Ultrasound Evaluation for Patients with Peripheral Vascular Disease and Lower Extremity Edema

Rationale for Arterial Ultrasound

The American College of Cardiology recommends duplex ultrasound of the extremities to diagnose anatomic location and degree of stenosis in patients with symptomatic peripheral arterial disease (PAD), especially those with multiple risk factors such as smoking history and neuropathy 1
Duplex ultrasound can identify significant stenoses and provide soft tissue diagnostic information that may be associated with PAD presentation, which is crucial in patients with PVD, smoking history, and neuropathy 2
Arterial ultrasound is useful in evaluating patients with new onset burning sensation in the thigh, which could represent ischemic symptoms, especially in those with known PVD 1

The Society of Radiologists in Ultrasound recommends a comprehensive duplex ultrasound protocol from thigh to ankle with Doppler at selected sites for patients suspected of having deep venous thrombosis (DVT) or chronic venous insufficiency, which can present with bilateral lower extremity edema 3
Venous ultrasound is the standard imaging test for patients suspected of having DVT and can identify chronic venous insufficiency, which commonly presents with bilateral lower extremity edema 3

The American College of Cardiology suggests evaluating for signs of both arterial and venous disease given the mixed presentation of bilateral edema and PVD, and recommends a comprehensive evaluation including duplex ultrasound with ABI measurement to assess arterial flow and identify stenoses 1
A comprehensive duplex ultrasound from thigh to ankle with Doppler at selected sites is recommended for venous ultrasound protocol to evaluate for both acute DVT and chronic venous insufficiency 3

Focusing only on venous causes for edema in a patient with known PVD may miss critical arterial pathology, and performing limited ultrasound protocols rather than comprehensive evaluations may miss significant pathology 2, 1, 3

The American College of Cardiology recommends checking for signs of venous insufficiency, such as varicosities and skin changes, in patients with lower extremity edema 4, 5
Ankle-brachial index (ABI) measurement is considered if peripheral arterial disease is suspected, particularly in patients with risk factors such as age ≥65 or known atherosclerotic disease in another vascular bed 4, 5

For acute unilateral lower extremity edema, the American College of Chest Physicians recommends using validated Wells criteria to determine pretest probability of deep vein thrombosis (DVT), and obtaining highly sensitive D-dimer for low pretest probability or proceeding directly to compression ultrasonography (CUS) of proximal veins for moderate to high pretest probability 6
For chronic bilateral lower extremity edema, the American College of Cardiology suggests performing duplex ultrasonography with reflux study to evaluate for chronic venous insufficiency, and considering ankle-brachial index (ABI) measurement if peripheral arterial disease is suspected 5

The American College of Cardiology recommends considering advanced imaging such as CT venography or MR venography when ultrasound is impractical or nondiagnostic, and using MRA of extremities to diagnose anatomic location and degree of stenosis of peripheral arterial disease 5, 6, 7
The American College of Cardiology suggests referring patients with acute limb ischemia to vascular surgery evaluation, and assessing patients with critical limb ischemia immediately by a vascular specialist 5, 8

The American College of Chest Physicians recommends ensuring clinical follow-up for patients who have had DVT excluded by diagnostic testing, as they still have a small possibility of thrombosis progression, and assessing patients with marked symptoms who have had DVT excluded to identify alternative diagnosis 6