To Örebro University

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 1107 patients underwent endovascular aortic occlusion, of these, 848 met inclusion criteria. The median age was 44 years [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 modelling 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%CI, 1.17-1.92; P = .001).

DISCUSSION: In patients who do not respond to initial resuscitation, the use of REBOA in SBP's between 60- 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.

STUDY TYPE: Observational Study. LEVEL OF EVIDENCE: Level IV.

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a method for temporary hemorrhage control used in haemodynamically unwell patients with severe bleeding. In haemodynamically unwell abdominal trauma patients, laparotomy remains the initial procedure of choice. Using REBOA in patients as a bridge to laparotomy is a novel option whose feasibility and efficacy remain unclear. We aimed to assess the clinical outcome in patients with abdominal injury who underwent both REBOA placement and laparotomy.

METHODS: This is a retrospective study, including trauma patients with an isolated abdominal injury who underwent both REBOA placement and laparotomy, during the period 2011-2019. All data were collected via the Aortic Balloon Occlusion Trauma Registry database.

RESULTS: One hundred and three patients were included in this study. The main mechanism of trauma was blunt injury (62.1%) and the median injury severity score (ISS) was 33 (14-74). Renal failure and multi-organ dysfunction syndrome (MODS) occurred in 15.5% and 35% of patients, respectively. Overall, 30-day mortality was 50.5%. Post balloon inflation systolic blood pressure (SBP) >80 mmHg was associated with lower 24-h mortality (p = 0.007). No differences in mortality were found among patients who underwent partial occlusion vs. total occlusion of the aorta.

CONCLUSIONS: Our results support the feasibility of REBOA use in patients with isolated abdominal injury, with survival rates similar to previous reports for haemodynamically unstable abdominal trauma patients. Post-balloon inflation SBP >80 mmHg was associated with a significant reduction in 24-h mortality rates, but not 30-day mortality. Total aortic occlusion was not associated with increased mortality, MODS, and complication rates compared with partial occlusion.

OBJECTIVE: This study aimed to investigate the association between intestinal fatty acid-binding protein, acute gastrointestinal injury grade, and gastrointestinal complications after fenestrated or branched endovascular aortic aneurysm repair.

METHODS: A total of 17 patients undergoing endovascular aortic repair for thoracoabdominal, juxtarenal, suprarenal or pararenal aneurysm between May 2017 and September 2018 were enrolled. Blood samples were collected preoperatively and during postoperative intensive care. The blood samples were analyzed for intestinal fatty acid-binding protein with enzyme-linked immunosorbent assay. Gastrointestinal function was assessed according to the acute gastrointestinal injury grade every day during postoperative intensive care.

RESULTS: Higher concentrations of intestinal fatty acid-binding protein at 24 h and 48 h correlated to higher acute gastrointestinal injury grade on postoperative days 1, 2 and 3 (p=0.032 and p=0.048, p=0.040 and p=0.018, and p=0.012 and p=0.016, respectively). Patients who developed a gastrointestinal complication within 90 days postoperatively had a higher overall acute gastrointestinal injury grade than those who did not develop a gastrointestinal complication (p<0.001), as well as higher concentrations of intestinal fatty acid-binding protein at 48 h (p=0.019). Patients developing gastrointestinal dysfunction (acute gastrointestinal injury grade ≥2) had a higher frequency of complications (p=0.009) and longer length of stay in the intensive care unit (p=0.008).

CONCLUSIONS: In patients undergoing endovascular aortic repair for complex aneurysm increased postoperative plasma intestinal fatty acid-binding protein concentrations and postoperative gastrointestinal dysfunction, evaluated using the acute gastrointestinal injury grade, were associated with gastrointestinal complications, indicating that these measures may be useful in the postoperative management of these patients.

BACKGROUND: The resuscitative endovascular balloon occlusion of the aorta (REBOA) technique controls abdominal, pelvic, junctional, and postpartum hemorrhage via aortic endoclamping. There are no protocols or clear indications guiding REBOA use in a two-tiered prehospital emergency medical system, as found in France. We conducted a Delphi study to clarify the indications and contraindications for REBOA application in such a system.

METHODS: We performed a Delphi study in three rounds with an international group of doctors with REBOA expertise and clinical experience (members of the EndoVascular and Trauma Management Society). Based on the consensus answers, complemented by existing data in the literature, we developed a protocol for REBOA use in a medicalized prehospital setting.

RESULTS: We identified 10 questions that were not answered in the literature and submitted them to 21 experts. Over three rounds, consensus was reached on these 10 questions. The most important ones were "In your opinion, in a hemorrhagic patient, vascularly well-filled and whose hemodynamics remain unstable with 3mg/h of norepinephrine, should we inflate a REBOA to prevent the patient's death and get them to the operating room alive?" and "In the case of REBOA placement (zone I) in the prehospital setting, would you agree that the maximum occlusion duration is approximately 30 minutes, with a partial or intermittent occlusion when possible?"

CONCLUSION: We propose a protocol for REBOA use in a medicalized prehospital setting. This protocol clarifies that hemorrhagic shock, despite a noradrenaline (also known as norepinephrine) dose of 0.6µg/kg/min, is considered too serious for the patient to be transported to the trauma center without REBOA. Moreover, it clarifies that a zone 1 REBOA should be inflated for maximum 30 minutes and with a partial occlusion strategy, if possible. This protocol should be updated based on feedback following the establishment of prehospital REBOA and large randomized studies.

