This test measures the effect of the venous insufficiency in the form of reflux that causes the blood to rush back into the veins in a reverse direction.
A sensor is placed on the skin of the patient over the long saphenous vein near the ankle and connected to the machine. The machine beeps 5 times and each time it beeps, the foot needs to be raised and lowered with movement at the ankle joint. This results in using the calf pump and blood is pumped out of the vein. After 5 beeps, the leg is kept stationary and the machine checks for how long it takes for the vein to refill.
Normally 50% of refilling (½VRT) should take more than 7 secs and 100% refilling (VRT) should take more than 20 secs. If there is incompetence or leakage of the uni-direction valves in the veins, the blood rushes in the reverse direction due to gravity and the vein refills faster. More the leakage, lesser the time required for refilling.
Hence time required to refill the vein (Venous Refill Time or VRT) predicts and quantifies the severity of the venous insufficiency and reflux.
This test takes only 5 minutes to perform, report is obtained immediately and can be done before and after treatment to evaluate the response to treatment.