Chapter 19 Operative Exposure in Abdominal Trauma: Exposure of the Distal Aorta and Iliac Vessels

This chapter will discuss the key vascular exposures that will be potentially lifesaving for patients with injury to or rupture of their distal aorta or iliac artery or vein.

Learning Objectives

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

1. Describe and demonstrate the steps to obtain vascular control of the distal aorta.
2. Describe and demonstrate the steps to obtain exposure of the right and left iliac arteries and veins.

Considerations

• The distal aorta and the iliac vessels are located in retroperitoneal Zones 1 and 3 (chapter 15), respectively. When injured, they can present life-threatening hemorrhage, with an associated high mortality rate.
• Penetrating wounds to the pelvis are the most common causes of distal aorta and iliac vessel injuries.
• Iliac vein injuries result in significant blood loss, and operative exposure is difficult. These veins may be ligated if necessary. Ligation of the external iliac vein distal to the bifurcation will place the patient at risk of developing lower extremity edema and/or deep venous thrombosis.
• The first priority is hemorrhage control.
• Ureteral injuries are commonly associated with iliac vessel injuries, and therefore the ureter should be evaluated after the vascular injuries have been addressed.

Operative Exposure

• Distal aorta and iliac vessel injuries are typically exposed through a midline incision as part of a trauma laparotomy.
• Understanding the anatomic relationships of the distal aorta and iliac vessels is critical to obtaining safe and rapid control. Remember that the iliac arteries are anterior to their corresponding veins.
• As outlined in chapter 15, right-to-left medial visceral rotation (Cattell-Braasch maneuver) can be performed rapidly and allows for the colon and small bowel to be mobilized up and off the distal aorta, inferior vena cava, and iliac vessels (Figures 1 and 2).
• The common iliac veins are intimately adherent to the back wall of the common iliac arteries.
• If not careful, mobilization of the artery may result in venous injury and profuse bleeding. The right common iliac vein and bifurcation are particularly difficult to expose.
• Occasionally, it may be necessary to transect the right common iliac artery to gain adequate exposure of the right common iliac vein, as depicted in Figures 3 and 4. Transection and ligation of the internal iliac artery can also improve exposure of the ipsilateral common iliac vein.
  • Excessive retraction of the external iliac artery to obtain better exposure of this vein may damage the artery.

Vascular Control of the Distal Aorta

• Injuries to the distal aorta and bifurcation may be temporarily controlled by local manual compression with a laparotomy pad, sponge stick, or fingers until proximal and distal vessel control can be achieved.
• REBOA, as described in chapter 22, can also provide temporary hemorrhage control.
• It is important to remember that the aorta proximal to the injury should be isolated with vessel loops and clamped, taking care to avoid injury to lumbar vessels. Additionally, both common iliac vessels distal to the injury need to be isolated.
• For suspected injuries to the distal aorta and its bifurcation, exposure can also be accomplished by entering the midline retroperitoneum at the root of the mesentery below the renal vessels, with the small bowel retracted upward to the right and the colon to the left (Figure 5).

Vascular Control of the Iliac Vessels

• Injury to the iliac artery or vein that results in an expanding hematoma or significant bleeding may necessitate manual compression until proximal and distal control can be obtained. Again, sponge sticks can be very helpful.
• Vessel loops can be passed around the common iliac artery for proximal control and around the external and internal iliac arteries (Figure 6).
• Bilateral iliac injury may be exposed using total pelvic vascular isolation, which consists of cross-clamping the distal abdominal aorta and inferior vena cava, as well as clamping both external iliac arteries and veins.
• A temporary arterial or venous shunt may be used to control hemorrhage and provide temporary restoration of distal blood flow in damage control situations.