The SSV is the major superficial truncal vein of the posterior leg. It begins at the lateral aspect of the foot, passes posterior to the lateral malleolus and ascends in midline on the superficial fascia between the two heads of the gastrocnemius. The termination of the SSV is variable. In 60-70% of people the SSV drains into the popliteal vein (deep system) at the saphenopopliteal junction. In the remaining people the course of the SSV can vary; it can extend into the thigh as a single vein and end in the gluteal region, or run around the medial aspect of the thigh to drain into the GSV via the vein of the Giacomini, or drain into multiple muscular veins or directly into the femoral vein via a perforator. Distally the SSV has a close association to the sural nerve in the distal leg that provides cutaneous fibres to the sensation of the skin over the distal lateral leg & lateral foot. This is the nerve that is vulnerable to injury with treatment of SSV.
