Resuscitative endovascular balloon occlusion of the aorta | |
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Specialty | Trauma surgery, vascular surgery, emergency medicine, interventional radiology |
Uses | Severe hemorrhage, non-compressible torso hemorrhage, pelvic hemorrhage, obstetric hemorrhage, gastrointestinal hemorrhage. |
Other options | Emergency Thoracotomy with Aortic Cross Clamping |
Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a minimally-invasive procedure performed during resuscitation of critically-injured trauma patients. Originally developed as a less invasive alternative to emergency thoracotomy with aortic cross clamping, REBOA is performed to gain rapid control of non-compressible truncal or junctional hemorrhage. [1] [2] REBOA is performed first by achieving access to the common femoral artery (CFA) and advancing a catheter within the aorta. [1] Upon successful catheter placement, an occluding balloon may be inflated either within the descending thoracic aorta (Zone 1) or infrarenal abdominal aorta (Zone 3). [1] [2] REBOA stanches downstream hemorrhage and improves cardiac index, cerebral perfusion, and coronary perfusion. [1] [3] [4] Although REBOA does not eliminate the need for definitive hemorrhage control, it may serve as a temporizing measure during initial resuscitation. [1] Despite the benefits of REBOA, there are significant local and systemic ischemic risks. [1] [5] Establishing standardized REBOA procedural indications and mitigating the risk of ischemic injury are topics of ongoing investigation. [1] [4] Although this technique has been successfully deployed in adult patients, it has not yet been studied in children. [6]
Severe hemorrhagic shock caused by non-compressible traumatic injury to the torso and junctional regions remains a major cause of death among civilian and military trauma victims. [1] [2] [3] [4] In contrast to peripheral hemorrhage caused by injury to an extremity, traumatic injuries to the torso and junctional regions are not amendable to direct pressure or tourniquet application. [1] [2] [4] Because non-compressible torso hemorrhages are not amendable to external interventions, these injuries account for approximately 90% of exsanguinating deaths. [4] Severe hemorrhage is managed either with vascular embolization or damage control surgical techniques such as abdominal packing or removal of non-essential organs. [2] However, in patients with severe hemorrhagic shock at risk for cardiovascular collapse, emergency thoracotomy with aortic cross clamping may be performed though outcomes are typically poor. [2] [3]
REBOA was developed as a rapidly deployable, minimally invasive alternative to emergency thoracotomy with aortic cross-clamping. Although there is no single indication criteria for the procedure, it is typically performed for patients with either blunt or penetrating traumatic injuries to the torso with severe hemorrhage refractory to blood product resuscitation. [7] REBOA is performed by gaining access to the common femoral artery and inserting a small endovascular catheter with an inflatable balloon within the aorta. [1] Upon inflation of the occluding balloon, blood flow across the descending aorta is either partially or completely obstructed which subsequently stanches downstream bleeding. [1] [2] [3] The adjustable catheter design of the REBOA device allows for variable positioning of the occluding balloon within the aorta based on the suspected source of bleeding. [1] [2] Zone 1 positioning in the descending thoracic aorta minimizes blood flow below the diaphragm and significantly reduces bleeding within the abdomen, pelvis, and lower extremities. [2] Alternatively, Zone 3 placement within the infrarenal descending abdominal aorta reduces bleeding within the pelvis and lower extremities while preserving blood supply within the abdomen. [2] Although REBOA does not replace the need for definitive surgical management, it may act as a temporizing measure by temporarily augmenting cardiac index to preserve cerebral and myocardial perfusion. [1] [3] [4] Immediately following successful REBOA deployment, patients must be considered for emergent surgical intervention. [1] [2] [7] [8]
The safety and efficacy of REBOA in the treatment of severe hemorrhagic shock is an area of ongoing research. Early studies reported conflicting data regarding mortality and failed to establish any clear benefit of REBOA when compared to emergency thoracotomy with aortic cross clamping. [1] [2] [4] However, design improvements of the REBOA device and continuously evolving patient selection criteria have subsequently improved REBOA outcomes. [1] Current literature demonstrates a survival benefit of REBOA deployment in patients with severe hemorrhagic shock who do not require cardiopulmonary resuscitation (CPR). [1] However, despite REBOA demonstrating its greatest efficacy when deployed prior to cardiovascular collapse, recent data has also shown promise when deployed during CPR. [1] Closed cardiopulmonary compressions with the REBOA device deployed has demonstrated improved cardiac compression fraction and end-tidal CO2 when compared to emergency thoracotomy with aortic cross clamping and cardiac massage. [1] Additionally, some centers have promoted REBOA deployment in patients with hypotension at risk for progression to severe hemorrhagic shock but who do not yet meet criteria for emergency thoracotomy with aortic cross clamping. [3] The variability in REBOA outcomes likely reflects the variability in institutional patient selection and indications criteria which highlights the need for ongoing evaluation. [2]
