Peripheral Vascular Disease

Basics

Description

  • Obstruction of the peripheral arteries secondary to embolism or thrombus (acute) or plaque (chronic)
  • Caused by atherosclerosis or embolus
  • Patients with PAD may also have coronary artery and cerebrovascular disease
  • Epidemiology:
    • Risks factors (selected):
      • Age
      • Smoking
      • Diabetes
      • Hyperlipidemia
      • HTN
    • Associated with morbidity and mortality from other forms of atherosclerosis (coronary artery disease, stroke)
    • Complications:
      • Aneurysm
      • Thrombosis
      • Ulceration
      • Limb loss
  • Chronic arterial insufficiency (CAI):
    • Progressive obstructing atherosclerotic disease causing subacute ischemia and pain (claudication)
    • Up to 10% develop critical leg ischemia
  • Acute arterial insufficiency (AAI):
    • Caused by arterial thrombosis (50%) or embolism
    • Trauma (including iatrogenic)
    • Causes acute limb ischemia with signs and symptoms of the 6 Ps (below)
  • Atheroembolism:
    • Caused by rupture or partial disruption of an atherosclerotic plaque (aorta, femoral, iliac)
    • Gives rise to cholesterol emboli that shower and obstruct arteriolar networks
    • May be precipitated by invasive arterial procedures such as cardiac catheterization

Etiology

  • Obstruction by atherosclerotic plaques (CAI)
  • Arterial thrombosis
  • Arterial emboli:
    • Cardiac emboli from dysrhythmias, valvular heart disease, atrial myxoma, or cardiomyopathy (80%)
    • Aneurysms
    • Infection
    • Tumor
    • Vasculitis or foreign body
    • Thrombosis of plaques from pre-existing CAI
  • Atheroembolism

Diagnosis

Signs and Symptoms

History
  • CAI:
    • Claudication:
      • Aching pain in the calves (femoropopliteal occlusion) or buttocks and thighs (aortoiliac region)
      • Occurs with activity and slowly relieved by rest or dependent positioning
      • Classic claudication presents in about 1/2 of patients with PVD
    • Severe disease presents with:
      • Limb pain at rest, usually starting in the foot
      • Rapidly progressive claudication or ulceration
      • Usually exacerbated at night with relief of pain when foot is hung off the bed
  • AAI:
    • Extremity pain:
      • Sudden onset
      • Gradual increase in severity
      • Starts distally and moves proximally over time
      • Decrease in intensity once ischemic sensory loss occurs
      • Embolism can occur proximally and move more distally in a minority of cases
  • Atheroembolism:
    • Complaint of cold and painful fingers or toes
    • Small atherosclerotic emboli may affect both extremities
    • Usually related to recent arteriography, vascular, or cardiac surgery
    • Can be related to aneurysm and/or stenotic disease of a more proximal source
    • Multiorgan involvement is common (renal, mesentery, skin, others)

Physical Exam

ALERT
Sudden onset of pain and pallor in extremity is limb and life threatening
  • CAI:
    • Absent or decreased peripheral pulses
    • Delayed capillary refill with cool skin
    • Increased venous filling time
    • Bruits
    • Pallor and dependent rubor of the leg
    • Muscle and skin atrophy
    • Thickened nails and loss of dorsal hair
    • Ulcerations (especially toes or heels) or gangrene with severe disease
  • AAI:
    • 6 Ps:
      • Pain (first, sometimes only symptom)
      • Pallor
      • Pulselessness
      • Poikilothermic
      • Paresthesias (late finding)
      • Paralysis (late finding)
    • Identification of a source of a possible embolic process is crucial (atrial fibrillation, cardiomegaly)
    • Assess paralysis segmentally in the limb by isolating muscle groups (i.e., holding the calf to assess intrinsic muscles of the foot)
  • Atheroembolism:
    • Ischemic and painful digits
    • “Blue-toe syndrome”
    • Livedo reticularis

