Endovascular Skills for Trauma and Resuscitative Surgery (ESTARS) course: curriculum development, content validation, and program assessment

Resuscitative Endovascular Balloon Occlusion of the Aorta Using a Low-Profile Device is Easy and Safe for Emergency Physicians in Cases of Life-Threatening Hemorrhage

BACKGROUND

Bleeding from hemorrhagic shock can be immediately controlled by blocking the proximal part of the hemorrhagic point using either resuscitative thoracotomy for aortic cross-clamping or insertion of a large-caliber (10-14Fr) resuscitative endovascular balloon occlusion of the aorta (REBOA) device via the femoral artery. However, such methods are very invasive and have various complications. With recent progress in endovascular treatment, a low-profile REBOA device (7Fr) has been developed.

OBJECTIVE

The objective of this study was to report our experience of this low-profile REBOA device and to evaluate the usefulness of emergency physician-operated REBOA in life-threatening hemorrhagic shock.

METHODS

Ten patients with refractory hemorrhagic shock underwent REBOA using this device via the femoral artery. All REBOA procedures were performed by emergency physicians. The success rate of the insertion, vital signs, and REBOA-related complications were evaluated.

RESULTS

Median age was 54 years (interquartile range 33-78 years). The causes of hemorrhagic shock were trauma (n = 4; 1 blunt and 3 penetrating), ruptured abdominal aortic aneurysm (n = 3), and obstetric hemorrhage (n = 3). Two patients had cardiopulmonary arrest upon arrival. REBOA procedure was successful in all patients, and all became hemodynamically stable to undergo definitive interventions after REBOA. There were no REBOA-related complications. The mortality rate within 24 h and 30 days was 40%.

CONCLUSIONS

This REBOA device was useful for emergency physicians in life-threatening hemorrhagic shock because of its ease in handling and low invasiveness.

The pitfalls of resuscitative endovascular balloon occlusion of the aorta: Risk factors and mitigation strategies

Despite technological advancements, REBOA is associated with significant risks due to complications of vascular access and ischemia-reperfusion. The inherent morbidity and mortality of REBOA is often compounded by coexisting injury and hemorrhagic shock. Additionally, the potential for REBOA-related injuries is exaggerated due to the growing number of interventions being performed by providers who have limited experience in endovascular techniques, inadequate resources, minimal training in the technique, and who are performing this maneuver in emergency situations. In an effort to ultimately improve outcomes with REBOA, we sought to compile a list of complications that may be encountered during REBOA usage. To address the current knowledge gap, we assembled a list of anecdotal complications from high-volume REBOA users internationally. More importantly, through a consensus model, we identify contributory factors that may lead to complications and deliberate on how to recognize, mitigate, and manage such events. An understanding of the pitfalls of REBOA and strategies to mitigate their occurrence is of vital importance to optimize patient outcomes.

Resuscitative Endovascular Balloon Occlusion of the Aorta: Principles, Initial Clinical Experience, and Considerations for the Anesthesiologist

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an endovascular technique that allows for temporary occlusion of the aorta in patients with severe, life-threatening, trauma-induced noncompressible hemorrhage arising below the diaphragm. REBOA utilizes a transfemoral balloon catheter inserted in a retrograde fashion into the aorta to provide inflow control and support blood pressure until definitive hemostasis can be achieved. Initial retrospective and registry clinical data in the trauma surgical literature demonstrate improvement in systolic blood pressure with balloon inflation and improved survival compared to open aortic cross-clamping via resuscitative thoracotomy. However, there are no significant reports of anesthetic implications and perioperative management in this challenging cohort. In this narrative, we review the principles, technique, and logistics of REBOA deployment, as well as initial clinical outcome data from our level-1 American College of Surgeons-verified trauma center. For anesthesiologists who may not yet be familiar with REBOA, we make several suggestions and recommendations for intraoperative management based on extrapolation from these initial surgical-based reports, opinions from a team with increasing experience, and translated experience from emergency aortic vascular surgical procedures. Further prospective data will be necessary to conclusively guide anesthetic management, especially as potential complications and implications for global organ function, including cerebral and renal, are recognized and described.

Fewer REBOA complications with smaller devices and partial occlusion: evidence from a multicentre registry in Japan

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) performed by emergency physicians has been gaining acceptance as a less invasive technique than resuscitative thoracotomy.

OBJECTIVE

To evaluate access-related complications and duration of occlusions during REBOA.

