Administration of Particulate Oxygen Generators Improves Skeletal Muscle Contractile Function Following Ischemia-Reperfusion Injury in the Rat Hind Limb

Extended tourniquet application, often associated with battlefield extremity trauma, can lead to severe ischemia-reperfusion (I/R) injury in skeletal muscle. Particulate oxygen generators (POGs) can be directly injected into tissue to supply oxygen to attenuate the effects of I/R injury in muscle. The goal of this study was to investigate the efficacy of a sodium percarbonate (SPO)-based POG formulation in reducing ischemic damage in a rat hind limb during tourniquet application. Male Lewis rats were anesthetized and underwent tourniquet application for 3 hours, at a pressure of 300 mmHg. Shortly after tourniquet inflation animals received intramuscular injections of either 0.2 mg/mL SPO with catalase (n=6) or 2.0 mg/mL SPO with catalase (n=6) directly into the tibialis anterior (TA) muscle. An additional Tourniquet-Only group (n=12) received no intervention. Functional recovery was monitored using in vivo contractile testing of the hind limb at 1-, 2-, and 4-weeks post-injury. By the 4 week time point, the Low Dose POGs group continued to show improved functional recovery (85% of baseline) compared to the Tourniquet-Only (48%) and High Dose POG (56%) groups. In short, the Low Dose POGs formulation appeared, at least in part, to mitigate the impact of ischemic tissue injury, thus improving contractile function following tourniquet application. Functional improvement correlated with maintenance of larger muscle fiber cross sectional area, and the presence of fewer fibers containing centrally located nuclei. As such, POGs represent a potentially attractive therapeutic solution for addressing I/R injuries associated with extremity trauma.

Femoral-Femoral Bypass for Limb Salvage to Correct Common Iliac Occlusion after Lower Extremity Trauma

Background Roadway injuries are a leading cause of lower extremity vascular trauma. Treating these injuries involves controlling life-threatening hemorrhage and restoring distal perfusion. Materials and Methods We describe a unique presentation of chronic iliac artery occlusion in the setting of blunt trauma requiring extra-anatomic bypass for maximal limb salvage. Results A 50-year-old male presented after a pedestrian versus auto accident. He had mangled bilateral lower extremities and was taken emergently for lower extremity amputations. He was found to have chronic left common iliac occlusion and a femoral-femoral bypass was performed to assist with healing his left below-the-knee amputation Discussion Lack of adequate perfusion can cause poor outcomes in limb salvage. This case demonstrated that lower extremity trauma can be complicated by chronic vascular disease. Reperfusion and adequate wound healing can be accomplished by using bypass grafting after more traditional reperfusion techniques fail.

Computed tomography angiography is associated with low added utility for detecting clinically relevant vascular injuries among patients with extremity trauma

BackgroundExtremity CT angiography (CTA) is frequently used to assess for vascular injury among patients with extremity trauma. The injured extremity index (IEI), defined as the ratio of systolic occlusion pressure between injured and uninjured extremities, has been implemented to screen patients being considered for CTA. Physical examination together with IEI is extremely sensitive for significant extremity vascular injury. Unfortunately, IEI cannot always be calculated. This study aimed to determine whether patients with normal pulse examinations and no hard signs of vascular injury benefitted from further imaging with CTA. We hypothesized that CTA has become overused among patients with extremity trauma, as determined by the outcome of vascular abnormalities that underwent vascular intervention but were missed by physical examination.MethodsThe charts of traumatically injured patients who underwent extremity CTA were retrospectively reviewed. This study was performed at a level 1 trauma center for patients who presented as trauma activations from September 1, 2019 to September 1, 2020.ResultsOne hundred and thirty-six patients with 167 injured limbs were included. Eight limbs (4.8%) underwent an open vascular operation, whereas five limbs (3.0%) underwent an endovascular procedure. One of the 167 limbs (0.6%) had a vascular injury seen on CTA and underwent intervention that was not associated with a pulse abnormality or hard signs of vascular injury. This patient presented in a delayed fashion after an initially normal IEI and examination. Proximity injuries and fractures alone were not highly associated with vascular injuries.DiscussionMany patients with normal pulse examination and no hard signs of vascular injury underwent CTA; the vast majority of these patients did not then have a vascular intervention. Given the consequences of missed vascular injuries, further work is required to prospectively assess the utility of CTA among patients with extremity trauma.Level of evidenceIII.

Beyond Limb Salvage: Limb Restoration Efforts Following Remote Combat-Related Extremity Injuries Optimize Outcomes and Support Sustained Surgical Readiness

ABSTRACT Introduction As the combat operational tempo of the military conflicts in Iraq and Afghanistan has declined over the last decade, there has been a decrease in the number of patients requiring acute limb salvage. In their place, a growing population of patients with persistent functional deficits, pain, and inadequate soft tissue coverage stemming from prior limb salvage strategies have returned to our institution seeking revision surgery. Herein, we examine our institution’s evolving surgical approach to extremity reconstruction from 2011 through 2019, culminating in the development of our limb restoration concept. We also discuss the impact of this orthoplastic approach on the acute management of complex extremity trauma and its role in providing sustained surgical readiness during interwar years. Materials and Methods We retrospectively reviewed all limb reconstructive procedures performed at our tertiary care military treatment facility between September 1, 2011 to December 31, 2019 to characterize the trends in extremity reconstruction procedures performed at our institution. Cases were identified as limb restoration procedures if they involved secondary/revision reconstructive procedures designed to optimize function, treat pain, or improve the durability of the injured extremity following initial reconstruction efforts. Results Nearly 500 limb restoration procedures were performed during the study period. These procedures steadily increased since 2011, reaching a maximum of 120 in 2018. Orthoplastic procedures such as osseointegration, targeted muscle reinnervation, regenerative peripheral nerve interface, agonist–antagonist myoneural interface, and soft tissue resurfacing flap reconstruction accounted for the rise in secondary/revision reconstruction performed during this time period. Conclusion Limb restoration is a collaborative orthoplastic approach that utilizes state-of-the-art surgical techniques for treating complex extremity trauma. Although limb restoration originally developed in response to managing the long-term sequelae of combat extremity trauma, the concept can be adapted to the acute management setting. Moreover, limb restoration provides military surgeons with a means for maintaining critical war-time surgical skills during the current low casualty rate era. Level of Evidence: V, therapeutic.