II. Background
- Claudication derived from latin claudicatio, to limp
III. Epidemiology: Prevalence
- Overall
- 7-12 million affected in United States
- 200 million affected worldwide
- Age
- Age over 60 years: 3 to 6%
- Age over 70 years: 10 to 18%
- Age over 85 years: 50%
- References
IV. Risk Factors
- Precautions
- Risks are additive (1.5 fold increase for 1 risk factor, 10 fold increase with 3 or more risk factors)
- Age over 60 (Odds Ratio 4.1)
- Cerebrovascular Disease (Odds Ratio 3.6)
- Coronary Artery Disease (Odds Ratio 3.5)
- Diabetes Mellitus (Odds Ratio 2.5)
- Hyperlipidemia (Odds Ratio 1.9)
-
Tobacco Abuse (risk persists >5 years after cessation)
- Cigarette smoking 20 per day: 2.11 Relative Risk
- Cigarette smoking 11-20 per day: 1.75 Relative Risk
- In one study, 80% of PAD cases were in current or former smokers
- Meijer (1998) Arterioscler Thromb Vasc Biol 18(20: 185-92 [PubMed]
- Black race
- Systolic Hypertension
- Hyperhomocysteinemia
- Increased Body Mass Index (Obesity)
- C-Reactive Protein increased
- Chronic Kidney Disease with GFR rate <60 ml/min/1.73m2
- Eraso (2014) Eur J Prev Cardiol 21(6): 704-11 [PubMed]
V. Associated Conditions
-
Coronary Artery Disease (Myocardial Infarction)
- Major adverse cardiac events (MI, CVA, CV-related death)
- Carotid Stenosis (Cerebrovascular Accident)
- Abdominal Aortic Aneurysm (9% comorbid Prevalence, 15.8% if age >75 years)
VI. Symptoms
- Presentations
- Classic Claudication: 10% of cases
- Atypical Leg Pain: 50% of cases
- Asymptomatic: 40% of cases
- Classic Claudication
-
Critical Limb Ischemia (1% of presentations)
- Tissue loss or gangrene
- Burning pain or numbness in the forefoot may awaken patient
- Pain improves with hanging leg over the side of the bed (with dependent redness or rubor)
- Chronic (>2 weeks) ischemic rest pain, often occurring soon after falling asleep
- Chronicity allows for collateral vessel development and preserved limb viability despite severe symptoms
-
Acute Limb Ischemia (see management below)
- Cold, painful, pale limb with diminished or absent pulses
- Motor weakness
- Decreased Sensation
- Abrupt onset allows for no collateral circulation, and a short window of viable tissue for revascularization
- Timing of symptoms related to degree of stenosis
- Exertional pain: 70% arterial pain
- Nocturnal pain: 70 to 90% arterial stenosis
- Ischemic rest pain: 90% arterial stenosis
VII. Exam
- Vascular Exam (Arterial Bruits or diminished pulses)
- Abdominal aorta bruit
- Femoral artery bruit
- Femoral artery pulse
- Dorsalis pedis pulse (absent in up to 3% of normal patients)
- Posterior tibial pulse
- Carotid Artery pulse and bruit (for comorbid Carotid Stenosis)
-
Neurologic Exam
- Critical in determining Acute Limb Ischemia degree (see Rutherford Classification below)
- Extremity Motor Exam
- Extremity Sensory Exam
VIII. Signs
- Most reliable signs of Peripheral Vascular Disease (Sensitivity, Specificity assumes ABI<0.9)
- Posterior tibial artery Doppler Ultrasound
- All 3 components present rules-out Peripheral Arterial Disease
- Only 1 of 3 components present is strongly suggestive of PAD (Positive Likelihood Ratio = 7.0)
- Dorsalis pedis AND posterior tibial pulse absent
- Test Sensitivity: 63%
- Test Specificity: 99%
- Femoral artery bruit
- Test Sensitivity: 29%
- Test Specificity: 95%
- Atypical Skin Color (pale, red, blue) of extremity
- Test Sensitivity: 35%
- Test Specificity: 87%
- Posterior tibial artery Doppler Ultrasound
- Local Signs of Peripheral Vascular Disease
- Dry, scaly, shiny atrophic skin
- Skin hairless over lower extremity (e.g. shin)
- Dystrophic, brittle Toenails
- Non-healing ulcers or other lower extremity wounds
- See Arterial Ulcer
- Ulcers are well-demarcated and appear to be "punched out"
- Decreased skin Temperature (cool feet)
- Decreased Capillary Refill Time
- Distal extremity color change with position