METHODS

Patients with haemorrhagic shock requiring REBOA, from 18 hospitals in Japan, included in the DIRECT-IABO Registry were studied. REBOA-related characteristics were compared between non-survivors and survivors at 24 hours. 24-Hour survivors were categorised into groups with small (≤8 Fr), large (≥9 Fr) or unusual sheaths (oversized or multiple) to assess the relationship between the sheath size and complications. Haemodynamic response, occlusion duration and outcomes were compared between groups with partial and complete REBOA.

RESULTS

Between August 2011 and December 2015, 142 adults undergoing REBOA were analysed. REBOA procedures were predominantly (94%) performed by emergency medicine (EM) physicians. The median duration of the small sheath (n=53) was 19 hours compared with 7.5 hours for the larger sheaths (P=0.025). Smaller sheaths were more likely to be removed using external manual compression (96% vs 45%, P<0.001). One case of a common femoral artery thrombus (large group) and two cases of amputation (unusual group) were identified. Partial REBOA was carried out in more cases (n=78) and resulted in a better haemodynamic response than complete REBOA (improvement in haemodynamics, 92% vs 70%, P=0.004; achievement of stability, 78% vs 51%, P=0.007) and allowed longer occlusion duration (median 58 vs 33 min, P=0.041). No statistically significant difference in 24-hour or 30-day survival was found between partial and complete REBOA.

CONCLUSION

In Japan, EM physicians undertake the majority of REBOA procedures. Smaller sheaths appear to have fewer complications despite relatively prolonged placement and require external compression on removal. Although REBOA is a rarely performed procedure, partial REBOA, which may extend the occlusion duration without a reduction in survival, is used more commonly in Japan.

Field and en route resuscitative endovascular occlusion of the aorta: A feasible military reality?

BACKGROUND

Severe noncompressible torso hemorrhage remains a leading cause of potentially preventable death in modern military conflicts. Resuscitative endovascular occlusion of the aorta (REBOA) has demonstrated potential as an effective adjunct to the treatment of noncompressible torso hemorrhage in the civilian early hospital and even prehospital settings-but the application of this technology for military prehospital use has not been well described. We aimed to assess the feasibility of both field and en route prehospital REBOA in the military exercise setting, simulating a modern armed conflict.

METHODS

Two adult male Sus Scrofa underwent simulated junctional combat injury in the context of a planned military training exercise. Both underwent zone I REBOA in conjunction with standard tactical combat casualty care interventions-one during point of injury care and the other during en route flight care. Animals were sequentially evacuated to two separate forward surgical teams by rotary wing platform where the balloon position was confirmed by chest x-ray. Animals then underwent different damage control thoracic and abdominal procedures before euthanasia.

RESULTS

The first swine underwent immediate successful REBOA at the point of injury 7 minutes and 30 seconds after the injury. It required 6 minutes total from initiation of procedure to effective aortic occlusion. Total occlusion time was 60 minutes. In the second animal, the REBOA placement procedure was initiated immediately after take off (17 minutes and 40 seconds after the injury). Although the movements and vibration of flight were not significant impediments, we only succeeded to put a 6-French (Fr) sheath into a femoral artery during the 14 minutes flight due to lighting and visualization challenges. After the sheath had been upsized in the forward surgical team, the REBOA catheter was primarily placed in zone I followed by its replacement to zone III. Both animals survived to study completion and the termination of training. No complications were observed in either animal.

CONCLUSION

Our study demonstrates the potential feasibility of REBOA for use during tactical field and en route (flight) care of combat casualties. Further study is needed to determine the optimal training and utilization protocols required to facilitate the effective incorporation of REBOA into military prehospital care capabilities.

Incremental balloon deflation following complete resuscitative endovascular balloon occlusion of the aorta results in steep inflection of flow and rapid reperfusion in a large animal model of hemorrhagic shock

INTRODUCTION

To avoid potential cardiovascular collapse after resuscitative endovascular balloon occlusion of the aorta (REBOA), current guidelines recommend methodically deflating the balloon for 5 minutes to gradually reperfuse distal tissue beds. However, anecdotal evidence suggests that this approach may still result in unpredictable aortic flow rates and hemodynamic instability. We sought to characterize aortic flow dynamics following REBOA as the balloon is deflated in accordance with current practice guidelines.

METHODS

Eight Yorkshire-cross swine were splenectomized, instrumented, and subjected to rapid 25% total blood volume hemorrhage. After 30 minutes of shock, animals received 60 minutes of Zone 1 REBOA with a low-profile REBOA catheter. During subsequent resuscitation with shed blood, the aortic occlusion balloon was gradually deflated in stepwise fashion at the rate of 0.5 mL every 30 seconds until completely deflated. Aortic flow rate and proximal mean arterial pressure (MAP) were measured continuously over the period of balloon deflation.

