They have valves which prevent blood flowing back (regurgitation) from deep to superficial veins in muscular systole[3] or contraction.

Perforator veins exist along the length of the lower limb, in greater number in the leg (anatomical ref to below knee) than in the thigh.

[4] The resulting reflux can cause a rapid deterioration in an existing varicose disease and be responsible for the development of venous ulcers.

[6] In this case, lower limbs venous ultrasonography plays an important role in evaluating which continent perforators can be used.

In 1985, G. Hauer described the Sub-fascial endoscopic perforator vein surgery (SEPS) technique[9] allowing IPVs to be clipped through a small incision.