Access to the common femoral artery is first achieved using ultrasound guided, open, or percutaneous technique. [1] The REBOA device is then positioned either within Zone 1 (descending thoracic aorta) or Zone 3 (infrarenal abdominal aorta) before the occluding balloon is inflated with saline. [1] Upon successful definitive hemorrhage control, the occluding balloon is slowly deflated and the patient is monitored for recurrent bleeding or metabolic derangement. [1] Finally, the REBOA sheath is removed and the patient is monitored for access site complications or potential ischemic complications. [1]
Despite the minimally invasive nature of the REBOA device, there are significant risks associated with its use. Although occlusion of the aorta may temporarily augment cardiac index to preserve cardiac and coronary perfusion, there is a significant risk of downstream ischemia which may lead to local ischemic changes or systemic metabolic derangement. [2] [3] Significant complications such as limb amputation, metabolic acidosis, and severe reperfusion injury have all been reported with REBOA use and are the subjects of ongoing research. [1] [2] [3] Although there is no definitive consensus within the academic or surgical communities, many centers recommend balloon occlusion times of less than 30 minutes whenever possible to minimize the risk of clinically significant ischemia. [3] Alternatively, some institutions have recommended partial aortic occlusion or intermittent balloon deflation to minimize the effect of downstream ischemia. [3] Although intermittent balloon deflation is less technically difficult to perform, partial occlusion of the aorta has been demonstrated to reduce uncontrolled hemorrhage while simultaneously limiting distal ischemia and extending safe occlusion times. [3]
Additional potential complications are listed below:
Shock is the state of insufficient blood flow to the tissues of the body as a result of problems with the circulatory system. Initial symptoms of shock may include weakness, fast heart rate, fast breathing, sweating, anxiety, and increased thirst. This may be followed by confusion, unconsciousness, or cardiac arrest, as complications worsen.
Coronary artery bypass surgery, also known as coronary artery bypass graft, is a surgical procedure to treat coronary artery disease (CAD), the buildup of plaques in the arteries of the heart. It can relieve chest pain caused by CAD, slow the progression of CAD, and increase life expectancy. It aims to bypass narrowings in heart arteries by using arteries or veins harvested from other parts of the body, thus restoring adequate blood supply to the previously ischemic heart.
Interventional radiology (IR) is a medical specialty that performs various minimally-invasive procedures using medical imaging guidance, such as x-ray fluoroscopy, computed tomography, magnetic resonance imaging, or ultrasound. IR performs both diagnostic and therapeutic procedures through very small incisions or body orifices. Diagnostic IR procedures are those intended to help make a diagnosis or guide further medical treatment, and include image-guided biopsy of a tumor or injection of an imaging contrast agent into a hollow structure, such as a blood vessel or a duct. By contrast, therapeutic IR procedures provide direct treatment—they include catheter-based medicine delivery, medical device placement, and angioplasty of narrowed structures.
Vascular surgery is a surgical subspecialty in which vascular diseases involving the arteries, veins, or lymphatic vessels, are managed by medical therapy, minimally-invasive catheter procedures and surgical reconstruction. The specialty evolved from general and cardiovascular surgery where it refined the management of just the vessels, no longer treating the heart or other organs. Modern vascular surgery includes open surgery techniques, endovascular techniques and medical management of vascular diseases - unlike the parent specialities. The vascular surgeon is trained in the diagnosis and management of diseases affecting all parts of the vascular system excluding the coronaries and intracranial vasculature. Vascular surgeons also are called to assist other physicians to carry out surgery near vessels, or to salvage vascular injuries that include hemorrhage control, dissection, occlusion or simply for safe exposure of vascular structures.