RESULTS

Graded balloon deflation resulted in variable initial return of aortic flow (median, 78 seconds; interquartile range [IQR], 68-105 seconds). A rapid increase in aortic flow during a single-balloon deflation step was observed in all animals (median, 819 mL/min; IQR, 664-1241 mL/min) and corresponded with an immediate decrease in proximal MAP (median, 30 mm Hg; IQR, 14.5-37 mm Hg). Total balloon volume and time to return of flow demonstrated no correlation (r = 0.016).

CONCLUSION

This study is the first to characterize aortic flow during balloon deflation following REBOA. A steep inflection point occurs during balloon deflation that results in an abrupt increase in aortic flow and a concomitant decrease in MAP. Furthermore, the onset of distal aortic flow was inconsistent across study animals and did not correlate with initial balloon volume or relative deflation volume. Future studies to define the factors that affect aortic flow during balloon deflation are needed to facilitate controlled reperfusion following REBOA.

A meta-analysis of resuscitative endovascular balloon occlusion of the aorta (REBOA) or open aortic cross-clamping by resuscitative thoracotomy in non-compressible torso hemorrhage patients

Background

The objective of this systematic review and meta-analysis was to determine the effect of REBOA, compared to resuscitative thoracotomy, on mortality and among non-compressible torso hemorrhage trauma patients.

Methods

Relevant articles were identified by a literature search in MEDLINE and EMBASE. We included studies involving trauma patients suffering non-compressible torso hemorrhage. Studies were eligible if they evaluated REBOA and compared it to resuscitative thoracotomy. Two investigators independently assessed articles for inclusion and exclusion criteria and selected studies for final analysis. We conducted meta-analysis using random effect models.

Results

We included three studies in our systematic review. These studies included a total of 1276 patients. An initial analysis found that although lower in REBOA-treated patients, the odds of mortality did not differ between the compared groups (OR 0.42; 95% CI 0.17–1.03). Sensitivity analysis showed that the risk of mortality was significantly lower among patients who underwent REBOA, compared to those who underwent resuscitative thoracotomy (RT) (RR 0.81; 95% CI 0.68–0.97).

Conclusion

Our meta-analysis, mainly from observational data, suggests a positive effect of REBOA on mortality among non-compressible torso hemorrhage patients. However, these results deserve further investigation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13017-017-0142-5) contains supplementary material, which is available to authorized users.

Smaller introducer sheaths for REBOA may be associated with fewer complications

INTRODUCTION

Large arterial sheaths currently used for resuscitative endovascular balloon occlusion of the aorta (REBOA) may be associated with severe complications. Smaller diameter catheters compatible with 7Fr sheaths may improve the safety profile.

METHODS

A retrospective review of patients receiving REBOA through a 7Fr sheath for refractory traumatic hemorrhagic shock was performed from January 2014 to June 2015 at five tertiary-care hospitals in Japan. Demographics were collected including method of arterial access; outcomes included mortality and REBOA-related access complications.

RESULTS

Thirty-three patients underwent REBOA at Zone 1 (level of the diaphragm). Most patients were male (70%), with a mean age (+SD) 50 ± 18 years, mean BMI 23 ± 4, and a median [IQR] ISS of 38 [34, 52]. Ninety-four percent of patients presented after sustaining injuries from blunt mechanisms. Twenty-four percent underwent CPR before arrival, and an additional 15% received CPR after admission. Percutaneous arterial access without ultrasound or fluoroscopy was achieved in all patients. Systolic blood pressure increased significantly following balloon occlusion (mean 62 ± 36 to 106 ± 40 mm Hg, p < 0.001). Median total duration of complete initial occlusion was 26 [range 10-35] minutes. Sixteen patients (49%) survived beyond 24 hours, and 14 patients (42%) survived beyond 30 days. Twenty-four-hour and 30-day survival were 48% and 42%, respectively. Of the patients surviving 24 hours (n = 16), median duration of sheath placement was 28 [range 18-45] hours with all removed using manual pressure to achieve hemostasis. Of 33 REBOAs, 20 were performed by Emergency Medicine practitioners, 10 by Emergency Medicine practitioners with endovascular training, and 3 by Interventional Radiologists. No complication related to sheath insertion or removal was identified during the follow-up period, including dissection, pseudoaneurysm, retroperitoneal hematoma, leg ischemia, or distal embolism.

CONCLUSIONS

7Fr REBOA catheters can significantly elevate systolic blood pressure with no access-related complications. Our results suggest that a 7Fr introducer device for REBOA may be a safe and effective alternative to large-bore sheaths, and may remain in place during the post-procedure resuscitative phase without sequelae.

