Peripheral Artery Disease

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Introduction

PAD is a substantial burden on people and populations.

It is often asymptomatic, underdiagnosed.

 

 

The Case of...

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Causes and Risk Factors

PAD can occur

Acute causes

Acute embolic occulsion, occuring in anyone. Emboli most often originate in the heart, following atrial fibrillation, myocardial infarction, or myxoma. Other causes include aneurysm.

Acute thrombotic occlusion is an acute on chronic disease following years of atherosclerotic buildup, often following dehydration, hypercoagulability, or other thrombotic situations.

trauma

 

Chronic Causes

Atherosclerosis, usually occurring in older patients, accounts for the majority of cases of chronic PAD. Risk factors include:

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Pathophysiology

Atherosclerosis develops over years with vessel damage, inflammation, and plaque buildup. As the lumen diameter decreases, velocity increases. At rest, distal structures receive sufficient blood, but with exercise and increased oxygen demand, symptoms arise.

Atherosclerosis commonly occurs in more than one site, causing stroke and coronary artery disease.

PAD normally develops over time. As vascular supply decreases, collaterals develop, slightly increasing perfusion. Worsening disease. further decreases

Normally, one joint below the site of arterial disease is affected.

Pain evetually develops while at rest, 1-20 years after claudication occurs. Rest pain is especially bad at night due to the lack of gravity. Walking a few steps or sleeping in a chair improves symptoms as gravity assists in foot perfusion.

Dependent rubor represents the accumulation of venous blood in areas

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Signs and Symptoms

PAD can be remembered by the five P's:

 

  • history
  • physical exam

History

acute ischemia

  • pain
  • pallor
  • pulselessness
  • polar (cold)
  • parasthesias
  • paralysis

History of present illness

  • intermittent claudication: pain, tightening, or cramping, brought on by exercise and relieved by rest.
  • night pain, rest pain
  • impairment of ADLs and IADLs

Past medical history

  • hypertension
  • diabetes
  • dyslipidemia

Family history

  • coronary artery disease
  • stroke

 

Physical Exam

Limbs should be examined for

  • size
  • symmetry
  • edema
  • muscle atrophy

Skin:

  • colour/pigmentation
  • texture
  • loss of hair
  • ulceration (venous vs arterial vs neuropathic)
  • scarring
  • gangrene
  • nails: colour and texture
  • venous distribution
  • stasis dermatitis
  • temperature
  • capillary refill

Peripheral pulses

  • dorsalis pedis, posterial tibial, popliteal, femoral
  • radial ulnar, brachial, carotid

Bruits can be heard over arteries in aorta or peripheral vessels

Pallor in elevated limbs

A reddened, mottled foot should be raised to distinguish between severe dependent rubor and lobster foot.

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Investigations

  • lab investigations
  • diagnostic imaging

Lab Investigations

Diagnostic Imaging

Ankle-brachial index (systolic) can be taken using doppler flow

  • abnormal hardening: >0.91
  • normal: 0.9-1.2
  • mild-moderate: 0.4-0.9
  • severe: <0.4

CTA

MRA

angiogram

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Differential Diagnosis

DVT

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Treatments

Treatment depends on chronic or acute etiology, disease severity, and patient co-morbidities.

 

Lifestyle

exercise, quitting smoking, diet modifaction.

 

Surgery

Chronic PAD has a relative indication while patients have claudication. Grafts have a limited lifetime, and patients will often die of other causes (ie stroke, myocardial infarction) before PAD becomes too severe.

and an absolute indication when the limb is threatened. Not everyone with chronic PAD

 

Acute disease

Acute emboli are treated by balloon catheterization and embolectomy.

Acute thrombosis is treated with arthroplasty or bypass.

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Consequences and Course

With severe PAD, ongoing ischemia can lead to ulcers,

Once rest pain develops, it is only weeks to months before total occlusion occurs and gangrene sets in. A threatened limb accordingly

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Additional Resources

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Topic Development

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