Peripheral Arterial Occlusive Disease

Aka: Peripheral Arterial Occlusive Disease, Peripheral Arterial Disease, Peripheral Vascular Disease, Arterial Insufficiency, Claudication, Vascular Claudication, Aortoilliac Occlusive Disease, Leriche's Syndrome, Iliofemoral Occlusive Disease, Femoropopliteal Occlusive Disease

1. History
   1. Claudication derived from latin claudicatio, to limp
2. Epidemiology: Prevalence
   1. Overall: 7-12 million affected in United States
   2. Age over 60 years: 3 to 6%
   3. Age over 70 years: 10 to 18%
3. Risk Factors
   1. Age over 60 (Odds ratio 4.1)
   2. Cerebrovascular Disease (Odds ratio 3.6)
   3. Coronary Artery Disease (Odds ratio 3.5)
   4. Diabetes Mellitus (Odds ratio 2.5)
   5. Hypercholesterolemia (Odds ratio 1.9)
   6. Tobacco abuse (risk persists >5 years after cessation)
      1. Cigarette smoking 20 per day: 2.11 relative risk
      2. Cigarette smoking 11-20 per day: 1.75 relative risk
   7. Systolic Hypertension
   8. Hyperhomocysteinemia
   9. Increased Body Mass Index (Obesity)
   10. C-Reactive Protein increased
4. Associated Comorbid Conditions
   1. Coronary Artery Disease (Myocardial Infarction)
   2. Carotid Stenosis (Cerebrovascular Accident)
5. Symptoms
   1. Claudication symptom characteristics
      1. Cramp-like Leg Pain with Exercise, better with rest
      2. Calf pain typical (pain may occur in thigh, buttock)
      3. Pain worse with exertion
      4. Pain relieved with several minutes rest (<10 minutes)
      5. Pain relieved with dependent position
   2. Timing of symptoms related to degree of stenosis
      1. Exertional pain: 70% arterial pain
      2. Nocturnal pain: 70 to 90% arterial stenosis
      3. Ischemic rest pain: 90% arterial stenosis
6. Signs (Sensitivity, Specificity assumes ABI<0.9)
   1. Most reliable signs of Peripheral Vascular Disease
      1. Posterior tibial artery doppler Ultrasound
         1. All 3 components present rules-out Peripheral Arterial Disease
         2. Only 1 of 3 components present is strongly suggestive of PAD (Positive Likelihood Ratio = 7.0)
      2. Dorsalis pedis and posterior tibial pulse absent
         1. Test Sensitivity: 63%
         2. Test Specificity: 99%
      3. Femoral artery bruit
         1. Test Sensitivity: 29%
         2. Test Specificity: 95%
      4. Atypical skin color (pale, red, blue) of extremity
         1. Test Sensitivity: 35%
         2. Test Specificity: 87%
   2. Vascular Exam (Arterial Bruits or diminished pulses)
      1. Abdominal aorta
      2. Iliac artery
      3. Femoral artery (and dorsalis pedis, posterior tibial)
      4. Carotid Artery
      5. Subclavian artery
   3. Neurologic Exam
      1. Critical in determining acute limb ischemia degree (see Rutherford Classification below)
      2. Extremity Motor Exam
      3. Extremity Sensory Exam
   4. Local Signs of Peripheral Vascular Disease
      1. Decreased skin temperature
      2. Dry, scaly, shiny atrophic skin
      3. Skin hairless over lower extremity (e.g. shin)
      4. Dystrophic, brittle Toenails
      5. Non-healing ulcers
      6. Distal extremity color change with position
         1. Skin rubor when leg dependent
         2. Skin pallor when leg elevated >1 minute
            1. Color returns within 15 seconds in mild cases
            2. Delay >40 seconds suggests severe ischemia
7. Signs: Acute Limb Ischemia (5 P's)
   1. Pain
   2. Pulselessness
   3. Pallor
   4. Paresthesias
   5. Paralysis
8. Signs: Occlusion Location
   1. Inflow Disease: Aortoilliac Occlusive Disease
      1. Also known as Leriche's Syndrome
      2. Bilateral leg diminished pulses throughout
      3. Slow Wound Healing legs
      4. Impotence
   2. Outflow Disease
      1. Iliofemoral Occlusive Disease
         1. Unilateral leg diminished pulses throughout
         2. Buttock Claudication may be present
      2. Femoropopliteal Occlusive Disease
         1. Thigh and calf Claudication
         2. Normal femoral pulses in groin
9. Classification
   1. Rutherford Classification of acute limb ischemia
      1. Category I: Viable (no immediate threat)
         1. No sensory deficit