LEVEL OF EVIDENCE

Therapeutic/care management, level V.

Design of a cost-effective, hemodynamically adjustable model for resuscitative endovascular balloon occlusion of the aorta (REBOA) simulation

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an adjunct technique for salvaging patients with noncompressible torso hemorrhage. Current REBOA training paradigms require large animals, virtual reality simulators, or human cadavers for acquisition of skills. These training strategies are expensive and resource intensive, which may prevent widespread dissemination of REBOA. We have developed a low-cost, near-physiologic, pulsatile REBOA simulator by connecting an anatomic vascular circuit constructed out of latex and polyvinyl chloride tubing to a commercially available pump. This pulsatile simulator is capable of generating cardiac outputs ranging from 1.7 to 6.8 L/min with corresponding arterial blood pressures of 54 to 226/14 to 121 mmHg. The simulator accommodates a 12 French introducer sheath and a CODA balloon catheter. Upon balloon inflation, the arterial waveform distal to the occlusion flattens, distal pulsation within the simulator is lost, and systolic blood pressures proximal to the balloon catheter increase by up to 62 mmHg. Further development and validation of this simulator will allow for refinement, reduction, and replacement of large animal models, costly virtual reality simulators, and perfused cadavers for training purposes. This will ultimately facilitate the low-cost, high-fidelity REBOA simulation needed for the widespread dissemination of this life-saving technique.

The AAST prospective Aortic Occlusion for Resuscitation in Trauma and Acute Care Surgery (AORTA) registry: Data on contemporary utilization and outcomes of aortic occlusion and resuscitative balloon occlusion of the aorta (REBOA)

INTRODUCTION

Aortic occlusion (AO) for resuscitation in traumatic shock remains controversial. Resuscitative endovascular balloon occlusion of the aorta (REBOA) offers an emerging alternative.

METHODS

The American Association for the Surgery of Trauma Aortic Occlusion for Resuscitation in Trauma and Acute Care Surgery registry prospectively identified trauma patients requiring AO from eight ACS Level 1 centers. Presentation, intervention, and outcome variables were collected and analyzed to compare REBOA and open AO.

RESULTS

From November 2013 to February 2015, 114 AO patients were captured (REBOA, 46; open AO, 68); 80.7% were male, and 62.3% were blunt injured. Aortic occlusion occurred in the emergency department (73.7%) or the operating room (26.3%). Hemodynamic improvement after AO was observed in 62.3% [REBOA, 67.4%; open OA, 61.8%); 36.0% achieving stability (systolic blood pressure consistently >90 mm Hg, >5 minutes); REBOA, 22 of 46 (47.8%); open OA, 19 of 68 (27.9%); p =0.014]. Resuscitative endovascular balloon occlusion of the aorta (REBOA) access was femoral cut-down (50%); US guided (10.9%) and percutaneous without imaging (28.3%). Deployment was achieved in Zones I (78.6%), II (2.4%), and III (19.0%). A second AO attempt was required in 9.6% [REBOA, 2 of 46 (4.3%); open OA, 9 of 68 (13.2%)]. Complications of REBOA were uncommon (pseudoaneurysm, 2.1%; embolism, 4.3%; limb ischemia, 0%). There was no difference in time to successful AO between REBOA and open procedures (REBOA, 6.6 ± 5.6 minutes; open OA, 7.2 ± 15.1; p = 0.842). Overall survival was 21.1% (24 of 114), with no significant difference between REBOA and open AO with regard to mortality [REBOA, 28.2% (13 of 46); open OA, 16.1% (11 of 68); p = 0.120].

CONCLUSION

Resuscitative endovascular balloon occlusion of the aorta has emerged as a viable alternative to open AO in centers that have developed this capability. Further maturation of the American Association for the Surgery of Trauma Aortic Occlusion for Resuscitation in Trauma and Acute Care Surgery database is required to better elucidate optimal indications and outcomes.

LEVEL OF EVIDENCE

Therapeutic/care management study, level IV.

Resuscitative Endovascular Balloon Occlusion of the Aorta: Indications, Outcomes, and Training

Exsanguinating torso hemorrhage is a leading killer of trauma patients. The most appropriate means of hemorrhage control must be used. Trauma surgeons should have expertise with all approaches for prompt hemorrhage control [laparotomy, thoracotomy, resuscitative endovascular balloon occlusion of the aorta (REBOA), and resuscitative thoracotomy]. REBOA is an exciting adjunct for hemorrhage control as it can be deployed quickly and placed percutaneously. Balloon inflation can vary dependent on patient physiology. REBOA is effective in hemorrhagic shock as a bridge to definitive hemostasis. Endovascular training is important for trauma surgeons caring for patients at high risk of death from traumatic hemorrhage.