- Skin rubor when leg dependent
- Skin pallor when leg elevated >1 minute
- Color returns within 15 seconds in mild cases
- Delay >40 seconds suggests severe ischemia
IX. Signs: Acute Limb Ischemia (5 P's)
- Early finding
- Pain
- Late findings
- Pulselessness
- Pallor
- Paresthesias
- Paralysis
X. Signs: Occlusion Location
- Inflow Disease: Aortoilliac Occlusive Disease
- Also known as Leriche's Syndrome
- Bilateral leg diminished pulses throughout
- Slow Wound Healing legs
- Impotence
- Outflow Disease
- Iliofemoral Occlusive Disease
- Unilateral leg diminished pulses throughout
- Buttock Claudication may be present
- Femoropopliteal Occlusive Disease
- Thigh and calf Claudication
- Normal femoral pulses in groin
- Iliofemoral Occlusive Disease
XI. Classification
- Rutherford Classification of Acute Limb Ischemia
- Category I: Viable (no immediate threat)
- No sensory deficit
- No motor deficit
- Arterial doppler audible but typically monophasic (but venous doppler audible)
- Category IIA: Marginally threatened (salvageable if promptly treated)
- Minimal sensory deficit (e.g. toes involved)
- No motor deficit
- Arterial doppler inaudible (but venous doppler audible)
- Category IIB: Immediately Threatened (salvageable if immediately revascularized)
- Sensory deficit with rest pain
- Mild to moderate motor deficit
- Arterial doppler inaudible (but venous doppler audible)
- Category III: Irreversible (major tissue loss with permanent nerve injury)
- Severe sensory deficit with complete Anesthesia
- Severe motor deficit with paralysis or rigor
- Arterial doppler inaudible (but venous doppler audible)
- Category I: Viable (no immediate threat)
- Fontaine Stage
- Stage I: Asymptomatic
- Ankle-Brachial Index < 0.9
- Decreased distal pulses
- Stage II: Intermittent Claudication
- Stage III: Daily rest pain
- Stage IV: Focal tissue necrosis (non-healing ulcers)
- Ankle-Brachial Index < 0.3 (50% block)
- Stage I: Asymptomatic
- Grading Claudication
- Initial Claudication Distance
- Distance patient first experiences exertional pain
- Absolute Claudication Distance
- Furthest distance patient is able to walk
- Initial Claudication Distance
XII. Differential Diagnosis
- See Leg Pain
- See Hip Pain
- See Knee Pain
- See Foot Pain
- Common and important other Leg Pain causes
- Lumbar Spinal Stenosis (Pseudoclaudication)
- Peripheral Neuropathy (e.g. Diabetic Neuropathy)
- Nerve Entrapment (e.g. Meralgia Paresthetica, Posterior Tarsal Tunnel Syndrome)
- Night Cramps
- Exertional Compartment Syndrome (or Chronic Compartment Syndrome)
- Stress Fracture
- Arthritis
- Intermittent Claudication (Peripheral Vascular Disease)
- Deep Vein Thrombosis (DVT)
- Venous Insufficiency
-
Acute Limb Ischemia differential diagnosis
- Congestive Heart Failure with superimposed PVD
- Identical presentation to limb ischemia
- Deep Venous Thrombosis
- Blue extremity without pallor
- Swollen, painful extremity
- Acute Spinal Cord Compression
- Skin Color normal
- Limb paralysis with pain and Paresthesias
- Congestive Heart Failure with superimposed PVD
-
Acute Limb Ischemia sites of compromise proximal to extremity
- Thoracic Aortic Dissection
- Abdominal Aortic Aneurysm (AAA)
- Embolic phenomenon from a cardiac source
XIII. Labs
- Complete Blood Count with Platelets
- Lipid profile
- Serum Homocysteine
- Apolipoprotein A
- Serum Creatinine
- Hemoglobin A1C or Fasting Serum Glucose
- Urinalysis for glucosuria or Proteinuria
- Consider screening for Hypercoagulability
XIV. Diagnosis
- See Edinburgh Claudication Questionnaire
- See PAD Score
- See Segmental Arterial Pressure
-
Ankle-Brachial Index
- ABI is the Vital Sign of Peripheral Arterial Disease
- Obtain for diagnosis and monitor periodically for disease progression
- Ankle-Brachial Ratio >1.4: Non-compressable vessels (False Negative)
- Ankle-Brachial Ratio >0.9: Normal
- Ankle-Brachial Ratio <0.5: Severe, multi-level disease