         2. No motor deficit
      2. Category IIA: Marginally threatened (salvageable if promptly treated)
         1. Minimal sensory deficit (e.g. toes involved)
         2. No motor deficit
      3. Category IIB: Immediately Threatened (salvageable if immediately revascularized)
         1. Sensory deficit with rest pain
         2. Mild to moderate motor deficit
      4. Category III: Irreversible (major tissue loss with permanent nerve injury)
         1. Severe sensory deficit with complete anesthesia
         2. Severe motor deficit with paralysis or rigor
   2. Fontaine Stage
      1. Stage I: Asymptomatic
         1. Ankle-Brachial Index < 0.9
         2. Decreased distal pulses
      2. Stage II: Intermittent Claudication
      3. Stage III: Daily rest pain
      4. Stage IV: Focal tissue necrosis (non-healing ulcers)
         1. Ankle-Brachial Index < 0.3 (50% block)
   3. Grading Claudication
      1. Initial Claudication Distance
         1. Distance patient first experiences exertional pain
      2. Absolute Claudication Distance
         1. Furthest distance patient is able to walk
10. Differential Diagnosis
    1. See Leg Pain
    2. Acute limb ischemia differential diagnosis
       1. Congestive Heart Failure with superimposed PVD
          1. Identical presentation to limb ischemia
       2. Deep Venous Thrombosis
          1. Blue extremity without pallor
          2. Swollen, painful extremity
       3. Acute spinal cord compression
          1. Skin color normal
          2. Limb paralysis with pain and Paresthesias
    3. Acute limb ischemia sites of compromise proximal to extremity
       1. Thoracic Aortic Dissection
       2. Abdominal Aortic Aneurysm (AAA)
       3. Embolic phenomenon from a cardiac source
11. Labs
    1. Complete Blood Count with platelets
    2. Lipid profile
    3. Serum Homocysteine
    4. Apolipoprotein A
    5. Serum Creatinine
    6. Hemoglobin A1C or fasting Serum Glucose
    7. Urinalysis for glucosuria or Proteinuria
    8. Consider screening for Hypercoagulability
12. Diagnosis
    1. See Edinburgh Claudication Questionnaire
    2. See PAD Score
    3. See Segmental Arterial Pressure
    4. See Ankle-Brachial Index
       1. ABI is the vital sign of Peripheral Arterial Disease
       2. Obtain for diagnosis and monitor periodically for disease progression
13. Grading
    1. History
       1. Degree of extremity pain
       2. Pain-free walking distance
    2. Questionaires (e.g. Walking Impairment Questionaire)
    3. Treadmill testing
       1. Maximal walking distance
       2. Pain-free walking distance
14. Course
    1. Typical course of non-critical ischemia
       1. Claudication remains stable in 80% of patients
       2. Five year risk of Claudication worsening: 16%
       3. Claudication requiring surgery: 25%
    2. Risk of limb loss (amputation)
       1. Stable non-critical ischemia
          1. Risk at five years: 4-7%
          2. Risk at ten years: 12%
       2. Critical limb ischemia
          1. Risk at 6-12 months from onset: 80-90%
    3. Five year Mortality from atherosclerotic cause: 29%
       1. Coronary Artery Disease deaths: 60%
       2. Cerebrovascular Accident related deaths: 15%
    4. Overall survival
       1. Survival at ten years: 38%
       2. Survival at fifteen years: 22%
15. Management
    1. See Claudication Management
    2. Cardiovascular Risk Reduction is critical
       1. Carries same risk as Coronary Artery Disease
16. Resources
    1. Vascular Disease Foundation
       1. http://www.vdf.org
17. References
    1. Boccalon (1999) Drugs Aging 14:247
    2. Boyd (1962) Proc R Soc Med 55:591-96
    3. Carman (2000) Am Fam Physician 61(4):1027-32
    4. Gardner (1995) JAMA 274(12):975-80
    5. Gey (2004) Am Fam Physician 69:525-33
    6. Hirsch (2001) JAMA 286(11):1317-24
    7. Imparato (1975) Surgery 78:795-9
    8. Samuelson (March, 2000) Fed Pract, p. 34-50
    9. Santilli (1999) Am Fam Physician 59(7):1899-908
    10. Santilli (1996) Am Fam Physician 53(4):1245-53
    11. Sontheimer (2006) Am Fam Physician 73(11):1971-6
    12. (1999) Med Lett Drugs Ther 41:(1052):44-6