The role of resuscitative endovascular balloon occlusion of the aorta (REBOA) as an adjunct to ACLS in non-traumatic cardiac arrest

Non-traumatic cardiac arrest is a major public health problem that carries an extremely high mortality rate. If we hope to increase the survivability of this condition, it is imperative that alternative methods of treatment are given due consideration. Balloon occlusion of the aorta can be used as a method of circulatory support in the critically ill patient. Intra-aortic balloon pumps have been used to temporize patients in cardiogenic shock for decades. More recently, resuscitative endovascular balloon occlusion of the aorta (REBOA) has been utilized in the patient in hemorrhagic shock or cardiac arrest secondary to trauma. Aortic occlusion in non-traumatic cardiac arrest has the effect of reducing the vascular volume that the generated cardiac output is distributed across. This augments myocardial and cerebral perfusion, increasing the probability of a return to a good quality of life for the patient. This phenomenon has been the subject of numerous animal studies dating back to the early 1980s; however, the human evidence is limited to several small case series. Animal research has demonstrated improvements in cerebral and coronary perfusion pressure during ACLS that lead to statistically significant differences in mortality. Several case series in humans have replicated these findings, suggesting the efficacy of this procedure. The objectives of this review are to: 1) introduce the reader to REBOA 2) review the physiology of NTCA and examine the current limitations of traditional ACLS 3) summarize the literature regarding the efficacy and feasibility of aortic balloon occlusion to support traditional ACLS.

Resuscitative endovascular balloon occlusion of the aorta for control of noncompressible truncal hemorrhage in the abdomen and pelvis

BACKGROUND

Noncompressible truncal hemorrhage is a leading cause of potentially preventable death in trauma and acute care surgery patients. These patients are at high risk of exsanguination before potentially life-saving surgical intervention may be performed. Temporary aortic occlusion is an effective means of augmenting systolic blood pressure and perfusion of the heart and brain in these patients. Aortic occlusion temporarily controls distal bleeding until permanent hemostasis can be achieved. The traditional method for temporary aortic occlusion is via resuscitative thoracotomy with cross clamping of the descending aorta. While effective, resuscitative thoracotomy is highly invasive and may worsen blood loss, hypothermia, and coagulopathy by opening an otherwise uninjured body cavity. Resuscitative endovascular balloon occlusion of the aorta (REBOA) achieves temporary aortic occlusion using an occlusive balloon catheter that is introduced into the aorta via endovascular access of the common femoral artery. For this reason it is thought that REBOA could provide a less-invasive method for temporary aortic occlusion. Our purpose is to describe our experience with the implementation of REBOA at our Level 1 trauma center.

METHODS

A retrospective case series describing all cases of REBOA performed at a prominent level 1 trauma center between October 2011 and September 2015. The study inclusion criteria were any patient that received a REBOA procedure in the acute phases after injury. There were no exclusion criteria. Data were collected from electronic medical records and the hospital's trauma registry.

RESULTS

A total of 31 patients underwent REBOA during the study period. The median age of REBOA patients was 47 (interquartile range [IQR] = 27 to 63) and 77% were male. A majority (87%) of patients sustained blunt trauma. The median injury severity score was 34 (IQR = 22 to 42). The overall survival rate was 32% but varied greatly between subgroups. Balloon inflation resulted in a median increase in systolic blood pressure of 55-mm Hg (IQR 33 to 60), in cases where the data were available (n = 20). A return to spontaneous circulation was noted in 60% of patients who had arrested before REBOA (n = 10). Overall, early death by hemorrhage was 28% with only 2 deaths in the emergency department before reaching the operating room.

CONCLUSIONS

REBOA is an effective method for achieving temporary aortic occlusion in trauma patients with noncompressible truncal hemorrhage. Balloon inflation correlated with increased blood pressure and temporary hemorrhage control in a vast majority of patients.

Resuscitative endovascular balloon occlusion of the aorta (REBOA): a population based gap analysis of trauma patients in England and Wales

Introduction

Non-compressible torso haemorrhage (NCTH) carries a high mortality in trauma as many patients exsanguinate prior to definitive haemorrhage control. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an adjunct that has the potential to bridge patients to definitive haemostasis. However, the proportion of trauma patients in whom REBOA may be utilised is unknown.

