Critical systolic blood pressure threshold for endovascular aortic occlusion-A multinational analysis to determine when to place a REBOA.

BACKGROUND: Systolic blood pressure (SBP) is a potential indicator that could guide when to use a resuscitative endovascular balloon occlusion of the aorta (REBOA) in trauma patients with life-threatening injuries. This study aims to determine the optimal SBP threshold for REBOA placement by analyzing the association between SBP pre-REBOA and 24-hour mortality in severely injured hemodynamically unstable trauma patients. METHODS: We performed a pooled analysis of the aortic balloon occlusion (ABO) trauma and AORTA registries. These databases record the details related to the use of REBOA and include data from 14 countries worldwide. We included patients who had suffered penetrating and/or blunt trauma. Patients who arrived at the hospital with a SBP pre-REBOA of 0 mm Hg and remained at 0 mm Hg after balloon inflation were excluded. We evaluated the impact that SBP pre-REBOA had on the probability of death in the first 24 hours. RESULTS: A total of 1,107 patients underwent endovascular aortic occlusion, of these, 848 met inclusion criteria. The median age was 44 years (interquartile range [IQR], 27-59 years) and 643 (76%) were male. The median injury severity score was 34 (IQR, 25-45). The median SBP pre-REBOA was 65 mm Hg (IQR, 49-88 mm Hg). Mortality at 24 hours was reported in 279 (32%) patients. Math modeling shows that predicted probabilities of the primary outcome increased steadily in SBP pre-REBOA below 100 mm Hg. Multivariable mixed-effects analysis shows that when SBP pre-REBOA was lower than 60 mm Hg, the risk of death was more than 50% (relative risk, 1.5; 95% confidence interval, 1.17-1.92; p = 0.001). DISCUSSION: In patients who do not respond to initial resuscitation, the use of REBOA in SBPs between 60 mm Hg and 80 mm Hg may be a useful tool in resuscitation efforts before further decompensation or complete cardiovascular collapse. The findings from our study are clinically important as a first step in identifying candidates for REBOA. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level IV.

Emergent vessel embolization for major traumatic and non-traumatic hemorrhage: Indications, tools and outcomes.

Endovascular embolization of bleeding vessels in trauma and non-trauma patients is frequently used and is an important tool for bleeding control. It is included in the EVTM (endovascular resuscitation and trauma management) concept and its use in patients with hemodynamic instability is increasing. When the correct embolization tool is chosen, a dedicated multidisciplinary team can rapidly and effectively achieve bleeding control. In this article, we will describe the current use and possibilities for embolization of major hemorrhage (traumatic and non-traumatic) and the published data supporting these techniques as part of the EVTM concept.

A 12-year experience of endovascular repair for ruptured abdominal aortic aneurysms in all patients.

OBJECTIVE: Endovascular aneurysm repair (EVAR) has been increasingly performed for ruptured abdominal aortic aneurysms (rAAAs). However, multiple randomized trials have failed to demonstrate a survival benefit compared with open aortic surgery. During a 12-year period, 100% of patients without a history of aneurysm surgery had undergone EVAR for a rAAA at Örebro University Hospital, with no emergent open aortic surgery performed. In the present study, we evaluated the mortality and technical success during this "EVAR-only" period. METHODS: A single-center, retrospective observational study was conducted. We identified all patients who had presented to Örebro University Hospital with a rAAA between October 2009 and September 2021. Patients with isolated iliac artery, thoracic, and thoracoabdominal aortic ruptures were not included. Patients who had received previous aortic interventions (open or endovascular) and patients who had received palliative treatment instead of surgical intervention were also excluded. The patient characteristics, perioperative and postoperative data, and mortality rate were investigated. RESULTS: EVAR had been performed in 100 patients. Preoperative hemodynamic instability had been present in 54 patients (54%), and 18 (18%) had undergone aortic balloon occlusion. The aneurysm location was infrarenal in 89 patients (89%). Bifurcated stent grafts had been used in 97 patients (97%), and adjunct endovascular techniques had been used for 27 patients (27%). Of 98 patients, EVAR had been performed with the patient under local anesthesia for 62 patients (63%). Peri- and postoperative complications at 30 days had occurred in 20 of 100 patients (20%) and 22 of 79 patients (28%), respectively. The overall mortality at 30 days was 27% (27 of 100 patients), and the mortality for those with an isolated infrarenal rAAA was 24% (21 of 89 patients). The overall mortality at 1 year was 39% (39 of 100 patients) and for those with an isolated infrarenal rAAA was 37% (33 of 89 patients). The presence of preoperative hemodynamic instability and the use of ABO were statistically significantly and independently associated with increased 30-day mortality on multivariate logistic regression analysis. CONCLUSIONS: All 100 patients who had undergone surgery for a rAAA had been treated using EVAR and endovascular adjuncts, with a relatively low mortality rate, thus continuing the "EVAR-only" approach. A low proportion of rAAA patients were considered surgically unsuitable. These findings support the applicability of EVAR for the treatment of all rAAAs at suitable centers.

