49.2: Vessels of the Lower Limb

Arteries

Arteries of the Gluteal Region

The gluteal muscles and skin are supplied by branches of the internal iliac artery; the superior and inferior gluteal arteries. These vessels exit the pelvis through the greater sciatic foramen, their position relative to the piriformis muscle. The inferior gluteal artery may descend for some distance into the thigh, supplying the knee flexors.

Arteries of the Thigh

Obturator Artery

The obturator artery usually arises from the anterior division of the internal iliac. It passes anteriorly along the medial surface of obturator internus to the obturator foramen, where it exits through the obturator canal. From here, it descends in the adductor compartment of the thigh, supplying the muscles therein.

Femoral Artery

The femoral artery is the continuation of the external iliac artery after it passes through the retroinguinal space. It passes through the femoral triangle on an inferior trajectory, passing behind sartorius to enter the adductor canal. This continues behind sartorius for about 15 cm before passing through the adductor hiatus, a gap in the tendon of adductor magnus. Beyond this point, the artery is known as the popliteal.

The femoral artery has several large branches in the femoral triangle but relatively few in the adductor canal.

Deep Artery of the Thigh

The deep artery of the thigh (profunda femoris, deep femoral artery) arises from the posterior surface of the femoral artery. It passes deep to adductor magnus towards the femur. It gives off several large branches (perforating arteries) that supply the quadriceps, adductors and hamstrings.

Lesser Branches

  • Lateral and medial circumflex femoral arteries form an anastamotic ring around the proximal femur, below the trochanters.
  • The superficial epigastric and superficial iliac arteries supply the skin and musculature of the anterolateral abdominal wall.
  • The external pudendal artery contributes to the vascular supply of the external genitalia and perineum.

Arteries of the Knee

Popliteal Artery

The popliteal artery is the continuation of the femoral artery, and begins at the adductor hiatus. Passing posteriorly and slightly laterally through the popliteal fossa, it divides below the knee joint into the anterior and posterior tibial arteries. Numerous genicular anastamoses form a plexus around the knee joint, and are important in the event of femoral artery occlusion.

Arteries of the Lower Leg

Anterior Tibial Artery

The anterior tibial artery is the smaller of the popliteal branches, and passes through a gap in the interosseous membrane to descend on its anterior surface. It supplies the muscles of the anterior compartment of the lower leg. It becomes the dorsalis pedis artery as it crosses the ankle joint, midway between the two malleoli.

Posterior Tibial Artery and Fibular Artery

The posterior tibial artery passes through the posterior compartment of the lower leg. It gives off a large branch, the fibular artery, which descends lateral to it, and posterior to the fibula. Both arteries are separated from the bones by the deep muscles of the posterior compartment. The fibular artery continues to the lateral malleolus beyond which its supply is less certain; the posterior tibial curves behind the medial malleolus to enter the plantar surface of the foot as medial and lateral plantar arteries.

Arteries of the foot

Dorsalis Pedis (Dorsal Surface)

The dorsalis pedis gives off the lateral tarsal artery, and together these form an arcade across the proximal, dorsal surface of the metatarsals. From this arcade arise dorsal metatarsal arteries which run along the space between each pair of metatarsals. The metatarsal arteries divide into dorsal digital arteries at the base of each toe. The dorsal arch communicates with the deep plantar arch through perforating arteries between the proximal parts of the metatarsals. The largest of these, the deep plantar artery, passes between the first and second metatarsal and forms the medial side of the deep plantar arch.

Medial and Lateral Plantar Arteries

The medial plantar artery passes along the medial sole of the foot to the great toe, occasionally anastamosing with the deep plantar arch. The lateral plantar artery is larger, and passes across the plantar surface of the foot to the 5th metatarsal. From here, it curves medially to form the deep plantar arch, which anastamoses with the deep plantar branch of the dorsalis pedis. Plantar metatarsal arteries, and their terminal plantar digital arteries, arise from the deep plantar arch.


Veins

The veins of the lower limb have both deep and superficial components.

Deep Venous Network

Veins of the Foot

Similar to the hand, there are paired dorsal and plantar veins of each digit. These unite to form dorsal/plantar metatarsal veins. These veins drain to the dorsal / plantar venous arches which run as vena comitantes with the dorsal and plantar arches.
From the dorsal arch, vena comitantes ascend with the lateral tarsal and dorsalis pedis arteries and continue with the anterior tibial artery. There are numerous connections to the origin of the great long saphenous vein, which ascends from the medial malleolus with the saphenous nerve and carries most venous blood away from the foot.
From the plantar arch, veins accompany the medial and lateral plantar vessels and continue as vena comitantes to the posterior tibial artery. Some vessels pass posterior to the lateral malleolus to ascend with the fibular artery. There are numerous connections to the short saphenous vein (via the lateral marginal vein of the foot), which begins superficial to the tendon of gastrocnemius and passes proximally with the sural nerve.
Importantly, most venous drainage from the foot is via the superficial network, in contrast to the rest of the leg.

Veins of the Lower Leg

The deep veins accompany the anterior tibial, posterior tibial and fibular arteries and unite at the base of the popliteal fossa as the popliteal vein. Most of the blood from the lower leg is returned via the deep veins, and the popliteal vein is usually single.

Veins of the Knee

The popliteal vein passes from the distal to the proximal part of the popliteal fossa, always superficial to the artery but contained within the same sheath. At about the level of the knee joint, the popliteal vein receives the short saphenous vein after it enters the popliteal fossa between the heads of gastrocnemius.

Veins of the Thigh

The popliteal vein accompanies the popliteal artery through the adductor hiatus and enters the anterior thigh, becoming the superficial femoral vein. This vein passes superiorly through the thigh, arriving at the apex of the femoral triangle medial to the artery. It then ascends through the triangle to just midline of the central inguinal ligament. Within the femoral triangle, it receives with the deep femoral vein and the termination of the long saphenous vein.
After passing through the retroinguinal space, the femoral vein becomes the external iliac vein and its course is described elsewhere.

Superficial Veins of the Leg

The short saphenous vein begins superficial to the tendon of gastrocnemius, and ascends superficial to this muscle to the inferior aspect of the popliteal fossa. Piercing the fascia covering the fossa, it empties into the popliteal vein at about the level of the knee joint.
The long saphenous vein begins at the medial malleolus, and ascends with the saphenous nerve (a branch of the femoral nerve). It passes posteriorly to the medial femoral condyle and travels in the subcutaneous tissue of the medial thigh to the femoral triangle. Within the triangle, it pierces the fascia lata through the saphenous opening, and drains into the femoral vein. This union is an important landmark for the deep lymph nodes of the inguinal region, which lie both above and below the junction. Distal superficial inguinal lymph nodes lie in the triangle, in close association with the long saphenous vein.


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