Resuscitative endovascular balloon occlusion of the aorta for thoracic trauma: A translational swine study

Tranexamic acid as an adjunct to resuscitative endovascular balloon occlusion of the aorta does not worsen outcomes in a porcine model of hemorrhage

Background

Non-compressible torso hemorrhage (NCTH) represents a leading cause of preventable mortality in trauma. Resuscitative endovascular balloon occlusion of the aorta (REBOA) stabilizes NCTH but may predispose patients to thrombus generation. REBOA must therefore be prospectively evaluated for coagulation risks with concomitant usage of anti-fibrinolytic tranexamic acid (TXA). Using a porcine model of hemorrhage, it was hypothesized that TXA with REBOA would worsen coagulation outcomes and organ damage.

Materials and methods

Thirty-two male Yorkshire swine underwent 30% blood volume hemorrhage with randomization to vehicle control (VC; normal saline), VC+REBOA, TXA, or TXA+REBOA. At T0, animals received 10 mL/minute of group-specific infusion (GSI) followed at T10 by 500 mL of whole blood (WB), second GSI at 13 mL/hour, and Zone 1 REBOA inflation in REBOA groups. At T40, REBOA was deflated, with additional 500 mL WB, and continuation of GSI for 3 hours. Physiological, coagulation, and inflammatory parameters were measured throughout the protocol, with postmortem histopathology.

Results

After REBOA deflation at T40, lactate was significantly higher for the REBOA groups versus the non-REBOA groups, and pH, bicarbonate, and base excess were all significantly lower than the non-REBOA groups. There were no significant differences observed between groups in coagulation, inflammatory, metabolic, or histopathologic parameters.

Conclusions

Administration of TXA with REBOA did not cause more deleterious coagulation outcomes. All significant changes were expected results of REBOA ischemia, and not attributable to TXA treatment. This suggests NCTH can safely be treated with both hemorrhage control methods without exacerbating clotting outcomes.

Level of evidence

Not applicable-basic animal research.

Evaluating the Shock Index, Revised Assessment of Bleeding and Transfusion (RABT), Assessment of Blood Consumption (ABC) and novel PTTrauma score to predict critical transfusion threshold (CAT) in penetrating thoracic trauma

The shock index (SI) has been associated with predicting transfusion needs in trauma patients. However, its utility in penetrating thoracic trauma (PTTrauma) for predicting the Critical Administration Threshold (CAT) has not been well-studied. This study aimed to evaluate the prognostic value of SI in predicting CAT in PTTrauma patients and compare its performance with the Assessment of Blood Consumption (ABC) and Revised Assessment of Bleeding and Transfusion (RABT) scores. We conducted a prognostic type 2, single-center retrospective observational cohort study on patients with PTTrauma and an Injury Severity Score (ISS) > 9. The primary exposure was SI at admission, and the primary outcome was CAT. Logistic regression and decision curve analysis were used to assess the predictive performance of SI and the PTTrauma score, a novel model incorporating clinical variables. Of the 620 participants, 53 (8.5%) had more than one CAT. An SI > 0.9 was associated with CAT (adjusted OR 4.89, 95% CI 1.64-14.60). The PTTrauma score outperformed SI, ABC, and RABT scores in predicting CAT (AUC 0.867, 95% CI 0.826-0.908). SI is a valuable predictor of CAT in PTTrauma patients. The novel PTTrauma score demonstrates superior performance compared to existing scores, highlighting the importance of developing targeted predictive models for specific injury patterns. These findings can guide clinical decision-making and resource allocation in the management of PTTrauma.

Balloon Rises Above: REBOA at Zone 1 May Be Superior to Resuscitative Thoracotomy

BACKGROUND

The use of Zone 1 REBOA for life-threatening trauma has increased dramatically.