Low profile REBOA device for increasing systolic blood pressure in hemodynamic instability: single-center 4-year experience of use of ER-REBOA.

BACKGROUND: Hemodynamic instability due to torso hemorrhage can be managed with the assistance of resuscitative endovascular balloon occlusion of the aorta (REBOA). This is a report of a single-center experience using the ER-REBOA™ catheter for traumatic and non-traumatic cases as an adjunct to hemorrhage control and as part of the EndoVascular resuscitation and Trauma Management (EVTM) concept. The objective of this report is to describe the clinical usage, technical success, results, complications and outcomes of the ER-REBOA™ catheter at Örebro University hospital, a middle-sized university hospital in Europe. METHODS: Data concerning patients receiving the ER-REBOA™ catheter for any type of hemorrhagic shock and hemodynamic instability at Örebro University hospital in Sweden were collected prospectively from October 2015 to May 2020. RESULTS: A total of 24 patients received the ER-REBOA™ catheter (with the intention to use) for traumatic and non-traumatic hemodynamic control; it was used in 22 patients. REBOA was performed or supervised by vascular surgeons using 7-8 Fr sheaths with an anatomic landmark or ultrasound guidance. Systolic blood pressure (SBP) increased significantly from 50 mmHg (0-63) to 95 mmHg (70-121) post REBOA. In this cohort, distal embolization and balloon rupture due to atherosclerosis were reported in one patient and two patients developed renal failure. There were no cases of balloon migration. Overall 30-day survival was 59%, with 45% for trauma patients and 73% for non-traumatic patients. Responders to REBOA had a significantly lower rate of mortality at both 24 h and 30 days. CONCLUSIONS: Our clinical data and experience show that the ER-REBOA™ catheter can be used for control of hemodynamic instability and to significantly increase SBP in both traumatic and non-traumatic cases, with relatively few complications. Responders to REBOA have a significantly lower rate of mortality.

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

BACKGROUND: The pre-hospital use of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is increasing, although it remains controversial, in part because of suggested contraindications such as acute cardiac tamponade (ACT). As both the pre-hospital and in-hospital use of REBOA might potentially occur with concurrent ACT, knowledge of the hemodynamic effect of REBOA in this setting is crucial. This study, therefore, aimed at investigating the physiological effects of REBOA in hemodynamic instability secondary to ACT in a porcine model. We hypothesize that REBOA can temporarily increase systemic blood pressure and carotid blood flow, and prolong survival, in hemodynamic shock caused by ACT. METHODS: Fourteen pigs (24-38 kg) underwent ACT, through true cardiac injury and hemorrhage into the pericardial space, and were allowed to hemodynamically deteriorate. At a systolic blood pressure (SBP) of 50 mm Hg (SBP50) they were randomized to total occlusion REBOA in zone 1 or to a control group. Survival, hemodynamic parameters, carotid blood flow (CBF), femoral blood flow (FBF), cardiac output (CO), end-tidal CO2, and arterial blood gas parameters were analyzed. RESULTS: REBOA intervention was associated with a significant increase in SBP (50 mm Hg to 74 mm Hg, P = 0.016) and CBF (110 mL/min to 195 mL/min, P = 0.031), with no change in CO, compared to the control group. At 20 min after SBP50, the survival rate in the intervention group was 86% and in the control group 14%, with time to death being significantly longer in the intervention group. CONCLUSIONS: This randomized animal study demonstrates that REBOA can help provide hemodynamic stabilization and prolong survival in hemodynamic shock provoked by ACT. It is important to stress that our study does not change the fact that urgent pericardiocentesis or cardiac surgery is, and should remain, the standard optimal treatment for ACT.Level of evidence: Prospective, randomized, experimental animal study. Basic science study, therapeutic.

