Does a double long saphenous vein exist?

Background: The incidence of reduplication of the long saphenous vein (LSV) reported in the literature is highly variable, perhaps due to the lack of a clear definition. Objective: To use ultrasonography to re-evaluate the incidence of LSV reduplication in healthy subjects and patients with varicose veins on the basis of a new definition of this anatomical aspect. Methods: The presence of two parallel superficial venous channels in the lower limb was sought in a series of 610 duplex ultrasound examinations. The LSV was identified, by the 'eye' sign, running deeply in the hypodermis, closely ensheathed by two hyperechogenic laminae (the saphenous compartment). Tributary veins were identified by their more superficial course, lying outside the compartment. True LSV reduplication was considered to be present when two venous channels were present within the saphenous compartment. Results: True reduplication of the LSV is extremely rare (1%) and only affects a segment of vein. Large tributaries running parallel to the LSV do not comprise true reduplication, but may act as a 'functional double vein': Better understanding of the anatomy of the LSV may Improve operative treatment for varicose veins and improve the use of saphenous veins as arterial grafts.