Peripheral Vascular Disease

PERIPHERAL VASCULAR DISEASE (aka PERIPHERAL ARTERY DISEASE)

PATHOLOGY:

• Circulation disorder involving the slow & progressive narrowing of arteries especially in upper/lower extremities
• Leading cause is atherosclerosis resulting from deposition of cholesterol & lipids within the vessel walls. This thickens the arterial walls but reduces the diameter of the lumen
• Clinical symptoms occur when vessels are 60% - 75% blocked
• In USA, 6% of adults >40 y/o and 13% of adults >60 y/o have PVD/PAD

RISK FACTORS:

Diabetics and those who smoke are at highest risk of developing complications from PVD, because their clinical manifestations also involve impaired blood flow

• Age (especially > 60 years old)
• Diabetes
• Smoking/tobacco use
• Coronary Artery Disease or history of CVD
• Hypertension
• More prevalent in men
• More prevalent in non-Hispanic African Americans
• Hyperlipidemia (elevated cholesterol & LDLs)
• Sedentary lifestyle or physical inactivity
• Obesity
• Family history of atherosclerosis

CLINICAL MANIFESTATIONS:

 Clinical manifestations depend on site & extent of blockage, and the amount of collateral circulation

• Intermittent claudication (ischemic muscle pain triggered by exercise & resolves with rest)
• Decreased or absent peripheral pulses
• Cap refill > 3 sec
• Paresthesia
• Loss of hair on legs, feet & toes
• Cool skin temp especially down the leg
• Thin, shiny & taut skin texture
• Thickened & brittle nails
• Elevation pallor (pallor or blanching of foot in response to leg elevation)
• Dependent rubor (hyperemia or redness of foot when limb is in dependent/dangling position)
• Rest pain in foot or toes especially when lying flat
• Limb ulcerations (thinned skin & compromised sensation ↑ risk of injury & wound formations)
• Critical limb ischemia (may lead to amputation of affected extremity)

COMPLICATIONS:

• Erectile dysfunction (if the PVD involves internal iliac arteries)
• Nonhealing arterial ulcers & gangrene (may lead to amputation)

DIAGNOSTIC TESTS: 

Tests that assess blood flow and outline the vascular system are utilized

• Health history & physical exam including palpation of peripheral pulses
• Doppler ultrasound with duplex imaging (maps blood flow throughout an entire region of artery)
• Segmental BPs (drop in segmental BP of ≥ 30 mmHg suggests PVD)
• Angiography & Magnetic Resonance Angiography (traces location & extent of PVD)
• Ankle-branchial index (this screening tool is not recommended for geriatrics or diabetics)

COLLABORATIVE CARE: 

Drug therapies are listed in the “Treatments” section

Interventions

• Confirm diagnosis through diagnostic tests (diagnostic tests listed above)
• Provide foot care
• ↓ ischemic pain
• Prevent/control infection

Risk Factor Modification

• Tight blood glucose control especially in diabetics
• Aggressive hyperlipidemia treatment (dietary interventions & drug therapy)
• Control hypertension

Patient Teaching

• Tobacco cessation
• Nutritional therapy

• Implement DASH diet
• Diet high in fruits, vegetables & whole grains, low in cholesterol & saturated fats
• Limit salt intake

• Regular physical exercise (walking is most effective exercise for patients with claudication)
• Achievement or maintenance of ideal body weight
• Teach proper foot & skin care

Goals & Outcomes

• Achieve adequate tissue perfusion
• Pain relief
• BP less than 130/80 mmHg
• Develop intact & healthy skin on extremities
• BMI < 25 kg/m2 for men & < 35 kg/m2 for women

TREATMENTS:

Drug Therapy

Anticoagulants ex. Warfarin (Coumadin) are not recommended for prevention of CVD events in PVD patients. Combination antiplatelet therapy with Aspirin + Clopidogrel (Plavix) is also not recommended. Note that effects of Clopidogrel (Plavix) are halved when taken with Omeprazole (Prilosec)

• Cilostazol (Pletal) & Pentoxifylline (Trantal) treat intermittent claudication (classic PVD symptom)
• Statins ex. Simvastatin (Zocor) to lower LDL
• Antiplatelet agents

• 75-100 mg/day Aspirin PO for patients with asymptomatic PVD
• 75-325 mg/day Aspirin PO for patients with symptomatic PVD
• Aspirin-intolerant patients may take Clopidogrel (Plavix) daily

• Antihypertensive therapy

• Thiazides ex. Chlorothiazide (Diuril)
• ACE inhibitors ex. Lisinopril

Surgical Therapy

Used to improve blood flow past a blocked artery

• Peripheral artery bypass surgery (involves usage of an autogenous or synthetic vein graft)
• Endarterectomy (opening of the artery & removing the obstructing plaque)
• Patch Graft Angioplasty (just like endarterectomy, but a patch is sawn to the opening to widen lumen or diameter of the vessel)
• Amputation (last resort)

Interventional Radiology Catheter-Based Procedures

Offer less invasive alternatives to open surgical approaches for treating lower extremity PVD.