The GSV is usually small further down the calf; the size transition seen on ultrasound guides where to access the GSV Occasionally, the puncture and treatment can be applied to superficial tributaries that remain relatively straight and parallel to the course of the GSV In this case, these so-called superficial accessory saphenous veins can be accessed directly at the most peripheral part of the straight segment.
This type of failure often involves an accessory saphenous vein.
Type III anatomic failure was found in 2 patients from this study, but without accessory saphenous vein and was treated with saphenofemoral junction flush ligation.
In the thigh it communicates with the femoral vein by perforator veins and receives numerous tributaries; those from the medial and posterior parts of the thigh frequently unite to form a large accessory saphenous vein which joins the main vein near the sapheno-femoral junction.