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To evaluate the mean aortic-right atrial pressure (AoP-RAP) gradients and mean coronary perfusion pressures (CPPs) observed during open cardiac massage (OCM) versus those obtained with selective aortic arch perfusion (SAAP) in post-mortem hypovolemic swine.Post-mortum, male swine, utilized in prior studies of hemorrhage, were included in the study. Animals were bled ∼25-50% of circulating volume prior to death. Animals either underwent clamshell thoracotomy and OCM immediately after death was confirmed (n = 6) or underwent SAAP within 5-15 min of death (n = 6). Aortic root and right atrial pressures were recorded continuously during each method of resuscitation using solid state blood pressure catheters. Representative five beat samples were extracted; short, similarly timed segments of SAAP were also extracted. Mean AoP-RAP gradient and CPPs were calculated and compared.Mean AoP-RAP gradient and CPP were significantly higher in SAAP animals compared to OCM animals (mean ± SD; 29.1 ± 8.4 vs. 24.5 ± 5.0, p 0.001; 28.9 ± 8.5 vs. 9.9 ± 6.0, p 0.001). Mean CPP was not significantly different from mean AoP-RAP gradient in SAAP animals (p = 0.92); mean CPP was significantly lower than mean AoP-RAP gradient in OCM animals (p 0.001). While 97% of SAAP segments had a CPP 15 mmHg, only 17% of OCM segments had a CPP 15 mmHg (p 0.001).SAAP appears to create a more favorable and efficient hemodynamic profile for obtaining ROSC when compared to OCM in this preclinical porcine study.

INTRODUCTION Penetrating cervical carotid artery injury is an uncommon but high-stake scenario associated with stroke and death. The objective of this study was to characterize and compare penetrating carotid injury in the military and civilian setting, as well as provide considerations for management. METHODS Cohorts with penetrating cervical carotid artery injury from the Department of Defense Trauma Registry (2002-2015) and the American Association for the Surgery of Trauma Prospective Observation Vascular Injury Treatment Registry (2012-2018) were analyzed. A least absolute shrinkage and selection operator multivariate analysis using random forest-based imputation was performed to identify risk factors affecting stroke and mortality. RESULTS There were a total of 157 patients included in the study, of which 56 (35.7%) were military and 101 (64.3%) were civilian. The military cohort was more likely to have been managed with open surgery (87.5% vs. 44.6%, p < 0.001) and to have had any procedure to restore or maintain flow to the brain (71.4% vs. 35.6%, p < 0.001), while the civilian cohort was more likely to undergo nonoperative management (45.5% vs. 12.5%, p < 0.001). Stroke rate was higher within the military cohort (41.1% vs. 13.9%, p < 0.001); however, mortality did not differ between the groups (12.5% vs. 17.8%, p = 0.52). On multivariate analysis, predictors for stroke were presence of a battle injury (log odds, 2.1; p < 0.001) and internal or common carotid artery ligation (log odds 1.5, p = 0.009). For mortality outcome, protective factors included a high Glasgow Coma Scale on admission (log odds, -0.21 per point; p < 0.001). Increased admission Injury Severity Score was a predictor of mortality (log odds, 0.05 per point; p = 0.005). CONCLUSION The stroke rate was higher in the military cohort, possibly reflecting complexity of injury; however, there was no difference in mortality between military and civilian patients. For significant injuries, concerted efforts should be made at carotid reconstruction to reduce the occurrence of stroke. LEVEL OF EVIDENCE Retrospective cohort analysis, level III.

Hemorrhage, and particularly noncompressible torso hemorrhage (NCTH) remains a leading cause of potentially preventable prehospital death from trauma in the United States and globally. A subset of severely-injured patients either die in the field or develop irreversible hemorrhagic shock before they can receive hospital definitive care, resulting in poor outcomes. The focus of this opinion paper is to delineate (a) the need for existing trauma systems to adapt so that potentially life-saving advanced resuscitation and truncal hemorrhage control interventions can be delivered closer to the point-of-injury in select patients, and (b) a possible mechanism through which some trauma systems can train and incorporate select prehospital advanced resuscitative care teams to deliver those interventions.

Objective The use of temporary intravascular shunts (TIVSs) allow for restoration of distal perfusion and reduce ischemic time in the setting of arterial injury. As a damage control method, adjunct shunts restore perfusion during treatment of life-threatening injuries, or when patients require evacuation to a higher level of care. Single-center reports and case series have demonstrate that TIVS use can extend the opportunity for limb salvage. However, few multi-institutional studies on the topic have been reported. The objective of the present study was to characterize TIVS use through a multi-institutional registry and define its effects on early limb salvage. Methods Data from the Prospective Observation Vascular Injury Treatment registry was analyzed. Civilian patients aged ≥18 years who had sustained an extremity vascular injury from September 2012 to November 2018 were included. Patients who had a TIVS used in the management of vascular injury were included in the TIVS group and those who had received treatment without a TIVS served as the control group. An unadjusted comparison of the groups was conducted to evaluate the differences in the baseline and outcome characteristics. Double robust estimation combining logistic regression with propensity score matching was used to evaluate the effect of TIVS usage on the primary end point of limb salvage. Results TIVS use was identified in 78 patients from 24 trauma centers. The control group included 613 patients. Unmatched analysis demonstrated that the TIVS group was more severely injured (mean ± standard deviation injury severity score, 18.83 ± 11.76 for TIVS vs 14.93 ± 10.46 for control; P = .002) and had more severely mangled extremities (mean ± standard deviation abbreviated injury scale, extremity, score 3.23 ± 0.80 for TIVS vs 2.95 ± 0.87 for control; P = .008). Logistic regression demonstrated that propensity-matched control patients had a three times greater likelihood of amputation compared with the TIVS patients (odds ratio, 3.6; 95% confidence interval, 1.2-11.1; P = .026). Concomitant nerve injury and orthopedic fracture were associated with a greater risk of amputation. The median follow-up for the TIVS group was 12 days (interquartile range, 4-25 days) compared with 9 days (interquartile range, 4-18 days) for the control group. Conclusions To the best of our knowledge, the present study is the first multicenter, matched-cohort study to characterize early limb salvage as a function of TIVS use in the setting of extremity vascular injury. Shunts expedite limb perfusion and resulted in lower rates of amputation during the early phase of care. The use of TIVS should be one part of a more aggressive approach to restore perfusion in the most injured patients and ischemic limbs.