STUDY DESIGN

The Aortic Occlusion for Resuscitation in Trauma and Acute Care Surgery database was queried for blunt and penetrating trauma between 2013 and 2021. Outcomes were examined both for mechanisms of injury combined and separately and for combinations of abdominal injury with and without traumatic brain injury and chest injuries (Abbreviated Injury Scale [AIS] score >2).

RESULTS

A total of 531 patients underwent REBOA (408 with blunt injury and 123 with penetrating injury) and 1,603 (595 with blunt injury and 1,008 with penetrating injury) underwent resuscitative thoracotomy (RT). Mean age was 38.5 ± 16 years and mean injury severity score was 34.5 ± 21; 57.7% had chest AIS score of more than 2, 21.8% had head AIS score of more than 2, and 37.3% had abdominal AIS score of more than 2. Admission Glasgow Coma Scale was 4.9 + 4, and systolic blood pressure at aortic occlusion (AO) was 22 + 40 mmHg. No differences in outcomes in REBOA or RT patients were identified between institutions (p > 0.5). After inverse probability weighting, Glasgow Coma Scale, age, injury severity score, systolic blood pressure at AO, CPR at AO, and blood product transfusion, REBOA was superior to RT in both blunt (odds ratio [OR] 4.7, 95% CI 1.9 to 11.7) and penetrating (OR 4.9, 95% CI 1.7 to 14) injuries, across all spectrums of injury (p < 0.01). Overall mortality was significantly higher for AO more than 90 minutes compared with less than 30 minutes in blunt (OR 4.6, 95% CI 1.5 to 15) and penetrating (OR 5.4, 95% CI 1.1 to 25) injuries. Duration of AO more than 60 minutes was significantly associated with mortality after penetrating abdominal injury (OR 5.1, 95% CI 1.1 to 22) and abdomen and head (OR 5.3, 95% CI 1.6 to 18).

CONCLUSIONS

In-hospital survival is higher for patients undergoing REBOA than RT for all injury patterns. Complete AO by REBOA or RT should be limited to less than 30 minutes. Neither hospital and procedure volume nor trauma verification level impacts outcomes for REBOA or RT.

Non-compressible truncal and junctional hemorrhage: A retrospective analysis quantifying potential indications for advanced bleeding control in Dutch trauma centers

BACKGROUND

Truncal and junctional hemorrhage is the leading cause of potentially preventable deaths in trauma patients. To reduce this mortality, the application of advanced bleeding control techniques, such as resuscitative endovascular balloon occlusion of the aorta (REBOA), junctional tourniquets, Foley catheters, or hemostatic agents should be optimized. This study aimed to identify trauma patients with non-compressible truncal and junctional hemorrhage (NCTJH) who might benefit from advanced bleeding control techniques during initial trauma care. We hypothesized that there is a substantial cohort of Dutch trauma patients that can possibly benefit from advanced bleeding control techniques.

METHODS

Adult trauma patients with an Abbreviated Injury Scale ≥3 in the torso, neck, axilla, or groin region, who were presented between January 1st, 2014 and December 31st, 2018 to two Dutch level-1 trauma centers, were identified from the Dutch Trauma Registry. Potential indications for advanced bleeding control in patients with NCTJH were assessed by an expert panel of three trauma surgeons based on injury characteristics, vital signs, response to resuscitation, and received treatment.

RESULTS

In total, 1719 patients were identified of whom 249 (14.5 %) suffered from NCTJH. In 153 patients (60.6 %), hemorrhagic shock could have been mitigated or prevented with advanced bleeding control techniques. This group was younger and more heavily injured: median age of 40 versus 48 years and median ISS 33 versus 22 as compared to the entire cohort. The mortality rate in these patients was 31.8 %. On average, each of the included level-1 trauma centers treated an NCTJH patient every 24 days in whom a form of advanced bleeding control could have been beneficial.

