Anatomy, Bony Pelvis and Lower Limb, Femoral Artery

After branching off of the deep femoral artery, the medial circumflex artery runs along the posterior side of the femur and supplies blood to the thigh adductors (longus, magnus, and brevis), gracilis, pectineus as well as the femoral head and neck.[5] The lateral circumflex courses laterally and supplies oxygenated blood to the major knee extensor group including vastus lateralis, vastus intermedius, and rectus femoris. Vastus medialis is supplied in part by both the superficial femoral artery and deep femoral artery. The perforating arteries of the deep femoral artery supply the four hamstring muscles (semitendinosus, semimembranosus, short and long head of biceps. After exiting the adductor canal, the superficial femoral artery continues distally as the popliteal artery which serves the entire calf and foot with oxygen-rich blood.[10]

Although many benign variants of the femoral artery exist, there are some that are considered to be rare and potentially dangerous to the patient. The origins of smaller arteries off of the femoral artery can be highly variable. Less common abnormalities include a duplicated or absent deep femoral artery, lateral and medial circumflex arteries most originating from the common or superficial femoral artery instead of the deep femoral. The clinical significance of this variant is that the common femoral artery may appear to trifurcate instead of bifurcate.[5] The precise level of the common femoral artery bifurcation may vary from person to person and often does not align with the inguinal crease. Ultrasound examination is routinely used for safe and effective vascular access.[1] Another potential abnormality of the femoral artery is the presence of a persistent sciatic artery. It occurs when the embryonic vessel fails to regress and thus remains the dominant feeding vessel to the lower extremity. Serious limb ischemia complications may arise due to higher rates of an aneurysm and thromboembolic complications in this unusual variant.[11] Finally, an even more unusual variant is the presence of duplicate superficial femoral arteries and knowledge of this plays a vital role in preprocedural planning.[12] 

The region of the anterior thigh that lies just inferior to the inguinal ligament is termed the femoral triangle. Within the femoral triangle, there is a discrete organization, and thorough understanding of these anatomical relationships are necessary to avoid inadvertent injury to the femoral artery, vein, and nerve during procedures such as hernia repairs and nerve blocks.  

During percutaneous vascular access procedures, the common femoral artery is often desirable as an access point because it is suitable for large-diameter catheters and sheaths to be placed which allows for a wide variety of endovascular procedures. It is essential to access the common femoral artery just superior to the bifurcation of the superficial and deep branches to reduce complications. Although the inguinal crease is frequently used as an initial landmark, ultrasound guidance is more precise when determining the relevant anatomy, specifically the common femoral artery bifurcation and inferior epigastric artery. Arteriotomy site should be between the bifurcation and the inferior epigastric artery. Fluoroscopy is also useful to identify the femoral head which is often an anatomical landmark for accessing the common femoral artery.[2][13]

Endovascular intervention is common in patients with clinically significant peripheral arterial disease. The atherosclerotic burden most afflicts the superficial femoral artery, common femoral artery and/or the popliteal artery. Patients with heavily calcified arteries exhibiting clinical signs and symptoms may require endovascular angioplasty (ballooning) with or without stenting to improve distal blood flow. If an artery is unable to be repaired endovascularly, vascular surgical consult may be necessary for an arterial bypass procedure.[12]

In individuals with peripheral arterial disease (PAD) the most common sites of involvement are the superficial femoral artery and the common femoral artery. Symptoms that indicate femoral artery disease may include claudication in the thighs and calves, cold, discolored extremities, poor wound healing below the lesion, change in sensation, and in end-stage disease, gangrene or necrosis of the digits. Chronic health conditions that increase a patient’s risk of PAD include age, obesity, diabetes, hypertension, hyperlipidemia, coronary atherosclerotic disease, vasculitis, sedentary lifestyle, and smoking. It is worth noting that the absence of these risk factors does not preclude a patient from having PAD.[10]

 In instances where the common and superficial femoral arteries are chronically occluded, extensive collaterals may be present between the deep femoral artery, and thus distal blood flow is more robust than expected.[14] Prior to any percutaneous endovascular intervention, a comprehensive clinical evaluation including palpating pulses, visual evaluation of the extremity, Doppler ultrasound, ankle-brachial indices, and patient symptoms should take place. If warranted, a CT-angiogram (CTA) of the lower extremities may be performed to better evaluate the extent of atherosclerotic disease and assist in further management.[10]

The course of the common femoral artery over the femoral head is important because it acts as a hard surface to which manual pressure can be effectively applied. Accessing more superiorly or inferiorly can make hemostasis difficult to achieve and lead to greater complications. Complications of femoral artery access include hematomas, pseudoaneurysms, injury to the femoral nerve, retroperitoneal hemorrhage, arteriovenous fistulas, and distal embolization of plaque. Hematomas and hemorrhage may occur with inadequate thrombosis of the arteriotomy and present in the groin or flank.[3] The level of the inferior epigastric artery is generally accepted as the superior boundary of potential arteriotomy sites. More superior than this puts the patient at high risk of bleeding into the retroperitoneal space. Alternatively, arteriotomies of the superficial femoral artery are at increased risk of avoidable complications.[15][16] Checking for complications post-procedurally and educating the patient about concerning signs for which they should seek immediate medical attention is of utmost importance.