Venous Reflux Assessment Using Duplex Ultrasound

Venous reflux assessment is the process of identifying abnormal backward blood flow within the leg veins using duplex ultrasound. It is a key diagnostic step in the assessment of venous disease and helps determine whether symptoms such as varicose veins, swelling, skin changes or ulceration are caused by underlying venous valve failure.

What Is Venous Reflux?

Venous reflux occurs when the valves within the leg veins fail to function properly, allowing blood to flow backwards rather than returning efficiently to the heart. This abnormal flow leads to increased pressure within the venous system, known as venous hypertension, which places strain on the veins and surrounding tissues. Over time, venous reflux can give rise to symptoms such as varicose veins, leg swelling, skin changes and discomfort, and may progress to more advanced conditions including chronic venous insufficiency and venous ulceration. Accurate identification of venous reflux is therefore essential in understanding the cause of symptoms and guiding appropriate management to reduce the risk of recurrence.

How Venous Reflux Is Assessed

Venous reflux is assessed using duplex ultrasound, a specialised imaging technique that allows real‑time evaluation of blood flow, valve function and vein anatomy. This examination enables accurate identification of abnormal reflux patterns within the superficial and deep venous systems and helps determine which veins are contributing to symptoms.

What Is a Venous Duplex Ultrasound?

A venous duplex ultrasound uses sound waves to create detailed images of the veins and a colour map of blood flow within them. By assessing both the structure of the veins and the direction of blood flow, duplex ultrasound allows precise diagnosis of venous reflux and supports evidence‑based treatment planning.

Before Your Duplex Scan

No preparation is required for a venous duplex ultrasound. The scan is usually performed during your initial consultation at The Vein Clinic. Some patients bring a spare pair of shorts to make the examination easier.

What Happens During the Scan?

Your scan may be performed with you lying on the examination table or standing beside it. Warm gel is applied to your leg(s), and a small handheld device called a transducer is placed over different areas to assess blood flow. Gentle calf compression may be used to assess valve function and venous reflux.

The sound waves create real‑time images on a monitor, allowing detailed assessment of venous flow patterns. Most consultations take around 30–40 minutes. If a full deep vein assessment is required, the examination may take longer.

After Your Duplex Scan

There are no special instructions to follow after your scan. The findings are reviewed and explained during your appointment, with discussion of what the results mean for your vein health and whether any treatment is recommended.

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