Peripheral artery disease resident survival guide

Peripheral artery disease Resident Survival Guide
Overview
Causes
Diagnosis
Treatment
Do's
Don'ts

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: José Eduardo Riceto Loyola Junior, M.D.[2]

Synonyms and keywords: Peripheral artery disease approach, Approach to claudication, Approach to the peripheral arterial disease

For the complete wikidoc page on claudication click here.

Overview

Claudication is the description of cramping muscle pain that occurs after a certain degree of exercise and is relieved by rest. Claudication is classically caused by peripheral arterial disease, in which an obstruction in the artery of the lower limbs can lead to an insufficient blood flow which is not enough to supply the demands from the muscles of that region, but there are other conditions that can mimic its symptoms such as nerve root compression, spinal stenosis, hip arthritis, symptomatic Baker's cyst, venous claudication and chronic compartment syndrome.

Causes

Life Threatening Causes

There are no life-threatening causes, which include conditions that may result in death or permanent disability within 24 hours if left untreated.

Common Causes

• Peripheral arterial disease
• Venous claudication
• Arterial thromboembolism
• Cholesterol embolism
• Vasculitis
• Nerve root compression (radiculopathy, plexopathy)
• Peripheral neuropathy
• Lumbar canal stenosis (pseudoclaudication)
• Spinal stenosis
• Arthritis/Connective tissue disease
• Baker's cyst
• Muscle strain
• Ligament/tendon injury
• Chronic compartment syndrome

Diagnosis

Shown below is a flowchart for diagnostic testing for suspected peripheral arterial disease according to the 2016 AHA/ACC guidelines:

Suspected PAD

Symptoms: ❑ Leg pain at rest ❑ Reduced or absent pulses ❑ Leg pain during exertion ❑ Gangrene ❑ Pale extremity ❑ Non healing wound ❑ Calf or foot cramping ❑ Paresthesias

Suspected critical limb ischemia

Order Ankle brachial index

≤ 0.90

Normal 1.00-1.40 Borderline 0.91-0.99

> 1.40

Order Exercise ankle-brachial index if exertion non-joint related leg symptoms If absent - search for alternative diagnosis

Order Toe-Brachial Index

Exercise ankle-brachial index

Does the patient have > 20% decrease in Postexercise ABI?

Is TBI < 0.7?

Yes

No

No

Yes

PAD confirmed

No PAD - search for alternative diagnosis

PAD confirmed

Lifestyle-limited claudication despite guideline-directed management and therapy, revascularization considered

Yes

No? Continue guideline-directed management and therapy

Anatomic assessment: (Class I) ❑ Duplex ultrasound ❑ Computed tomography angiography ❑ Magnetic resonance angiography

Anatomic assessment: (Class IIa) ❑ Invasive angiography

Shown below is a table summarizing the differential diagnosis of claudication according the age and clinical presentation:

Differential Diagnosis of Intermittent Claudication and Lower Limb Pain

In younger patients
Diagnosis	Clinical Features	Diagnostic Method of Choice	Treatment
Buerger's Disease	Rare vasculitis mostly seen in young Asians males who are smokers. Causes inflammation and thrombosis of the arteries of the legs, feet, forearms, and hands.	Conventional angiography - multilevel occlusions and segmental narrowing of the lower extremity arteries with extensive collateral flow showing a corkscrew or “tree root” appearance	Smoking cessation
Extrinsic Compression by Bone Lesions	Not a common cause, 40% of osteochondromas arise from the posterior aspect of distal femur compressing the femoral artery.	MRI, limb x-ray or CT scan	Excision of the lesion and repair of the affected artery
Popliteal Artery Entrapment Syndrome	Common in young patients with claudication, especially athletes - compression of the popliteal artery by the medial head of the gastrocnemius muscle.	Stress angiography	Surgery
Fibromuscular Dysplasia	Affects young women of childbearing age, affects mostly renal, cerebral and visceral arteries but may affect limbs as well.	Angiography - string-of-beads appearance	Angioplasty
Takayasu's Arteritis	Rare vasculitis mostly seen on Asian and South American women. Stenosis of the abdominal aorta and iliac arteries are present in 17% of the patients and may cause claudication.	Conventional angiography	Corticosteroids, methotrexate, azathioprine, and cyclophosphamide
Cystic Adventitial Disease	1 in 1200 cases of claudication, most common in men, 20-50 years without risk factors for atherosclerosis. It is caused by repetitive trauma, which causes the formation of a mucin-containing cystic structure in the wall of the popliteal artery.	Conventional angiography, MRI	Complete excision of the cyst with prosthetic and vein replacement, as well as bypass
In older patients
Spinal Stenosis	Motor weakness is the most important symptom, which may be accompanied by pain. It starts soon after standing up, and may be relieved by sitting or bending (lumbar spine flexion)	MRI	Analgesic drugs, physical therapy, acupuncture or surgery (gold standard)
Peripheral Arterial Disease	May present with absent or reduced peripheral pulses, and audible bruits but some patients may not present with these symptoms. A low ankle-brachial pressure index (<0.9) is suggestive of the disease but if normal it does not exclude it. An exercise ankle-brachial pressure index can be done on patients that don't present with these signs. Other clinical features include decreased skin temperature, shiny, hairless skin over the lower extremities, pallor on the elevation of the extremity, dystrophic toenails, and rubor when the limb is dependent.	Handheld Doppler, conventional angiography	Smoking cessation, antiplatelet drugs, statins, diabetes and blood pressure control, exercise, percutaneous transluminal angioplasty.
Nerve Root Compression	caused by compression of the nerve root by other structure, such as an herniated disc. The pain usually radiates down the back of the leg and is described as sharp lancinating pain. It may be relieved by adjusting the position of the back (leaning forward).	MRI	Surgery
Hip Arthritis	Pain starts when the patient undergoes weight bearing and is worsened by activity. The pain is continuous and intensified by weight bearing, with inflammatory signs such as tenderness, swelling, and hyperthermia.	MRI	Surgery
Baker's Cyst	Pain is worsened with activity, not relieved by resting, and may have tenderness and swelling behind the knee.	Ultrasound, MRI	Surgery

