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Retrograde open mesenteric stenting (ROMS) has become a mainstay in treatment of mesenteric ischemia; however, follow-up in contemporary studies is limited.A single-center retrospective review of patients undergoing ROMS from 2007 to 2020 was conducted. Demographics, presentation, and procedural details were reviewed. End points were morbidity and mortality, technical success, primary patency, reinterventions, and freedom from clinical recurrence.ROMS was performed in 34 patients, 19 female (56%). Mean age was 71 ± 10 years. Eighteen patients (53%) presented with acute mesenteric ischemia (AMI), 11 (32%) with acute-on-chronic, and 5 (15%) with chronic mesenteric ischemia. Etiology was chronic atherosclerosis with/without in-situ thrombosis in 28 patients (82%), superior mesenteric artery dissection in 3, and 1 each with embolic, vasculitic, and nonocclusive ischemia. Four patients (12%) had prior mesenteric procedures (3 Celiac/1 superior mesenteric artery stent) and 1 had unsuccessful transbrachial stenting attempt. Technical success, defined as successful stenting through a retrograde approach was attained in 31 patients (91%), with the 3 remaining patients treated with transbrachial stenting in 2 and iliomesenteric bypass in 1. Covered stents were used in 21 patients (64%) with or without stent extension with bare-metal stents. Eight patients (23%) required thromboembolectomy and 9 (26%) underwent patch angioplasty. Thirty-day mortality rate was 35%, all in patients with AMI (10) or acute-on-chronic (2). Eighteen patients (53%) underwent bowel resection, all presenting acutely. Early reinterventions within the first 30 days were required in 5 patients (15%), including 2 redo ROMS with thrombectomy and endarterectomy, 2 percutaneous stent extensions, and 1 aortic septum fenestration with coiling of a jejunal branch pseudoaneurysm. With a median follow-up of 3.7 (interquartile range: 0.8-5.0) years, in patients surviving discharge, 5 required reintervention yielding freedom from reintervention rates of 87% at 1 year and 71% at 3 years. All postdischarge reinterventions were endovascular with no conversion to bypass. The overall 1-year and 3-year primary patency rates were 70% and 61% (primary-assisted patency at 1 and 3 years was 87% and secondary patency at 1 and 3 years was 97%). The freedom from symptom recurrence was 95% at 1 and 3 years.ROMS carries high rates of technical success in patients with mesenteric ischemia, despite a high chronic atherosclerotic burden. Although mid-term patency rates are acceptable, AMI is still associated with high early morbidity and mortality, with high rates of associated bowel resection. ROMS is a valuable tool in the armamentarium of vascular surgeons.

Objective The aim of this study was to analyze malpractice claims for aortic pathologies and to assess if there has been a change in rate of malpractice lawsuits with evolution of endovascular therapy. Methods Malpractice lawsuits were individually screened and compiled from the Westlaw database from 2000 to 2017 through use of relevant search terms. Data were collected of allegations, diagnoses, and outcomes of each case and compared. Results 268 unique cases were included in this study, with aneurysms (54%, n = 145) and dissection (35%, n = 94) making up the majority. There was a defendant verdict in 53% (n = 141), plaintiff verdict in 24% (n = 65), and settlements in 23% (n = 62) of lawsuits. Litigation was higher in the Midwest and Northeast. There was a gradual decline in litigation overall, however endovascular case numbers remained constant. There was negligible difference in the primary allegation underlying the litigation for various aortic pathologies, time to litigation and award between open and endovascular procedures. Conclusion The proportion of litigation for clinical negligence in endovascular cases amongst all vascular surgical lawsuits is increasing. As novel methods of endovascular therapy emerge, it is imperative that physicians remain vigilant to legal considerations to minimize malpractice risk.

