Performance of a novel temporary arterial shunt in a military-relevant controlled hemorrhage swine model.

BACKGROUND: In military trauma, temporary vascular shunts restore arterial continuity until delayed vascular reconstruction, often for a period of hours. A novel US Air Force-developed trauma-specific vascular injury shunt (TS-VIS) incorporates an accessible side port for intervention or monitoring, which may improve patency under adverse hemodynamic conditions. Our objective was to evaluate TS-VIS patency in the setting of volume-limited resuscitation from hemorrhagic shock. METHODS: Female swine (70-90 kg) underwent 30% hemorrhage and occlusion of the left external iliac artery for 30 minutes. Animals were allocated to one of three groups (n = 5 per group) by left external iliac artery treatment: Sundt shunt (SUNDT), TS-VIS with arterial pressure monitoring (TS-VIS), or TS-VIS with heparin infusion (10 µ/kg per hour, TS-VISHep). Animals were resuscitated with up to 3 U of whole blood to maintain a mean arterial pressure (MAP) of >60 mm Hg and were monitored for 6 hours. Bilateral femoral arterial flow was continuously monitored with transonic flow probes, and shunt thrombosis was defined as the absence of flow for greater than 5 minutes. RESULTS: No intergroup differences in MAP or flow were observed at baseline or following hemorrhage. Animals were hypotensive at shunt placement (MAP, 35.5 ± 7.3 mm Hg); resuscitation raised MAP to >60 mm Hg by 26.5 ± 15.5 minutes. Shunt placement required 4.5 ± 1.8 minutes with no difference between groups. Four SUNDT thrombosed (three before 60 minutes). One SUNDT thrombosed at 240 minutes, and two TS-VIS and one TS-VISHep thrombosed between 230 and 282 minutes. Median patency was 21 minutes for SUNDT and 360 minutes for both TS-VIS groups (p = 0.04). While patent, all shunts maintained flow between 60% and 90% of contralateral. CONCLUSION: The TS-VIS demonstrated sustained patency superior to the Sundt under adverse hemodynamic conditions. No benefit was observed by the addition of localized heparin therapy over arterial pressure monitoring by the TS-VIS side port.

Therapeutic cardiac arrest as an adjunct to resuscitative endovascular balloon occlusion of the aorta: Bridging the gap from fatal hemorrhage to definitive surgical control in swine.

BACKGROUND: Uncontrolled hemorrhage is the leading cause of potentially survivable combat casualty mortality, with 86.5% of cases resulting from noncompressible torso hemorrhage. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a minimally invasive technique used to stabilize patients with noncompressible torso hemorrhage; however, its application can take an average of 8 minutes to place. One therapeutic capable of bridging this gap is adenosine-lidocaine-magnesium (ALM), which at high doses induces a reversible cardioplegia. We hypothesize by using ALM as an adjunct to REBOA, the ALM-induced cardiac arrest will temporarily halt exsanguination and reduce blood loss, allowing for REBOA placement and control of bleeding. METHODS: Male Yorkshire swine (60-80 kg) were randomly assigned to REBOA only or ALM-REBOA (n = 8/group). At baseline, uncontrolled hemorrhage was induced via a 1.5-cm right femoral arteriotomy, and hemorrhaged blood was quantified. One minute after injury (S1), ALM was administered, and 7 minutes later (T0), zone 1 REBOA inflation occurred. If cardiac arrest ensued, cardiac function either recovered spontaneously or advanced life support was initiated. At T30, surgical hemostasis was obtained, and REBOA was deflated. Animals were resuscitated until they were humanely euthanized at T90. RESULTS: During field care phase, heart rate and end-tidal CO2 of the ALM-REBOA group were significantly lower than the REBOA only group. While mean arterial pressure significantly decreased from baseline, no significant differences between groups were observed throughout the field care phase. There was no significant difference in survival between the two groups (ALM-REBOA = 89% vs. REBOA only = 100%). Total blood loss was significantly decreased in the ALM-REBOA group (REBOA only = 24.32 ± 1.89 mL/kg vs. ALM-REBOA = 17.75 ± 2.04 mL/kg, p = 0.0499). CONCLUSION: Adenosine-lidocaine-magnesium is a novel therapeutic, which, when used with REBOA, can significantly decrease the amount of blood loss at initial presentation, without compromising survival. This study provides proof of concept for ALM and its ability to bridge the gap between patient presentation and REBOA placement.

Noninvasive Cerebral Perfusion and Oxygenation Monitoring Augment Prolonged Field Care in a Non-Human Primate Model of Decompensated Hemorrhage and Resuscitation.

BACKGROUND: Decompensated hemorrhagic shock (DHS) is the leading cause of preventable death in combat casualties. "Golden hour" resuscitation effects on cerebral blood flow and perfusion following DHS in prolonged field care (PFC) are not well investigated. Using an established non-human primate model of DHS, we hypothesized noninvasive regional tissue oxygenation (rSO2) and Transcranial Doppler (TCD) would correlate to the invasive measurement of partial pressure of oxygen (PtO2) and mean arterial pressure (MAP) in guiding hypotensive resuscitation in a PFC setting. METHODS: Ten rhesus macaques underwent DHS followed by a 2 h PFC phase (T0-T120), and subsequent 4 h hospital resuscitation phase (T120-T360). Invasive monitoring (PtO2, MAP) was compared against noninvasive monitoring systems (rSO2, TCD). Results were analyzed using t tests and one-way repeated measures ANOVA. Linear correlation was determined via Pearson r. Significance = P < 0.05. RESULTS: MAP, PtO2, rSO2, and mean flow velocity (MFV) significantly decreased from baseline at T0. MAP and PtO2 were restored to baseline by T15, while rSO2 was delayed through T30. At T120, MFV returned to baseline, while the Pulsatility Index significantly elevated by T120 (1.50 ±â€Š0.31). PtO2 versus rSO2 (R2 = 0.2099) and MAP versus MFV (R2 = 0.2891) shared very weak effect sizes, MAP versus rSO2 (R2 = 0.4636) displayed a low effect size, and PtO2 versus MFV displayed a moderate effect size (R2 = 0.5540). CONCLUSIONS: Though noninvasive monitoring methods assessed here did not correlate strongly enough against invasive methods to warrant a surrogate in the field, they do effectively augment and direct resuscitation, while potentially serving as a substitute in the absence of invasive capabilities.

