The femoral vein is a large vessel located deep within the thigh. It is sometimes referred to as the superficial femoral vein in order to distinguish it from the deep femoral vein. This term is, however, misleading and rarely used due to the fact that the vessel is located deep in the thigh.
The femoral vein is a direct continuation of the popliteal vein just proximal to the knee. The vein ascends to the inguinal region, where it passes posterior to the inguinal ligament as the external iliac vein to enter the abdomen.
The main function of the femoral vein is to drain the lower limb.
|Drains from||Popliteal vein|
|Tributaries||Deep femoral vein, great saphenous vein, lateral circumflex femoral veins, medial circumflex femoral veins|
|Drains to||External iliac vein|
|Drainage area||Lower limb|
This article will discuss the anatomy and function of the femoral vein.
Anatomy and course
The femoral vein begins at the adductor hiatus of the adductor magnus muscle as the proximal continuation of the popliteal vein, into the anterior aspect of the thigh. It courses proximally through the adductor canal (subsartorial canal or Hunter's canal) into the femoral triangle, accompanying the femoral artery. The femoral vein then traverses the femoral sheath, just lateral to the femoral canal. It terminates posterior to the inguinal ligament as the external iliac vein, which drains into the common iliac vein and ultimately into the inferior vena cava.
The relationship of the femoral vein to the femoral artery usually varies at different locations along its course. Distally, the vein lies posterolateral to the artery, while proximally, at the apex of the femoral triangle, the vein lies posterior to the artery. At the base of the femoral triangle and within the femoral sheath, however, the vein lies medial to the artery. The femoral vein typically has four to five valves at various points along its length.
Along its course, the femoral vein receives several tributaries that drain structures of the lower limb. The main tributaries include:
- The deep femoral vein (deep vein of the thigh) empties into the femoral vein posteriorly, about 8 cm distal to the inguinal ligament. It is formed by perforating veins that drain the surrounding muscles. Proximal to the entry point of the deep femoral vein, the femoral vein is often referred to as the common femoral vein.
- The great saphenous vein (long saphenous vein) lies within the subcutaneous tissue of the lower limb. It joins the femoral vein anteriorly, about 3 cm inferolateral to the pubic tubercle. This vein receives numerous tributaries along its course and forms several anastomoses with deep veins of the leg and thigh. Typically, at its proximal end, the great saphenous vein receives the external pudendal, superficial circumflex iliac, superficial epigastric and accessory saphenous veins, prior to joining the femoral vein.
- The lateral and medial circumflex femoral veins accompany their corresponding arteries and drain surrounding structures including muscles and the proximal femur into the proximal end of the femoral vein.
To learn more about the veins of the lower limb, explore our articles, quizzes, video tutorials and labeled diagrams.
Femoral vein access
The femoral vein is a common site of venous access for catheterisation and venous sampling mainly because it offers easy access to the right atrium of the heart. A good appreciation of the arrangement of structures within the femoral triangle is required to safely perform this procedure. Under sterile conditions, physicians first palpate for the femoral pulse about 1 cm to 2 cm inferior to the inguinal ligament. The femoral artery is located at the midpoint between the anterior superior iliac spine and the pubic symphysis. With the femoral pulse identified, the femoral vein is accessed about 0.5 cm to 1 cm medial to the pulsation. This procedure is, however, often performed under ultrasound guidance to improve accuracy and to provide additional information about vessels and surrounding structures.