Venous Reflux

Venous reflux occurs when the valves in the leg veins fail to close properly, letting blood flow backward and pool. Over time this can cause swelling, aching, skin changes, and varicose veins, and may progress to chronic venous insufficiency.

• Non-invasive and painless
• Assesses valve competence through venous refill
• Helps localize superficial versus deep reflux

VasoGuard assesses reflux with photoplethysmography (PPG) rather than ultrasound imaging. A PPG sensor on the lower leg tracks skin blood volume while the patient performs a series of dorsiflexions (a calf-pump exercise) to empty the leg veins. The system then measures the venous refill time — how long the veins take to refill once the calf pump stops.

A healthy refill is slow (generally longer than about 20 seconds). A rapid refill indicates that incompetent valves are letting blood flow backward. An optional tourniquet — placed at the thigh, above the knee, or below the knee — occludes the superficial veins: if the refill time normalizes, the reflux is superficial; if it stays short, the deep system is involved.

• Photoplethysmography venous refill time (VRT)
• Dorsiflexion calf-pump to empty the veins
• Optional tourniquet to separate superficial from deep reflux

Venous reflux testing supports:

• Screening for chronic venous insufficiency
• Localizing reflux to the superficial or deep system to guide treatment
• Documenting venous function before intervention and monitoring afterward

Non-invasive refill-time testing is a quick, point-of-care complement to duplex ultrasound — useful for screening and functional assessment.

VasoGuard's Venous Reflux study runs as a guided protocol:

• PPG venous refill time with a configurable abnormal-refill alert threshold
• Optional thigh, above-knee, or below-knee tourniquet to localize reflux
• High-resolution waveform with on-screen refill-time cursors and report export

See also the venous tests overview and MVO / Venous Capacitance for venous outflow obstruction.