An infection-resistant, immediately available conduit for trauma and urgent vascular reconstruction remains a critical need for successful limb salvage. While autologous vein remains the gold standard, vein-limited patients and size mismatch are common issues. The Human Acellular Vessel (HAV) (Humacyte, Inc., Durham, NC) is a bioengineered conduit with off-the-shelf availability and resistance to infection, ideal characteristics for patients with challenging revascularization scenarios. This report describes HAV implantation in patients with complex limb-threatening ischemia and limited conduit options who may have otherwise faced limb loss.The Food and Drug Administration (FDA) expanded-access program was used to allow urgent implantation of the HAV for arterial reconstruction. Electronic medical records were reviewed with extraction of relevant data including patient demographics, surgical implantation, patency, infectious complications, and mortality.The HAV was implanted in 8 patients requiring vascular reconstruction. Graft or soft tissue infection was present in 2 patients. One patient with severe penetrating pelvic injury had 4 HAV placed to repair bilateral external iliac artery and vein injuries. There was 1 technical failure due to poor outflow, 2 patients died unrelated to HAV use, and 5 lower extremity bypasses maintained patency at an average of 11.4 months (range: 4-20 months). No HAV infectious complications were identified.This report is the first United States series describing early outcomes using the HAV under the FDA expanded-access program for urgent vascular reconstruction. The HAV demonstrates resistance to infection, reliable patency, and offers surgeons an immediate option when confronted with complex revascularization scenarios. Assessment of long-term outcomes will be important for future studies.

Selective aortic arch perfusion (SAAP) is an endovascular technique that consists of aortic occlusion with perfusion of the coronary and cerebral circulation. It been shown to facilitate return of spontaneous circulation (ROSC) after exanguination cardiac arrest (ECA), but it is not known how long arrest may last before the myocardium can no longer be durably recovered. The aim of this study is to assess the myocardial tolerance to exsanguination cardiac arrest before successful ROSC with SAAP.Male adult swine (n = 24) were anesthetized, instrumented, and hemorrhaged to arrest. Animals were randomized into three groups: 5, 10, and 15 min of cardiac arrest before resuscitation with SAAP. Following ROSC, animals were observed for 60 min in a critical care environment. Primary outcomes were ROSC, and survival at 1-h post-ROSC.Shorter cardiac arrest time was associated with higher ROSC rate and better 1-h survival. ROSC was obtained for 100% (8/8) of the 5-min ECA group, 75% (6/8) of the 10-min group, 43% (3/7) of the 15-min group (P = 0.04). One-hour post-ROSC survival was 75%, 50%, and 14% in 5-, 10-, and 15-min groups, respectively (P = 0.02). One-hour survivors in the 5-min group required less norepinephrine (1.31 mg ± 0.83 mg) compared with 10-SAAP (0.76 mg ± 0.24 mg), P = 0.008.Whole blood SAAP can accomplish ROSC at high rates even after 10 min of unsupported cardiac arrest secondary to hemorrhage, with some viability beyond to 15 min. This is promising as a tool for ECA, but requires additional optimization and clinical trials.Animal Use Protocol, IACUC: 0919015.

Fast-growing abdominal aortic aneurysms (AAA) have a high rupture risk and poor outcomes if not promptly identified and treated. Our primary objective is to improve the differentiation of small AAAs' growth status (fast versus slow-growing) through a combination of patient health information, computational hemodynamics, geometric analysis, and artificial intelligence. 3D computed tomography angiography (CTA) data available for 70 patients diagnosed with AAAs with known growth status were used to conduct geometric and hemodynamic analyses. Differences among ten metrics (out of ninety metrics) were statistically significant discriminators between fast and slow-growing groups. Using a support vector machine (SVM) classifier, the area under receiving operating curve (AUROC) and total accuracy of our best predictive model for differentiation of AAAs' growth status were 0.86 and 77.50%, respectively. In summary, the proposed analytics has the potential to differentiate fast from slow-growing AAAs, helping guide resource allocation for the management of patients with AAAs.

Acute arterial occlusion of the lower extremity is a time-dependent emergency that requires prompt revascularization. Lower extremity extracorporeal distal revascularization (LEEDR) is a technique that can be initiated bedside when definitive therapy is delayed. The aim of this study is to evaluate this technique in a swine model of prolonged extremity ischemia.Anesthetized swine underwent right femoral and left posterior tibial artery cannulation, left iliac venous flow monitoring (mL/min), and continuous left anterior compartment pressure (CP) monitoring (mm Hg). The iliac artery was clamped for 6 hr. LEEDR animals underwent 5 hr of extracorporeal femoral-to-tibial blood flow at 150 mL/min; controls had no intervention. At 6 hr, LEEDR was discontinued, iliac flow restored, and anterior CP monitored for 3 hr.Baseline characteristics were similar across both the groups. Iliac clamping saw an expected fall in iliac venous flow (258 ± 30 to 82 ± 19; P 0.001). LEEDR resulted in a rise in iliac venous flow (82 ± 20 to 181 ± 16; P 0.001); control arm flow remained reduced (71 ± 8; P 0.001). Once inflow was restored, venous flow returned to baseline. Revascularization provoked a higher peak CP in the control arm versus in the LEEDR group (25 ± 5 vs. 6 ± 1; P = 0.02).An extracorporeal circuit can temporarily revascularize an extremity in a swine model of prolonged ischemia, mitigating reperfusion injury and maintaining normal CPs. This concept should undergo further evaluation as a bedside tool to mitigate extremity ischemia prior to definitive revascularization.

