Femoral sheath

Anatomical structure surrounding the femoral vessels

The femoral sheath is a funnel-shaped fascial compartment located in the upper thigh. It encloses the femoral artery, femoral vein, and the femoral canal, but notably does not contain the femoral nerve. The sheath is an important anatomical structure as it facilitates the passage of these vessels from the abdomen into the thigh.

Diagram of the femoral sheath and its contents.

Anatomy

The femoral sheath is formed by a downward extension of the transversalis fascia and the iliac fascia. It is divided into three compartments:

• The lateral compartment contains the femoral artery.
• The intermediate compartment contains the femoral vein.
• The medial compartment, known as the femoral canal, contains lymphatic vessels and a lymph node, often referred to as the node of Cloquet.

The femoral sheath extends approximately 4 cm below the inguinal ligament and is continuous with the adventitia of the femoral vessels.

Function

The primary function of the femoral sheath is to allow the femoral vessels to glide smoothly beneath the inguinal ligament during movements of the hip joint. This reduces friction and potential damage to the vessels as they pass from the abdomen into the thigh.

Clinical significance

The femoral sheath is clinically significant because it is a site where femoral hernias can occur. A femoral hernia is a protrusion of abdominal contents through the femoral canal. This condition is more common in females and can lead to complications such as incarceration or strangulation of the herniated tissue.

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Cross-section showing the femoral sheath and its compartments.

Surgical considerations

During surgical procedures involving the femoral vessels, such as femoral artery catheterization, the femoral sheath is an important landmark. Understanding its anatomy helps in avoiding complications such as bleeding or damage to the femoral nerve, which lies outside the sheath.

Related pages

• Femoral artery
• Femoral vein
• Femoral canal
• Femoral hernia
• Inguinal ligament