Peripheral Arterial Disease
Peripheral arterial disease (PAD) is a circulatory condition that causes narrowing of the peripheral arteries, most commonly in the legs. As podiatrists, PAD is highly relevant to our practice. This in-depth guide will cover everything related to PAD– from risk factors and pathogenesis, to signs, diagnosis, treatment, prevention, and patient education.
What is Peripheral Arterial Disease?
Peripheral arterial disease refers to atherosclerotic blockages in the arteries supplying the extremities, most frequently the legs. It’s estimated that up to 10% of people over 70 have PAD.
In PAD, fatty plaque buildup inside the artery walls leads to progressive narrowing and restricted blood flow, primarily in the lower limb arteries. This can cause leg pain with use, non-healing foot ulcers, cool extremities, and other ischemic symptoms.
While often asymptomatic early on, untreated PAD can progress and lead to critical limb ischemia, gangrene, limb loss, or contributing to heart attacks and strokes. As podiatrists, diagnosing PAD early and managing it appropriately is very important.
Causes and Risk Factors
The predominant underlying cause of PAD is systemic atherosclerosis. Plaque accumulation within arteries occurs throughout the body but the leg arteries have higher susceptibility.
Major risk factors for developing PAD include:
Smoking – Cigarette smoking is the #1 risk factor for PAD due to direct arterial damage. Smokers have 4 times higher risk.
Diabetes – High blood glucose accelerates atherosclerosis. 1 in 3 diabetics over 50 have PAD.
High blood pressure – Adds stress to artery walls and accelerates plaque growth.
High cholesterol – Leads to fatty deposits on artery walls.
Older age – Prevalence rises steadily over 50 yrs old. 10-15% of seniors have PAD.
Family history of PAD – Genetic tendencies toward atherosclerosis.
Kidney disease – Uremia promotes vascular calcification.
Metabolic syndrome/obesity – Underlying inflammation and insulin resistance.
Lack of exercise – Sedentary lifestyles worsen atherosclerosis.
PAD Pathophysiology
In PAD, atherosclerotic plaques accumulate in the tunica intima of arterial walls over decades, leading to progressive stenosis (narrowing) of the peripheral leg arteries. This limits oxygen-rich blood flow to the legs and feet.
The segments most often affected are the femoral and popliteal arteries above the knee, and the tibial and peroneal arteries below the knee. However, PAD can involve the more proximal iliac and aortic branches, or more distal foot arteries.
As stenosis worsens, completely blocked arteries force collateral blood vessels to attempt to compensated. But this cannot adequately perfuse the extremities over the long term. Ischemic injury begins without sufficient blood supply.
In more advanced PAD, chronically ischemic limbs are prone to foot ulcers and poorer healing, claudication pain, cool/cyanotic feet, hair loss, and gangrene. Critical limb ischemia indicates severe, advanced PAD.
Symptoms of PAD
The symptoms of PAD in the legs can range from mild to severe depending on the degree of arterial narrowing:
Atypical leg pain – Mild heaviness, tiredness, cramping, or achiness in the calves, thighs or buttocks that occurs with walking then resolves with rest. This is called intermittent claudication.
Rest pain – More severe pain in the forefoot and toes even at rest, worsening at night and with elevation, indicating critical ischemia.
Numbness or tingling – Due to nerve damage from prolonged ischemia.
Cool, hairless, shiny skin – Palpable pedal pulses still present. Reflects mild chronic ischemia.
Non-healing foot ulcers – Due to impaired tissue perfusion and poor wound healing.
Gangrene – Black necrotic tissue indicating critically impaired perfusion.
Mild PAD may have no symptoms initially and is found incidentally by absent pedal pulses on exam. More advanced PAD manifests with classic claudication pain, however atypical leg pain is more common. Rest pain, ulcers, and gangrene indicate critical limb ischemia.
Clinical Evaluation
A thorough clinical assessment helps evaluate for possible PAD:
Medical history – Age, risk factors, comorbidities, medication use, family history of PAD. History of leg pain, ulcers, walking impairment.
Vascular review – Leg pain onset, duration, location, aggravating/relieving factors. Pain severity and progression.
Physical exam – Inspection for hair loss, skin atrophy, ulcers. Palpate pedal and popliteal pulses, compare bilaterally. Ankle-brachial index testing.
Foot exam - Assessment of protective sensation, ulcer location and severity, tissue perfusion.
Clinical suspicion then guides further vascular testing to confirm PAD diagnosis.
Diagnostic Testing
Some diagnostics we can order or perform to evaluate PAD include:
Ankle-brachial index – Compares systolic pressures at ankles to arms. ABA <0.9 indicates PAD. Simple, noninvasive.
Segmental pressure measurements – Assesses pressures along the leg. Helps localize stenosis sites.
Doppler arterial ultrasound – Visualizes plaque lesions in leg arteries and measures stenosis severity.
CT or MR angiography – Contrast enhanced imaging outlines arterial anatomy.