Background Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an emergency procedure that is potentially lifesaving in major noncompressible torso hemorrhage. It may also improve outcome in nontraumatic cardiac arrest. However, the procedure can be technically challenging and requires the immediate presence of a qualified operator. Thus, evidence-based training and assessment of operator skills are essential for successful implementation and patient safety. A prerequisite for this is a valid and reliable assessment tool specific for the procedure. The aim of this study was to develop a tool for assessing procedural competence in REBOA based on best-available knowledge from international experts in the field. Methods We invited international REBOA experts from multiple specialties to participate in an anonymous three-round iterative Delphi study to reach consensus on the design and content of an assessment tool. In round 1, participants suggested items to be included. In rounds 2 and 3, the relevance of each suggested item was evaluated by all participants to reach consensus. Interround data processing was done systematically by a steering group. Results Forty panelists representing both clinical and educational expertise in REBOA from 16 countries (in Europe, Asia, and North and South America) and seven different specialties participated in the study. After 3 Delphi rounds and 532 initial item suggestions, the panelists reached consensus on a 10-item assessment tool with behaviorally anchored rating scales. It includes assessment of teamwork, procedure time, selection and preparation of equipment, puncture technique, guidewire handling, sheath handling, placement of REBOA catheter, occlusion, and evaluation. Conclusion We present the REBOA-RATE assessment tool developed systematically by international experts in the field to optimize content validity. Following further studies of its validity and reliability, this tool represents an important next step in evidence-based training programs in REBOA, for example, using mastery learning. Level of evidence Therapeutic, level V.

Thoracic endovascular aortic repair (TEVAR) is the preferred operative treatment of blunt thoracic aortic injuries (BTAIs). Its use is associated with improved outcomes compared with open surgical repair and nonoperative management. However, the optimal time from injury to repair is unknown and remains a subject of debate across different societal practice guidelines. The purpose of this study was to evaluate national trends in the management of BTAI, with a specific focus on the impact of timing of repair on outcomes.Using the National Trauma Data Bank, we identified adult patients with BTAI between 2012 and 2017. Patients with prehospital or emergency department cardiac arrest or incomplete data sets were excluded from analysis. Patients were classified according to timing of repair: group 1, 24 hours; and group 2, ≥24 hours. The primary outcome evaluated was in-hospital mortality; secondary outcomes included overall hospital and intensive care unit length of stay. Multivariable logistic regression was performed to identify independent predictors of mortality.The analysis was completed for 2821 patients who underwent TEVAR for BTAI with known operative times. The overall mortality in the patient cohort was 8.4% (238/2821); 75% of patients undergoing TEVAR were repaired within 24 hours. Mortality was more than twofold greater in group 1 compared with group 2 (9.8% [207/2118] vs 4.4% [31/703]; P = .001). This mortality benefit persisted across injury severity groups and was independent of the presence of serious extrathoracic injuries. Logistic regression analysis, adjusting for age ≥65 years, Glasgow Coma Scale score ≤8, systolic blood pressure ≤90 mm Hg at admission, and serious extrathoracic injuries, showed a higher adjusted mortality in group 1 (odds ratio, 2.54; 95% confidence interval, 1.66-3.91; P = .001).The majority of patients with BTAI undergo endovascular repair within 24 hours of injury. Patients undergoing delayed repair have improved survival compared with those repaired within the first 24 hours of injury in spite of similar injury patterns and severity. In patients with BTAIs without signs of imminent rupture, delaying endovascular repair beyond 24 hours after injury should be considered.

Purpose: Use of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) as adjunct for temporary hemorrhage control in patients with exsanguinating torso hemorrhage is increasing. Characteristics of aortic occlusion balloons (AOB) are diverse and evolving as efforts are made to improve the technology. It is important to select a device that fits the requirements of the medical situation to minimize the risk of failure and complications. The aim of this study is to appraise guidance in the choice of an AOB in a specific situation. Methods: We assessed 29 AOB for differences and outline possible advantages and disadvantages of each. Bending stiffness was measured with a three-point bending device. Results: Diameter of the AOB ranged from 6 (ER-REBOA™) to 10 (Coda®-46) French. However, some need large-bore access sheaths up to 22 French (Fogarty®-45 and LeMaitre®-45) or even insertion via cut-down (Equalizer™-40). Bending stiffness varied from 0.08 N/mm (± 0.008 SD; Coda®-32) to 0.72 N/mm (± 0.024 SD; Russian prototype). Rescue Balloon™ showed kinking of the shaft at low bending pressures. The only non-compliant AOB is REBOA Balloon®. ER-REBOA™, Fogarty®, LeMaitre®, REBOA Balloon®, and Rescue Balloon™ are provided with external length marks to assist blind positioning. Conclusion: In resource-limited settings, a guidewire- and fluoroscopy-free, rather stiff device, such as ER-REBOA™, Fogarty®, and LeMaitre®, is warranted. Of these devices, ER-REBOA™ is the only catheter compatible with seven French sheaths and specifically designed for emergency hemorrhage control. Of the over-the-wire devices, Q50® has several features that facilitate use and reduce the risk of malplacement or vessel damage.

BackgroundIn this review, we assess the state of Resuscitative Endovascular Occlusion of the Aorta (REBOA) today with respect to out-of-hospital (OOH) vs. inhospital (H) use in blunt and penetrating trauma, as well as discuss areas of promising research that may be key in further advancement of REBOA applications.MethodsTo analyze the trends in REBOA use, we conducted a review of the literature and identified articles with human or animal data that fit the respective inclusion and exclusion criteria. In separate tables, we compiled data extracted from selected articles in categories including injury type, zone and duration of REBOA, setting in which REBOA was performed, sample size, age, sex and outcome. Based on these tables as well as more detailed review of some key cases of REBOA usage, we assessed the current state of REBOA as well as coagulation and histological disturbances associated with its usage. All statistical tests were 2-sided using an alpha=0.05 for significance. Analysis was done using SAS 9.5 (Cary, NC). Tests for significance was done with a t-test for continuous data and a Chi Square Test for categorical data.ResultsIn a total of 44 cases performed outside of a hospital in both military and civilian settings, the overall survival was found to be 88.6%, significantly higher than the 50.4% survival calculated from 1,807 cases of REBOA performed within a hospital (pConclusionsFurther research related to human use of REBOA must be focused on earlier initiation of REBOA after injury which may depend on development of rapid vascular access devices and techniques more so than on any new improvements in REBOA. Future animal studies should provide detailed multisystem organ assessment to accurately define organ injury and metabolic burden associated with REBOA application. Overall, animal studies must involve realistic models of injury with severe clinical scenarios approximating human trauma and exsanguination, especially with long-term follow-up after injury.

Background Resuscitative endovascular balloon occlusion of the aorta (REBOA) reduces blood loss and improves hemodynamics. Complete occlusion results in distal ischemia, limiting its use for prolonged care. This study evaluated two next-generation partial REBOA (pREBOA) catheters and their ability to achieve targeted distal aortic flow. Materials and methods Swine underwent hemorrhagic shock, complete aortic occlusion, controlled continuous balloon deflation, and targeted distal perfusion (TDP; 300-mL/min) phases. They were randomized into three groups (n = 6/group), one managed with the current ER-REBOA (ER), and two with the new pREBOA technologies: a bilobed (BL) device and a semicompliant pREBOA-PRO (PRP). Hemodynamics including flow rates and mean arterial pressures at the carotid artery and infrarenal aorta were recorded. Results Hemodynamics were comparable between groups during hemorrhage and complete occlusion phases. During the controlled continuous balloon deflation phase, the distal aortic flow rate strongly correlated with percent balloon volume in BL and PRP groups, suggesting a precise control of distal perfusion. The slope of flow-balloon-volume curves was greater in the ER group than BL and PRP groups, indicating the change in distal aortic flow rate was more sensitive to the balloon volume (less titratable) when using ER. During the TDP phase, variation in distal aortic flow and mean arterial pressure with respect to the target flow was lower in ER and PRP groups, than the BL group. Conclusions Pressure-regulated occlusion using the next-generation pREBOA catheters is more controlled than the first-generation ER-REBOA catheter and allow for targeted and precise distal perfusion.