Methods

We conducted a population based analysis of 2012–2013 Trauma Audit and Research Network (TARN) data. We identified the number of patients in whom REBOA may have been utilised, defined by an Abbreviated Injury Scale score ≥3 to abdominal solid organs, abdominal or pelvic vasculature, pelvic fracture with ring disruption or proximal traumatic lower limb amputation, together with a systolic blood pressure <90 mm Hg. Patients with non-compressible haemorrhage in the mediastinum, axilla, face or neck were excluded.

Results

During 2012–2013, 72 677 adult trauma patients admitted to hospitals in England and Wales were identified. 397 patients had an indication(s) and no contraindications for REBOA with evidence of haemorrhagic shock: 69% men, median age 43 years and median Injury Severity Score 32. Overall mortality was 32%. Major trauma centres (MTCs) received the highest concentration of potential REBOA patients, and would be anticipated to receive a patient in whom REBOA may be utilised every 95 days, increasing to every 46 days in the 10 MTCs with the highest attendance of this injury type.

Conclusions

This TARN database analysis has identified a small group of severely injured, resource intensive patients with a highly lethal injury that is theoretically amenable to REBOA. The highest density of these patients is seen at MTCs, and as such a planned evaluation of REBOA should be further considered in these hospitals.

Resuscitative endovascular balloon occlusion of the aorta might be dangerous in patients with severe torso trauma: A propensity score analysis

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a key procedure in early trauma care that provides hemorrhage control in hemodynamically unstable torso trauma patients. However, the clinical efficacy of REBOA remains uncertain. The objective of this study was to estimate the efficacy of REBOA in surgically treated severe torso trauma patients.

METHODS

We obtained data from the nationwide trauma registry in Japan (the Japan Trauma Data Bank) for trauma subjects who had undergone emergency surgery or transcatheter embolization against torso trauma. A logistic regression analysis estimated a propensity score to predict REBOA use from available predictors of in-hospital mortality. We then used a propensity score matching analysis to compare in-hospital mortality and door-to-primary surgery time in subjects who underwent REBOA and those who did not. In addition, we used an instrumental variable method to adjust for unmeasured confounding variables as a sensitivity analysis.

RESULTS

Overall, 12,053 of the 183,457 trauma patients registered in the Japan Trauma Data Bank were eligible based on selection criteria. Propensity score matching selected 625 patients each for the with-REBOA and without-REBOA groups. The in-hospital mortality was significantly higher in subjects who underwent REBOA (61.8% vs. 45.3%; absolute difference, +16.5%; 95% confident interval, +10.9% to +22.0%). Door-to-primary surgery time was shorter in subjects who underwent REBOA than in those who did not (97 minutes vs. 110 minutes; absolute difference, -14 minutes; 95% confidence interval, -25 minutes to -3 minutes). The sensitivity analysis with the instrumental variable method did not alter the results and estimated nonsignificantly higher in-hospital mortality in REBOA subjects (+16.4%; 95% confidence interval, -0.6% to 33.3%).

CONCLUSION

This study showed an association between the use of REBOA and excess mortality in patients with hemodynamically unstable torso trauma that had a median door-to-primary surgery time of 97 minutes. Further observational studies with detailed REBOA data are necessary to assess whether selected trauma subgroups could benefit from REBOA.

LEVEL OF EVIDENCE

Therapeutic study, level III.

Partial Resuscitative Endovascular Balloon Occlusion of the Aorta in Swine Model of Hemorrhagic Shock

BACKGROUND

Complete resuscitative endovascular balloon occlusion of the aorta (C-REBOA) increases proximal mean arterial pressure (MAP) at the cost of distal organ ischemia, limiting the duration of intervention. We hypothesized that partial aortic occlusion (P-REBOA) would maintain a more physiologic proximal MAP and reduce distal tissue ischemia. We investigated the hemodynamic and physiologic effects of P-REBOA vs C-REBOA.

STUDY DESIGN

Fifteen swine were anesthetized, instrumented, splenectomized, and subjected to rapid 25% blood volume loss. They were randomized to C-REBOA, P-REBOA, or no intervention (controls). Partial REBOA was created by partially inflating an aortic balloon catheter to generate a 50% blood pressure gradient across the balloon. Hemodynamics were recorded and serum makers of ischemia and inflammation were measured. After 90 minutes of treatment, balloons were deflated to evaluate the immediate effects of reperfusion. End organs were histologically examined.

RESULTS

Complete REBOA produced supraphysiologic increases in proximal MAP after hemorrhage compared with more modest augmentation in the P-REBOA group (p < 0.01), with both groups significantly greater than controls (p < 0.01). Less rebound hypotension after balloon deflation was seen in the P-REBOA compared with C-REBOA groups. Complete REBOA resulted in higher serum lactate than both P-REBOA and controls (p < 0.01). Histology revealed early necrosis and disruption of duodenal mucosa in all C-REBOA animals, but none in P-REBOA animals.

