Vasculature of the lower limb ANA 208 Arterial

Vasculature of the lower limb ANA 208

Arterial Supply SUPERIOR GLUTEAL ARTERY • Branch of the internal iliac artery • Enters the buttock through the greater sciatic foramen above the piriformis muscle. • Anastomoses with the lateral circumflex, medial circumflex, and inferior gluteal artery. 2

INFERIOR GLUTEAL ARTERY • Branch of the internal iliac artery • Enters the buttock through the greater sciatic foramen below the piriformis muscle. • Participates in the cruciate anastomosis • Anastomoses with the superior gluteal artery, internal pudendal artery, and obturator artery. 3

OBTURATOR ARTERY • Continuation of the internal iliac artery • Passes through the obturator foramen. Gives off the following branches: • Muscular branches to the adductor muscles • Artery of the ligamentum teres (artery to the head of the femur). - Considerable importance in children because it supplies the head of the femur proximal to the epiphyseal growth plate. - After the epiphyseal growth plate closes in the adult, this artery plays an insignificant role in supplying blood to the head of the femur. 4

FEMORAL ARTERY • Continuation of the external iliac artery • Enters the femoral triangle posterior to the inguinal ligament and midway between the ASIS and the symphysis pubis. • Used for percutaneous arterial catheterization because it is superficial and easily palpated • The preferred entry site is below the inguinal ligament at the level of the midfemoral head (a site that is confirmed by fluoroscopy). • If the femoral artery is punctured above the inguinal ligament or below the femoral head, control of hemostasis is difficult or impossible. 5

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Femoral artery gives off the following branches: 1. Superficial Epigastric Artery 2. Superficial Circumflex Iliac Artery 3. Superficial External Pudendal Artery 4. Deep External Pudendal Artery 5. Descending Genicular Artery 6. Profunda femoris (deep femoral) artery branches into the following: • a. Four perforating arteries supply the adductor magnus and the hamstring muscles. The first perforating artery participates in the cruciate anastomosis with the inferior gluteal artery and the medial and lateral circumflex arteries. • b. Medial circumflex artery participates in the cruciate anastomosis and provides the main blood supply to the head and neck of the femur in the adult. • c. Lateral circumflex artery participates in the cruciate anastomosis and also sends a descending branch of the lateral circumflex artery to participate in the genicular anastomosis around the knee joint. 7

POPLITEAL ARTERY • Continuation of the femoral artery at the adductor hiatus in the adductor magnus muscle • Extends through the popliteal fossa Gives off the following branches: • Genicular arteries • Anterior tibial artery • Posterior tibial artery 8

Genicular arteries • Participate in the genicular anastomosis around the knee joint and supply the capsule and ligaments of the knee joint. • Four genicular arteries: - superior lateral - inferior lateral - superior medial - inferior medial 9

Anterior tibial artery • Descends with the deep fibular nerve and terminates as the dorsalis pedis artery. • - Gives off the following branches: Anterior tibial recurrent artery Medial malleolar artery Lateral malleolar artery 10

Dorsalis pedis artery • Lies between the extensor hallucis longus and extensor digitorum longus tendons • Gives off the following branches: - Lateral tarsal artery anastomoses with the arcuate artery. - Arcuate artery gives rise to the second, third, and fourth dorsal metatarsal arteries. Dorsal metatarsal arteries branch into two dorsal digital arteries. - First dorsal metatarsal artery - Deep plantar artery enters the sole of the foot and joins the lateral plantar artery to form the plantar arch. 11

Posterior tibial artery • Passes behind the medial malleolus with the tibial nerve. • Gives off the following branches: - Fibular artery passes behind the lateral malleolus, gives rise to the posterior lateral malleolar artery, and ends in branches around the ankle and heel. - Medial plantar artery gives rise to a superficial branch, which forms three superficial digital branches, and a deep branch, which supplies the big toe. - Lateral plantar artery arches medially across the foot to form the plantar arch in conjunction with the deep plantar artery (from the dorsalis pedis artery). • Plantar arch gives rise to four plantar metatarsal arteries and three perforating branches, which anastomose with the arcuate artery. • Plantar metatarsal arteries branch into two plantar digital arteries. 12

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COLLATERAL CIRCULATION Cruciate anastomosis • Around the hip joint • Involves the following arteries: a. Inferior gluteal artery (a branch of the internal iliac artery) b. Medial femoral circumflex artery c. Lateral femoral circumflex artery d. First perforating branch of profundus femoris artery 17

