Previously Unreported Case of Variant Posterior Tibial Vein Forming a Loop Adjacent to the Posterior Tibial Artery.

The posterior tibial vein (PTV) is formed distally by the medial and lateral plantar veins and ends proximally at the joining with the peroneal vein. Variations of the PTV can result in unique clinical presentations. Such variations at the proximal location have been classified previously, but few have been identified distally. In an adult male cadaver, we identified a unilateral distal PTV variation that bifurcated posterior to the medial malleolus. This bifurcation rejoined inferiorly to the medial malleolus and formed a loop that was transected by the posterior tibial artery from deep to superficial. Although this PTV variation is rare, we believe it could be clinically significant for tarsal tunnel syndrome (TTS) and catheter-directed thrombolysis (CDT) of deep vein thrombosis (DVT). Such anatomical variations should be documented and added to clinical databases to improve patient outcomes and diagnostic techniques.