intermittent claudication; vascular claudication; Charcot's syndrome; myasthenia angiosclerotica

Introduction

A condition caused by peripheral arterial disease (PAD) resulting in ischemia of muscles. It is characterized by attacks of lameness & pain, brought on by walking, chiefly in the muscles of the calf. Other muscle groups may be involved.

Etiology

• atherosclerosis (most common cause)
• risk factors
  • smoking (most significant risk factor)
  • diabetes mellitus
  • hyperlipidemia
  • hypertension
  • moderate alcohol consumption (beer & wine) may reduce risk
• arteritis
  • connective tissue diseases
  • giant cell (temporal) arteritis
  • thromboangiitis obliterans (Buerger's disease)
  • Raynaud's disease
  • artery entrapment
• symptoms of abrupt onset, digit or upper extremity involvement, or a patient < 40 years of age suggest an uncommon etiology

Epidemiology

• commonly presents after the 5th decade of life
• 1-2% of adults & 10% of individuals over 70 years have symptomatic PAD
• progressive deterioration occurs in 15-20% of patients
• 10% of patients with lower extremity PAD have high grade carotid artery stenosis
• 50% of patients with lower extremity PAD have high grade coronary artery stenosis

Clinical manifestations

• pain in lower extremities (buttocks & calves)
  • most commonly involves calf muscles, also buttocks, thigh, foot
  • cramping, pain, weakness or numbness in affected muscles
  • symptoms predictably elicited by walking a certain speed or distance
  • symptoms relieved by rest; relief within 5 minutes
• a decrease in claudication threshold correlates with progression of disease
• pain at rest occurs in advanced disease
  • generally involves the foot distal to the metatarsals (nocturnal metatarsalgia)
  • aggravated by elevation of legs or cool temperatures
• concurrent coronary artery disease (CAD) &/or risk factors for CAD
• diminished pulses (dorsalis pedis & posterior tibial)
• arterial bruits (femoral, Hunter's canal)
• diminished temperature in affected extremities
• ischemic ulcers
  • generally painful
  • generally located on distal portion of toes, interdigital areas, or pressure sites
• signs of arterial insufficiency
  • dry, scaly, atrophic skin
  • extremity hair loss
  • brittle nails
  • dependent rubor
• dependent edema
• muscle weakness &/or atrophy
• lower extremity pallor within 1 minute after leg elevation to 60 degrees with return of color delayed more than 15 seconds after lowering
• disparate ankle/brachial systolic blood pressure index (ABI)
  • < 0.9 is abnormal
  • < 0.8 indicates moderate disease
  • < 0.6 indicates severe disease
  • < 0.4 associated with ulcers & gangrene
  • 20% decrease post exercise indicates PAD in patients with normal resting ABI
  • ankle pressures in diabetic may be falsely elevated due to medial calcinosis of arteries
• 50% of patients with clinically significant PAD are asymptomatic
• nocturnal leg cramps & cold feet generally are not symptoms of PAD

Diagnostic procedures

• ankle/brachial index (ABI) see peripheral arterial disease
  • exercise testing ABI if ABI equivocal
• ultrasound with doppler velocity analysis
  • pulse volume recordings
• magnetic resonance angiography (MRA)
• CT angiography, digital subtraction angiography
• other
  • impedance plethysmography
  • arteriogram (aortogram with runoffs, invasive)

Differential diagnosis

• arthritis
• lumbar spinal stenosis
  • symptoms elicited by walking or prolonged standing
  • symptoms relieved by flexing spine (i.e sitting)
  • numbness, tingling or paresthesias
  • time to relief < 30 min vs < 5 min for intermittent claudication
• herniated lumbar disc, lumbar radiculopathy
• peripheral neuropathy
• muscle cramps
• restless legs syndrome
• shin splints
• venous claudication
  • venous stasis & edema
  • generally associated with pain at rest
• chronic compartment syndrome
  • chronic exertional compartment syndrome 10 severe peripheral arterial disease
  • chronic limb-threatening ischemia
• nerve entrapment, popliteal nerve

Management

• medical management of stable intermittent claudication
• conditioning exercises - supervised program
  • most effective treatment for improving maximum walking distance & pain-free walking distance
  • as effective as revascularization procedures
  • arm exercises improve walking distance
• smoking cessation
• control contributing diseases
  • diabetes, hyperlipidemia, hypertension, CHF, COPD
• antiplatelet agents may reduce progression of PAD
  • aspirin (preferred)
  • clopidogrel
  • no evidence to suggest benefit of dual antiplatelent therapy
• pharmacologic agents of marginal benefit
  • vasodilators
    • may diminish systemic blood pressure & decrease collateral blood flow
    • ramipril improves ABI & exercise tolerance,
      • study finding ramipril improves pain-free & total walking time retracted
  • pentoxifylline (Trental) 400 mg TID of no benefit
  • cilostazol (Pletal) better than pentoxifylline
    • improves pain-free walking & overall walking distance
    • contraindication in patients with heart failure
    • preferred option prior to referral to vascular surgery
  • beta-blockers
    • do NOT affect walking capacity in patients with mild to moderate peripheral arterial disease
    • relatively contraindicated in patients with critical limb ischemia
  • statins may be of benefit
    • treat dyslipidemia (see peripheral arterial disease)
      • high-intensity statin therapy
  • other agents have been suggested
    • ketanserin, heparan sulfate, prostaglandin I2, ticlopidine, Ca+2 channel blockers, EDTA chelation therapy, fish oil, dipyridamole, ridogel, L-carnitine, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (BFGF), Gingko biloba
• hydration with >= 2500 mL if fkuid daily benefifial
• intermittent pneumatic comression (> 2.5 hours/day) may improve walking distance
• revascularization procedures
  • improves ABI & treadmill walking in combination with exercise therapy or medical therapy
  • alone, no better than exercise therapy alone
  • reserve for patients with risk of limb loss or those who have severe limitaton despite conservative therapy
  • improves function, symptoms, & quality of life relative to medical therapy
  • revascularized patients with higher rates of chronic limb ischemia & amputation than medically managed patients
  • higher rates of adverse outomes with angioplasty, stenting, atherectomy ' within 6 months of diagnosis unless limb-threatening ischemia
  • angioplasty
    • iliac artery:
      • with stenting
      • 80% 1 year & 60% 5 year patency
    • popliteal artery:
      • 65% 1 year & 40% 5 year patency
      • bypass is procedure of choice
  • stent placement further increases patency rates
  • peripheral artery bypass
    • success rates similar to angioplasty
    • procedure of choice for popliteal artery or tibial artery occlusion
    • aortoiliac revascularization
      • aortofemoral/aortobifemoral bypass
      • subcutaneous axillofemoral & femoral-femoral prosthetic bypass grafts
    • infrainguinal bypass graft
      • use of saphenous vein (with valves removed) connected proximally & distally to the arterial lesion
    • polytetrafluoroethylene grafts yield lower patency rates than native grafits
• foot care
  • inspect feet daily
  • avoid hot water when washing feet & do not use heating pads
  • dry between toes to prevent maceration
  • apply moisturizing lotion to feet
  • keep nails trimmed
  • wear comfortable shoes
  • do not walk barefoot
  • seek professional help for corns & callouses
• risk of progressing to critical ischemia is < 5% annually with stable symptoms

More general terms

• claudication
• peripheral arterial disease
• syndrome

Additional terms

• leg pain