Internal bleeding is a loss of blood from a blood vessel that collects inside the body, and is not usually visible from the outside. It can be a serious medical emergency but the extent of severity depends on bleeding rate and location of the bleeding. Severe internal bleeding into the chest, abdomen, pelvis, or thighs can cause hemorrhagic shock or death if proper medical treatment is not received quickly. Internal bleeding is a medical emergency and should be treated immediately by medical professionals.
Hypovolemic shock is a form of shock caused by severe hypovolemia. It can be caused by severe dehydration or blood loss. Hypovolemic shock is a medical emergency; if left untreated, the insufficient blood flow can cause damage to organs, leading to multiple organ failure.
Embolization refers to the passage and lodging of an embolus within the bloodstream. It may be of natural origin (pathological), in which sense it is also called embolism, for example a pulmonary embolism; or it may be artificially induced (therapeutic), as a hemostatic treatment for bleeding or as a treatment for some types of cancer by deliberately blocking blood vessels to starve the tumor cells.
The intra-aortic balloon pump (IABP) is a mechanical device that increases myocardial oxygen perfusion and indirectly increases cardiac output through afterload reduction. It consists of a cylindrical polyurethane balloon that sits in the aorta, approximately 2 centimeters (0.79 in) from the left subclavian artery. The balloon inflates and deflates via counter pulsation, meaning it actively deflates in systole and inflates in diastole. Systolic deflation decreases afterload through a vacuum effect and indirectly increases forward flow from the heart. Diastolic inflation increases blood flow to the coronary arteries via retrograde flow. These actions combine to decrease myocardial oxygen demand and increase myocardial oxygen supply.
Hemoperitoneum is the presence of blood in the peritoneal cavity. The blood accumulates in the space between the inner lining of the abdominal wall and the internal abdominal organs. Hemoperitoneum is generally classified as a surgical emergency; in most cases, urgent laparotomy is needed to identify and control the source of the bleeding. In selected cases, careful observation may be permissible. The abdominal cavity is highly distensible and may easily hold greater than five liters of blood, or more than the entire circulating blood volume for an average-sized individual. Therefore, large-scale or rapid blood loss into the abdomen will reliably induce hemorrhagic shock and, if untreated, may rapidly lead to death.
Traumatic aortic rupture, also called traumatic aortic disruption or transection, is a condition in which the aorta, the largest artery in the body, is torn or ruptured as a result of trauma to the body. The condition is frequently fatal due to the profuse bleeding that results from the rupture. Since the aorta branches directly from the heart to supply blood to the rest of the body, the pressure within it is very great, and blood may be pumped out of a tear in the blood vessel very rapidly. This can quickly result in shock and death. Thus traumatic aortic rupture is a common killer in automotive accidents and other traumas, with up to 18% of deaths that occur in automobile collisions being related to the injury. In fact, aortic disruption due to blunt chest trauma is the second leading cause of injury death behind traumatic brain injury.
Endovascular aneurysm repair (EVAR) is a type of minimally-invasive endovascular surgery used to treat pathology of the aorta, most commonly an abdominal aortic aneurysm (AAA). When used to treat thoracic aortic disease, the procedure is then specifically termed TEVAR for "thoracic endovascular aortic/aneurysm repair." EVAR involves the placement of an expandable stent graft within the aorta to treat aortic disease without operating directly on the aorta. In 2003, EVAR surpassed open aortic surgery as the most common technique for repair of AAA, and in 2010, EVAR accounted for 78% of all intact AAA repair in the United States.
The following outline is provided as an overview of and topical guide to cardiology, the branch of medicine dealing with disorders of the human heart. The field includes medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease and electrophysiology. Physicians who specialize in cardiology are called cardiologists.
Injury of the thoracic aorta refers to any injury which affects the portion of the aorta which lies within the chest cavity. Injuries of the thoracic aorta are usually the result of physical trauma; however, they can also be the result of a pathological process. The main causes of this injury are deceleration and crush injuries. There are different grades to injuries to the aorta depending on the extent of injury, and the treatment whether surgical or medical depends on that grade. It is difficult to determine if a patient has a thoracic injury just by their symptoms, but through imaging and a physical exam the extent of injury can be determined. All patients with a thoracic aortic injury need to be treated either surgically with endovascular repair or open surgical repair or with medicine to keep their blood pressure and heart rate in the appropriate range. However, most patients that have a thoracic aortic injury do not live for 24 hours.
