Chapter 22 Introduction to Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA)

This chapter will review the indications for and technical steps of performing resuscitative endovascular balloon occlusion of the aorta (REBOA). The major emphasis of this module will be to review options for obtaining access to the common femoral artery (CFA), as well as the use of the two most common REBOA catheter systems in North America. This module is designed to be an introduction and is not intended to replace formal REBOA training courses such as the Basic Endovascular Surgery for Trauma (BEST®) course administered by the American College of Surgeons Committee on Trauma.

Learning Objectives

By the end of this module, participants should be able to do the following:

1. Discuss indications for the use of REBOA.
2. Identify external landmarks for common femoral artery (CFA) access.
3. Describe options available to access the CFA.
4. Demonstrate surgical exposure of the CFA and the basic steps of REBOA insertion.
5. Describe the external landmarks for the aortic occlusion zones.
6. List the technical differences of the two REBOA catheters most commonly used in North America.
7. Describe the potential complications of REBOA.

General Considerations and Indications

• Noncompressible torso hemorrhage (NCTH) is a leading cause of potentially preventable death in both civilian and military trauma settings.
• NCTH resulting in profound hypotension or shock requires proximal control of blood flow while increasing cardiac afterload and central aortic pressure until direct hemostasis can be achieved.
• Proximal control in such circumstances is typically obtained by resuscitative thoracotomy (RT), as discussed in chapter 10, or less commonly via intra-abdominal control of the aorta, as described in chapter 15.
• REBOA is an alternative approach to proximal aortic control in patients at risk of imminent cardiovascular collapse or in traumatic arrest. It can be performed through a CFA approach without the need for thoracotomy. During arrest, it can be performed concurrently with closed chest compressions (CPR).
• REBOA is most useful when the site of hemorrhage is below the diaphragm and open thoracic vascular intervention is not required.
• RT remains the procedure of choice for patients with significant thoracic or cardiac injury, and REBOA is contraindicated in these conditions, as the procedure will likely increase thoracic bleeding. Additionally, RT remains the gold standard for aortic occlusion in traumatic arrest.
• Patients exsanguinating from abdominal, pelvic, or junctional lower extremity trauma may be candidates for REBOA.
• Early recognition of hemorrhagic shock will facilitate identification of patients who may benefit from REBOA. Mechanisms of injury likely to benefit include penetrating injuries to abdomen or pelvis, blast or blunt mechanism with a positive FAST, suspected pelvic fracture, or massive proximal lower extremity trauma.
• REBOA has also been used successfully for proximal aortic occlusion in ruptured abdominal aortic aneurysms, elective oncologic resections, orthopaedic procedures, gastrointestinal bleeds, and hemorrhage from obstetric and gynecologic conditions.
• In patients with risk factors for impending cardiovascular collapse, consider placing an arterial line in the CFA, as this will facilitate subsequent placement of a REBOA catheter if needed.
• Ideally, REBOA should be performed prior to cardiac arrest.
• Exsanguinating hemorrhage in the chest must be ruled out (by chest X ray, ultrasound, or chest tube placement) prior to placing a REBOA catheter, as endovascular occlusion of the aorta may fatally increase such bleeding.
• Practitioners wishing to perform REBOA should be experienced in obtaining surgical exposure of the CFA, as up to 50 percent of patients in need of REBOA will require cut-down on the CFA to insert the sheath.
• REBOA is a temporary, minimally invasive bridge to definitive surgical or endovascular hemorrhage control.

REBOA Catheters

• A number of catheters that can be used for REBOA are available internationally, but in North America, two are commonly used: the Coda® Balloon Catheter (Cook Medical) and the ER-REBOA™ Catheter (Prytime Medical).
• The Coda Balloon Catheter is a 9 French device with a 32 mm balloon that is 120 cm in length.
• It requires a 12 French introducer sheath and a 260 cm guide wire. Placement requires a significant length of sterile field (Figure 1).

• Due to the size of the introducer sheath of the Coda Balloon Catheter, insertion into the CFA will require cut-down and repair of the vessel.
• The ER-REBOA Catheter is a 6 French catheter with a 32 mm balloon that is 72 cm in length and can be inserted via a 7 French introducer sheath. It does not require a guide wire. Additionally, this catheter has centimeter markings along the length, a secondary lumen allowing for monitoring of arterial blood pressure above the balloon, an atraumatic
• tip, and a compliant balloon with radiopaque markers on either end allowing for confirmation of placement with plain radiography (Figure 2).
• The smaller size of the ER-REBOA makes the need for repair of the artery much less likely upon removal of the required 7 French introducer sheath.