CONCLUSIONS

More than half of included Dutch trauma patients with NCTJH may benefit from in-hospital application of advanced bleeding control techniques, such as REBOA, during initial trauma care. Widespread implementation of these techniques in the Dutch trauma system may contribute to reduction of mortality and morbidity from non-compressible truncal and junctional hemorrhage.

The Underlying Cardiovascular Mechanisms of Resuscitation and Injury of REBOA and Partial REBOA

Introduction: Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is used for aortic control in hemorrhagic shock despite little quantification of its mechanism of resuscitation or cardiac injury. The goal of this study was to use pressure-volume (PV) loop analysis and direct coronary blood flow measurements to describe the physiologic changes associated with the clinical use of REBOA. Methods: Swine underwent surgical and vascular access to measure left ventricular PV loops and left coronary flow in hemorrhagic shock and subsequent placement of occlusive REBOA, partial REBOA, and no REBOA. PV loop characteristics and coronary flow are compared graphically with PV loops and coronary waveforms, and quantitatively with measures of the end systolic and end pressure volume relationship, and coronary flow parameters, with accounting for multiple comparisons. Results: Hemorrhagic shock was induced in five male swine (mean 53.6 ± 3.6 kg) as demonstrated by reduction of stroke work (baseline: 3.1 vs. shock: 1.2 L*mmHg, p < 0.01) and end systolic pressure (ESP; 109.8 vs. 59.6 mmHg, p < 0.01). ESP increased with full REBOA (178.4 mmHg; p < 0.01), but only moderately with partial REBOA (103.0 mmHg, p < 0.01 compared to shock). End systolic elastance was augmented from baseline to shock (1.01 vs. 0.39 ml/mmHg, p < 0.01) as well as shock compared to REBOA (4.50 ml/mmHg, p < 0.01) and partial REBOA (3.22 ml/mmHg, p = 0.01). Percent time in antegrade coronary flow decreased in shock (94%-71.8%, p < 0.01) but was rescued with REBOA. Peak flow increased with REBOA (271 vs. shock: 93 ml/min, p < 0.01) as did total flow (peak: 2136, baseline: 424 ml/min, p < 0.01). REBOA did not augment the end diastolic pressure volume relationship. Conclusion: REBOA increases afterload to facilitate resuscitation, but the penalty is supraphysiologic coronary flows and imposed increase in LV contractility to maintain cardiac output. Partial REBOA balances the increased afterload with improved aortic system compliance to prevent injury.

Hemodynamic Effect of Resuscitative Endovascular Balloon Occlusion of the Aorta in Hemodynamic Instability Secondary to Acute Cardiac Tamponade in a Porcine Model

BACKGROUND

The pre-hospital use of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is increasing, although it remains controversial, in part because of suggested contraindications such as acute cardiac tamponade (ACT). As both the pre-hospital and in-hospital use of REBOA might potentially occur with concurrent ACT, knowledge of the hemodynamic effect of REBOA in this setting is crucial. This study, therefore, aimed at investigating the physiological effects of REBOA in hemodynamic instability secondary to ACT in a porcine model. We hypothesize that REBOA can temporarily increase systemic blood pressure and carotid blood flow, and prolong survival, in hemodynamic shock caused by ACT.

METHODS

Fourteen pigs (24-38 kg) underwent ACT, through true cardiac injury and hemorrhage into the pericardial space, and were allowed to hemodynamically deteriorate. At a systolic blood pressure (SBP) of 50 mm Hg (SBP50) they were randomized to total occlusion REBOA in zone 1 or to a control group. Survival, hemodynamic parameters, carotid blood flow (CBF), femoral blood flow (FBF), cardiac output (CO), end-tidal CO2, and arterial blood gas parameters were analyzed.

RESULTS

REBOA intervention was associated with a significant increase in SBP (50 mm Hg to 74 mm Hg, P = 0.016) and CBF (110 mL/min to 195 mL/min, P = 0.031), with no change in CO, compared to the control group. At 20 min after SBP50, the survival rate in the intervention group was 86% and in the control group 14%, with time to death being significantly longer in the intervention group.