The 6-hour threshold to revascularization of an ischemic limb is ubiquitous in the trauma literature, however, contemporary evidence suggests that this threshold should be less. This study aims to characterize the relationship between the duration of limb ischemia and successful limb salvage following lower extremity arterial trauma.This is a cohort study of the United States and UK military service members injured while serving in Iraq or Afghanistan between 2003 and 2013. Consecutive patients who sustained iliac, femoral, or popliteal artery injuries, and underwent surgery to attempt revascularization, were included. The association between limb outcome and the duration of limb ischemia was assessed using the Kaplan-Meier method.One hundred twenty-two patients (129 limbs) who sustained iliac (2.3%), femoral (56.6%), and popliteal (41.1%) arterial injuries were included. Overall, 87 limbs (67.4%) were successfully salvaged. The probability of limb salvage was 86.0% when ischemia was ≤1 hour; 68.3% when between 1 and 3 hours; 56.3% when between 3 and 6 hours; and 6.7% when6 hours ( P0.0001). Shock more than doubled the risk of failed limb salvage [hazard ratio=2.42 (95% confidence interval: 1.27-4.62)].Limb salvage is critically dependent on the duration of ischemia with a 10% reduction in the probability of successful limb salvage for every hour delay to revascularization. The presence of shock significantly worsens this relationship. Military trauma systems should prioritize rapid hemorrhage control and early limb revascularization within 1 hour of injury.

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.

The aim of the present study was to evaluate the presentation trends, intervention, and survival of patients who had been treated for late abdominal aortic aneurysm rupture (LAR) after open repair (OR) or endovascular aortic aneurysm repair (EVAR).We reviewed the clinical data from a single-center, retrospective database for patients treated for LAR from 2000 to 2020. The end points were the 30-day mortality, major postoperative complication, and survival. The outcomes between LAR managed with EVAR (group I) vs OR were compared (group II).Of 390 patients with infrarenal aortic rupture, 40 (10%) had experienced aortic rupture after prior aortic repair and comprised the LAR cohort (34 men; age 78 ± 8 years). LAR had occurred before EVAR in 30 and before OR in 10 patients. LAR was more common in the second half of the study with 32 patients after 2010. LAR after prior OR was secondary to ruptured para-anastomotic pseudoaneurysms. After initial EVAR, LAR had occurred despite reintervention in 17 patients (42%). The time to LAR was shorter after prior EVAR than after OR (6 ± 4 vs 12 ± 4 years, respectively; P = .003). Treatment for LAR was EVAR for 25 patients (63%; group I) and OR for 15 (37%, group II). LAR after initial OR was managed with endovascular salvage for 8 of 10 patients. Endovascular management was more frequent in the latter half of the study period. In group I, fenestrated repair had been used for seven patients (28%). Salvage for the remaining cases was feasible with EVAR, aortic cuffs, or limb extensions. The incidence of free rupture, time to treatment, 30-day mortality (8% vs 13%; P = .3), complications (32% vs 60%; P = .1), and disposition were similar between the two groups. Those in group I had had less blood loss (660 vs 3000 mL; P .001) and less need for dialysis (0% vs 33%; P .001) than those in group II. The median follow-up was 21 months (interquartile range, 6-45 months). The overall 1-, 3-, and 5-year survival was 76%, 52%, and 41%, respectively, and was similar between groups (28 vs 22 months; P = .48). Late mortality was not related to the aorta.LAR after abdominal aortic aneurysm repair has been encountered more frequently in clinical practice, likely driven by the frequency of EVAR. However, most LARs, including those after previous OR, can now be salvaged with endovascular techniques with lower morbidity and mortality.

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.

This article discusses the VenoValve bioprosthetic device, which is designed to improve valvular competence in the deep venous system of the lower extremities and treat deep venous insufficiency.

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.