Acute limb ischaemia (ALI) occurs when there is a sudden lack of blood flow to a limb within 14 days of symptoms onset. On the other hand, when the symptoms exceed 14 days, it is called critical limb ischemia (CLI). CLI is the end stage of peripheral vascular disease where there is still some collateral circulation that bring some blood flow to the distal parts of the limbs. While limbs in both acute and chronic limb ischemia may be pulseless, a chronically ischemic limb is typically warm and pink due to a well-developed collateral artery network and does not need emergency intervention to avoid limb loss, whereas ALI is a vascular emergency.
Permissive hypotension or hypotensive resuscitation is the use of restrictive fluid therapy, specifically in the trauma patient, that increases systemic blood pressure without reaching normotension. The goal blood pressure for these patients is a mean arterial pressure of 40-50 mmHg or systolic blood pressure of less than or equal to 80. This goes along with certain clinical criteria. Following traumatic injury, some patients experience hypotension that is usually due to blood loss (hemorrhage) but can be due to other causes as well. In the past, physicians were very aggressive with fluid resuscitation to try to bring the blood pressure to normal values. Recent studies have found that there is some benefit to allowing specific patients to experience some degree of hypotension in certain settings. This concept does not exclude therapy by means of i.v. fluid, inotropes or vasopressors, the only restriction is to avoid completely normalizing blood pressure in a context where blood loss may be enhanced. When a person starts to bleed the body starts a natural coagulation process that eventually stops the bleed. Issues with fluid resuscitation without control of bleeding are thought to be secondary to dislodgement of the thrombus that is helping to control further bleeding. Thrombus dislodgement was found to occur at a systolic pressure greater than 80mm Hg. In addition, fluid resuscitation will dilute coagulation factors that help form and stabilize a clot, hence making it harder for the body to use its natural mechanisms to stop the bleeding. These factors are aggravated by hypothermia.
Todd E. Rasmussen, MD, FACS is an American professor and Vice Chair for Education in the Department of Surgery at Mayo Clinic, Rochester, and a Senior Associate Consultant in the Division of Vascular and Endovascular Surgery. Prior to joining the Mayo Clinic, he had a 28-year career in the military, retiring as an Air Force Colonel in 2021. His most recent military assignment was as Associate Dean or Research at the Uniformed Services University of the Health Sciences and an attending surgeon at the Walter Reed National Military Medical Center.
Open aortic surgery (OAS), also known as open aortic repair (OAR), describes a technique whereby an abdominal, thoracic or retroperitoneal surgical incision is used to visualize and control the aorta for purposes of treatment, usually by the replacement of the affected segment with a prosthetic graft. OAS is used to treat aneurysms of the abdominal and thoracic aorta, aortic dissection, acute aortic syndrome, and aortic ruptures. Aortobifemoral bypass is also used to treat atherosclerotic disease of the abdominal aorta below the level of the renal arteries. In 2003, OAS was surpassed by endovascular aneurysm repair (EVAR) as the most common technique for repairing abdominal aortic aneurysms in the United States.
Ischemia-reperfusion (IR) tissue injury is the resultant pathology from a combination of factors, including tissue hypoxia, followed by tissue damage associated with re-oxygenation. IR injury contributes to disease and mortality in a variety of pathologies, including myocardial infarction, ischemic stroke, acute kidney injury, trauma, circulatory arrest, sickle cell disease and sleep apnea. Whether resulting from traumatic vessel disruption, tourniquet application, or shock, the extremity is exposed to an enormous flux in vascular perfusion during a critical period of tissue repair and regeneration. The contribution of this ischemia and subsequent reperfusion on post-traumatic musculoskeletal tissues is unknown; however, it is likely that similar to cardiac and kidney tissue, IR significantly contributes to tissue fibrosis.
Endovascular and hybrid trauma and bleeding management is a new and rapidly evolving concept within medical healthcare and endovascular resuscitation. It involves early multidisciplinary evaluation and management of hemodynamically unstable patients with traumatic injuries as well as being a bridge to definitive treatment. It has recently been shown that the EVTM concept may also be applied to non-traumatic hemodynamically unstable patients.
Selective aortic arch perfusion (SAAP) is an experimental treatment for haemorrhage-induced traumatic cardiac arrest. It has been shown in animal studies to be superior to Zone 1 REBOA once cardiac arrest has occurred.