Angiography – Gold standard test. Contrast injected to highlight obstructions under live x-ray.
Treadmill testing – Assesses claudication onset and distance walked.
These allow characterization of PAD extent, location, and severity to guide management.
PAD Treatment Overview
As podiatrists, we collaborate with vascular specialists on managing PAD. Goals involve reducing risk factors, relieving leg symptoms, preventing progression, treating foot complications, and improving quality of life.
Treatment options include:
Risk factor modification – Smoking cessation, diabetes control, medication for high blood pressure and lipids. Diet and exercise.
Medications – Antiplatelets like aspirin or clopidogrel. Cilostazol to improve walking distance.
Supervised exercise program – Helps improve claudication walking distance when compliant.
Angioplasty or stenting – Percutaneous revascularization procedures to open blocked arteries. Often done on iliac arteries.
Bypass surgery – Grafts used to bypass severely obstructed segments.
Atherectomy – Removal of plaque material within arteries.
Amputation – For unsalvageable, critically ischemic limbs with gangrene. A last resort.
Treatment is tailored to the individual based on PAD extent, symptoms, comorbidities and risk factors. Conservative medical therapy combined with risk reduction forms the foundation. Revascularization or amputation are last line options for critical limb ischemia.
Medications for PAD
There are several pharmaceuticals we may prescribe or recommend to patients with PAD:
Antiplatelets – Low dose aspirin or clopidogrel help prevent thrombotic complications.
Anticoagulants – In those at higher clotting risk. Requires careful monitoring.
Cilostazol – Phosphodiesterase inhibitor to improve walking distance.
Statins – Lower cholesterol and may stabilize plaque. Important for risk reduction.
ACE inhibitors – Reduce hypertension and may slow PAD progression.
Pain control – As needed for symptomatic relief of leg pain.
Medication selection depends on the individual’s medical profile and PAD severity. Conservative drug therapy forms the basis of initial treatment.
Wound Care for PAD Leg Ulcers
Due to impaired perfusion, PAD often complicates foot ulcer healing. We help manage ischemic ulcers with:
Offloading – Removes pressure and shear to optimize healing. Total contact casting ideal.
Debridement – Removes debris and nonviable tissue carefully. Stimulates healing factors.
Infection control – Oral or intravenous antibiotics if osteomyelitis or cellulitis present.
Moist wound healing – Promotes granulation. Hydrogels, hydrocolloids or alginates.
Negative pressure – Vacuum-assisted closure devices enhance perfusion.
Advanced modalities – Bioengineered skin, growth factors, and cellular products may be trialed.
Despite our best efforts, PAD ulcers can be very challenging to heal. Revascularization procedures may be required for ulcers showing no improvement after 4-6 weeks maximum of conservative care. Referral for limb salvage is made promptly in cases of failed wound healing.
Revascularization for PAD
For suitable patients with intractable claudication or critical limb ischemia, we refer to vascular surgery for revascularization procedures. These aim to restore arterial blood flow and perfusion.
Endovascular techniques include:
Angioplasty – balloon dilation of narrowed artery segments
Atherectomy – physical removal of plaque material within arteries
Stenting – scaffolds inserted to keep arteries open
Vascular bypass surgery uses autogenous or synthetic conduits to bypass severely obstructed arteries that cannot be repaired endovascularly.
Candidates for revascularization are those with significant limitations in quality of life from ischemic leg symptoms, non-healing ulcers, or limb-threatening ischemia. These procedures aim to re-establish perfusion, relieve symptoms, heal ulcers, and prevent limb loss.
Preventing PAD Progression
Patients slow the progression of PAD through:
Smoking cessation – The single most important intervention to prevent worsening PAD.
Blood pressure control – Keeping levels <140/90, or lower in diabetics, slows atherosclerosis.
Lipid management – Reducing LDL cholesterol with statins stabilizes plaque.
Diabetes control – Keeping HgbA1c <7% reduces microvascular complications.
Antiplatelet therapy – Low dose aspirin prevents thrombotic events.
Exercise – Supervised walking programs improve symptoms and perfusion.
Healthy diet – Limiting fat, sodium, and refined carbohydrates.
With medication compliance, risk factor modification, frequent follow up care, and patient engagement in self-management, it is possible to stabilize PAD and maintain quality of life. However, poor compliance leads to disease progression, and critical limb ischemia.
Takeaways on PAD and Podiatry
Peripheral arterial disease causes progressive narrowing of the lower extremity arteries.
Major risks we watch for: smoking, diabetes, high blood pressure, high cholesterol.
Symptoms range from leg pain on exertion to non-healing foot ulcers or gangrene.
Diagnostic testing quantifies blockages and narrowing to guide management.
Conservative treatment focuses on risk factor modification and medication.
Revascularization used for intractable leg symptoms or critical limb ischemia.
Patient education on self-care and risk reduction is key.
With early detection and diligent care, we can help stabilize PAD and maintain quality of life.
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