Medical evacuation (MEDEVAC) from a combat zone requires complex decision-making and coordination of assets. A MEDEVAC helicopter team transports not only battle-injured patients but also patients with urgent non-battle-related medical diagnoses from extremely remote locations and are at the mercy of terrain, weather, and enemy contact. The military represents a young population particularly susceptible to venous thoracic outlet syndrome (vTOS) given the rigorous physical activity demands. Current literature supports immediate anticoagulation and surgical decompression within 14 days of diagnosis of vTOS to prevent long-term morbidity. Presented is a case of service member with vTOS presenting at an extremely remote military clinic who underwent a prompt evacuation ∼7,000 miles utilizing rotary-wing transport, followed by three to four more fixed-wing flights to a military treatment facility in the United States. Immediate recognition and ultrasound of this patient to confirm vTOS upon presentation and effective communication to non-medical military commanders and the receiving medical personnel at each Echelon was necessary to ensure an expedited evacuation. The surgeons treating this patient recommend prompt evacuation of deployed service members with suspected vTOS, venogram at the Role 3 if ultrasound is inconclusive, anticoagulation, and return to a Role 4 CONUS facility for definitive surgical management within 14 days. This case is an example of the efficiency of the military MEDEVAC system on a global scale, ensuring optimum medical care for all service members deployed.

Targeted regional optimization (TRO) describes partial resuscitative endovascular balloon occlusion of the aorta strategy that allows for controlled distal perfusion to balance hemostasis and tissue perfusion. This study characterized hemodynamics at specific targeted distal flow rates in a swine model of uncontrolled hemorrhage to determine if precise TRO by volume was possible.Anesthetized swine were subjected to liver laceration and randomized into TRO at distal flows of 300 mL/min (n = 8), 500 mL/min (n = 8), or 700 mL/min (n = 8). After 90 min, the animals received damage control packing and were monitored for 6 h. Hemodynamic parameters were measured continuously, and hematology and serologic labs obtained at predetermined intervals.During TRO, the average percent deviation from the targeted flow was lower than 15.9% for all cohorts. Average renal flow rates were significantly different across all cohorts during TRO phase (P 0.0001; TRO300 = 63.1 ± 1.2; TRO500 = 133.70 ± 1.93; TRO700 = 109.3 ± 2.0), with the TRO700 cohort having less renal flow than TRO500. The TRO500 and TRO700 average renal flow rates inverted during the intensive care unit phase (P 0.0001; TRO300 = 86.20 ± 0.40; TRO500 = 148.50 ± 1.45; TRO700 = 181.1 ± 0.70). There was higher blood urea nitrogen, creatinine, and potassium in the TRO300 cohort at the end of the experiment, but no difference in lactate or pH between cohorts.This study demonstrated technical feasibility of TRO as a strategy to improve outcomes after prolonged periods of aortic occlusion and resuscitation in the setting of ongoing solid organ hemorrhage. A dose-dependent ischemic end-organ injury occurs beginning with partial aortic occlusion that progresses through the critical care phase, with exaggerated effect on renal function.

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.

To describe and compare the aortic-right atrial pressure (AoP-RAP) gradients and mean coronary perfusion pressures (CPPs) generated during open chest selective aortic arch perfusion (OCSAAP) with those generated during open cardiac massage (OCM) in hypovolemic swine.Ten male Hanford swine utilized in a prior poly-trauma study were included in the study. Animals were rendered hypovolemic via a 30% volume bleed. Upon confirmation of death, animals underwent immediate clamshell thoracotomy and aortic cross-clamping followed by 5 min of OCM. A catheter suitable for OCSAAP was then inserted into the aorta and animals underwent 1 min of OCSAAP at a rate of 10 mL/kg/min. Aortic and right atrial pressures were recorded continuously using solid-state blood pressure catheters. Representative 10-s intervals from each resuscitation method were extracted. Hemodynamic parameters including AoP-RAP gradients and CPPs were calculated and compared.At baseline, time from death to intervention was significantly shorter for OCM. However, mean CPPs and AoP-RAP gradients were significantly higher in animals undergoing OCSAAP. 98% of OCSAAP segments had a mean CPP 15, compared to 35% of OCM intervals. While OCM had a significant negative correlation between time to intervention and maximum CPP, this correlation was not significant for OCSAAP.OCSAAP generates favorable and potentially time-resistant pressure gradients when compared to those generated by OCM. Further investigation of the technique of OCSAAP is warranted, as it may have potential utility as a therapy during resuscitative thoracotomy (RT).