The Military Health System (MHS) has a medical research program aimed at a wide range of health-, disease-, and injury-related topic areas that works with civilian academic institutions and the biomedical industry to accomplish its goals. There are many opportunities for civilian academic institutions and the biomedical industry to engage with this program, but its unique features are important to understand to optimize the chances for successful partnerships. Unlike the National Institutes of Health, which uses an "investigator-initiated" approach, the Department of Defense (DoD) aligns its funding with specific needs, also referred to as requirements; thus, DoD research is often described as "requirements-driven" research. At the highest level, requirements are aligned with the National Security Strategy and National Defense Strategy, though requirements documents list specific areas in medicine with unmet needs. Military labs and the Uniformed Services University of the Health Sciences, which can also receive DoD appropriations to conduct medical research, serve as hubs that interface with civilian academic institutions and the biomedical industry and organize and track the overall progress of DoD investments. As a mechanism to propel findings from "bench to bedside," the military budgets funds for the various phases of research and development for a given topic area. Research programs are most effective when they are integrated into the MHS learning health system, which allows MHS clinical communities to inform and track research investments and evaluate the utility of research products in real clinical practice settings. This Perspective provides introductory information and a basic framework for those interested in performing DoD-funded medical research or collaborating with researchers in military labs. It is hoped that as academic institutions and the biomedical industry look to increase efficiency in medical research, they will find ways to engage with DoD research opportunities and consider elements of the military's approach useful.

OBJECTIVES Estimating the likely success of limb revascularization in patients with lower-extremity arterial trauma is central to decisions between attempting limb salvage and amputation. However, the projected outcome is often unclear at the time these decisions need to be made, making them difficult and threatening sound judgement. The objective of this study was to develop and validate a prediction model that can quantify an individual patient's risk of failed revascularization. METHODS A BN prognostic model was developed using domain knowledge and data from the US joint trauma system. Performance (discrimination, calibration, and accuracy) was tested using ten-fold cross validation and externally validated on data from the UK Joint Theatre Trauma Registry. BN performance was compared to the mangled extremity severity score. RESULTS Rates of amputation performed because of nonviable limb tissue were 12.2% and 19.6% in the US joint trauma system (n = 508) and UK Joint Theatre Trauma Registry (n = 51) populations respectively. A 10-predictor BN accurately predicted failed revascularization: area under the receiver operating characteristic curve (AUROC) 0.95, calibration slope 1.96, Brier score (BS) 0.05, and Brier skill score 0.50. The model maintained excellent performance in an external validation population: AUROC 0.97, calibration slope 1.72, Brier score 0.08, Brier skill score 0.58, and had significantly better performance than mangled extremity severity score at predicting the need for amputation [AUROC 0.95 (0.92-0.98) vs 0.74 (0.67-0.80); P < 0.0001]. CONCLUSIONS A BN (https://www.traumamodels.com) can accurately predict the outcome of limb revascularization at the time of initial wound evaluation. This information may complement clinical judgement, support rational and shared treatment decisions, and establish sensible treatment expectations.

Background The treatment of venous thoracic outlet syndrome (VTOS) requires surgical decompression often combined with catheter-directed thrombolysis and venoplasty. Surgical options include transaxillary, supraclavicular, or infraclavicular approaches to first rib resection. The optimal method, however, has yet to be defined. The purpose of this study is to compare the outcomes of patients who underwent infraclavicular versus supraclavicular surgical decompression for VTOS. Methods A retrospective review of patients who underwent surgical management for VTOS from December 2010 to November 2017 was performed. During the study period, supraclavicular and infraclavicular approaches were chosen according to surgeon preference. Patient demographics, pre- and postdecompression interventions, perioperative outcomes for each group of patients were analyzed. Results Thirty patients underwent surgical management of VTOS, of which 15 (50%) underwent infraclavicular decompression and 15 (50%) supraclavicular decompression. The mean age of patients was 32.1 ± 13.6 years and 80% were male. Twenty-six patients (86.7%) presented with thrombotic VTOS. Acute axillosubclavian vein thrombosis was present in 20 (76.9%) of these patients, 10 patients in each group. Subacute or chronic thrombosis was encountered in the remaining 6 (23%) patients, 2 patients in the infraclavicular group and 4 patients in the supraclavicular group. Preoperative thrombolysis was utilized in 7 (46.7%) and 6 (40%) patients in the infraclavicular and supraclavicular groups, respectively (P = 1.00). Patients without postdecompression venography were removed from analysis and included 1 patient in the infraclavicular group and 5 patients in the supraclavicular group. Initial postdecompression venogram, prior to any endovascular intervention, demonstrated a residual axillosubclavian vein stenosis of greater than 50% in 6 (42.9%) patients in the infraclavicular decompression group and 7 (70%) patients in the supraclavicular decompression group (P = 0.24). Crossing the stenosis after surgical decompression was more easily accomplished in the infraclavicular group, 14 (100%) versus 5 (50%), (P = 0.01). Following endovascular venoplasty, calculated residual stenosis greater than 50% was found in 0 (0%) and 3 (30%) patients in the infraclavicular and supraclavicular approaches, respectively (P = 0.047). Infraclavicular thoracic outlet decompression was associated with fewer patients with postoperative symptoms, 0 of 15 (0%) versus 8 of 15 (53.3%), (P = 0.0022), and infraclavicular thoracic outlet decompression demonstrated improved patency, 15 of 15 (100%) versus 8 of 15 (53.3%), (P = 0.028) at a mean combined follow-up of 8.47 ± 10.8 months. Conclusions Infraclavicular thoracic outlet decompression for the surgical management of VTOS was associated with fewer postoperative symptoms and improved axillosubclavian vein patency compared to the supraclavicular approach. Prospective analysis is warranted to determine long-term outcomes following infraclavicular decompression.

This article reviews four emerging endovascular hemorrhage control and extracorporeal perfusion techniques for management of trauma patients with profound hemorrhagic shock including hemorrhage-induced traumatic cardiac arrest: resuscitative endovascular balloon occlusion of the aorta, selective aortic arch perfusion, extracorporeal life support, and emergency preservation and resuscitation. The preclinical and clinical studies underpinning each of these techniques are summarized. We also present an integrated conceptual framework for how these emerging technologies may be used in the future care of trauma patients in both resource-rich and austere environments.

