents occlusive vascular events
- Reduce incidence of major cardiovascular events
Why is clopidogrel preferred to aspirin in PVD?
It is at least as effective as aspirin, and has a better side-effect profile
What is naftidrofuryl oxalate?
An oral peripheral vasodilator
Where is naftidrofuryl oxalate recommended in PVD?
As an option for treatment of intermittent claudication in people with PVD, when supervised exercise has not lead to a satisfactory impovement, and the patient does not want surgery
When is revascularisation essential in PVD?
In patients with critical limb ischaemia
How useful is revascularisation surgery in mild-to-moderate claudication?
It has not been shown that revascularisation is superior to exercise and best medical treatment in patients with mild-to-moderate claudication
What are the indications for surgery in PVD?
- Disabling claudication
- Critical limb ischaemia
- Weak or absent femoral pulses
How long after diagnosis of critical limb ischaemia should revascularisation surgery be attempted?
Without delay
What are the surgical options for revascularisation in critical limb ischaemia
- Angioplasty and stening
- Bypass surgery and grafts
What should the decision about wether to perform angioplasty or bypass surgery in PVD take into account?
- Co-morbidities
- Pattern of disease
- Availability of a vein
- Patient preference
What are the amputation rates in critical limb ischaemia?
5-20%
When is amputation considered in critical limb ischaemia?
Mainly in patients unsuitable for revascularisation, neurologically impaired, or non-ambulatory
It should only be offered to patients when all options for revascularisation have been considered
Which surgical approach to revascularisation is generally favoured?
Angioplasty and stenting
Why is angioplasty and stenting generally favoured?
Due to reduced morbidity and mortality
What is the major drawback of endovascular internentions (angioplasty and stenting) compared with surgery (bypass grafting)?
Lower long-term patency
Which lesions is the patency after angioplasty and stenting greatest?
Those in the common iliac artery, and then patency decreases distally
What factors reduce the change of long-term patency after angioplasty?
- Increasing length
- Multiple and diffuse lesions
- Poor-quality run off
- Diabetes
- Chronic kidney disease
When should angioplasty be offered to people with intermittent claudication?
When risk factor modification has been discussed, supervised exercise has failed to improve symptoms, and imaging shows angioplasty is suitable for the patients
When is bypass grafting typically used in PVD?
Diffuse disease
When should bypass surgery be offered to people with intermittent claudication?
Only in people with severe, lifestyle-limiting intermittent claudication, when angioplasty has been unsuccessful or is unsuitable, and imaging has confirmed that bypass surgery is appropriately for the person
What is the effect of PVD on quality of life?
Quality of life is often significantly impaired, particularly as a result of reduced mobility
What are the potential complications of PVD?
- Acute limb ischaemia may result from thrombosis arising within a peripheral artery or from embolic occlusion
- Infection and poor healing of tissue with reduced blood supply
- Ulceration
- Gangrene
- Amputation
- Multi-organ dysfunction