CONCLUSIONS

In a porcine hemorrhagic shock model, P-REBOA resulted in more physiologically tolerable hemodynamic and ischemic changes compared with C-REBOA. Additional work is needed to determine whether the benefits associated with P-REBOA can both extend the duration of intervention and increase survival.

Implementation of resuscitative endovascular balloon occlusion of the aorta as an alternative to resuscitative thoracotomy for noncompressible truncal hemorrhage

BACKGROUND

Hemorrhage remains the leading cause of death in trauma patients. Proximal aortic occlusion, usually performed by direct aortic cross-clamping via thoracotomy, can provide temporary hemodynamic stability, permitting definitive injury repair. Resuscitative endovascular balloon occlusion of the aorta (REBOA) uses a minimally invasive, transfemoral balloon catheter, which is rapidly inserted retrograde and inflated for aortic occlusion, and may control inflow and allow time for hemostasis. We compared resuscitative thoracotomy with aortic cross-clamping (RT) with REBOA in trauma patients in profound hemorrhagic shock.

METHODS

Trauma registry data was used to compare all patients undergoing RT or REBOA during an 18-month period from two Level 1 trauma centers.

RESULTS

There was no difference between RT (n = 72) and REBOA groups (n = 24) in terms of demographics, mechanism of injury, or Injury Severity Scores (ISSs). There was no difference in chest and abdominal Abbreviated Injury Scale (AIS) scores between the groups. However, the RT patients had lower extremity AIS score as compared with REBOA patients (1.5 [0-3] vs. 4 [3-4], p < 0.001). Of the 72 RT patients, 45 (62.5%) died in the emergency department, 6 (8.3%) died in the operating room, and 14 (19.4%) died in the intensive care unit. Of the 24 REBOA patients, 4 (16.6%) died in the emergency department, 3 (12.5%) died in the operating room, and 8 (33.3%) died in the intensive care unit. In comparing location of death between the RT and REBOA groups, there were a significantly higher number of deaths in the emergency department among the RT patients as compared with the REBOA patients (62.5% vs. 16.7%, p < 0.001). REBOA had fewer early deaths and improved overall survival as compared with RT (37.5% vs. 9.7%, p = 0.003).

CONCLUSION

REBOA is feasible and controls noncompressible truncal hemorrhage in trauma patients in profound shock. Patients undergoing REBOA have improved overall survival and fewer early deaths as compared with patients undergoing RT.

LEVEL OF EVIDENCE

Therapeutic study, level IV.

Evidence for Endovascular Simulation Training: A Systematic Review

BACKGROUND

Simulation training in endovascular surgery provides opportunities for trainees to practice and learn from non-patient based experience. Several types of endovascular simulators are available commercially. Previous studies on endovascular simulation training can be categorized into trials in which only a simulator was used when measuring performance metrics or "trials within simulation"; patient specific procedure rehearsals; and randomized, controlled trials (RCTs) or translational studies.

OBJECTIVES

To examine whether endovascular simulation training can improve surgeon techniques and patient outcomes in real clinical settings.

METHODS

A literature review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. All searches were done via PubMed and Embase. Review articles, and papers that were not related to endovascular surgery and not within the scope of interest were excluded. References of review articles were further screened according to the exclusion criteria.

RESULTS

In total, 909 records were identified and 290 duplicates were removed. Thirty-one were included in the qualitative analysis. Twenty-three were trials within simulation and most of them found statistically significant improvements in procedure time, fluoroscopy time, and contrast volume. Five were patient specific procedure rehearsals and showed that simulation significantly affected the fluoroscopy angle and improved performance metrics. Three were RCTs and revealed mainly positive results on a Global Rating Scale and procedure specific rating scale.

CONCLUSIONS

Contemporary evidence shows that performance metrics within endovascular simulations improve with simulation training. Successful translation to in vivo situations is observed in patient specific procedure rehearsals and RCTs on real procedures. However, there is no level I evidence to show that predictive validity of simulation can definitively improve patient outcomes. Current literature supports the idea that there is a beneficial role of simulation in endovascular training. Future studies are needed to confirm the efficacy of simulation in endovascular surgical training and to see if simulation is superior to traditional training in the operating theatre.

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.