We believe that the rapid and widespread adoption of resuscitative endovascular balloon occlusion of the aorta as well as enthusiasm for catheter-based strategies has led to increased interest in basic endovascular techniques among trauma surgeons. The aim of this article was to describe the most commonly performed endovascular procedures for trauma patients, the basic capital equipment and room set up, and a parsimonious inventory of disposable supplies needed to perform each procedure. Together, these make a standardized trauma-specific endovascular inventory. LEVEL OF EVIDENCE: Economic/decision, level V.

The ideal conduit for vascular reconstruction is one that can be obtained “off the shelf” and demonstrates long-term patency, tissue incorporation and resistance to infection. Currently available conduits, such as autologous vein and synthetic grafts, are limited in one or more of these areas. The Human Acellular Vessel (HAV), a bioengineered, acellular blood vessel, can be obtained “off the shelf” and has shown promise in each of these properties. We describe a case in which the HAV was utilized for open bypass reconstruction in a patient with chronic limb-threatening ischemia who lacked alternative reconstructive options. The case is followed by a discussion of potential broader applications of this novel implant, specifically in the management of vascular trauma.

Introduction Exsanguination cardiac arrest is the leading preventable cause of death in trauma. Treatment modalities are limited, and prognosis remains dismal. Selective aortic arch perfusion (SAAP) is an emerging endovascular resuscitation technique consisting of aortic occlusion and perfusion of coronary and cerebral circulation with oxygenated resuscitation fluid. Translational research has demonstrated promising outcomes; however, little is known about the duration of cardiac arrest beyond which the myocardium cannot be resuscitated. The aims of this study are to assess the myocardial tolerance to exsanguination cardiac arrest before successful return of spontaneous circulation (ROSC) following resuscitation with SAAP, and 1-hour survival. Method 23 male adult swine were anaesthetised and instrumented. Controlled hemorrhage was performed until cardiac arrest defined by MAP Result Baseline characteristics were similar between groups (P > 0.05). ROSC was 100% (8/8) in the 5 min group, 75% (6/8) and 43% (3/7) in 10- and 15-min groups respectively (P = 0.042). 60 min survival was 75%, 50% and 14% in 5-, 10- and 15-min groups respectively (P = 0.015). 1-hour survivors in the 5 min group required less noradrenaline 23.6 (±7.4) compared to other animals 40.9 (±25.8), (P = 0.008). Conclusion Selective aortic arch perfusion is an effective resuscitative tool in eliciting ROSC in a swine model of exsanguination cardiac arrest lasting >5 min. Sustainable resuscitability using SAAP declines after 10 min of exsanguination cardiac arrest. Take-home Message SAAP is an emerging resuscitation technique with promising outcomes in exsanguination cardiac arrest and may be a segway to Extracorporeal life support. The time limit for resuscitability of the myocardium lies somewhere between 10 and 15 min after the start of exsanguination cardiac arrest.

Swine are frequently used in medical research given their similar cardiac physiology to that of humans. Measuring cardiac parameters such as stroke volume and cardiac output are essential in this type of research. Contrast ventriculography, thermodilution, and pressure-volume loop (PV-loop) catheters can be used to accurately obtain cardiac performance data depending on which resources and expertise are available. For this study,five Yorkshire swine were anesthetized and intubated. Central venous and arterial access was obtained to place the necessary measurement instruments.A temperature probe was placed in the aortic root. A cold saline bolus was delivered to the right atrium and temperature deflection curve was recorded. Integration of the area under the curve allowed for the calculation of the current cardiac output.A pigtail catheter was percutaneously placed in the left ventricle and 30 mL of iodinated contrast was power injected over 2 seconds. Digital subtraction angiography images were uploaded to volumetric analysis software to calculate the stroke volume and cardiac output. A pressure volume-loop catheter was placed into the left ventricle (LV) and provided continuous pressure and volume data of the LV, which allowed the calculation of both stroke volume and cardiac output.All three methods demonstrated good correlation with each other. The PV-loop catheter and thermodilution exhibited the best correlation with a 3% error and a Pearson coefficient of 0.99, with 95% CI=0.97 to 1.1, (p=0.002). The PV-loop catheter against ventriculography also showed good correlation with a 6% error and a Pearson coefficient of 0.95, 95% CI=0.96 to 1.1 (p=0.01). Finally, thermodilution against ventriculography had a 2% error with r=0.95, 95% CI=0.93 to 1.11, (p=0.01). In conclusion, we state that the PV-loop catheter, contrast ventriculography, and thermodilution each offer certain advantages depending on the researcher's requirements. Each method is reliable and accurate for measuring various cardiac parameters in swine such as the stroke volume and cardiac output.

Background Administering antithrombotics (AT) to the multiply injured patient with blunt cerebrovascular injury (BCVI) requires a thoughtful assessment of the risk of stroke and death associated with nontreatment. Large, multicenter analysis of outcomes stratified by injury grade and vessel injured is needed to inform future recommendations. Methods Nine hundred and seventy-one BCVIs were identified from the PROspective Vascular Injury Treatment registry in this retrospective analysis. Using multivariate analysis, we identified predictors of BCVI-related stroke and death. We then stratified these risks by injury grade and vessel injured. We compared the risk of adverse outcomes in the nontreatment group with those treated with antiplatelet agents and/or anticoagulants. Results Stroke was identified in 7% of cases. Overall mortality was 12%. Both increased with increasing BCVI grade. Treatment with ATs was associated with lower mortality and was not significantly affected by the choice of agent. Withholding ATs was associated with an increased risk of stroke and/or death across all subgroups (Grade I/II: odds ratio [OR], 4.66; 95% confidence interval [CI], 2.48-8.75; Grade III: OR, 7.0; 95% CI, 2.01-24.5; Grade IV: OR, 4.43; 95% CI, 1.76-11.1) even after controlling for covariates. Predictors of death included more severe trauma, Grade IV injury, and the occurrence of stroke. Arterial occlusion, hypotension, and endovascular intervention were significant predictors of stroke. Patients that experienced a BCVI-related stroke were at a 4.2× increased risk of death. The data set lacked the granularity necessary to evaluate AT timing or dosing regimen, which limited further analysis of stroke prevention strategies. Conclusion Stroke and death remain significant risks for all BCVI grades regardless of the vessel injured. Antithrombotics represent the only management strategy that is consistently associated with a lower incidence of stroke and death in all BCVI categories. In the multi-injured BCVI patient with a high risk of bleeding on anticoagulation, antiplatelet agents are an efficacious alternative. Given the 40% mortality rate in patients who survived their initial trauma and developed a BCVI-related stroke, nontreatment may no longer be a viable option. Level of evidence Epidemiological III; Therapeutic IV.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) allows for effective temporization of exsanguination from non-compressible hemorrhage (NCTH) below the diaphragm. However, the therapeutic window for aortic occlusion is time-limited given the ischemia-reperfusion injury generated. Significant effort has been put into translational research to develop new strategies to alleviate the ischemia-reperfusion injury and extend the application of endoaortic occlusion. Targeted regional optimization (TRO) is a partial REBOA strategy to augment proximal aortic and cerebral blood flow while targeting minimal threshold of distal perfusion beyond the zone of partial aortic occlusion. The objective of TRO is to reduce the degree of ischemia caused by complete aortic occlusion while providing control of distal hemorrhage. This review provides a synopsis of the concept of TRO, pre-clinical, translational experiences with TRO and early clinical outcomes. Early results from TRO strategies are promising; however, further studies are needed prior to large-scale implementation into clinical practice.

