ANATOMY

All veins in the body are either part of the superficial venous system or the deep venous system. The principal superficial veins of the lower extremity(leg) are the small saphenous vein (SSV), which usually runs from ankle to knee and the great saphenous vein (GSV), which usually runs from ankle to groin.

Superficial collecting veins deliver their blood into the great and small saphenous veins, which deliver most of their blood into the deep system. Superficial veins are also connected to a variable number of perforating veins (PV) that pass through openings in the deep fascia to join deep veins of the calf or thigh either directly or through smaller plexus of smaller veins.

All venous blood is eventually received by the deep venous system on its way back to the right atrium of the heart.

PATHOANATOMY

The veins have one-way valves to prevent them from the backward flow. The correct functioning of the venous system depends on a complex series of valves. It has been known that varicose veins in the legs are caused by the weakening of the veins and valves in the great saphenous veins and/or small saphenous veins. When the valves in these malfunctions, blood begins to collect in the legs resulting in the buildup of pressure. The veins become enlarged and knotted and are visible near the surface of the skin as a varicose vein.

Major valves which dysfunctions in the caution of varicose vein are saphenofemoral junction (SFJ) and saphenopopliteal junction (SPJ). The termination point of the GSV into the common femoral vein, located proximally at the groin, is called the Saphenofemoral junction. The terminal valve of the GSV is located within the junction itself. In most cases, at least one additional subterminal valve is present within the first few centimetres of the GSV. Most patients have a single subterminal valve that can be readily identified approximately 1 cm distal to the junctional valve.

PATHOPHYSIOLOGY

The pathophysiology behind their formation is complicated and involves the concept of ambulatory venous hypertension.

In healthy veins, the flow of venous blood is through the superficial system into the deep system and up the leg and toward the heart. One-way venous valves are found in both systems and the perforating veins. Incompetence in any of these valves can lead to a disruption in the unidirectional flow of blood toward the heart and result in ambulatory venous hypertension (AVH).

Incompetence in the superficial venous system alone usually results from failure at valves located at the SFJ and SPJ. The gravitational weight of the column of blood along the length of the vein creates hydrostatic pressure, which is worse at the more distal aspect of the length of vein.

Varicose veins in legs are veins that are permanently swollen while standing and have a minimum diameter of 3 mm. The clinicians categorise them according to the “CEAP”-classification(Clinical severity – Etiology – Anatomy – Pathophysiology).