Chapter 3 Exposure of Vascular Injuries to the Lower Extremity: Iliac, Common Femoral, and Femoral Bifurcation

This chapter will discuss techniques for exposure and proximal control of injuries to the vasculature of the lower extremity, from the iliac arteries to the femoral artery and its bifurcation. Though the major emphasis of this lab is operative exposure, the topics of preoperative considerations, positioning, and management of specific injuries will be briefly discussed.

Learning Objectives

By the end of the ASSET course, participants should be able to do the following:

1. Describe and demonstrate the groin incision used to gain exposure of the common femoral, profunda femoral, and superficial femoral arteries.
2. Demonstrate surgical exposure of the iliac artery and vein in the retroperitoneum using an incision above the inguinal ligament.
3. Demonstrate further exposure of the iliac and common femoral arteries by extension of the above incision across the inguinal ligament and down onto the leg (“hockey stick” incision).

General Considerations

• Exposure of the vessels of the pelvis and lower extremities is needed for definitive bleeding control and for preparation for reconstruction of damage to lower extremity vasculature.
• Ligation of the internal iliac vessels can also be used as a damage control adjunct for uncontrolled hemorrhage accompanying a pelvic fracture.
• Preoperatively, bleeding should be controlled with direct pressure.
• Blind clamping of structures should be avoided in the emergency department, as this often results in additional injury.

Prepping and Positioning

• Patients should be prepped and draped from “neck to knees” to ensure adequate breadth of field. The involved leg(s) should be prepped to include the foot to allow for evaluation of distal flow and fasciotomy if indicated.
• Access to bilateral groins should be anticipated for saphenous vein graft harvesting.
• For femoral and iliac exposure, the patient should be supine.
• If time permits, a small roll may be placed under the buttock of the operative side to elevate the pelvis 10–15° to aid exposure.
• For femoral exposure, the thigh should be in abduction and in slight external rotation.

Exposure of the Iliac Artery And Vein

Common Iliac

• Access to the common iliac for emergent control of bleeding is best accomplished through the abdomen, a process covered in chapter 19.

External Iliac

• Though the external iliac can be exposed via a transabdominal approach with entry into the pelvis, it is often more expedient to gain control from a retroperitoneal approach above the inguinal ligament, especially if proximal control is needed.
• The classic injury in which the retroperitoneal approach is useful is injury to the femoral artery just below the inguinal ligament (the “Blackhawk Down” injury), which requires rapid proximal control.
• A curvilinear incision (similar to the incision used during kidney transplantation) is made from a point about one to two fingerbreadths above the anterior superior iliac spine (ASIS) and extending to a point just above the inguinal ligament (Figure 1).
• This incision is carried down through the skin and subcutaneous tissues to expose the external oblique fascia. The fascia is incised, and the oblique transversus muscles, as well as the transversalis fascia, are opened laterally while avoiding entry into the peritoneum. This dissection allows entry into the retroperitoneal space (Figure 2).
• The peritoneum is left intact and retracted medially to allow exposure of the pelvic retroperitoneal space and control of the iliac vessels (Figure 3).
• If needed, this incision can be extended down onto the thigh by dividing the inguinal ligament (“hockey stick” incision), allowing exposure of the distal external iliac and proximal common femoral arteries (Figure 4).

Potential Pitfalls to the Retroperitoneal Approach

• Injury to iliac veins and branches
• Injury to ureters
• Injury to spermatic cord
• Iatrogenic injury to inferior epigastric or circumflex iliac branches when dividing the inguinal ligament (and failure to recognize these injuries)

Common Femoral Artery and Vein

Exposure

• The femoral artery runs from the inguinal ligament (Poupart’s ligament), through the adductor (Hunter’s) canal, to the popliteal fossa.
• The femoral artery lies superficially at the inguinal ligament and becomes deeper and more medial along its course to the eak popliteal fossa.
• The inguinal ligament, which courses from the ASIS to the pubic tubercle, is used to define the upper limit of the incision (Figure 5).
• A common mistake is to believe that the crease where the lower abdominal skin joins the groin represents the inguinal ligament. This results in an incision that is made too low onto the thigh and dissection of the underlying superficial femoral artery (SFA) rather than the common femoral artery (CFA).
• The incision to expose the CFA should be made from a point approximately two fingerbreadths lateral to the pubic tubercle and 1–2 cm above the pubic tubercle, extending caudally along the medial border of the sartorius muscle and down onto the upper thigh (Figure 5).
• The edges of the femoral triangle are formed by the inguinal ligament, the medial edge of the sartorius muscle, and the medial border of the adductor longus (Figure 6).
• Expedient exposure of the CFA is an important adjunct for individuals practicing resuscitative endovascular balloon occlusion of the aorta (REBOA), which is described in detail in chapter 22.
• Using the lower edge of the inguinal ligament as a landmark, the femoral vessels are exposed in the femoral triangle (Figure 7).
• Within the femoral triangle, the femoral sheath is opened anteriorly while remaining on top of the femoral artery to expose the CFA and the bifurcation (Figure 8).
• Deep dissection of the artery should be lateral to the saphenous vein and inguinal nodes.

Profunda and Proximal Superficial Femoral Artery

Anatomy

• The profunda femoris (deep femoral) artery (PFA) is the largest branch of the CFA and is usually found 4–6 centimeters below the inguinal ligament. It follows a posterolateral course (Figure 9).
• The superficial femoral artery (SFA) is a continuation of the CFA. It descends into the adductor (Hunter’s) canal from the femoral triangle and courses anteromedially through the thigh to the popliteal fossa.
• The lateral femoral circumflex vein (often referred to as the “vein of woe”) crosses the origin of the PFA and should be avoided, as it is easily injured and will bleed profusely (Figure 9).

Exposure of the SFA and PFA

• The CFA and SFA are gently dissected free from the surrounding tissues, while staying close to the vessel.
• The origin of the PFA is marked by an abrupt change in the diameter of the CFA (Figure 9) and is typically found 4–6 cm below the inguinal ligament.
• Upward traction on the CFA and SFA with vessel loops can help locate the origin of the PFA.
• Rather than dissecting out the PFA and risking injury to the lateral femoral circumflex vein, it is safer to encircle the origin of the vessel by passing a vessel loop or tape under the CFA above the PFA and passing the other end under the SFA to encircle and control the origin of the PFA without actually dissecting it free (Figures 10–12).
• This technique is shown in a detailed, stepwise fashion in Figure 11.
• Using this technique, the CFA, SFA, and PFA can all be controlled with vessel loops while avoiding injury to the lateral femoral circumflex vein (Figures 11 and 12).
• In hemodynamically stable patients, the proximal PFA should be repaired because of its collateral supply to the lower extremity; however, it may be ligated in unstable patients, if necessary.
• The SFA supplies a significant portion of blood flow to the lower leg, and ligation of this vessel is likely to result in critical ischemia and/or amputation. As such, it should be repaired or, in unstable patients, shunted. If possible, the superficial femoral vein should also be repaired or shunted as well.
• Patients with injuries to the femoral vessels are at increased risk of compartment syndrome, and strong consideration should be given to performing a fasciotomy of the lower leg.

Potential Pitfalls to Exposure of the Femoral Vessels

• If the groin crease is mistaken for the inguinal ligament, the incision will be made too low for adequate exposure of the CFA. The SFA will then be mistaken for the CFA.
• Femoral vein injury if dissecting too far medially
• Femoral nerve injury if dissecting too far laterally