Trochanteric anastomosis • Around the head of the femur • Involves the following arteries: a. Superior gluteal artery b. Inferior gluteal artery c. Medial femoral circumflex artery d. Lateral femoral circumflex artery 18

Genicular anastomosis • Around the knee joint • Maintains blood supply to the leg during full flexion and involves the following arteries: a. Superior lateral genicular artery b. Inferior lateral genicular artery c. Superior medial genicular artery d. Inferior medial genicular artery e. Descending genicular artery (from the femoral artery) f. Descending branch of the lateral femoral circumflex artery g. Anterior tibial recurrent artery 19

Genicular anastomosis 20

CLINICAL CONSIDERATIONS • Femoral artery can be ligated anywhere along its course in the anterior compartment of the thigh. - Collateral circulation in the lower limb is not as robust as in the upper limb. • Acute arterial occlusion most frequently occurs where the femoral artery gives off the profunda femoris artery. Clinical signs include pain, paralysis, paresthesia, pallor, poikiloderma, and pulselessness (i. e. , the 6 P’s). 21

• Chronic arterial occlusive disease - caused by atherosclerosis, involves the femoral artery near the adductor hiatus and popliteal artery, anterior tibial artery, posterior tibial artery, and fibular artery. • Compartment syndrome within compartment leading to muscle and nerve damage involving the femoral artery and femoral nerve, and the anterior tibial artery and deep fibular nerve. 22

Venous Drainage SUPERFICIAL VEINS OF THE LOWER LIMB • Great saphenous vein • Small saphenous vein 23

Great saphenous vein • Has 10 to 12 valves • Formed by the union of the dorsal vein of the big toe and the dorsal venous arch of the foot. • Passes anterior to the medial malleolus (travels with the saphenous nerve) • Anastomoses with the small saphenous vein. • Courses along the medial aspect of the leg and thigh • Empties into the femoral vein within the femoral triangle. 24

Small saphenous vein • Formed by the union of the dorsal vein of the little toe and the dorsal venous arch of the foot. • Passes posterior to the lateral malleolus (travels with the sural nerve). • Courses along the lateral border of the calcaneal tendon, ascends between the heads of the gastrocnemius muscle • Empties into the popliteal vein within the popliteal fossa. 25

DEEP VEINS OF THE LOWER LIMB • Follow the arterial pattern of the leg leading to the femoral vein. COMMUNICATING VENOUS SYSTEM (Venae communicantes) • Network of perforating veins • Penetrate the deep fascia • Connect the superficial veins with the deep veins. • Allows flow of blood only from the superficial veins to the deep veins • Enables muscular contractions to propel blood toward the heart against gravity. 26

CLINICAL CONSIDERATION Deep venous thrombosis (DVT) • Blood clot (thrombus) within the deep veins of the lower limb which may lead to a pulmonary embolus. • Caused by venous stasis (e. g. , prolonged immobilization, congestive heart failure, obesity), hypercoagulation, or endothelial damage. • Treatment includes intravenous heparin for 5 to 7 days. Incompetent valves • Allow backflow of blood into the superficial veins (superficial veins to deep veins), causing dilation of the superficial veins and leading to varicose veins 27

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Lumbosacral Plexus. Components include: i. Rami are the L 1– 5 and S 1– 4 ventral primary rami of spinal nerves. ii. Divisions (anterior and posterior) are formed by rami dividing into anterior and posterior divisions. iii. Branches: 1. Femoral Nerve (L 2– 4) 2. Obturator Nerve (L 2– 4) 3. Superior Gluteal Nerve (L 4– 5, S 1) 4. Inferior Gluteal Nerve (L 5, S 1, S 2) 5. Common fibular nerve (L 4, L 5, S 1, S 2) divides into the: • a. Superficial fibular nerve • b. Deep fibular nerve 6. Tibial nerve (L 4, L 5, S– 3). The tibial nerve and common fibular nerve comprise the sciatic nerve. 29

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Saphenous Nerve • Longest and most widely distributed cutaneous branch of the femoral nerve • Only branch to extend beyond the knee. Sural Nerve Formed by • Medial sural cutaneous nerve from the tibial nerve) • Sural communicating branch(common fibular nerve) 34