Positioning and Arterial Access

• The patient should be in the supine position with wide prep of the groin. Pertinent anatomical landmarks should be visible, including the anterosuperior iliac crest
• and the pubic bone. A line drawn from the anterosuperior iliac crest to the pubic bone represents the inguinal ligament (Figure 3).
• The CFA is the preferred site of insertion of the sheath required to place the REBOA catheter. Cannulation of the superficial femoral artery (SFA) should be avoided as its diameter is smaller than that of the CFA, leading to possible arterial injury and hemorrhage, ischemia, thrombosis, and/or amputation.
• Percutaneous, ultrasound-guided (if available) cannulation (Figure 3) is the preferred method for accessing the CFA. After the CFA has been entered with a needle, the Seldinger technique is used to place an introducer sheath into the artery for REBOA placement (Figures 4 and 5).
• Percutaneous cannulation of the CFA in the setting of cardiac arrest can be technically challenging. In these situations, ultrasound guidance should be used or open access via a femoral artery cut down should be pursued
• (Figure 6). Regardless of the size of introducer sheath used for REBOA, approximately half of the patients require an open groin cut-down for access (as described in chapter 3).
• The inguinal ligament is a crucial anatomic landmark for accessing the CFA. The inguinal crease is often incorrectly assumed to correlate with the inguinal ligament. However, the relationship between the inguinal crease and inguinal ligament is highly variable, with the inguinal crease often lying well below the inguinal ligament.

Catheter Insertion

• The catheter for REBOA is placed in either Aortic Zone I or Aortic Zone III, which are illustrated in Figure 7. Aortic Zone I is the area from the distal aortic arch down to the celiac artery. Aortic Zone III is the area from just below the renal arteries down to the aortic bifurcation. Aortic Zone II is the area between Zones I and III and includes the mesenteric and renal arteries.
• The depth of insertion of the balloon catheter is determined by the most likely source of the bleeding to be temporarily controlled.
• The REBOA catheter is placed and inflated in Aortic Zone I when the source of exsanguination is believed to be intra-abdominal or retroperitoneal hemorrhage. Aortic Zone I is also used in patients with traumatic arrest in lieu of performing a resuscitative thoracotomy, keeping in mind that REBOA should not be performed if the etiology of the shock or arrest is secondary to injury in the chest.
• Aortic Zone III is occluded with the REBOA catheter when the suspected source of exsanguination is pelvic, junctional, or proximal lower extremity hemorrhage.
• The radiographs seen in Figures 8 and 9 demonstrate balloon inflation in Aortic Zones I and III, respectively.
• Proper positioning of the balloon can be achieved by the use of external landmarks on the patient followed by confirmatory radiography prior to balloon inflation.
• Different external landmarks are used for the Coda Balloon Catheter and the ER-REBOA Catheter, as detailed below.

Insertion of the Coda Balloon Catheter

• The Coda Balloon Catheter has no external length markers. Therefore, an external indicator must be placed on the actual catheter prior to placement to indicate the depth of insertion required to reach either Aortic Zone I or III. A marking pen or sterile tape can be employed for this task.
• The external landmark for Aortic Zone I occlusion when using the Coda catheter is the xiphoid process; proper placement requires orienting the bottom of the balloon about 2 cm above the xiphoid process (Figure 10).
• The external landmark for Aortic Zone III occlusion when using the Coda catheter is the umbilicus; proper placement involves orienting the bottom of the balloon about 2 cm above this landmark (Figure 11).
• Radiographic confirmation of placement should be obtained prior to balloon inflation. This step can be omitted if the patient is in arrest with ongoing CPR, but radiographic confirmation should be obtained if and when return of spontaneous circulation occurs.

Insertion of the ER-REBOA Balloon Catheter

• The ER-REBOA Catheter has external distance markers printed on the catheter, which helps estimate depth of insertion at the hub of the CTA introducer sheath.
• The external landmark for Aortic Zone I occlusion is the suprasternal (jugular) notch, orienting the tip of the catheter just below the notch (Figure 12).
• The external landmark for Aortic Zone III occlusion is the xiphoid process, placing the tip of the catheter just below this landmark (Figure 13).
• Radiographic confirmation of placement is obtained prior to balloon inflation, if possible (Figure 14).
• The arterial port is flushed and then attached to monitoring tubing in order to provide pre- and post-inflation systolic blood pressures.