Resuscitative endovascular balloon occlusion of the aorta

The management of non-compressible torso hemorrhage can be problematic. Current therapy requires either open or interventional radiologic control of bleeding vessels and/or organs. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a new tool to stabilize patients in shock by achieving temporary inflow occlusion of non-compressible torso hemorrhage. This proactive technique represents a paradigm shift in achieving hemodynamic stability in patients as a bridge to definitive hemostasis. REBOA is applicable by trauma professionals, including emergency physicians, at the bedside in the emergency department, but its use needs to be considered within the context of available evidence and a robust system encompassing training, accreditation, multidisciplinary involvement and quality assurance. We review the evolving role of REBOA and discuss unanswered questions and future applications.

Survival of severe blunt trauma patients treated with resuscitative endovascular balloon occlusion of the aorta compared with propensity score-adjusted untreated patients

BACKGROUND

Despite a growing call for use of resuscitative endovascular balloon occlusion of the aorta (REBOA) for critically uncontrolled hemorrhagic shock, there is limited evidence of treatment efficacy. We compared the mortality between patients who received a REBOA with those who did not, adjusting for the likelihood of treatment and injury severity, to measure efficacy.

METHODS

We analyzed observational prospective data from the Japan Trauma Data Bank (2004-2011) to compare the mortality between adult patients who received a REBOA with those who did not. To adjust for potential treatment bias, we calculated the likelihood of REBOA treatment via a propensity score (PS) using available pretreatment variables (vital signs, age, sex, as well as anatomic and physiologic injury severity) and matched treated patients to up to five similar PS untreated patients. We compared survival to discharge between treated and untreated groups using conditional logistic regression and Cox proportional hazards regression.

RESULTS

Of 45,153 patients who met inclusion, 452 patients (1.0%) received REBOA placement. These patients were seriously injured (median Injury Severity Score [ISS], 35) and had high mortality (76%). Patients who did not receive a REBOA had significantly lower injury severity (median ISS, 13; p < 0.0001) and lower mortality (16%). After matching REBOA patients with controls with similar PSs for treatment, the crude conditional odds ratio of survival by REBOA treatment was 0.30 (95% confidence interval, 0.23-0.40).

CONCLUSION

REBOA treatment is associated with higher mortality compared with similarly ill trauma patients who did not receive a REBOA. The higher observed mortality among REBOA-treated patients may signal "last ditch" efforts for severity not otherwise identified in the trauma registry.

LEVEL OF EVIDENCE

Epidemiologic study, level III; therapeutic study, level IV.

The use of resuscitative endovascular balloon occlusion of the aorta to control hemorrhagic shock during video-assisted retroperitoneal debridement or infected necrotizing pancreatitis

INTRODUCTION

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a technique that has been shown to provide central vascular control to support proximal aortic pressure and minimize hemorrhage in a wide variety of clinic settings, however the role of REBOA for emergency general surgery is less defined.

CASE DESCRIPTION

This is a report of a 44 year old man who experienced hemorrhagic shock during video-assisted retroperitoneal debridement (VARD) for necrotizing pancreatitis where REBOA was used to prevent ongoing hemorrhage and death.

DISCUSSION

This is the first documented report REBOA being used during pancreatic debridement in the literature and one of the first times it has been used in emergency general surgery. The use of REBOA is an option for those in hemorrhagic shock whom conventional aortic cross-clamping or supra-celiac aortic exposure is either not possible or exceedingly dangerous.

CONCLUSION

REBOA allows for adequate resuscitation and can be used as a bridge to definitive therapy in a range of surgical subspecialties with minimal morbidity and complications. The risks associated with insertion of wires, sheaths, and catheters into the arterial system, as well as the risk of visceral and spinal cord ischemia due to aortic occlusion mandate that the use of this technique be utilized in only appropriate clinical scenarios.

Virtual operating room for team training in surgery

BACKGROUND

We proposed to develop a novel virtual reality (VR) team training system. The objective of this study was to determine the feasibility of creating a VR operating room to simulate a surgical crisis scenario and evaluate the simulator for construct and face validity.

METHODS

We modified ICE STORM (Integrated Clinical Environment; Systems, Training, Operations, Research, Methods), a VR-based system capable of modeling a variety of health care personnel and environments. ICE STORM was used to simulate a standardized surgical crisis scenario, whereby participants needed to correct 4 elements responsible for loss of laparoscopic visualization. The construct and face validity of the environment were measured.

RESULTS

Thirty-three participants completed the VR simulation. Attendings completed the simulation in less time than trainees (271 vs 201 seconds, P = .032). Participants felt the training environment was realistic and had a favorable impression of the simulation. All participants felt the workload of the simulation was low.

CONCLUSIONS

Creation of a VR-based operating room for team training in surgery is feasible and can afford a realistic team training environment.