PURPOSE: Combining resuscitative endovascular balloon occlusion of the aorta (REBOA) and the inferior vena cava (REBOVC) with open surgery is a new hybrid approach for treating retrohepatic vena caval injuries. We compared endovascular total hepatic isolation with supraceliac REBOA ± suprahepatic REBOVC and no occlusion in experimental retrohepatic vena cava bleeding regarding survival, bleeding volume, hemodynamic stability, and arterial collateral blood flow.

METHODS: Twenty-five anesthetized pigs (n = 6-7/group) were randomized to REBOA; REBOA + REBOVC; REBOA + infra and suprahepatic REBOVC + portal vein occlusion (endovascular Heaney maneuver, four-balloon-occlusion, 4BO) or no occlusion. After balloon inflation, free bleeding was initiated from an open sheath in the retrohepatic vena cava. Bleeding volume, right internal thoracic artery (RITA) blood flow, hemodynamics, and arterial blood variables were measured until death or up to 90 min.

RESULTS: The REBOA group had a longer median survival time (63 min) compared with the 4BO (24 min, P = 0.02) and no occlusion (30 min, P = 0.02) groups, not versus the REBOA + REBOVC group (49 min, P > 0.05). The first 15 min accumulated bleeding was comparable in all groups (P > 0.05); Thereafter, bleeding volume was higher in the REBOA group versus the 4BO group (P < 0.05), not versus the other groups. RITA blood flow and MAP were higher in the REBOA group versus the other groups after 10 min of bleeding (P < 0.05).

CONCLUSIONS: Endovascular Heaney maneuver was not beneficial for survival or hemodynamic stability in this porcine model, whereas supraceliac REBOA was. Anatomical differences in thoracoabdominal collaterals between pigs and humans must be considered when interpreting these results.

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 orebro 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 Orebro 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.

OBJECTIVES: In fluoroscopy-free settings, alternative safe and quick methods for placing resuscitative endovascular balloon occlusion of the aorta (REBOA) and resuscitative endovascular balloon occlusion of the inferior vena cava (REBOVC) are needed. Ultrasound is being increasingly used to guide the placement of REBOA in the absence of fluoroscopy. Our hypothesis was that ultrasound could be used to adequately visualize the suprahepatic vena cava and guide REBOVC positioning, without significant time-delay, when compared with fluoroscopic guidance, and compared with the corresponding REBOA placement.

METHODS: Nine anesthetized pigs were used to compare ultrasound-guided placement of supraceliac REBOA and suprahepatic REBOVC with corresponding fluoroscopic guidance, in terms of correct placement and speed. Accuracy was controlled by fluoroscopy. Four intervention groups: (1) fluoroscopy REBOA, (2) fluoroscopy REBOVC, (3) ultrasound REBOA and (4) ultrasound REBOVC. The aim was to carry out the four interventions in all animals. Randomization was performed to either fluoroscopic or ultrasound guidance being used first. The time required to position the balloons in the supraceliac aorta or in the suprahepatic inferior vena cava was recorded and compared between the four intervention groups.

RESULTS: Ultrasound-guided REBOA and REBOVC placement was completed in eight animals, respectively. All eight had correctly positioned REBOA and REBOVC on fluoroscopic verification. Fluoroscopy-guided REBOA placement was slightly faster (median 14 s, IQR 13-17 s) than ultrasound-guided REBOA (median 22 s, IQR 21-25 s, p=0.024). The corresponding comparisons of the REBOVC groups were not statistically significant, with fluoroscopy-guided REBOVC taking 19 s, median (IQR 11-22 s) and ultrasound-guided REBOVC taking 28 s, median (IQR 20-34 s, p=0.19).

CONCLUSION: Ultrasound adequately and quickly guide the placement of supraceliac REBOA and suprahepatic REBOVC in a porcine laboratory model, however, safety issues must be considered before use in trauma patients.

LEVEL OF EVIDENCE: Prospective, experimental, animal study. Basic science study.

BACKGROUND: The definition of partial resuscitative endovascular balloon occlusion of the aorta (pREBOA) is not yet determined and clinical markers of the degree of occlusion, metabolic effects and end-organ injury that are clinically monitored in real time are lacking. The aim of the study was to test the hypothesis that end-tidal carbon dioxide (ETCO2) targeted pREBOA causes less metabolic disturbance compared to proximal systolic blood pressure (SBP) targeted pREBOA in a porcine model of hemorrhagic shock.

MATERIALS AND METHODS: Twenty anesthetized pigs (26-35 kg) were randomized to 45 min of either ETCO2 targeted pREBOA (pREBOAETCO2, ETCO2 90-110% of values before start of occlusion, n = 10) or proximal SBP targeted pREBOA (pREBOASBP, SBP 80-100 mmHg, n = 10), during controlled grade IV hemorrhagic shock. Autotransfusion and reperfusion over 3 h followed. Hemodynamic and respiratory parameters, blood samples and jejunal specimens were analyzed.

RESULTS: ETCO2 was significantly higher in the pREBOAETCO2 group during the occlusion compared to the pREBOASBP group, whereas SBP, femoral arterial mean pressure and abdominal aortic blood flow were similar. During reperfusion, arterial and mesenteric lactate, plasma creatinine and plasma troponin concentrations were higher in the pREBOASBP group.

CONCLUSIONS: In a porcine model of hemorrhagic shock, ETCO2 targeted pREBOA caused less metabolic disturbance and end-organ damage compared to proximal SBP targeted pREBOA, with no disadvantageous hemodynamic impact. End-tidal CO2 should be investigated in clinical studies as a complementary clinical tool for mitigating ischemic-reperfusion injury when using pREBOA.