Prominent superficial veins Lateral venous anomaly 2011-12-01T03:16:02Z Lateral marginal vein of Servelle Embryonic leg veins usually regress before birth, but in Klippel-Trenaunay syndrome (KTS) a persistent embryonic vein (PEV) may be located on the lateral aspect of the affected leg. Known PEVs of the leg are the lateral marginal vein (LMV) and the persistent sciatic vein (PSV). The nomenclature can be confusing because various terms are used to indicate the same aberrant leg vein in KTS (e.g. vein of Servelle, Klippel-Trenaunay vein, lateral marginal vein). UMLS:C4020945 Vein of Servelle HP:0100885 Klippel-Trenaunay vein Persistence of the embryonic dorsal or sciatic vein system that normally should have involuted around the tenth to twelfth week of intrauterine life.