Femoral vessel injuries: High mortality and low morbidity injuries

Anatomy

The femoral artery is a direct continuation of the external iliac artery, which courses from the inguinal ligament to the adductor canal (subsartorial or Hunter’s canal), where it exits as the popliteal artery. The common femoral artery lies at a point midway between the anterior superior iliac spine and the pubic symphysis. Proximally, the femoral vessels course through the femoral triangle, the borders of which are composed of the inguinal ligament superiorly, the sartorius muscle laterally, and the adductor longus medially. The femoral artery starts superficially and progresses deep and medially together with the femoral vein, which is located medial to the artery.

The proximal common femoral artery and vein are wrapped in the femoral sheath, which is a continuation of the iliac, pectineal, and transversalis endoabdominal fascia. The femoral sheath contains three compartments: the lateral compartment contains the femoral artery, the middle (or intermediate) compartment contains the femoral vein, and the most medial compartment is the femoral canal, which accommodates the passage of lymphatics.

The common femoral artery is the most proximal portion of the femoral artery arising posterior to the inguinal ligament. Branches of the common femoral artery include the superficial circumflex iliac, superficial epigastric, and superficial external pudendal arteries.

Approximately 4 cm below the inguinal ligament, the common femoral artery bifurcates into the profunda (deep) femoral artery and the superficial femoral artery (SFA) ( Fig. 1 ). The profunda femoral artery arises from the posterolateral aspect of the common femoral artery and courses deep into the thigh muscles where it receives numerous collaterals from branches of the hypogastric artery. Within 2 to 3 cm of its origin, the profunda femoral artery bifurcates into the medial and lateral circumflex arteries.

The SFA is a continuation of the common femoral artery and courses from an anterior location to a posterior medial position as it proceeds distally in the thigh where it transitions to the popliteal artery at the opening of the adductor magnus or Hunter’s canal. The descending genicular artery forms a collateral anastomosis with genicular arteries of the popliteal artery and is the only significant branch of the SFA.

The femoral vein is a continuation of the popliteal vein and receives drainage from two major tributaries, the deep femoral vein and the greater saphenous vein. The latter enters the femoral sheath via the fossa ovalis in the fascia lata, piercing the femoral sheath on its anterior aspect. The femoral vein ends at the inferior edge of the inguinal ligament where it becomes the external iliac vein.

The femoral nerve courses lateral to the femoral artery outside of the femoral sheath. The nerve divides into both anterior and posterior divisions, which contain branches that innervate the anterior compartment of the thigh.

Incidence and mechanism of injury

Femoral vessel injuries account for 70% of all arterial trauma, and young males are disproportionately affected by these injuries. Although the vast majority of studies examining extremity vascular injuries have been performed in adult patient populations, several recent civilian and military studies in the pediatric population have reported an incidence of 0.68% to 3.5%.

Penetrating mechanisms account for the vast majority of femoral vessel injuries (>80%), and high-velocity gunshot wounds ( Fig. 2 ) are much more common than stab wounds ( Fig. 3 ). Due to the kinetic energy and cavitation associated with ballistic injuries, significant soft tissue and bony injuries usually accompany femoral vessel injuries.

Blunt mechanisms are uncommon and may account for up to 12% to 14% of all femoral vessel injuries. Anterior dislocation of the hip is a rare but potential etiology for blunt injury to the proximal femoral vessels, whereas distal femur fractures may be associated with superficial femoral or supragenicular popliteal artery injuries. In comparison with upper extremity vascular injuries, in which the brachial artery is the most commonly injured vessel, lower extremity vascular injuries occur more commonly and are associated with a higher incidence of adverse outcomes including amputation and death. The type of injury often dictates the clinical presentation ( Table 1 ).