Resuscitative endovascular balloon occlusion of the aorta for thoracic trauma in the setting of platelet dysfunction: A translational swine study.

BACKGROUND: In patients with noncompressible torso hemorrhage, antiplatelet medications may lead to worse outcomes. Resuscitative endovascular balloon occlusion of the aorta (REBOA) may potentially stabilize these patients, but currently, major thoracic bleeding is a contraindication. The goal of this study was to determine if REBOA use for shock with major thoracic bleeding has worse outcomes in the setting of platelet dysfunction (PD). METHODS: Forty-one male Yorkshire swine (60-80 kg) underwent a 30% hemorrhage and then were randomized to three thoracic injuries, with and without zone 1 REBOA occlusion: pulmonary parenchymal injury (PI), thoracic venous injury (VI), or subclavian artery injury (AI). All animals were given aspirin to produce PD. Following hemorrhage, thoracic injuries were induced (T0) and allowed to bleed freely. Resuscitative endovascular balloon occlusion of the aorta groups had zone 1 occlusion, with deflation at T30. All groups received whole blood resuscitation at T30 and were euthanized at T90. Survival, total blood loss, hemodynamics, and arterial blood gas parameters were analyzed. RESULTS: The PD-VI-REBOA group had 87.5% survival where PD-VI survival was 28.6%. No difference in survival was seen in the PI or AI groups. The PD-VI-REBOA group had total blood loss of 575.0 ± 339.1 mL, which was less than the PD-VI group (1,086.0 ± 532.1 mL). There was no difference in total thoracic blood loss in the PI and AI groups with the addition of REBOA. All groups showed an equivalent decrease in HCO3 and base excess and increase in lactate at the end of the 30-minute prehospital phase. CONCLUSION: In this study, zone 1 REBOA improved survival and decreased blood loss with major VI, where no differences were seen in parenchymal and subclavian artery injuries. For thoracic bleeding without surgical capability, outcomes may be improved with REBOA, and these findings challenge current guidelines stating the contraindication of REBOA use in this setting.

Resuscitative endovascular balloon occlusion of the aorta for thoracic trauma: A translational swine study.

Noncompressible torso hemorrhage in trauma is particularly lethal. Resuscitative endovascular balloon occlusion of the aorta (REBOA) has the potential to stabilize these patients, but currently is contraindicated for major thoracic bleeding. The goal of this study was to evaluate the effect of REBOA on the hemodynamic and metabolic profile as well as its effect on early survival in a porcine model of thoracic hemorrhage and shock. METHODS: Forty-eight male Yorkshire swine (60-80 kg) underwent 30% hemorrhage and were randomized to three thoracic injuries, with and without zone 1 REBOA occlusion: pulmonary parenchymal injury, thoracic venous injury, or subclavian artery injury. Following hemorrhage, thoracic injuries were induced (time of major thoracic injury) and allowed to bleed freely. The REBOA groups had zone 1 occlusion after the thoracic injury, with deflation at the end of prehospital. All groups had whole blood resuscitation at the end of prehospital and were euthanized at end of the hospital care phase. Survival, total blood loss, mean arterial pressure, end-tidal CO2, and arterial blood gas parameters were analyzed. Statistical significance was determined by t tests and two-way repeated-measures analysis of variance. RESULTS: The use of REBOA improved the hemodynamics in all three injury patterns, with no differences observed in the outcomes of short-term survival and thoracic blood loss between the REBOA and non-REBOA groups. All groups showed equivalent changes in markers of shock (pH, HCO3, and base excess) prior to resuscitation. CONCLUSION: In this animal study of hemorrhage and major thoracic bleeding, the addition of zone 1 REBOA did not significantly affect short-term survival or blood loss, while providing hemodynamic stabilization. Therefore, in noncompressible thoracic bleeding, without immediate surgical capability, long-term outcomes may be improved with REBOA, and thoracic hemorrhage should not be considered contraindications to REBOA use.

Clinical and Quality of Life Assessment of Patients Undergoing Laparoscopic Hiatal Hernia Repair.

Hiatal hernia repair (HHR) and fundoplication are similarly performed among all hiatal hernia types with similar techniques. This study evaluates the effect of HHR using a standardized technique for cruroplasty with a reinforcing polyglycolic acid and trimethylene carbonate mesh (PGA/TMC) on patient symptoms and outcomes. A retrospective review of patient perioperative characteristics and postoperative outcomes was conducted for cases of laparoscopic hiatal hernia repair (LHHR) using a PGA/TMC mesh performed over 21 months. Gastroesophageal reflux disease symptom questionnaire responses were compared between preoperative and three postoperative time points. Ninety-six patients underwent LHHR with a PGA/TMC mesh. Postoperatively, the number of overall symptoms reported by patients decreased across all postoperative periods (P < 0.001). Patients reported a significant reduction in antacid use long term (P < 0.001). Laryngeal and regurgitation symptoms decreased at all time points (P < 0.05). There was no difference in dysphagia preoperatively and postoperatively at any time point. Individuals undergoing HHR with PGA/TMC mesh experienced improved regurgitation and laryngeal symptoms, and decreased use of antacid medication.