CONCLUSIONS

This randomized animal study demonstrates that REBOA can help provide hemodynamic stabilization and prolong survival in hemodynamic shock provoked by ACT. It is important to stress that our study does not change the fact that urgent pericardiocentesis or cardiac surgery is, and should remain, the standard optimal treatment for ACT.Level of evidence: Prospective, randomized, experimental animal study. Basic science study, therapeutic.

Damage control surgery for thoracic outlet vascular injuries: the new resuscitative median sternotomy plus REBOA

Thoracic vascular trauma is associated with high mortality and is the second most common cause of death in patients with trauma following head injuries. Less than 25% of patients with a thoracic vascular injury arrive alive to the hospital and more than 50% die within the first 24 hours. Thoracic trauma with the involvement of the great vessels is a surgical challenge due to the complex and restricted anatomy of these structures and its association with adjacent organ damage. This article aims to delineate the experience obtained in the surgical management of thoracic vascular injuries via the creation of a practical algorithm that includes basic principles of damage control surgery. We have been able to show that the early application of a resuscitative median sternotomy together with a zone 1 resuscitative endovascular balloon occlusion of the aorta (REBOA) in hemodynamically unstable patients with thoracic outlet vascular injuries improves survival by providing rapid stabilization of central aortic pressure and serving as a bridge to hemorrhage control. Damage control surgery principles should also be implemented when indicated, followed by definitive repair once the correction of the lethal diamond has been achieved. To this end, we have developed a six-step management algorithm that illustrates the surgical care of patients with thoracic outlet vascular injuries according to the American Association of the Surgery of Trauma (AAST) classification.

Damage control surgery in lung trauma

Damage control techniques applied to the management of thoracic injuries have evolved over the last 15 years. Despite the limited number of publications, information is sufficient to scatter some fears and establish management principles. The severity of the anatomical injury justifies the procedure of damage control in only few selected cases. In most cases, the magnitude of the physiological derangement and the presence of other sources of bleeding within the thoracic cavity or in other body compartments constitutes the indication for the abbreviated procedure. The classification of lung injuries as peripheral, transfixing, and central or multiple, provides a guideline for the transient bleeding control and for the definitive management of the injury: pneumorraphy, wedge resection, tractotomy or anatomical resection, respectively.

Identification of specific patterns such as the need for resuscitative thoracotomy, or aortic occlusion, the existence of massive hemothorax, a central lung injury, a tracheobronchial injury, a major vascular injury, multiple bleeding sites as well as the recognition of hypothermia, acidosis or coagulopathy, constitute the indication for a damage control thoracotomy. In these cases, the surgeon executes an abbreviated procedure with packing of the bleeding surfaces, primary management with packing of some selected peripheral or transfixing lung injuries, and the postponement of lung resection, clamping of the pulmonary hilum in the most selective way possible. The abbreviation of the thoracotomy closure is achieved by suturing the skin over the wound packed, or by installing a vacuum system. The management of the patient in the intensive care unit will allow identification of those who require urgent reintervention and the correction of the physiological derangement in the remaining patients for their scheduled reintervention and definitive management.

