Most patients with varicose veins and saphenous reflux have a saphenous pulse detectable by ultrasound after they have been standing for a minute. When a previously elevated leg is brought to a dependent position, reflux (continuous red) is observed with the probe over the saphenous vein. After 30 seconds or so the reflux disappears leaving a state of no flow (black). A few seconds later pulsation is observed (intermittent blue). The cause of this is not known but it may represent failure of the micro-circulatory resistance from the build up of venous back pressure resulting in the appearance of an arterial impulse.
Saphenous pulsation observed in the distal part of the GSV
Saphenous pulsation observed in the proximal part of the GSV