The vagus nerve descends from the jugular foramen posteriorly between the internal jugular vein and the internal carotid artery. The ansa hypoglossi comes off the vagus nerve anteriorly and supplies the strap muscles. The facial vein enters the internal jugular vein. To expose the carotid bifurcation, division and ligation of the ansa hypoglossi and facial vein may be required. The hypoglossal nerve is often encountered as it descends from the jugular foramen in the carotid sheath traveling over the internal carotid artery and anterior to the external carotid artery toward the tongue.

The abdominal portion of the aorta extends from the diaphragmatic hiatus to the level of the fourth lumbar vertebra (Fig. 17.1). It terminates as the left and right common iliac arteries, and the middle sacral artery. The abdominal aorta gives off visceral branches as the celiac, superior, and inferior mesenteric arteries and the suprarenal, spermatic, and renal arteries. Originating anteriorly from the aorta are the celiac, superior mesenteric, and inferior mesenteric arteries. The parietal branches off the abdominal aorta include the paired inferior phrenic arteries arising near the aortic hiatus and the multiple lumbar arteries, which divide into ventral and dorsal branches at the border of the psoas muscle.

The infrainguinal region is bounded medially by the pectineus muscle and laterally by the tensor fascia lata muscle. Its superior border is the inguinal ligament, which is a strong, fibrous band that stretches from the anterior superior iliac spine to the pubic tubercle.

The external iliac artery becomes the common femoral artery as it emanates from a point under the middle of the inguinal ligament. The artery is relatively superficial proximally, but somewhat deeper where it terminates. Approximately 5 cm below the inguinal ligament, the profunda femoral branch takes origin from the common femoral artery, usually arising posterolaterally.

The femoral artery continues down the thigh as the superficial femoral artery (Fig. 17.2). The profunda femoris artery passes beneath the adductor longus muscle, while the superficial femoral artery remains above it. The profunda femoris tends to remain patent in patients with superficial femoral artery occlusive disease and thus provides a source of collateral circulation. It has several important branches: lateral and medial circumflex femoral arteries (though they may occasionally arise from the common femoral artery) and the supreme geniculate artery. Distally, the superficial femoral artery courses under the sartorius muscle and into the adductor (Hunter’s) canal.

From superficial to deep, the adductor canal is composed of the following muscles: adductor longus, adductor brevis, and adductor magnus. The superficial femoral artery becomes the popliteal artery as it emerges anterior to the adductor magnus. The popliteal artery then courses anterior to the semimembranosus, gastrocnemius, plantaris, and soleus muscles; this depth often makes palpating a popliteal pulse difficult.

Distal to the popliteus muscle, the popliteal artery bifurcates into the anterior tibial artery and the tibioperoneal trunk. The anterior tibial continues down the leg, anterior to the tibia, and becomes the dorsalis pedis artery in the foot. The peroneal and posterior tibial arteries arise from the tibioperoneal trunk, approximately 2 cm below the tendon of the soleus muscle. The peroneal artery divides into calcaneal branches as it passes behind the inferior tibiofibular articulation. The posterior tibial artery travels along the medial aspect of the leg and posterior to the medial malleolus.

The great saphenous vein starts on the medial side of the foot, just anterior to the medial malleolus. It continues along the medial aspect of the calf and thigh and courses anteriorly as it enters the femoral vein just below the inguinal ligament. The great saphenous is an ideal conduit for use in bypass surgery because of its convenient location next to the femoral artery and its superficial course in the subcutaneous tissue exterior to the investing fascia.