Consensus on resuscitative endovascular balloon occlusion of the Aorta: A first consensus paper using a Delphi method.

BACKGROUND: To further strengthen the evidence base on the use of Resuscitative Endovascular Balloon occlusion of the Aorta (REBOA) we performed a Delphi consensus. The aim of this paper is to establish consensus on the indications and contraindications for the use of REBOA in trauma and non-trauma patients based on the existing evidence and expertise. STUDY DESIGN: A literature review facilitated the design of a three-round Delphi questionnaire. Delphi panelists were identified by the investigators. Consensus was reached when at least 70% of the panelists responded to the survey and more than 70% of respondents reached agreement or disagreement. RESULTS: Panel members reached consensus on potential indications, contra-indications and settings for use of REBOA (excluding the pre hospital environment), physiological parameters for patient selection and indications for early femoral access. Panel members failed to reach consensus on the use of REBOA in patients in extremis (no pulse, no blood pressure) and the use of REBOA in patients with two major bleeding sites. CONCLUSIONS: Consensus was reached on indications, contra indications, physiological parameters for patient selection for REBOA and early femoral access. The panel did not reach consensus on the use of REBOA in patients in pre-hospital settings, patients in extremis (no pulse, no blood pressure) and in patients with 2 or more major bleeding sites. Further research should focus on the indications of REBOA in pre hospital settings, patients in near cardiac arrest and REBOA inflation times.

Vascular access training for REBOA placement: a feasibility study in a live tissue-simulator hybrid porcine model.

BACKGROUND: The use of resuscitative endovascular balloon occlusion of the aorta (REBOA) in patients with severe haemorrhagic shock is increasing. Obtaining vascular access is a necessary prerequisite for REBOA placement in these situations. METHODS: During the EVTM workshop (September 2017, Örebro, Sweden), 21 individuals participated in this study, 16 participants and five instructors. A formalised curriculum was constructed including basic anatomy of the femoral region and basic training in access materials for REBOA placement in zone 1. Key skills: (1) preparation of endovascular toolkit, (2) achieving vascular access in the model and (3) bleeding control with REBOA. Scoring ranged from 0 to 5 for non-anatomical skills. Identification of anatomical structures was either sufficient (score=1) or insufficient (score=0). Five consultants performed a second identical procedure as a post test. RESULTS: Consultants had significantly better overall technical skills in comparison with residents (p=0.005), while understanding of surgical anatomy showed no difference. Procedure times differed significantly (p<0.01), with residents having a median procedure time of 3 min and 24 s, consultants 2:33 and instructors 1:09. CONCLUSION: This comprehensive training model using a live tissue-simulator hybrid porcine model can be used for femoral access and REBOA placement training in medical personnel with different prior training levels. Higher levels of training are associated with faster procedure times. Further research in open and percutaneous access training is necessary to simulate real-life situations. This training method can be used in a multistep training programme, in combination with realistic moulage and perfused cadaver models.

Feasibility Study Vascular Access and REBOA Placement: From Zero to Hero.

BACKGROUND: Vascular access is a necessary prerequisite for REBOA placement in patients with severe hemorrhagic shock. METHODS: During an EVTM workshop, 10 Special Forces (SOF) medics, five combat nurses, four military nonsurgeon physicians, and four military surgeons participated in our training program. The military surgeons functioned as the control group. A formalized curriculum was constructed including basic anatomy and training in access materials for resuscitative endovascular balloon occlusion of the aorta (REBOA) placement. Key skills were (1) preparation of endovascular toolkit, (2) achieving vascular access in the model, and (3) bleeding control with REBOA. RESULTS: The baseline knowledge of anatomy for SOF medics was significantly less than that for nurses and physicians. Medics had a median time of 3:59 minutes to sheath insertion; nurses, 2:47; physicians, 2:34; and surgeons, 1:39. Military surgeons were significantly faster than medics and military nurses (ρ = .037 resp. 0.034). Medics had a median total time from start to REBOA inflation of 5:05 minutes; nurses, 4:06; military physicians, 3:36; and surgeons, 2:36. CONCLUSION: This study showed that a comprehensive theoretical and practical training program using a task training model can be used for percutaneous femoral access and REBOA placement training of military medical personnel without prior ultrasound or endovascular experience. Higher levels of training reduce procedure times.