Essential Workup

  • CAI:
    • Ankle–brachial index (ankle systolic BP divided by higher arm systolic BP)
    • Formal arterial doppler
    • Bedside test to determine whether CAI is present (see NEJM video reference)
    • Ratio of <0.9 is abnormal and <0.4–5 indicates severe disease
    • Calcific arteries (diabetes) can have false-negative ABI or elevated ABI (>1.3)
  • AAI:
    • Physical diagnosis using the 6 Ps
    • Those with acute-on-CAI tolerate limb ischemia better than those without CAI, due to well-developed collateral circulation
  • Atheroembolism:
    • Clinical diagnosis: Affected areas painful, tender, and may be either dusky or necrotic
    • Workup may investigate source of emboli with duplex US, CT angiogram, ECG

Diagnostic Tests and Interpretation

Lab
  • CBC
  • Electrolytes, BUN, creatinine, glucose
  • Coagulation studies
  • Creatine phosphokinase to evaluate for ischemia
  • Special tests for suspected etiologies:
    • Hold blood for hypercoagulable studies
    • Sedimentation rate and CRP for vasculitis
    • Blood cultures for endocarditis

Imaging
  • Doppler US:
    • Visualizes both venous and arterial systems
    • Identifies level of arterial occlusion, as well as thrombosis and aneurysm
    • Sensitivity and specificity >80–90% for occlusion of vessels proximal to the popliteal vessels
  • Plethysmography/segmental pressure measurements:
    • Uses measurements of the volume and/or limb pressure to characterize the arterial perfusion
    • Variable availability depending on the quality of the duplex technician as well as the equipment utilized
    • Approximates US in sensitivity and specificity
  • Angiography:
    • Determines details about the anatomy, including the level of occlusion, stenosis, and collateral flow
    • Useful where the diagnosis of AAI is uncertain or before emergent bypass grafting
    • Advantage is intervention (atherectomy, angioplasty, percutaneous thrombectomy, and/or intraluminal thrombolytics) can be done at the time of diagnosis
    • Can be used to plan future open revascularization
  • CT angiogram:
    • CT is useful for diagnosis of occlusive aortic disease or dissection
    • Rapidly available and reliable
    • Many centers have moved to CT angiogram as the first-line diagnostic tool. The decision for operative or angiographic intervention is based on the CT angiogram
    • Requires contrast, therefore may not be first line for patients with renal insufficiency
  • MRI:
    • Sensitive for evaluation of CAI and dissection
    • Plaques can be identified within the vasculature
    • Disadvantages are that MRI is time consuming and expensive, therefore, limiting its utility in the ED

Differential Diagnosis

  • Acute thrombosis or emboli
  • Arterial dissection
  • Deep venous thrombosis
  • Venous insufficiency
  • Venous aneurysm
  • Popliteal entrapment syndrome
  • Baker cyst
  • Extrinsic mass compression (i.e., tumor)
  • Compartment syndrome
  • Buerger disease
  • Spinal stenosis
  • Neuropathy
  • Bursitis
  • Arthritis
  • Reflex sympathetic dystrophy

Treatment

Pre Hospital

  • Maintain hemodynamic stability with fluids
  • Apply cardiac monitor to assess for potential dysrhythmia
  • Place the ischemic limb at rest and in a dependent position
  • Provide oxygen if low oxygen saturation or pulmonary symptoms

Initial Stabilization/Therapy

  • IV fluid bolus for hypotension
  • ECG, monitor, pulse oximetry
  • Supplemental oxygen
  • Pain control
  • Avoid temperature extremes