Vascular injury is a leading cause of death and disability in military and civilian settings. Most wartime and an increasing amount of civilian vascular trauma arises from penetrating mechanisms of injury due to gunshot or explosion. The objective of this study was to provide a comprehensive examination of penetrating lower extremity arterial injury and to characterize long-term limb salvage and differences related to mechanisms of injury.The military trauma registries of the United States and the United Kingdom were analyzed to identify service members who sustained penetrating lower limb arterial injury (2001-2014). Treatment and limb salvage data were studied and comparisons made of patients whose penetrating vascular trauma arose from explosion (group 1) vs gunshot (group 2). Standardized statistical testing was used, with Bonferroni corrections for multiple comparisons.The cohort consisted of 568 combat casualties (mean age, 25.2 years) with 597 injuries (explosion, n = 416; gunshot, n = 181). Group 1 had higher Injury Severity Score (P .05) and Mangled Extremity Severity Score (P .0001), required more blood transfusion (P .05), and had more tibial (P .01) and popliteal (P .05) arterial injuries; group 2 had more profunda femoris injuries (P .05). Initial surgical management for the whole cohort included vein interposition graft (33%), ligation (31%), primary repair with or without patch angioplasty (16%), temporary vascular shunting (15%), and primary amputation (6%). No difference in patency of arterial reconstruction was found between group 1 and group 2, although group 1 had a higher incidence of primary (13% vs 2%; P .05) and secondary (19% vs 9%; P .05) amputation. Similarly, longer term freedom from amputation was lower for group 1 than for group 2 (68% vs 89% at 5.5 years; Cox hazard ratio, 0.30; P .0001), as was physical functioning (36-Item Short Form Health Survey data; mean, 39.80 vs 43.20; P .05).The majority of wartime lower extremity arterial injuries result from an explosive mechanism that preferentially affects the tibial vasculature and results in poorer long-term limb salvage compared with those injured with firearms. The mortality associated with immediate limb salvage attempts is low, and delayed amputations occur weeks later, affording the patient involvement in the decision-making and rehabilitation planning. We recommend assertive attempts at vascular repair and limb salvage for service members injured by explosive and gunshot mechanisms.

Objectives Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) has been used clinically to limit torso bleeding and restore central perfusion. The objective of this study was to determine the sequelae of prolonged REBOA in a nonhuman primate animal model. Summary background data Prolonged duration of REBOA is associated with adverse clinical outcomes. Threshold occlusion values tied to relative risk have yet to be determined. Methods Juvenile baboons were subjected to 40% to 55% total blood volume hemorrhage to achieve profound hypotension and shock. Zone I REBOA was performed for 60 minutes to assess acute injury and survival at 4 hours (group 1; n = 7). Post-REBOA 10-day survival and complications were then compared between 60 minutes (group 2; n = 8) and 30 minutes (group 3; n = 6) REBOA animals. Results Overall survival was 20/21 (95%). IL-6 and IL-8 were elevated at 1 and 4 hours in group 1 (P = 0.005; P = 0.001). Comparing 60-minute REBOA with 30-minute REBOA, there was (1) hypertension compared with normotension (P = 0.005), (2) increased base deficit (P = 0.003), (3) elevated Troponin I (P = 0.04), and histological evidence of kidney injury (P = 0.004). In addition, group 2 demonstrated paralysis with histopathologic changes of spinal cord ischemia (SCI) in 4/8 (50%), with no SCI in group 3 (P = 0.033). Conclusions REBOA limits mortality in the primate model of severe hemorrhagic shock. However, unopposed balloon inflation in the distal thoracic aorta for 60 minutes results in high rates of spinal cord ischemia, an effect mitigated by limiting balloon inflation to 30 minutes.

This review discusses the trends in management of vascular trauma comparing open management with endovascular strategies. Endovascular vascular approaches to vascular trauma has evolved significantly in the past several decades, providing an option for reduced morbidity and mortality in the carefully selected trauma patient. While open surgery is a critical skill to maintain, there are strategies more than ever before that can be applied to a hemorrhaging trauma patient which include stent-graft placement, the use of temporary vascular shunts, and vascular balloon occlusion. Vascular trauma management has evolved over the last several decades, introducing promising endovascular treatment strategies, particularly in junctional and torso hemorrhage.

Objective Vascular injury is a leading cause of death and disability in military and civilian trauma. Although a previous interim study defined the distribution of vascular injury during the wars in Iraq and Afghanistan, a contemporary epidemiologic assessment has not been performed. The objective of this study was to provide a current analysis of vascular injury during the final 7 years of the war in Afghanistan, including characterization of anatomic injury patterns, mechanisms of injury, and methods of acute management. Methods The Department of Defense Trauma Registry was analyzed to identify U.S. military service members who sustained a battle-related vascular injury and survived to be treated at a surgical facility in Afghanistan between January 1, 2009, and December 31, 2015. All battle-related injuries (nonreturn to duty) were used as a denominator to establish the injury rate. Mechanism and anatomic distribution of injury as well as the acute management strategies of revascularization, ligation, and use of endovascular techniques were defined. Results Of 3900 service members who sustained a battle-related injury, 685 patients (17.6%) had 1105 vascular injuries (1.6 vascular injuries per patient). Extremity trauma accounted for 72% (n = 796) of vascular injuries, followed by the torso (17%; n = 188) and cervical (11%; n = 118) regions. Lower extremity vascular injury was the most prevalent anatomic location (45%; 501/1105). Explosion with fragment penetration accounted for 70% (477/685) of injuries, whereas gunshot wounds accounted for 30% (205/685). Open repair was performed in 559 cases (57%; 554/981), whereas ligation was the initial management strategy in 40% (395/981) of cases. In addition, 374 diagnostic endovascular procedures were completed, 27 therapeutic endovascular interventions to include stent placement and angioplasty were performed and 55 inferior vena cava filters were placed. Mortality of the vascular injury cohort was 5%. Conclusions The rate of vascular injury in modern combat is higher than that reported in previous wars. Open reconstruction is performed in half of cases, although ligation is an important damage control option, especially for minor or distal vessel injuries. Angiographic techniques are increasingly being used and documented within wartime registries more than ever. Proficiency with open and endovascular methods of vascular injury management remains a critical need for the U.S. military and will require partnership with civilian institutions to attain and maintain.