A systematic review and meta-analysis of the use of resuscitative endovascular balloon occlusion of the aorta in the management of major exsanguination.

BACKGROUND: Circulatory collapse is a leading cause of mortality among traumatic major exsanguination and in ruptured aortic aneurysm patients. Approximately 40% of patients die before hemorrhage control is achieved. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an adjunct designed to sustain the circulation until definitive surgical or endovascular repair. A systematic review was conducted for the current clinical use of REBOA in patients with hemodynamic instability and to discuss its potential role in improving prehospital and in-hospital outcome. METHODS: Systematic review and meta-analysis (1900-2017) using MEDLINE, Cochrane, EMBASE, Web of Science and Central and Emcare using the keywords "aortic balloon occlusion", "aortic balloon tamponade", "REBOA", and "Resuscitative Endovascular Balloon Occlusion" in combination with hemorrhage control, hemorrhage, resuscitation, shock, ruptured abdominal or thoracic aorta, endovascular repair, and open repair. Original published studies on human subjects were considered. RESULTS: A total of 490 studies were identified; 89 met criteria for inclusion. Of the 1436 patients, overall reported mortality was 49.2% (613/1246) with significant differences (p < 0.001) between clinical indications. Hemodynamic shock was evident in 79.3%, values between clinical indications showed significant difference (p < 0.001). REBOA was favored as treatment in trauma patients in terms of mortality. Pooled analysis demonstrated an increase in mean systolic pressure by almost 50 mmHg following REBOA use. CONCLUSION: REBOA has been used in trauma patients and ruptured aortic aneurysm patients with improvement of hemodynamic parameters and outcomes for several decades. Formal, prospective study is warranted to clarify the role of this adjunct in all hemodynamic unstable patients.

The use of aortic balloon occlusion in traumatic shock: first report from the ABO trauma registry.

PURPOSE: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a technique for temporary stabilization of patients with non-compressible torso hemorrhage. This technique has been increasingly used worldwide during the past decade. Despite the good outcomes of translational studies, clinical studies are divided. The aim of this multicenter-international study was to capture REBOA-specific data and outcomes. METHODS: REBOA practicing centers were invited to join this online register, which was established in September 2014. REBOA cases were reported, both retrospective and prospective. Demographics, injury patterns, hemodynamic variables, REBOA-specific data, complications and 30-days mortality were reported. RESULTS: Ninety-six cases from 6 different countries were reported between 2011 and 2016. Mean age was 52 ± 22 years and 88% of the cases were blunt trauma with a median injury severity score (ISS) of 41 (IQR 29-50). In the majority of the cases, Zone I REBOA was used. Median systolic blood pressure before balloon inflation was 60 mmHg (IQR 40-80), which increased to 100 mmHg (IQR 80-128) after inflation. Continuous occlusion was applied in 52% of the patients, and 48% received non-continuous occlusion. Occlusion time longer than 60 min was reported as 38 and 14% in the non-continuous and continuous groups, respectively. Complications, such as extremity compartment syndrome (n = 3), were only noted in the continuous occlusion group. The 30-day mortality for non-continuous REBOA was 48%, and 64% for continuous occlusion. CONCLUSIONS: This observational multicenter study presents results regarding continuous and non-continuous REBOA with favorable outcomes. However, further prospective studies are needed to be able to draw conclusions on morbidity and mortality.

A small case series of aortic balloon occlusion in trauma: lessons learned from its use in ruptured abdominal aortic aneurysms and a brief review.