Use of REBOA in the universe of magical realism: a real-world review

While reading the novella “Chronicle of a Death Foretold” by the Colombian Nobel Laureate Gabriel García-Marquez, we were surprised to realize that the injuries sustained by the main character could have been successfully treated had he received modern trauma care in which REBOA may have been considered. This is a discussion of Mr. Nasar's murder to explore whether he could have been saved by deploying REBOA as a surgical adjunct to bleeding control and resuscitation. In reading García-Marquez's novel we noted the events that unfolded at the time of Santiago Nasar's murder. To contextualize the claim that Mr. Nasar could have survived, had his injuries been treated with REBOA, we explored and illustrated what could have done differently and why. On the day of his death, Mr. Nasar sustained multiple penetrating stab wounds. Although he received multiple stab wounds to his torso, the book describes seven potentially fatal injuries, resulting in hollow viscus, solid viscus, and major vascular injuries. We provided a practical description of the clinical and surgical management algorithm we would have followed in Mr. Nasar's case. This algorithm included the REBOA deployment for hemorrhage control and resuscitation. The use of REBOA as part of the surgical procedures performed could have saved Mr. Nasar's life. Based on our current knowledge about REBOA in trauma surgery, we claim that its use, coupled with appropriate surgical care for hemorrhage control, could have saved Santiago Nasar's life, and thus prevent a death foretold.

American Association for the Surgery of Trauma-World Society of Emergency Surgery guidelines on diagnosis and management of abdominal vascular injuries

Abdominal vascular trauma accounts for a small percentage of military and a moderate percentage of civilian trauma, affecting all age ranges and impacting young adult men most frequently. Penetrating causes are more frequent than blunt in adults, while blunt mechanisms are more common among pediatric populations. High rates of associated injuries, bleeding, and hemorrhagic shock ensure that, despite advances in both diagnostic and therapeutic technologies, immediate open surgical repair remains the mainstay of treatment for traumatic abdominal vascular injuries. Because of their devastating nature, abdominal vascular injuries remain a significant source of morbidity and mortality among trauma patients. The American Association for the Surgery of Trauma in conjunction with the World Society of Emergency Surgery seek to summarize the literature to date and provide guidelines on the presentation, diagnosis, and treatment of abdominal vascular injuries. LEVEL OF EVIDENCE: Review study, level IV.

Therapeutic cardiac arrest as an adjunct to resuscitative endovascular balloon occlusion of the aorta: Bridging the gap from fatal hemorrhage to definitive surgical control in swine

BACKGROUND

Uncontrolled hemorrhage is the leading cause of potentially survivable combat casualty mortality, with 86.5% of cases resulting from noncompressible torso hemorrhage. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a minimally invasive technique used to stabilize patients with noncompressible torso hemorrhage; however, its application can take an average of 8 minutes to place. One therapeutic capable of bridging this gap is adenosine-lidocaine-magnesium (ALM), which at high doses induces a reversible cardioplegia. We hypothesize by using ALM as an adjunct to REBOA, the ALM-induced cardiac arrest will temporarily halt exsanguination and reduce blood loss, allowing for REBOA placement and control of bleeding.

METHODS

Male Yorkshire swine (60-80 kg) were randomly assigned to REBOA only or ALM-REBOA (n = 8/group). At baseline, uncontrolled hemorrhage was induced via a 1.5-cm right femoral arteriotomy, and hemorrhaged blood was quantified. One minute after injury (S1), ALM was administered, and 7 minutes later (T0), zone 1 REBOA inflation occurred. If cardiac arrest ensued, cardiac function either recovered spontaneously or advanced life support was initiated. At T30, surgical hemostasis was obtained, and REBOA was deflated. Animals were resuscitated until they were humanely euthanized at T90.

RESULTS

During field care phase, heart rate and end-tidal CO2 of the ALM-REBOA group were significantly lower than the REBOA only group. While mean arterial pressure significantly decreased from baseline, no significant differences between groups were observed throughout the field care phase. There was no significant difference in survival between the two groups (ALM-REBOA = 89% vs. REBOA only = 100%). Total blood loss was significantly decreased in the ALM-REBOA group (REBOA only = 24.32 ± 1.89 mL/kg vs. ALM-REBOA = 17.75 ± 2.04 mL/kg, p = 0.0499).

CONCLUSION

Adenosine-lidocaine-magnesium is a novel therapeutic, which, when used with REBOA, can significantly decrease the amount of blood loss at initial presentation, without compromising survival. This study provides proof of concept for ALM and its ability to bridge the gap between patient presentation and REBOA placement.