Objectives Swine ( Sus Scrofa) are utilized broadly in research settings, given similarities to human vessel size and function; however, there are some important differences for clinicians to understand in order to interpret and perform translational research. This review article uses angiograms acquired in the course of a translational research program to present a description of the functional anatomy of the swine. Methods Digital subtraction angiography and computed tomography angiography were obtained throughout the course of multiple studies utilizing power injection with iodinated contrast. Subtracted two-dimensional images and three-dimensional multiplanar reformations were utilized post image acquisition to create maximal intensity projections and three-dimensional renderings of using open-source software (OsiriX). These imaging data are presented along with vessel measurements for reference. Results An atlas highlighting swine vascular anatomy, with an emphasis on inter-species differences that may influence how studies are conducted and interpreted, was compiled. Conclusions Swine are utilized in broad-reaching fields for preclinical research. While many similarities between human and swine vasculature exist, there are important differences to consider when conducting and interpreting research. This review article highlights these differences and presents accompanying images to inform clinicians gaining experience in swine research.

BACKGROUND Adequate cerebral perfusion is crucial for a positive neurological outcome in trauma; however, it is difficult to characterize in the acute setting with noninvasive methods. Intra-arterial computed tomography perfusion may offer a solution. The aim of this study was to develop an intra-arterial computed tomography perfusion protocol for resuscitation research. METHODS The study examined intra-arterial contrast administration for computed tomography perfusion (CTP) acquisition. It consisted of three phases: intra-arterial contrast dose finding, evaluation of reproducibility, and evaluation during hypotension. Blood pressure and laser Doppler flow data were collected. In phase 1, animals underwent CTPs using several intra-arterial contrast injection protocols. In phase 2, animals underwent two CTPs 7 hours apart using the 2.5 mL/s for 3-second protocol. In phase 3, animals underwent CTPs at several pressures following a computer-controlled bleed including euvolemia and at systolic pressures of 60, 40, and 20 mm Hg. Phase 1 CTPs were evaluated for contrast-to-noise ratio. In phase 2, CTPs were compared within each animal and with laser Doppler flow using linear regression. Phase 3 CTPs were graphed against systolic pressure and fitted with a nonlinear fit. RESULTS The protocol using 2.5mL/s for 3 seconds was optimal, demonstrating a contrast-to-noise ratio of 40.1 and a superior arterial input function curve compared with the 1 mL/s bolus. Cerebral blood flow demonstrated high concordance between baseline and end of study CTPs (R2 = 0.82, p < 0.001). Cerebral blood flow also compared moderately well against laser Doppler flow during 8 (R2 = 0.53, p = 0.03); however, laser Doppler flow did not perform well during hypovolemia, and the favorable concordance was not maintained (R2 = 0.45, p = 0.06). Cerebral blood flow was graphed against systolic blood pressure and fitted with a nonlinear fit (R2 = 0.95, p = 0.003). CONCLUSION Computed tomography perfusion using intra-arterial contrast injection may offer a novel alternative to traditional CTP protocols that could prove a useful additional tool in the setting of resuscitation research.

Severe traumatic brain injury (TBI) is a leading cause of death and disability worldwide, especially in low- and middle-income countries, and in austere, rural, and remote settings. The purpose of this Perspective is to challenge the notion that accurate and actionable diagnosis of the most severe brain injuries should be limited to physicians and other highly-trained specialists located at hospitals. Further, we aim to demonstrate that the great opportunity to improve severe TBI care is in the prehospital setting. Here, we discuss potential applications of prehospital diagnostics, including ultrasound and near-infrared spectroscopy (NIRS) for detection of life-threatening subdural and epidural hemorrhage, as well as monitoring of cerebral hemodynamics following severe TBI. Ultrasound-based methods for assessment of cerebrovascular hemodynamics, vasospasm, and intracranial pressure have substantial promise, but have been mainly used in hospital settings; substantial development will be required for prehospital optimization. Compared to ultrasound, NIRS is better suited to assess certain aspects of intracranial pathology and has a smaller form factor. Thus, NIRS is potentially closer to becoming a reliable method for non-invasive intracranial assessment and cerebral monitoring in the prehospital setting. While one current continuous wave NIRS-based device has been FDA-approved for detection of subdural and epidural hemorrhage, NIRS methods using frequency domain technology have greater potential to improve diagnosis and monitoring in the prehospital setting. In addition to better technology, advances in large animal models, provider training, and implementation science represent opportunities to accelerate progress in prehospital care for severe TBI in austere, rural, and remote areas.

Hemorrhage constitutes the majority of potentially preventable deaths from trauma. There is growing interest in endovascular resuscitation techniques such as selective aortic arch perfusion (SAAP) for patients in cardiac arrest. This involves active perfusion of the coronary circulation via a thoracic aortic balloon catheter and is approaching clinical application. However, the technique is complex and requires refinement in animal models before human use can be considered. This paper describes a large animal model of exsanguination cardiac arrest treated with a bespoke SAAP system. Swine were anesthetized, instrumented and a splenectomy was performed before a controlled, logarithmic exsanguination was initiated. Animals were heparinized and the shed blood collected in a reservoir. Once cardiac arrest was observed, the blood was pumped through an extra-corporeal circuit into an oxygenator and then delivered through a 10 Fr balloon catheter placed in the thoracic aorta. This resulted in the return of a spontaneous circulation (ROSC) as demonstrated by ECG and aortic root pressure waveform. This model and accompanying SAAP system allow for standardized and reproducible recovery from exsanguination cardiac arrest.

BACKGROUND Resuscitative endovascular balloon occlusion of the aorta (REBOA) is becoming a standardized adjunct for the management in patients with severe non-compressible torso hemorrhage (NCTH). Although guidelines have been developed to help with the best indications for REBOA utilization, no studies have addressed the significance of change in systolic blood pressure (ΔSBP) after REBOA insufflation. We hypothesized that ΔSBP would predict mortality in patients with NCTH and have utility as a surrogate marker for hemorrhage status. STUDY DESIGN This was an international, multicenter retrospective review of all patients managed with REBOA from the ABOTrauma Registry and the AORTA database. ΔSBP was defined as the difference between pre- and post-REBOA insertion SBP. Based on post-insertion SBP, patient hemorrhage status was categorized as responder or non-responder. A non-responder was defined as a hypotensive patient with systolic blood pressure

