Which ultrasound (US) is needed to assess varicose veins in legs?

Duplex Ultrasound Is Required for Assessment of Varicose Veins in Legs

Duplex ultrasound is the gold standard for evaluating varicose veins in the legs and should be performed in the erect position by a specialist trained in ultrasonography. 1

Rationale for Duplex Ultrasound

Duplex ultrasound combines:

• B-mode imaging (visualization of anatomy)
• Color Doppler (blood flow visualization)
• Spectral Doppler (quantification of flow)

This comprehensive approach is essential because:

1. Physical examination alone is unreliable in detecting sources of reflux in varicose veins 2
2. Hand-held Doppler (HHD) ultrasonography is insufficient, with sensitivity of only 73% at the saphenofemoral junction, 77% at the saphenopopliteal junction, and 51% for thigh perforators 2
3. Surgery planned using HHD imaging alone would leave residual sites of reflux in 24% of cases 2

Proper Technique for Varicose Vein Assessment

The complete duplex ultrasound examination should include:

• Patient positioned in erect position 1, 3
• Compression of deep veins from inguinal ligament to ankle (including posterior tibial and peroneal veins) 4
• Right and left common femoral vein spectral Doppler waveforms to evaluate symmetry 4
• Popliteal spectral Doppler 4
• Color Doppler images 4
• Compression performed at 2-cm intervals 4
• Assessment of symptomatic areas for superficial venous thrombosis or other pathology 4

Diagnostic Criteria

When evaluating varicose veins, the following diagnostic criteria should be used:

• Retrograde venous flow exceeding 500 milliseconds indicates abnormal reflux 1
• Diagnosis is confirmed when venous reflux, vein dilation, and clinical manifestations corresponding to the CEAP classification system are present 1
• For pelvic-origin varicose veins, diagnostic criteria include dilated tortuous pelvic vein >4 mm, slow/reversed blood flow, and dilated arcuate vein in myometrium communicating with pelvic varicosities 1

Special Considerations

• For women with suspected pelvic origin varicose veins, transvaginal duplex ultrasound (TVS) using the Holdstock-Harrison protocol is recommended 3
• For men or women unable to have TVS, venography or cross-sectional imaging may be needed 3
• Examination should be performed by a specialist trained in ultrasonography, optimally not the doctor who performs the treatment 3

Pitfalls to Avoid

• Limited protocols that do not include calf veins are not recommended as they require a second study in 5-7 days to safely exclude DVT 4
• Misdiagnosis of pelvic-origin varices can lead to incorrect treatment 1
• Failure to identify underlying causes such as undiagnosed cardiac conditions can result in recurrent varices 1
• Relying solely on physical examination or hand-held Doppler is inadequate and may miss significant sources of reflux 2

Post-Treatment Assessment

After treatment of varicose veins, follow-up duplex ultrasound is essential:

• Early follow-up within 1-2 weeks to confirm successful closure and rule out complications like endovenous heat-induced thrombosis (EHIT) 1
• Timing of outcome investigations should be classified as immediate (1-4 weeks), short-term (1 year), midterm (2-3 years), and long-term (5 years or more) 5
• Standard methodology should be employed with formally described variables tailored to the intervention that was undertaken 5

By using duplex ultrasound for assessment of varicose veins, clinicians can accurately identify sources of reflux, plan appropriate interventions, and monitor treatment outcomes, ultimately improving patient care and quality of life.