What is the aetiology of varicose veins?

The aetiology of varicose veins can be primary (95%) or secondary:

• Primary varicose veins are caused by incompetence of valves in the connecting veins between the deep and superficial venous systems. This leads to back flow of blood from the deep into the superficial veins leading to an increase in pressure and development of varicosities.

• Secondary varicose veins develop due to occlusion of the deep system (thrombosis) leading to diversion of venous flow to the superficial veins.

What are the common sites of venous incompetence?

• Sapheno-femoral junction between the greater saphenous vein and the femoral vein in the groin (90%)

• Sapheno-popliteal junction between the greater saphenous vein and the popliteal vein in the popliteal fossa

• Midthigh perforator

• 23 perforators in the calf

What is the surface marking of the greater saphenous vein?

The greater or long saphenous vein (LSV) starts at the midportion of the medial arch of the foot. It ascends anterior to the medial malleolus on the medial aspect of the lower leg. At the knee it passes about a hands breath behind the medial femoral condyle before passing towards the anteromedial thigh. It joins the femoral vein at the sapheno-femoral junction medial to the femoral artery (femoral pulse) about 3 cm below the inguinal ligament.