Damage Control Resuscitation (DCR) seeks to combat metabolic decompensation of the severely injured trauma patient by battling on three major fronts: Permissive Hypotension, Hemostatic Resuscitation, and Damage Control Surgery (DCS). The aim of this article is to perform a review of the history of DCR/DCS and to propose a new paradigm that has emerged from the recent advancements in endovascular technology: The Resuscitative Balloon Occlusion of the Aorta (REBOA). Thanks to the advances in technology, a bridge has been created between Pre-hospital Management and the Control of Bleeding described in Stage I of DCS which is the inclusion and placement of a REBOA. We have been able to show that REBOA is not only a tool that aids in the control of hemorrhage, it is also a vital tool in the hemodynamic resuscitation of a severely injured blunt and/or penetrating trauma patient. That is why we propose a new paradigm "The Fourth Pillar": Permissive Hypotension, Hemostatic Resuscitation, Damage Control Surgery and REBOA.La resucitación en control de daños busca combatir la descompensación metabólica del paciente severamente traumatizado mediante tres ejes: la hipotensión permisiva, la resucitación hemostática y la cirugía de control de daños. El objetivo de este artículo es hacer una revisión de la historia de la resucitación en control de daños y la cirugía de control de daños proponiendo un nuevo paradigma basado en los recientes avances de la tecnología endovascular. Un puente ha sido creado entre el manejo prehospitalario y el control del sangrado, descrito antes de la etapa I de la cirugía de control de daños, que es la inclusión y colocación de un REBOA. Esta es una herramienta adicional en el control de la hemorragia y de soporte en la resucitación hemodinámica de los pacientes con trauma severo de tipo cerrado y/o penetrante. Por lo que se propone un nuevo paradigma “El cuarto pilar”: Hipotensión permisiva, resucitación hemostática, cirugía de control de daños y REBOA.

Background Cervical carotid artery injuries entail high morbidity and mortality and are technically challenging to repair. This retrospective study describes the management and outcomes of cervical carotid injuries sustained during the recent wars in Iraq and Afghanistan. Methods The Department of Defense Trauma Registry was queried to identify US military personnel who sustained battle-related cervical carotid injury between January 2002 and December 2015. Retrospective chart reviews of the military Electronic Health Record were performed on patients identified. Demographics, injury characteristics, surgical management, and outcomes were reviewed. Statistical analysis was performed to identify associations between injury and management factors, as well as stroke and mortality. Results In total, 67 patients (100% male; age, 25 ± 7 years) were identified with cervical carotid artery injuries. Fifty-six patients (84%) sustained a common carotid artery (CCA) or internal carotid artery (ICA) injury, and 11 patients (16%) had an isolated external carotid artery (ECA) injury. The anatomic distribution of injury was as follows: CCA, 26 (38.8%); ICA, 24 (35.8%); CCA and ICA 2 (3%); ICA and ECA 3 (4.5%); and CCA, ICA, and ECA 1 (1.5%). Of the 56 CCA or ICA injuries, 39 underwent vascular repair, 9 (16%) were managed with ligation, 1 was treated with a temporary vascular shunt but succumbed to injuries before vascular repair, and 7 (13%) were treated nonoperatively. Seven (23%) of 30 ICA injuries were ligated compared with 2 (7.7%) of 26 injuries isolated to the CCA (p = 0.02). Compared with repair, ligation of the CCA/ICA was associated with a higher rate of stroke (89% vs. 33%, p = 0.003) and increased mortality without statistical significance (22% vs. 10%, p = 0.3). Every patient who underwent ICA ligation had a stroke (7/7). There was no difference in Injury Severity Score between the ligation and repair groups (23.8 ± 10.6 vs. 24.7 ± 13.4, p = 0.9). At a mean follow-up of 34.5 months, 10 of 17 stroke survivors had permanent neurologic deficits. Conclusion In modern combat, penetrating injuries involving the cervical carotid arteries are relatively infrequent. In this experience, isolated ICA injuries were three times more likely to be ligated than those involving the CCA. As a surgical maneuver, ICA ligation resulted in stroke in all cases. Level of evidence Retrospective cohort analysis, level III.

Background The US military has prioritized battlefield hemorrhage control. Researchers credit tourniquet use, and a novel trauma care training program, with saving 1000–2000 lives in Iraq and Afghanistan. The Stop the Bleed campaign translates these lessons learned to the public. This is the first analysis of the potential impact of this newfound knowledge about tourniquet use for extremity fatal vascular access hemorrhage in a civilian population. Fatal vascular access hemorrhage includes bleeding from arteriovenous fistulas and grafts used for hemodialysis and central venous catheters. Methods This is a retrospective study of decedent records. We selected Maryland death records from 2002–2017 using the following search terms: “graft,” “shunt,” “fistula,” “dialysis,” and “central venous catheter.” The records were analyzed for potential survivability with a checklist of military criteria modified for a civilian population. Suicides were excluded. Two reviewers independently classified the deaths as either potentially survivable or non‐survivable, and a third reviewer broke ties. Results There were 111 deaths included in the final analysis. Ninety‐two of the 111 decedents had potentially survivable extremity fatal vascular access hemorrhage. The remaining 19 records were excluded, because they did not have extremity hemorrhage. Zero decedents had hemorrhage deemed to be non‐survivable with prompt tourniquet application. Conclusion This study identified 92 Maryland extremity fatal vascular access hemorrhage decedents who potentially could have survived with tourniquet use—an average of 6 per year. These results suggest the need for further epidemiology investigation, as well as exploration of the risks and benefits of teaching and equipping vascular access patients and their caregivers to use tourniquets for life‐threatening bleeding.

Explosions were the most common source of injury during Operation Enduring Freedom and Operation Iraqi Freedom. A single blast can generate numerous casualties with complex injuries. When these patients overwhelm a medical system, a mass casualty incident occurs. The United States Military has been at the forefront of trauma management, and this includes the management of blast injuries and mass casualty incidents. Following the establishment of scene and medical facility security, the management of a mass casualty incident begins with appropriate triage. The ultimate goal of triage is to provide the greatest good for the greatest number of patients. The triage officer, ideally an experienced trauma surgeon, assigns patients to four possible triage categories: immediate, delayed, minimal, and expectant. While most civilian emergency departments are concerned with undertriage, overtriage can be especially dangerous during a mass casualty incident due to the resulting resource misallocation. During the triage process, patients should be entered into a patient identification system and medical record should be generated. Mass casualty incidents require a surge of resources to include blood products. Blast injury patients are more likely to require massive transfusions as compared to injuries from small arms. A potential source of blood products is fresh whole blood. For the military, the management of injuries is divided amongst defined four roles of care. Each role has a set amount of resources and skills that the next higher role builds upon. This ensures the orderly flow of injured patients from austere environments back to United States medical centers, such as the Walter Reed National Military Medical Center. Ultimately, effective mass casualty incident management depends on an established system that has undergone simulations and practice before the real event. In addition, each mass casualty incident should provide “lessons-learned” to ensure proper preparation for the next event.

