The relations of the femoral artery are as follows:
Anteriorly: In the upper part of its course, it is superficial and is covered by skin and fascia. In the lower part of its course, it passes behind the sartorius muscle.
Posteriorly: The artery lies on the psoas, which separates it from the hip joint, the pectineus, and the adductor longus. The femoral vein intervenes between the artery and the adductor longus.
Medially: It is related to the femoral vein in the upper part of its course.
The superficial epigastric artery is a small branch that crosses the inguinal ligament and runs to the region of the umbilicus.
The superficial external pudendal artery is a small branch that runs medially to supply the skin of the scrotum.
The deep external pudendal artery runs medially and supplies the skin of the scrotum.
The profunda femoris artery is a large and important branch that arises from the lateral side of the femoral artery about 1.5 in. below the inguinal ligament. It passes medially behind the femoral vessels and enters the medial fascial compartment of the thigh. It ends by becoming the fourth perforating artery. At its origin, it gives off the medial and lateral femoral circumflex arteries, and during its course it gives off three perforating arteries.
The descending genicular artery is a small branch that arises from the femoral artery near its termination within the adductor canal. It assists in supplying the knee joint.
Segments
In clinical parlance, the femoral artery has the following segments:
The common femoral artery is the segment of the femoral artery between the inferior margin of the inguinal ligament and the branching point of the deep femoral artery.
The subsartorial artery or superficial femoral artery are designations for the segment between the branching point of the deep femoral vein and the adductor hiatus, passing through the subsartorial canal. However, usage of the term superficial femoral is discouraged by many physicians because it leads to confusion among general medical practitioners, at least for the femoral vein that courses next to the femoral artery. In particular, the adjacent femoral vein is clinically a deep vein, where deep vein thrombosis indicates anticoagulant or thrombolytic therapy, but the adjective "superficial" leads many physicians to falsely believe it is a superficial vein, which has resulted in patients with femoral thrombosis being denied proper treatment. Therefore, the terms subsartorial artery and subsartorial vein have been suggested for the femoral artery and vein, respectively, distally to the branching points of the deep femoral artery and vein.
Clinical significance
Pulse
As the femoral artery can often be palpated through the skin, it is often used as a catheter access artery. From it, wires and catheters can be directed anywhere in the arterial system for intervention or diagnostics, including the heart, brain, kidneys, arms and legs. The direction of the needle in the femoral artery can be against blood flow, for intervention and diagnostic towards the heart and opposite leg, or with the flow for diagnostics and intervention on the same leg. Access in either the left or right femoral artery is possible and depends on the type of intervention or diagnostic. The site for optimally palpating the femoral pulse is in the inner thigh, at the mid-inguinal point, halfway between the pubic symphysis and anterior superior iliac spine. Presence of a femoral pulse has been estimated to indicate a systolic blood pressure of more than 50 mmHg, as given by the 50% percentile. The femoral artery can be used to draw arterial blood when the blood pressure is so low that the radial or brachial arteries cannot be located.
Peripheral arterial disease
The femoral artery is susceptible to peripheral arterial disease. When it is blocked through atherosclerosis, percutaneous intervention with access from the opposite femoral may be needed. Endarterectomy, a surgical cut down and removal of the plaque of the femoral artery is also common. If the femoral artery has to be ligated surgically to treat a poplitealaneurysm, blood can still reach the popliteal artery distal to the ligation via the genicular anastomosis. However, if flow in the femoral artery of a normal leg is suddenly disrupted, blood flow distally is rarely sufficient. The reason for this is the fact that the genicular anastomosis is only present in a minority of individuals and is always undeveloped when disease in the femoral artery is absent.
History
Textbook illustrations of the genicular anastomosis, such as that shown in the sidebox, all appear to have been derived from the idealized image first produced by Gray's Anatomy in 1910. Neither the 1910 illustration nor any subsequent version, was made of an anatomical dissection but rather from the writings of John Hunter and Astley Cooper which described the genicular anastomosis many years after ligation of the femoral artery for Popliteal aneurysm. The genicular anastomosis has not been demonstrated even with modern imaging techniques such as X-ray computed tomography or angiography.
