Great saphenous vein

It is an anatomical structure. Knowing it matters because it is the most frequent seat of the reflux that gives rise to varicose veins, and the main target of treatments for superficial reflux.

Anatomy

The great saphenous vein is the longest vein in the body. It belongs to the superficial venous network, located between the skin and the muscular fascia, distinct from the deep network.

Its course is constant. It arises on the inner side of the foot, runs up in front of the medial malleolus, follows the inner side of the leg and then of the thigh, and drains into the femoral vein at the groin, at the saphenofemoral junction. All along this course, valves ensure the one-way direction of flow toward the heart. It is their incompetence that opens the way to reflux.

The nomenclature

The name "great saphenous vein" is that of the international anatomical terminology, the reference that harmonizes the names of the structures of the human body. This terminology set aside the old label "internal saphenous vein", still present in older usage.

The change is not cosmetic. The old opposition of "internal" and "external" was liable to cause confusion. The terms "great" and "small" saphenous vein describe two distinct trunks without ambiguity, the great on the inner side of the limb, the small on the posterior side of the leg. Using the current nomenclature avoids mapping errors, in a context where anatomical precision governs the treatment.

The target of treatments

Incompetence of the great saphenous vein is the most frequent cause of varicose veins of the lower limbs. On that basis, this trunk is the main target of treatments for superficial reflux.

The 2022 European guidelines retain endovenous thermal ablation as the first choice for great saphenous vein incompetence. HIFU treatment targets the same trunk, by a different route, from outside the body. The great saphenous vein is thus a shared target of endovenous techniques and extracorporeal treatment, which makes it a shared anatomical reference for describing and comparing the modalities.