Composite Graft Pretreatment With Hydrogen Sulfide Delays the Onset of Acute Rejection.

Introduction: Vascularized composite allotransplantation can reconstruct devastating tissue loss by replacing like-with-like tissues, most commonly in the form of hand or face transplantation. Unresolved technical and ethical challenges have meant that such transplants remain experimental treatments. The most significant barrier to expansion of this field is the requirement for systemic immunosuppression, its toxicity and effect on longevity.

A Hyperbaric Warm Perfusion System Preserves Tissue Composites Ex vivo and Delays the Onset of Acute Rejection.

Background:  Ischemia-reperfusion injury (IRI) precipitates acute rejection of vascularized composite allografts (VCA). Hyperbaric preservation of tissues ex vivo, between harvest and revascularization, may reduce IRI and mitigate acute rejection of VCA.

Methods:  A porcine heterotopic musculocutaneous gracilis flap model was used.

A Porcine Orthotopic Forelimb Vascularized Composite Allotransplantation Model: Technical Considerations and Translational Implications.

Background: The restoration of complex tissue deficits with vascularized composite allotransplantation is a paradigm shift in reconstructive surgery. Clinical adoption of vascularized composite allotransplantation is limited by the need for systemic immunosuppression, with associated morbidity and mortality. Small-animal models lack the biological fidelity and preclinical relevance to enable translation of immunologic insights to humans.

C1 esterase inhibitor ameliorates ischemia reperfusion injury in a swine musculocutaneous flap model.

Purpose: Free tissue transfer is a powerful reconstructive surgical technique. The ischemia reperfusion injury (IRI) at revascularization affects the flap and the patient; reducing this insult could improve outcomes. This study evaluated the effect of C1 esterase inhibitor (C1-inh) on IRI in a porcine musculocutaneous flap model.

Prophylactic fasciotomy in a porcine model of extremity trauma.

Background: Extremity injury, with concomitant hemorrhagic shock, can result in ischemia-reperfusion injury and the formation of compartment syndrome requiring fasciotomy. As the benefit of prophylactic fasciotomy is unclear, the objective of this study is to determine the functional recovery of an ischemic limb with hemorrhagic shock after prophylactic fasciotomy.

Material And Methods: Yorkshire swine underwent 35% blood volume hemorrhage, followed by 1, 3, and 6 h of ischemia (n = 17; 1HR, 3HR, and 6HR) via iliac artery occlusion followed by repair and reperfusion.

The inflammatory sequelae of aortic balloon occlusion in hemorrhagic shock.

Background: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a hemorrhage control and resuscitative adjunct that has been demonstrated to improve central perfusion during hemorrhagic shock. The aim of this study was to characterize the systemic inflammatory response associated and cardiopulmonary sequelae with 30, 60, and 90 min of balloon occlusion and shock on the release of interleukin 6 (IL-6) and tumor necrosis factor alpha.

Materials And Methods: Anesthetized female Yorkshire swine (Sus scrofa, weight 70-90 kg) underwent a 35% blood volume-controlled hemorrhage followed by thoracic aortic balloon occlusion of 30 (30-REBOA, n = 6), 60 (60-REBOA, n = 8), and 90 min (90-REBOA, n = 6).

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

Background: The management of hemorrhage shock requires support of central aortic pressure including perfusion to the brain and heart as well as measures to control bleeding. Emerging endovascular techniques including resuscitative endovascular balloon occlusion of the aorta serve as potential lifesaving adjuncts in this setting. The Endovascular Skills for Trauma and Resuscitative Surgery (ESTARS) course was developed to provide fundamental endovascular training for trauma surgeons.

Hydrogen sulfide mitigates reperfusion injury in a porcine model of vascularized composite autotransplantation.

Background: Devastating extremity injuries are prevalent but often survivable on the modern battlefield. These complex injuries require advanced methods of reconstruction, involving prolonged ischemic periods and reperfusion injury. Using our group's validated porcine model of gracilis myocutaneous flap transplantation, this study demonstrates that an interim perfusion of hydrogen sulfide (H2S) mitigates the effects of reperfusion injury in the setting of delayed restoration of blood flow.

A novel fluoroscopy-free, resuscitative endovascular aortic balloon occlusion system in a model of hemorrhagic shock.

Background: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a potentially lifesaving maneuver in the setting of hemorrhagic shock. However, emergent use of REBOA is limited by existing technology, which requires large sheath arterial access and fluoroscopy-guided balloon positioning. The objectives of this study were to describe a new, fluoroscopy-free REBOA system and to compare its efficacy to existing technology.

Physiologic tolerance of descending thoracic aortic balloon occlusion in a swine model of hemorrhagic shock.