Ed Treatment/Procedures

  • CAI:
    • Antiplatelet therapy with aspirin 81–325 mg/d or clopidogrel 75 mg/d may be used as first-line treatment. Dual therapy has not been shown to improve outcomes, although may be indicated in other forms of atherosclerosis
    • Other drugs include: Cilostazol 100 mg b.i.d, pentoxifylline 400 mg t.i.d, and dipyridamole 200 mg b.i.d
    • Revascularization depending on the severity and location of obstruction:
      • Balloon angioplasty with possible stent placement
      • Atherectomy
      • Bypass grafting
    • Risk-factor modification:
      • Tobacco cessation
      • Aggressive management of hyperlipidemia, HTN, diabetes
      • Exercise therapy
  • AAI:
    • Limit further clot propagation with IV heparin 80 U/kg IV bolus → 18 U/kg/hr IV gtt
    • Do not anticoagulate patients suspected of having an aortic dissection or symptomatic aneurysm
    • Emergent consultation with vascular surgery or interventional specialty (radiology and/or cardiology):
      • To determine which diagnostic study is best to make the diagnosis
      • To begin arrangements for possible operative therapy and/or other intervention
      • Options for operative therapy include percutaneous thrombectomy, embolectomy, angioplasty, regional arterial thrombolysis, bypass grafting
      • Blood flow to the affected limb must be re-established within 4–6 hr after onset of ischemic symptoms
    • Complications of AAI include:
      • Compartment syndrome
      • Irreversible ischemia requiring amputation
      • Rhabdomyolysis, renal failure
      • Electrolyte disturbances
  • Atheroembolism:
    • Treat conservatively if a limited amount of tissue is involved and renal function is not significantly compromised
    • No clear therapy for the ischemic digits besides supportive wound care and analgesia
    • Formal arterial US
    • Some studies have tried corticosteroids to decrease inflammation, statins to stabilize plaque, aspirin, or dipyridamole
    • Amputation for irreversibly necrotic toes
    • Vascular surgeon referral within 12–24 hr of ED visit
    • Prevent further embolic events by a thorough investigation and correction of the source of atheroemboli

Medication

  • Aspirin: 81–325 mg PO per day
  • Cilostazol: 100 mg PO b.i.d
  • Clopidogrel: 75 mg PO per day
  • Heparin: 80 U/kg bolus IV followed by 18 U/kg/hr IV
  • Pentoxifylline: 400 mg PO t.i.d
  • Medical optimization (antiplatelet agents, statins, control of hypertension, diabetes, cardiac and renal functions)

Ongoing Care

Disposition

Admission Criteria
  • All patients with AAI are admitted for evaluation and revascularization
  • CAI: Consider admission for rapidly progressive claudication or ischemic pain at rest:
    • To undergo heparinization and angiography to rule out an acute thrombosis
  • Atheroembolism admission indicated with large areas involved, significant pain, infection, or renal compromise

Discharge Criteria
  • Atheroembolism:
    • If they have small lesions, adequate pain control, no evidence of renal compromise or superinfection, and follow-up within 24 hr
  • CAI:
    • No evidence of rapid progression, critical leg ischemia, gangrene, or infection

Issues for Referral
  • CAI will need urgent referral to vascular surgery
  • Atheroembolism, depending on the origin of the emboli, may need referral to vascular surgery or to cardiology

Follow-Up Recommendations

CAI without acute ischemia and atheroembolism with minimal involvement should have close follow-up to evaluate the extent of their disease

Additional Reading

  • Alonso-Coello P, Bellmunt S, McGorrian C, et al. Antithrombotic therapy in peripheral artery disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed.: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141:e669S–e690S.
  • Grenon SM, Gagnon J, Hsiang Y. Video in clinical medicine. Ankle–brachial index for assessment peripheral arterial disease. N Engl J Med. 2009;361:e40.
  • Morley RL, Sharma A, Horsch AD, et al. Peripheral artery disease. BMJ. 2018;360:5842.
  • Patel MR, Conte MS, Cutlip DE, et al. Evaluation and treatment of patients with lower extremity peripheral artery disease: Consensus definitions from Peripheral Academic Research Consortium (PARC). J Am Coll Cardiol. 2015;65:931–941.
  • Rooke TW, Hirsch AT, Misra S, et al. 2011 ACCF/AHA focused update of the guideline for the management of patients with peripheral artery disease (updating the 2005 guideline): A report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2011;58:2020–2045.

See Also

Authors

Lindsay Taylor
Sally A. Santen


© Wolters Kluwer Health Lippincott Williams & Wilkins