The femoral sheath is a vital anatomical structure located in the upper thigh region. It plays a crucial role in housing and providing support to the femoral vessels. Understanding its anatomy and function is essential for healthcare professionals, as it has clinical significance in various medical procedures and conditions. Let’s explore the femoral sheath in detail.

Anatomy of the Femoral Sheath

The femoral sheath is a funnel-shaped sleeve of fascia that encloses the upper 4cm of the femoral vessels, in the femoral triangle and extends donwards from the tip of the femoral triangle, to the adductor canal. It is an asymmetrical structure, with different attachments and compartments. Here are the key anatomical features of the femoral sheath:

Boundaries of the Femoral Sheath

The femoral sheath is formed by the following prolongations of fascia:

• Anteriorly: Fascia transversalis (from the anterior wall) and iliacus fascia (from the posterior wall)
• Inferiorly: It merges with the adventitia of the femoral vessels

Compartments within the Femoral Sheath

he femoral sheath consists of three compartments, each serving a specific purpose. The lateral compartment, also known as the arterial compartment, contains the femoral artery, which is responsible for supplying blood to the lower limb. Additionally, this compartment houses the femoral branch of the genitofemoral nerve.

The intermediate compartment, referred to as the venous compartment, houses the femoral vein. The femoral vein plays a crucial role in draining blood from the lower limb. Within this compartment, you can also find the femoral lymph node, which is involved in the lymphatic drainage process.

Lastly, the medial compartment, known as the lymphatic/femoral canal, contains the femoral lymph node of Cloquet/Rosenmuller. This compartment serves as a pathway for lymphatic drainage from the lower limb to the external iliac nodes.

Compartment	Structures
Lateral Compartment (Arterial Compartment)	– Femoral artery: – Femoral branch of the genitofemoral nerve.
Intermediate Compartment (Venous Compartment)	– Femoral vein: – Femoral lymph node.
Medial Compartment (Lymphatic/Femoral Canal)	– Femoral lymph node of Cloquet/Rosenmuller.

Function of the Femoral Sheath

The femoral sheath serves important functions related to the femoral vessels and lymphatic drainage. Here are its key functions:

1. Dead Space for Expansion of the Femoral Vein:

• The femoral sheath provides a specialized space for the expansion of the femoral vein during variations in blood flow and pressure.
• This dead space accommodates changes in venous volume, ensuring efficient blood circulation in the lower limb.

1. Lymphatic Pathway from the Lower Limb:

• The femoral sheath’s medial compartment, known as the femoral canal, plays a crucial role in lymphatic drainage from the lower limb.
• Lymphatic vessels carry excess fluid, waste products, and immune cells from the lower limb to the external iliac nodes for filtration and processing.

Understanding the anatomy and function of the femoral sheath is important for healthcare professionals involved in procedures such as arterial blood gas sampling, catheterization, and assessing the femoral pulse.

In conclusion, the femoral sheath is a specialized fascial structure that encloses and supports the femoral vessels in the upper thigh. Its compartments house the femoral artery, femoral vein, and lymphatic structures, contributing to the efficient circulation and drainage of the lower limb.