Treatment

Shown below is an algorithm summarizing the diagnosis of claudication due to peripheral arterial disease according the the British Medical Journal guidelines.

Evaluate affected limb - check for color and trophic changes, early ulcerations, skin temperature, capillary refill time, pulses at the groin and popliteal fossa, and the pedal pulses.

If peripheral arterial disease is suspected: Screening test: ankle-brachial index (systolic blood pressure of the dorsalis pedis, posterior tibialis, or fibularis artery is obtained with a handheld Doppler and divided by the higher of the two brachial pressures) - if <0.9 confirms peripheral arterial disease.

Secondary prevention for coronary arterial disease: start aspirin 75mg daily and statins

Control cardiovascular risk factors (hyperglycemia, obesity, dyslipidemia, smoking)

Advise the patient to exercise for 30 minutes twice daily to increase pain-free walking and total walking distance by stimulating collateral blood flow)

Cilostazol may be used for improving symptoms

Be aware of the 5 Ps—pain, pale, pulseless, paraesthesia, paralysis—indicating an acute limb ischemia

Do's

• Assess for peripheral arterial disease, as it is the most common cause for intermittent claudication, but do consider other causes depending on the age;
• Confirm the diagnosis by measuring the ankle-brachial pressure indices;
• Assess the risk factors for atherosclerosis and mitigate them. Encourage patients to cease smoking, to control their blood glucose, prescribe antiplatelet drugs, optimize antihypertensive medication doses, start statins and encourage exercise;
• If there is no improvement, symptoms are disabling or diagnosis is uncertain, refer to a specialist.
• The best treatment options for peripheral arterial disease are: open surgery, endovascular therapy, and exercise therapy. These were superior to medical management in achieving longer walking distance and managing claudication.
• Antiplatelet drugs with either aspirin or clopidogrel alone is recommended to reduce myocardial infarction, stroke, and vascular death in patients with symptomatic PAD.
• In patients with claudication, supervised exercise programs increases functional status and reduces leg symptoms.
• Patients with diabetes mellitus should be oriented to perform self-foot examination and healthy foot behaviors. Quick diagnosis and treatment of foot infections can prevent amputation.

Don'ts

• Symptomatic treatment of the claudication and leg pain must not overshadow the reduction of cardiovascular risk, as these patients have a significantly increased risk of death.
• When treating peripheral arterial disease, always attempt reducing symptoms with less invasive treatment options such as exercising, do not immediately refer patients to more invasive treatment options;
• Don't forget to address other causes of claudication if the patient is presenting it at a younger age, or if the treatment doesn't improve the symptoms.
• Do not perform invasive or non-invasive anatomic assessments for asymptomatic patients.
• In patients who are not at increased risk of peripheral arterial disease, and without a history of physical examination findings suggestive of PAD, the ankle-brachial index is not recommended.
• Anticoagulation should not be used to reduce the risk of cardiovascular ischemic events in patients with PAD.
• Pentoxifylline is not effective for treatment of claudication.

References