- Ankle-Brachial Ratio <0.3: Limb Threatening Ischemia (requires emergent intervention)
- Ankle-Brachial Ratio <0.2: Gangrenous extremity
- Alternative Studies
- Toe-Brachial Ratio
- Typically 0.7 to 0.8
- Abnormal <0.7 (severe if <0.4)
- Exercise ABI Testing
- Obtain ABI immediately after walking 5 minutes on treadmill at 12% grade and 2.0 miles/h OR
- Symptoms require patient to stop
- Six-Minute Walk Test
- Toe-Brachial Ratio
XV. Imaging
-
Ultrasound
- Ultrasound Ankle-Brachial Index
- Segmental Arterial Doppler Ultrasound
-
Abdominal Aorta Ultrasound
- Consider at time of periperal arterial disease diagnosis (due to association with AAA)
- CT Angiography
- CTA Abdomen and Pelvis with limb runoff
- Preferred definitive study in Acute Limb Ischemia
XVI. Screening: Indications with Ankle-Brachial Index
- Guidelines vary per organization
- USPTF does not recommend routine screening unless symptomatic
- Symptom Example: Exertional Leg Pain or non-healing distal extremity wounds
- Cardiovascular Risk Reduction even without PAD diagnosis will benefit PAD in addition to other vascular disease
- USPTF does not recommend routine screening unless symptomatic
-
Diabetes Mellitus (ADA, ACC/AHA)
- Start at age 50 years or earlier if other comorbid PAD Risk Factors
- Other example risks: Tobacco Abuse, Hyperlipidemia, Diabetes Mellitus >10 years
- Repeat every 5 years
- Start at age 50 years or earlier if other comorbid PAD Risk Factors
- Age over 65 years old (ACC/AHA)
- Age 50 to 64 years old AND atherosclerosis risks (Hypertension, Diabetes Mellitus, Hyperlipidemia, Tobacco, FHx PAD)
- Known vascular disease affecting another system (e.g. AAA, Carotid Stenosis, Coronary Artery Disease, Mesenteric Ischemia)
XVII. Grading
- History
- Degree of extremity pain
- Pain-free walking distance
- Questionaires (e.g. Walking Impairment Questionaire)
- Treadmill testing
- Maximal walking distance
- Pain-free walking distance
XVIII. Course
- Typical course of non-critical ischemia
- Claudication remains stable in 80% of patients
- Five year risk of Claudication worsening: 16%
- Claudication requiring surgery: 25%
- Risk of limb loss (amputation)
- Stable non-critical ischemia
- Risk at five years: 4-7%
- Risk at ten years: 12%
- Critical Limb Ischemia
- Risk at 6-12 months from onset: 80-90%
- Stable non-critical ischemia
- Five year Mortality from atherosclerotic cause: 29%
- Coronary Artery Disease deaths: 60%
- Cerebrovascular Accident related deaths: 15%
- Overall survival
- Survival at ten years: 38%
- Survival at fifteen years: 22%
XIX. Management
- Acute Limb Ischemia (Emergency management)
- Chronic Claudication
- See Peripheral Vascular Disease Management (Claudication Management)
- Cardiovascular Risk Reduction is critical
- PAD carries same risk as Coronary Artery Disease
XX. Prognosis
- See Peripheral Arterial Disease 10-Year Mortality Index
- Intermittent Claudication progresses to Critical Limb Ischemia in 21% of cases
- Critical Limb Ischemia is associated with a 25% annual mortality rate (esp. due to cardiovascular cause)
XXI. Resources
- Vascular Disease Foundation
XXII. References
- Boccalon (1999) Drugs Aging 14:247
- Broder (2024) Crit Dec Emerg Med 38(4): 23-4
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- Carman (2000) Am Fam Physician 61(4):1027-32 [PubMed]
- Firnhaber (2019) Am Fam Physician 99(6): 362-9 [PubMed]
- Firnhaber (2022) Am Fam Physician 105(1): 65-72 [PubMed]
- Gardner (1995) JAMA 274(12):975-80 [PubMed]
- Gey (2004) Am Fam Physician 69:525-33 [PubMed]
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- Hirsch (2001) JAMA 286(11):1317-24 [PubMed]
- Imparato (1975) Surgery 78:795-9 [PubMed]
- Samuelson (March, 2000) Fed Pract, p. 34-50
- Santilli (1999) Am Fam Physician 59(7):1899-908 [PubMed]
- Santilli (1996) Am Fam Physician 53(4):1245-53 [PubMed]
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