Resuscitative Endovascular Balloon Occlusion of Aaorta Use in Nontrauma Emergency General Surgery: A Multi-institutional Experience.

BACKGROUND: The aim of this study was to determine the current utilization patterns of resuscitative endovascular balloon occlusion of aorta (REBOA) for hemorrhage control in nontrauma patients. METHODS: Data on REBOA use in nontrauma emergency general surgery patients from six centers, 2014-2019, was pooled for analysis. We performed descriptive analyses using Fisher's exact, Student's t, chi-squared, or Mann-Whitney U tests as appropriate. RESULTS: Thirty-seven patients with acute hemorrhage from nontrauma sources were identified. REBOA placement was primarily performed by trauma attendings (20/37, 54%) and vascular attendings (13/37, 35%). In seven patients (19%), balloons were positioned prophylactically but never inflated. In 24 (65%) of 37 patients, REBOA was placed in the operating room. 28/37 balloons (76%) were advanced to zone 1, 8/37 (22%) were advanced to zone 3, and there was one REBOA use in the inferior vena cava. Most common indications were gastrointestinal and peripartum bleeding. In the 30 cases of balloon inflation, 24 of 30 (80%) resulted in improved hemodynamics. Eleven of 30 patients (37%) died before discharge. One patient developed a distal embolism, but there were no reports of limb loss. Twelve patients (40% of all REBOA inflations and 63% of survivors) were discharged to home. CONCLUSIONS: REBOA has been used in a range of acutely hemorrhaging emergency general surgery patients with low rates of access-related complications. Mortality is high in this patient population and further research is needed; however, appropriate patient selection and early use may improve survival in these life-threatening cases.

Pre-hospital CPR and early REBOA in trauma patients - results from the ABOTrauma Registry.

BACKGROUND: Severely injured trauma patients suffering from traumatic cardiac arrest (TCA) and requiring cardiopulmonary resuscitation (CPR) rarely survive. The role of resuscitative endovascular balloon occlusion of the aorta (REBOA) performed early after hospital admission in patients with TCA is not well-defined. As the use of REBOA increases, there is great interest in knowing if there is a survival benefit related to the early use of REBOA after TCA. Using data from the ABOTrauma Registry, we aimed to study the role of REBOA used early after hospital admission in trauma patients who required pre-hospital CPR. METHODS: Retrospective and prospective data on the use of REBOA were collected from the ABOTrauma Registry from 11 centers in seven countries globally between 2014 and 2019. In all patients with pre-hospital TCA, the predicted probability of survival, calculated with the Revised Injury Severity Classification II (RISC II), was compared with the observed survival rate. RESULTS: Of 213 patients in the ABOTrauma Registry, 26 patients (12.2%) who had received pre-hospital CPR were identified. The median (range) Injury Severity Score (ISS) was 45.5 (25-75). Fourteen patients (54%) had been admitted to the hospital with ongoing CPR. Nine patients (35%) died within the first 24 h, while seventeen patients (65%) survived post 24 h. The survival rate to hospital discharge was 27% (n = 7). The predicted mortality using the RISC II was 0.977 (25 out of 26). The observed mortality (19 out of 26) was significantly lower than the predicted mortality (p = 0.049). Patients not responding to REBOA were more likely to die. Only one (10%) out of 10 non-responders survived. The survival rate in the 16 patients responding to REBOA was 37.5% (n = 6). REBOA with a median (range) duration of 45 (8-70) minutes significantly increases blood pressure from the median (range) 56.5 (0-147) to 90 (0-200) mmHg. CONCLUSIONS: Mortality in patients suffering from TCA and receiving REBOA early after hospital admission is significantly lower than predicted by the RISC II. REBOA may improve survival after TCA. The use of REBOA in these patients should be further investigated.

