In a battlefield hospital in Korea more than five decades ago, a surgeon fought to save the lives of three critically injured soldiers who were bleeding out. With nothing to lose, he tried a never-before-attempted technique: threading a balloon catheter through the femoral artery into the thoracic portion of each soldier's aorta and inflating the balloon to occlude blood flow and increase life-sustaining blood pressure and perfusion to the heart and brain.
One of the soldiers, for whom the surgeon did not have time to attempt the technique, died almost immediately. The other two survived long enough with endovascular occlusion of the aorta to undergo open surgical repair of obvious abdominal damage, although they later died from their injuries. A 1954 article describes this first-of-its-kind case series by the surgeon, then-Lieutenant Colonel Carl Hughes, MD, a pioneer in arterial repair who ultimately rose to the rank of Major General and Chief of Surgery at Walter Reed Army Medical Center in Bethesda, MD. He theorized that earlier intervention with the technique might have improved the men's chances of survival. (Surgery 1954;36:65.)
Decades after Dr. Hughes' desperate experiment, catheter-based techniques, also referred to as endovascular techniques, exploded onto the medical scene for managing age-related vascular disease. For the better part of the 1980s, 1990s, and 2000s, catheter-based diagnostic and therapeutic procedures were the purview of interventional cardiologists, radiologists, and recently vascular surgeons. Despite sporadic reports of endovascular techniques used in emergency settings for trauma and shock, use of these approaches has not been used outside of the operating room or specialized interventional radiology or cardiology suites.
This practice paradigm may be about to change, however. A revised approach to Dr. Hughes' original procedure, resuscitative endovascular balloon occlusion of the aorta (REBOA), has gained new traction among trauma experts. Most agree that REBOA is not yet ready for prime time, though evidence from research studies and new technologies suggest REBOA will be coming to a trauma bay near you.
Noncompressible hemorrhage remains the leading cause of preventable death from trauma with mortality rates from intra-abdominal, pelvic, and groin hemorrhage approaching 50 percent. Underscoring the urgency to find better ways to manage this injury pattern, noncompressible bleeding in the torso has been labeled the leading cause of potentially preventable traumatic death in civilian and military settings. (Eur J Vasc Endovasc Surg 2012;44:203.)
“We've known for ages that hemorrhage is a significant problem, and if left unattended, [it] leads to mortality or severe morbidity,” said Col. Todd Rasmussen, MD, the director of the U.S. Combat Casualty Care Research Program at Fort Detrick, MD, and the Harris B. Shumacker Jr. Professor of Surgery at the Uniformed Services University of the Health Sciences in Bethesda. “But the military's prolonged experience with managing hemorrhagic shock during the recent long wars in Iraq and Afghanistan has provided new understanding of and placed a new focus on this significant problem in trauma and emergency medicine.”
Extremity hemorrhage can be effectively managed with tourniquets and topical hemostatic agents, and hemorrhage from the junctional regions between the torso and legs/arms can often be amenable to direct compression. “But even the surgeon cannot compress bleeding from, say, a spleen injury without making a large abdominal incision,” Dr. Rasmussen said.
Military epidemiological research has largely led the way in examining several methods of managing torso hemorrhage, including blood component-based resuscitation and pharmacological agents like tranexamic acid (TXA). (Read more about TXA on the EMN website at http://bit.ly/TXA-EMN.) What has been lacking is a procedural adjunct to be applied quickly for noncompressible hemorrhage and progressive shock, which has led to the reappraisal of less invasive endovascular techniques like REBOA that may not need to be confined to fixed operating rooms or imaging suites.
“These wars have compelled the military to try to find new ways to put resuscitative procedures in the hands of non-surgeons, so they can be used at the bedside of the hemorrhaging patient who is at the point of or near cardiovascular collapse,” said Dr. Rasmussen. “In many cases, this scenario plays out in locations other than in a traditional fixed operating room. Emergency physicians or providers are often those most likely to be at the bedside of a hemorrhaging patient in the acute setting.”
Megan Brenner, MD, an associate professor of surgery in trauma/surgical critical care and vascular surgery at the RA Cowley Shock Trauma Center, University of Maryland School of Medicine, has been a leader in the movement to bring REBOA to the resuscitation area. She recently published a case series and an article demonstrating that REBOA skills can be effectively taught to acute care surgeons via simulator. (J Trauma Acute Care Surg 2013;75:506 and 2014;77:286.)
“It's been used in trauma patients before, but up until recently the procedure has been performed by interventionalists. We've modified the procedure in a way that allows it to be performed by acute care surgeons in the resuscitation bay using portable x-ray and a few simple endovascular devices,” she said.
Use of the proximal aortic balloon occlusion technique has reduced surgical mortality for patients with ruptured aortic aneurysms, noted Dr. Brenner, who is now using it in patients with severe pelvic hemorrhage.
“It has dramatically changed the way we take care of our patients, for example, those with severe pelvic or abdominal hemorrhage. We no longer pack the pelvis as we did in select patients before REBOA. Patients in arrest from intra-abdominal hemorrhage are candidates for an open thoracotomy and aortic cross-clamping. This has been replaced by REBOA in many cases,” she said.
Bridge to Hemostasis
Dr. Brenner said the balloon provides proximal hemorrhage control as a bridge to hemostasis, whether that is in the angiography suite, operating room, or hybrid OR. It can be done quickly and safely by providers who are competent in percutaneous procedures and certainly many emergency physicians, particularly those with additional critical care training, she said.
But a few more things need to happen before REBOA is ready for the average ED or even the prehospital setting, not the least of which is that the technology must change. Much of the innovation in catheters, guide wires, and balloons over the past decades has been focused on age-related cardiovascular disease such as arterial occlusive and aneurysm disease. Now, leading endovascular companies in the United States are beginning to explore the development of trauma-focused tools.
“The REBOA catheter needs to be engineered to be smaller and less complex, so the risk of injury to the access vessel is less and the procedure can be done more quickly in [the] emergency setting,” Dr. Rasmussen said. “The existing technology for large vessel balloon occlusion generally comes in what are considered as large 10-14 French catheters, although [one manufacturer] produces a 7 French balloon catheter, which has been described for use in the emergency setting in Japan.”
Dr. Rasmussen added that the applicability of REBOA catheters would be improved by obviating the need for an x-ray to confirm catheter placement and doing away with the cumbersome over-the-wire maneuver. He also noted that appropriate regulatory approval through the U.S. Food and Drug Administration and other international regulatory bodies is important to ensure safety and efficacy of any REBOA catheters intended for use in emergency settings.
He also said having a REBOA catheter that could serve as a central arterial line — initially without balloon inflation — would allow the emergency provider to have aortic monitoring with the option to provide aortic occlusion at an appropriate time during the resuscitation. He refers to this concept as proactive rather than reactive aortic monitoring and control.
Several prospective observational studies of REBOA in the trauma setting using existing catheter technology are now ongoing, including one referred to as the Aortic Occlusion for Resuscitation in Trauma and Acute Care Surgery (AORTA) trial, which is being conducted under the auspices of the American Association for the Surgery of Trauma and reports having data on more than 100 patients having undergone resuscitative aortic occlusion at more than 10 centers around the country.
“The REBOA technique is now used fairly routinely in operating rooms by trained surgeons and endovascular specialists,” Dr. Rasmussen said. “If catheter-based, REBOA technologies can be improved in the next two to three years, there's every reason to think that it can be moved out of traditional operating rooms to the resuscitation room and possibly even to the pre- or out-of-hospital setting.”
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