Procedure – Venous Access

Master answer

Femoral triangle (aka Scarpa’s triangle)

• The major boundaries can be recalled with the mnemonic SAIL:
  • lateral border: medial border of sartorius
  • medial border: medial border of adductor longus
  • superior border: inguinal ligament
  • floor: iliopsoas (laterally) and pectineus (medially)
  • roof: skin, subcutaneous tissue, a continuation of Scarpa’s fascia, great saphenous vein (joins the femoral vein), superficial lymph nodes, fascia lata
• Contents (From lateral to medial):
  • femoral nerve
  • femoral sheath (thickening of the deep fascia of the thigh) which has three compartments (from lateral to medial):
  • femoral artery and its branches (within the lateral compartment of the femoral sheath) and the femoral branch of the genitofemoral nerve
  • femoral vein (within the intermediate compartment of the femoral sheath) and deep lymph nodes
  • femoral canal (the medial compartment of the femoral sheath) which contains fat and lymph nodes (of Cloquet)

Femoral sheath

• Situated within the triangle.
• Formed from the fusion and invagination of the psoas and transversalis fascia.
• Contains femoral artery, vein and tributaries, and femoral canal

Femoral Vein

Main deep vein of the thigh and accompanies the superficial femoral artery and common femoral artery.

Course:

• Forms as the continuation of the popliteal vein at the adductor opening.
• Proximal to the confluence with the deep femoral vein, the femoral vein is commonly known as the common femoral vein. It becomes the external iliac vein as it ascends posterior to the inguinal ligament.
• In the distal adductor canal, the vein is posterolateral to the superficial femoral artery. Proximally in the canal, the vein lies posterior to the artery in the distal femoral triangle and medial to the artery at the base of the triangle.
• In the upper thigh, the vein is between the common femoral artery and femoral canal and therefore occupies the intermediate/middle compartment of the femoral sheath.
• Tributaries
  • numerous muscular tributaries
  • profunda femoris vein joins the femoral vein posteriorly 4-12 cm distal to the inguinal ligament
  • the great saphenous vein enters anteriorly or anteromedially
  • lateral and medial circumflex femoral veins are usually tributaries of the femoral vein
• Surface Anatomy:
  • 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 about 0.5 cm to 1 cm medial to the pulsation.

Sources: Gray’s Anatomy, Radiopedia

JC 2019

Answer by JC