Accessory saphenous vein

IN gray's anatomy, the term "Accessory saphenous vein" is describe as: The venous tibutaries from the medial and posterior parts of the thigh frequently unite to form a large accessory saphenous vein which joins the main vein at a variable level. Near the fossa ovalis it is joined by the superficial epigastric, superficial iliac circumflex, and superficial external pudendal veins.

For other sources , the term "accessory saphenous vein" refers to the variabel longitudinal venous trunks in the lower extremity that run parallel to the great saphenous vein (GSV), but are anatomically distinct. The most clinically relevant is the anterior saphenous vein (ASV), which courses in the deep subcutaneous layer of the anteromedial thigh, parallel and anterior to the GSV. The ASV is enclosed within a defined fascial compartment, delimited deeply by the muscular fascia and superficially by a duplication of the saphenous fascia, similar to the GSV and small saphenous vein (SSV). This fascial ensheathment distinguishes the ASV from superficial tributaries, which lack such compartmentalization.

The ASV may originate from the anterior thigh circumflex vein, directly from the trunk of the GSV (sometimes resembling a duplication), or from epifascial veins of the anteromedial thigh. Its course is typically above the sartorius and vastus medialis muscles, running parallel to the femoral vessels and reaching the fossa ovalis at the groin, where it may connect with inguinal lymph node veins and superficial abdominal wall tributaries.

Posterior accessory saphenous veins also exist, most commonly joining the GSV below the knee, and are seen in approximately half of limbs with chronic venous disease.