Balloon Inflation

• Once the position of the balloon has been confirmed with radiographic imaging, the catheter should be secured to the introducer sheath before, during, and after inflation. Failure to secure the catheter to the sheath may result in distal migration, possible aortic intimal injury, and loss of hemorrhage control.
• The balloon should be inflated cautiously, as overinflation could result in injury to the aorta.
• Watch for hemodynamic changes during inflation, remembering that a vasoconstricted distal abdominal aorta can be less than 1 cm in diameter. With low-profile systems such as the ER-REBOA Catheter, resistance to inflation is largely from the shaft lumen, with little feedback from the balloon itself.

• The maximum inflation volume of the aortic balloon differs based upon the REBOA catheter being used. Users are obligated to be familiar with the system being utilized and the maximum inflation volumes for the specific catheter being used, as well as the estimated aortic diameter of the patient.
• The recommended initial inflation of the ER- REBOA Catheter balloon is 8 cc for Aortic Zone I and 3 cc for Aortic Zone III (“3 to 8, don’t overinflate”).
• If hemostasis is not obtained after inflation in Aortic Zone III, then the balloon should be deflated, advanced, and inflated in Aortic Zone I.
• Once the balloon has been inflated, the time of inflation should be recorded in the medical record, and the patient should undergo emergent surgical or catheter-based control of bleeding.
• The exact duration of safe occlusion of the aorta using REBOA is not well defined, but longer is definitely worse. Current clinical experience and published guidelines recommend limiting occlusion of Aortic Zone I to 15 to 30 minutes (with 60 minutes as the extreme).
• The occlusion time tolerated by Aortic Zone III is longer than Aortic Zone I but is also not well established. Published series show a survival advantage for shorter occlusion times in both zones.
• Partial balloon inflation has been proposed as a way to extend safe occlusion times but cannot currently be supported as standard practice.

Balloon Deflation and Aftercare

• Once definitive hemorrhage control has been obtained, the REBOA balloon should be slowly deflated and removed from the sheath.
• Be prepared to treat rebound hypotension and to reinflate the balloon if necessary.
• Reperfusion injury should be anticipated and can lead to cardiac arrest upon balloon deflation.
• The technique for sheath removal is dependent upon the size of the sheath utilized. If a 12 or 14 Fr system is used, or if the 7 Fr sheath was placed via open cut-down (Figure 6), exploration of the CFA must be performed, with open repair of the arteriotomy.
• If a 7 Fr or smaller system is used percutaneously, the sheath can be pulled once the patient has stabilized and coagulopathy has reversed. Thirty minutes of correctly applied manual compression is recommended and has not been found to be inferior to any available arterial closure device.
• Following sheath removal, the extremity must be assessed for adequate perfusion. The color and temperature should be compared with the opposite side. Pulses should be examined digitally; if not palpable, the use of Doppler ultrasound can be helpful in characterizing symmetry. Inadequate perfusion must be acted upon promptly, either by further imaging or by surgical exploration of the accessed groin.
• In the setting of percutaneous access, patients should undergo a duplex ultrasound examination at 24 to 72 hours to assess for pseudoaneurysm formation.
• Early involvement of vascular surgeons for any suspected or proven REBOA-related complication provides optimal outcomes.

Pitfalls

• Failure to recognize the clinical indications for REBOA.
• Performing REBOA when the capability of surgically controlling hemorrhage is not immediately available.
• Difficulty locating and accessing the CFA in the groin—Patients who are obese or in profound shock will likely require open cut-down on the groin to access the CFA.
• Failure to recognize or address chest pathology—Placing a REBOA catheter in the setting of uncontrolled bleeding in the chest will likely increase bleeding and be fatal.
• Overinflation of the occlusion balloon may cause balloon rupture and may also damage the vessel.
• Leaving the balloon inflated too long—Actively bleeding sites should be controlled with temporizing measures (clamping or packing) to allow for the earliest deflation of the REBOA balloon, with most suturing, ligating, solid organ removing, and vascular shunting deferred until after the balloon is deflated.
• Failure to work with a sense of urgency once the balloon is inflated—Prolonged aortic occlusion may lead to fatal complications or spinal cord injury due to prolonged ischemia.
• Failure to adequately secure the catheter before balloon inflation, with resultant migration.
• Deflating the balloon too quickly before adequate volume resuscitation of the patient.
• Removal of arterial sheath too soon—These patients are likely to be coagulopathic, and this should be corrected prior to sheath removal. Additionally, leaving the sheath in place may allow for subsequent angiographic evaluation and treatment of other bleeding sites.
• Injury to the artery, with possible re-bleeding, thrombosis, intimal injury, arterial disruption, dissection, pseudoaneurysms, and limb- threatening ischemia.
• Aortoiliac injuries are possible, and unintended inflation of the balloon in the iliac vessels may lead to rupture or thrombosis.