Aortic balloon occlusion (REBOA) in pelvic ring injuries: preliminary results of the ABO Trauma Registry.

EndoVascular and Hybrid Trauma Management (EVTM) has been recently introduced in the treatment of severe pelvic ring injuries. This multimodal method of hemorrhage management counts on several strategies such as the REBOA (resuscitative endovascular balloon occlusion of the aorta). Few data exist on the use of REBOA in patients with a severely injured pelvic ring. The ABO (aortic balloon occlusion) Trauma Registry is designed to capture data for all trauma patients in hemorrhagic shock where management includes REBOA placement. Among all patients included in the ABO registry, 72 patients presented with severe pelvic injuries and were the population under exam. 66.7% were male. Mean and median ISS were respectively 43 and 41 (SD ± 13). Isolated pelvic injuries were observed in 12 patients (16.7%). Blunt trauma occurred in 68 patients (94.4%), penetrating in 2 (2.8%) and combined in 2 (2.8%). Type of injury: fall from height in 15 patients (23.1%), traffic accident in 49 patients (75.4%), and unspecified impact in 1 patient (1.5%). Femoral access was gained pre-hospital in 1 patient, in emergency room in 43, in operating room in 12 and in angio-suite in 16. REBOA was positioned in zone 1 in 59 patients (81,9%), in zone 2 in 1 (1,4%) and in zone 3 in 12 (16,7%). Aortic occlusion was partial/periodical in 35 patients (48,6%) and total occlusion in 37 patients (51,4%). REBOA associated morbidity rate: 11.1%. Overall mortality rate was 54.2% and early mortality rate (≤ 24 h) was 44.4%. In the univariate analysis, factors related to early mortality (≤ 24 h) are lower pH values (p = 0.03), higher base deficit (p = 0.021), longer INR (p = 0.012), minor increase in systolic blood pressure after the REBOA inflation (p = 0.03) and total aortic occlusion (p = 0.008). None of these values resulted significant in the multivariate analysis. In severe hemodynamically unstable pelvic trauma management, REBOA is a viable option when utilized in experienced centers as a bridge to other treatments; its use might be, however, accompanied with severe-to-lethal complications.

Metabolic Response to Claudication in Peripheral Arterial Disease: A Microdialysis Pilot Study.

OBJECTIVES: This is a pilot study, and the objective of the study was to investigate the possible uses of microdialysis in the calf muscle to assess the metabolic response to intermittent claudication (IC) and in addition evaluate the simultaneous systemic inflammatory reaction. METHODS: Dialysate and venous blood sampling was performed before, during and after walking on a treadmill to maximal tolerable claudication (controls 10 min) using 1 microdialysis catheter inserted in the gastrocnemius muscle, 1 subcutaneously in the pectoral region (as a reference), and a peripheral venous catheter. RESULTS: A total of 9 participants were recruited, 6 patients with IC and 3 healthy control subjects. At baseline, patients with IC and control subjects did not differ in metabolic findings (glucose, lactate, pyruvate, and glycerol) in the gastrocnemius muscle. Subcutaneous glucose concentration was higher in control subjects. After physical exertion, gastrocnemius and subcutaneous glycerol, lactate, and pyruvate concentrations increased in patients with IC. Plasma concentrations of tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), interleukin-1ß (IL-1ß), hepatocyte growth factor, and vascular endothelial growth factor were higher in IC subjects at baseline, and TNF-α, IL-6, and IL-18 increased after walking as did IL-6 and IL-1ß in control subjects. The muscle catheters did not show any signs of harm. CONCLUSIONS: Microdialysis can be used to study the ongoing metabolic response during walking and claudication. Our results suggest both an acute local and a systemic inflammatory reaction during development of claudication.