Background: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an emerging technique in trauma; however, the physiologic sequelae have not been well quantified. The objectives of this study were to characterize the burden of reperfusion and organ dysfunction of REBOA incurred during 30 or 90 min of class IV shock in a survivable porcine model of hemorrhage.

Methods: After induction of shock, animals were randomized into 4 groups (n = 6): 30 min of shock alone (30-Shock) or with REBOA (30-REBOA) and 90 min of shock alone (90-Shock) or with REBOA (90-REBOA).

Microvascular porcine model for the optimization of vascularized composite tissue transplantation.

Background: Devastating extremity injuries are prevalent but most often survivable on the modern battlefield. The complexity of these injuries requires advanced methods of reconstruction. This study is designed to validate the feasibility of gracilis myocutaneous flap transplantation via microvascular free tissue transfer in a porcine model.

Aortic balloon occlusion is effective in controlling pelvic hemorrhage.

Background: The objective of this study was to evaluate the efficacy of resuscitative endovascular aortic balloon occlusion (REBOA) of the distal aorta in a porcine model of pelvic hemorrhage.

Methods: Swine were entered into three phases of study: injury (iliac artery), hemorrhage (45 s), and intervention (180 min). Three groups were studied: no intervention (NI, n = 7), a kaolin-impregnated gauze (Combat Gauze) (CG, n = 7), or REBOA (n = 7).

Direct vascular control results in less physiologic derangement than proximal aortic clamping in a porcine model of noncompressible extrathoracic torso hemorrhage.

Background: The optimal method of vascular control and resuscitation in patients with life-threatening, extrathoracic torso hemorrhage remains debated. Guidelines recommend emergency department thoracotomy (EDT) with aortic clamping, although transabdominal aortic clamping followed by vascular control and direct vascular control (DVC) without aortic clamping are alternatives. The objective of this study is to compare the effectiveness of three approaches to extrathoracic torso hemorrhage in a large animal model.

Endovascular balloon occlusion of the aorta is superior to resuscitative thoracotomy with aortic clamping in a porcine model of hemorrhagic shock.

Background: Noncompressible torso hemorrhage is the leading cause of potentially preventable death on the modern battlefield. The objective of this study is to characterize resuscitative aortic balloon occlusion (BO) compared to thoracotomy with aortic clamping in a model of hemorrhagic shock.

Methods: A total of 18 swine (3 groups; 6 animals/group) were used in this study.

A porcine model for evaluating the management of noncompressible torso hemorrhage.

Background: Noncompressible hemorrhage from central vascular injuries remains the leading cause of preventable death in modern combat. This report introduces a large animal model of noncompressible torso hemorrhage, which permits assessment of the various approaches to this problem.

Methods: Yorkshire swine were anesthetized and monitoring devices for central aortic pressure, carotid flow, and intracerebral and transcutaneous brain oximetry were applied.

Hemorrhagic shock worsens neuromuscular recovery in a porcine model of hind limb vascular injury and ischemia-reperfusion.

Background: In order to advance beyond basic statistical limb salvage to improved functional or quality limb salvage, a better understanding of the ischemic threshold of the limb is required. To date, models of extremity ischemia and reperfusion involve small animals and few include survival with physiologic measures of nerve and muscle recovery. In addition, the effect of hemorrhagic shock on the ischemic threshold of the extremity is unknown.

The impact of ischemic intervals on neuromuscular recovery in a porcine (Sus scrofa) survival model of extremity vascular injury.

Background: Despite advances in revascularization following extremity vascular injury, the relationship between time to restoration of flow and functional limb salvage is unknown. The objectives of this study are to describe a large animal survival model of hind limb ischemia/reperfusion and define neuromuscular recovery following increasing ischemic periods.

Methods: Sus scrofa swine (N = 38; weight, 87 ± 6.

A large animal survival model (Sus scrofa) of extremity ischemia/reperfusion and neuromuscular outcomes assessment: a pilot study.

Background: Extremity ischemia/reperfusion has been studied mostly in small-animal models with limited characterization of neuromuscular or functional outcome. The objective of this experiment was to report a large-animal survival model of extremity ischemia/reperfusion using circulating, electromyographic (EMG), gate, and histologic measures of injury and limb recovery.

Methods: Sus scrofa swine (n = 6; mean, 83 kg) were randomized to iliac artery occlusion for 0 (control), 1 (1 HR), 3 (3 HR), or 6 (6 HR) hours.

Early versus delayed restoration of flow with temporary vascular shunt reduces circulating markers of injury in a porcine model.

Background: Temporary vascular shunting to restore flow after vascular injury has been advocated. The effectiveness of this adjunct in protecting against ischemic injury has not been established. This study will assess the temporal impact of shunts on ischemic injury and arterial flow.