Introduction Several reviews of resuscitative thoracotomy (RT) use over the last five decades have been conducted, most recently the evidence-based practice management guideline (PMG) of the Eastern Association for the Surgery of Trauma (EAST). The present study was designed to examine contemporary RT utilization and outcomes compared with historical data (n = 10,238) from the EAST PMG review from published series 1974 to 2013. Methods The American Association for the Surgery of Trauma Aortic Occlusion for Trauma and Acute Care Surgery (AORTA) registry was utilized to identify patients undergoing RT in the emergency department (ED) from November 2013 to December 2016. Demographics, injury data, physiologic presentation, and outcomes were reviewed and compared with those of the EAST PMG review. Results Three-hundred ten RT patients from 16 contributing AORTA centers were identified. The majority were injured by penetrating mechanisms (197/310, 64% [gunshot (163/197, 83%)]). Signs of life (SOL) (organized electrical activity, pupillary response, spontaneous movement, or appreciable pulse/blood pressure) were present on arrival in 47% (147/310). When compared with the EAST PMG results, there was no difference in either hospital survival (5% vs. 8%) or neurologically intact survival between historical controls or AORTA registry patients in any category combination of mechanism/anatomic location/presenting signs of life. Blunt injuries W/O SOL on admission continue to constitute 14% (45/310) of RTs in the ED, without documented survivors. Conclusion Comparison of historical RT controls to more contemporary patients from the AORTA registry suggests that practices and outcomes following RT have not changed. Despite a wealth of accumulated data over several decades, RT continues to be performed for patients after blunt mechanisms of injury who present W/O SOL despite lack of demonstrated hope for survival benefit.

Wartime vascular injury can be particularly challenging due to the complexity of the case, concomitant injuries, resource limitations, and often lack of expertise of the operating surgeon. The proliferation of vascular shunting has been of particular importance as a damage control surgery technique to restore perfusion and temporize the immediate need for definitive repair necessary for limb salvage, particularly in austere locations. Diagnosis of vascular injury can be made using a variety of techniques, from physical examination to ankle-brachial indices to the use of CT angiography or invasive angiographic techniques. Operative planning and judgment are therefore critical in deciding both how and whether to operate. Surgeons likely to deploy should take every opportunity to practice vascular exposures and techniques through clinical practice and laboratory courses.

This clinical practice guideline (CPG) reviews the range of accepted management approaches to profound shock and post-traumatic cardiac arrest and establishes indications for considering Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) as a hemorrhage control adjunct. The specific management approach - within the parameters of mission, resources, and tactical situation - will depend on the casualty's physical location, mechanism and pattern of injury, and the experience level of the surgeon. The optimal management strategy is best determined by the surgeon at the bedside.

Trauma is among the leading causes of death in the United States. Technological advancements have led to the development of resuscitative endovascular balloon occlusion of the aorta (REBOA) which offers a pre-hospital option to non-compressible hemorrhage control. Due to the prevalence of concomitant traumatic brain injury (TBI), an understanding of the effects of REBOA on cerebral physiology is critical. To further this understanding, we employed a rat model of penetrating ballistic-like brain injury (PBBI). PBBI produced an injury pattern within the right frontal cortex and striatum that replicates the pathology from a penetrating ballistic round. Aortic occlusion was initiated 30 min post-PBBI and maintained continuously (cAO) or intermittently (iAO) for 30 min. Continuous measurements of mean arterial pressure (MAP), intracranial pressure (ICP), cerebral blood flow (CBF), and brain tissue oxygen tension (PbtO2) were recorded during, and for 60 min following occlusion. PBBI increased ICP and decreased CBF and PbtO2. The arterial balloon catheter effectively occluded the descending aorta which augmented MAP in the carotid artery. Despite this, CBF levels were not changed by aortic occlusion. iAO caused sustained adverse effects to ICP and PbtO2 while cAO demonstrated no adverse effects on either. Temporary increases in PbtO2 were observed during occlusion, along with restoration of sham levels of ICP for the remainder of the recordings. These results suggest that iAO may lead to prolonged cerebral hypertension following PBBI. Following cAO, ICP, and PbtO2 levels were temporarily improved. This information warrants further investigation using TBI-polytrauma model and provides foundational knowledge surrounding the non-hemorrhage applications of REBOA including neurogenic shock and stroke.

Observational/retrospective/historic controls, level IV.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) for control of noncompressible torso hemorrhage is a technology that is increasingly being utilized in the combat casualty setting. Its use in the resource restricted environment holds potential to improve hemorrhage control, decrease blood product utilization, decrease morbidity, and improve combat mortality. The objective of this report is to present the single largest series of REBOA use on severely injured combat casualties.Over an 18-month period, austere surgical teams comprised of coalition partners provided initial damage control resuscitation (DCR) and surgical stabilization for over 2,300 combat casualties prior to transferring patients to the next level of trauma care.Twenty patients presented with injuries from explosion and gunshot wounds with mean initial heart rate of 129 bpm and mean initial systolic blood pressure of 71 mm Hg. Femoral cutdowns were used in six patients. Aortic occlusion was achieved with REBOA catheter placement in Zone 1 (n = 17) and Zone 3 (n = 2). Systolic blood pressure increased an average of 56 mm Hg with aortic occlusion. There were no access related site complications. All patients survived transport to the next level of care. The majority of blood products transfused in this cohort were whole blood, largely supported by emergent blood drives.This series demonstrates the potential for REBOA as a lifesaving technique for the patient who presents with hemodynamic instability and noncompressible torso hemorrhage. Resuscitative endovascular balloon occlusion of the aorta allows austere surgical teams to rapidly stabilize severely injured combat casualties, expand capability, and provide enhanced DCR while minimizing personnel, resources, and blood product utilization. The use of "whole blood only" strategy for DCR shows potential to be superior to traditional component therapy, and when combined with "proactive" REBOA utilization, provides significant improvements in hemodynamics and hemorrhage control.Case series, level V.

Objective To describe the long-term outcomes of military lower-extremity vascular injuries, and the decision making of surgeons treating these injuries. Background Lower-extremity vascular trauma is an important cause of preventable death and severe disability, and decisions on amputation or limb salvage can be difficult. Additionally, the complexity of the condition is not amenable to controlled study, and there is limited data to guide clinical decision making and establish sensible treatment expectations during rehabilitation. Methods A cohort study of 554 US service members who sustained lower-extremity vascular injury in Iraq or Afghanistan (March 2003 to February 2012) was performed using the military's trauma registry, its electronic health record, patient interviews, and quality-of-life surveys. Long-term surgical and functional outcomes, and the timing and rationale of surgical decisions, were analyzed. Results Of 579 injured extremities, 49 (8.5%) underwent primary amputation and 530 (91.5%) an initial attempt at salvage. Ninety extremities underwent secondary amputation, occurring in the early (n = 60; 30 days) phases after injury. For salvage attempts, freedom from amputation 10 years after injury was 82.7% (79.1%-85.7%). Long-term physical and mental health outcomes were similar between service members who underwent reconstruction and those who underwent amputation. Conclusion This military experience provides data that will inform an array of military and civilian providers who care for patients with severe lower-extremity injury. While the majority salvage attempts endure, success is hindered by ischemia and necrosis during the acute stage and pain, dysfunction and infection in the later phases of recovery. Level of evidence Therapeutic/prognostic, level III.