BACKGROUND: EndoVascular and Hybrid Trauma Management (EVTM) is an emerging concept for the early treatment of trauma patients using aortic balloon occlusion (ABO), embolization agents and stent grafts to stop ongoing traumatic bleeding. These techniques have previously been implemented successfully in the treatment of ruptured aortic aneurysm. AIMS: We describe our very recent experience of EVTM using ABO in bleeding patients and lessons learned over the last 20 years from the endovascular treatment of ruptured abdominal aortic aneurysms (rAAA). We also briefly describe current knowledge of ABO usage in trauma. METHODS: A small series of educational cases in our hospital is described, where endovascular techniques were used to gain temporary hemorrhage control. The methods used for rAAA and their applicability to EVTM with a multidisciplinary approach are presented. RESULTS: Establishing femoral arterial access immediately on arrival at the emergency room and use of an angiography table in the surgical suite may facilitate EVTM at an early stage. ABO may be an effective method for the temporary stabilization of severely hemodynamically unstable patients with hemorrhagic shock, and may be useful as a bridge to definitive treatment of the bleeding patients. CONCLUSION: EVTM, including the usage of ABO, can be initiated on patient arrival and is feasible. Further data need to be collected to investigate proper indications for ABO, best clinical usage, results and potential complications. Accordingly, the ABOTrauma Registry has recently been set up. Existing experiences of EVTM and lessons from the endovascular treatment of rAAA may be useful in trauma management.

Abdominal hypertension and decompression: the effect on peritoneal metabolism in an experimental porcine study.

OBJECTIVE: The aim of this study was to investigate the abdominal metabolic response and circulatory changes after decompression of intra-abdominal hypertension in a porcine model. METHODS: This was an experimental study with controls. Three-month-old domestic pigs of both sexes were anesthetized and ventilated. Nine animals had a pneumoperitoneum-induced IAH of 30 mmHg for 6 hours. Twelve animals had the same IAH for 4 hours followed by decompression, and were monitored for another 2 hours. Hemodynamics, including laser Doppler-measured mucosal blood flow, urine output, and arterial blood samples were analyzed every hour along with glucose, glycerol, lactate and pyruvate concentrations, and lactate-pyruvate (l/p) ratio, measured by microdialysis. RESULTS: Laser Doppler-measured mucosal blood flow and urine output decreased with the induction of IAH and showed a statistically significant resolution after decompression. Both groups developed distinct metabolic changes intraperitoneally on induction of IAH, including an increased l/p ratio, as signs of organ hypoperfusion. In the decompression group the intraperitoneal l/p ratio normalized during the second decompression hour, indicating partially restored perfusion. CONCLUSION: Decompression after 4 hours of IAH results in an improved intestinal blood flow and a normalized intraperitoneal l/p ratio.

Intra-peritoneal microdialysis and intra-abdominal pressure after endovascular repair of ruptured aortic aneurysms.

OBJECTIVES: This study aims to evaluate intra-peritoneal (ip) microdialysis after endovascular aortic repair (EVAR) of ruptured abdominal aortic aneurysm (rAAA) in patients developing intra-abdominal hypertension (IAH), requiring abdominal decompression. DESIGN: Prospective study. MATERIAL AND METHODS: A total of 16 patients with rAAA treated with an emergency EVAR were followed up hourly for intra-abdominal pressure (IAP), urine production and ip lactate, pyruvate, glycerol and glucose by microdialysis, analysed only at the end of the study. Abdominal decompression was performed on clinical criteria, and decompressed (D) and non-decompressed (ND) patients were compared. RESULTS: The ip lactate/pyruvate (l/p) ratio was higher in the D group than in the ND group during the first five postoperative hours (mean 20 vs. 12), p = 0.005 and at 1 h prior to decompression compared to the fifth hour in the ND group (24 vs. 13), p = 0.016. Glycerol levels were higher in the D group during the first postoperative hours (mean 274.6 vs. 121.7 µM), p = 0.022. The IAP was higher only at 1 h prior to decompression in the D group compared to the ND group at the fifth hour (mean 19 vs. 14 mmHg). CONCLUSIONS: Ip l/p ratio and glycerol levels are elevated immediately postoperatively in patients developing IAH leading to organ failure and subsequent abdominal decompression.