 The accessory saphenous vein (ASV), either anterior or posterior, is an important GSV collateral frequently responsible for varicose veins located on the anterior and lateral aspect of the thigh. The anterior ASV is more anterior than the ASV and is outside the femoral vessels plan. The two veins terminate in a common trunk near the groin, the sapheno-femoral junction. Here, the ASV can be located aligned with the femoral vessels at the "alignment sign". Also, at the groin it can be seen at the outside of the great saphenous vein, and together with the common femoral vein (CFV) these three create an image, the so-called "Mickey Mouse sign". Some authors, inspired by this sign (presented for the first time at CHIVA's 2002 meeting in Berlin), described a "Mickey Mouse view" at the groin, an image formed by the common femoral vein, the GSV and the superficial femoral artery. When the ASV is incompetent, its flow becomes retrograde and tries to drain in the superior fibular perforator, at the side of the knee, or sometimes it runs down towards the ankle to drain in the inferior fibular perforator.
