[Therapeutic and diagnostic complex in intestinal failure syndrome in patients with closed abdominal trauma]. / Lechebno-diagnosticheskii kompleks pri sindrome kishechnoi nedostatochnosti u patsientov s zakrytoi travmoi zhivota.

Currently, severe combined abdominal trauma ranks third among all causes of mortality In Russia, second only to cardiovascular and oncologic diseases. In the period from 2019 to 2020 in our country, a slight decrease in traumatism is noted due to a decrease in the number of traffic accidents as the main cause of combined and multiple trauma. The number of abdominal injuries from the total number of injuries In Russian regions ranges from 1.5 to 36.5% and is accompanied by a high level of disability (25-80% in combined trauma and 5-8% in isolated trauma). Despite modern medical advances, lethality in combined trauma of abdominal organs varies from 10.7 to 69.7%, with closed abdominal trauma accounting for up to 6% of fatal outcomes. OBJECTIVE: Improving treatment outcomes in patients with closed abdominal trauma through comprehensive diagnosis of SCN and optimization of enteral therapy in patients with closed abdominal trauma. MATERIAL AND METHODS: The study included 40 patients (29 (72.5%) men and 11 (27.5%) women), who underwent examination and treatment at the State Budgetary Institution "Research Institute of SP. Im. N.V. Sklifosovsky Research Institute of St. Petersburg State Medical Center with the diagnosis: Closed abdominal trauma. The age of the patients varied from 25 to 81 years (Mean age was 49.6±13.1). To evaluate the effectiveness of intensive therapy, the patients were divided into 2 groups: the comparison group (n=26) included patients who were treated with complex conservative therapy. Patients of the main group (n=14) conservative therapy was supplemented with the use of ER to restore the functional activity of the intestine under the control of ultrasound and assessment of the degree of intra-abdominal hypertension, as well as with Intestamine to stimulate the intestinal trauma. RESULTS: In the course of the study it was found that, as a result of complex enteral therapy in the patients of the main group, starting from the 7th day of stay in the ORIT, positive dynamics was observed, consisting in a statistically significant decrease in the levels of lactate, ALT, AST, LDH, and CRP. By the 14th day there was also a statistically significant decrease in leukocyte and PCT levels. The lethality in the main group amounted to 7.2%, n=1. At the same time, in patients of the comparison group only by the 7th day there was a decrease in concentration of CRP (p=0.065), by the 10th day - ALT (<0.001) and by the 14th day there was a decrease in leukocytes level (p=0.038). Lethality in this group amounted to 23.1%, n=6. CONCLUSION: Timely initiation of pathogenetic enteral therapy contributes to faster normalization of clinical and laboratory parameters, protection of intestinal barrier function, prevention of complications associated with bacterial translocation and bacterial overgrowth syndrome, increase in immunoresistance of the organism.

Characterizing and Modeling Ovine Hide and Costal Cartilage for Use in Modeling High-Rate Non-Penetrating Blunt Impact.

INTRODUCTION: High-rate non-penetrating blunt impacts to the thorax, such as from impacts to protective equipment, can lead to a wide range of thoracic injuries. These injuries can include rib fractures, lung contusions, and abdominal organ contusions. Ovine animals have been used to study such impacts, in a variety of ways, including in silico. To properly model these impacts in silico, it is imperative that the tissues impacted are properly characterized. The objective of this study is to characterize and validate two tissues impacted that are adjacent to the point of impact-costal cartilage and hide. Heretofore, these materials have not been characterized for use in computational models despite their nearly immediate engagement in the high-rate, non-penetrating loading environment. MATERIALS AND METHODS: Ovine costal cartilage and hide samples were procured from a local abattoir following USDA regulations. Costal cartilage samples were then cut into ASTM D638 Type V tensile coupons and compressive disks for testing. The cartilage tensile coupons were tested at 150 ε/s, and the compressive samples were tested at -150 ε/s. Identical coupons and disks were then simulated in LS-Dyna using a hyperelastic material model based on test data and experimental boundary conditions. Hide samples were shaved and cut into ASTM D638 Type V tensile coupons and validated in silico using identical boundary conditions and an Ogden rubber model based on test data. RESULTS: The structural responses of costal cartilage and hide are presented and exhibit typical behavior for biological specimens. The respective model fits in LS-Dyna were a hyperelastic- based "simplified rubber" for the costal cartilage and an Ogden rubber for the hide. The costal cartilage had a mean failure strain of 0.094 ± 0.040 in tension and -0.1755 ± 0.0642 in compression. The costal cartilage was also noted to have an order-of-magnitude difference in the stresses observed experimentally between the tensile and compressive experiments. Hide had a mean failure strain of 0.2358 ± 0.1362. The energies for all three simulations showed material stability. CONCLUSIONS: Overall, we successfully characterized the mechanical behavior of the hide and costal cartilage in an ovine model. The data are intended for use in computational analogs of the ovine model for testing non-penetrating blunt impact in silico. To improve upon these models, rate sensitivity should be included, which will require additional mechanical testing.

Behind Armor Blunt Trauma: Liver Injuries Using a Live Animal Model.

INTRODUCTION: While the 44-mm clay penetration criterion was developed in the 1970s for soft body armor applications, and the researchers acknowledged the need to conduct additional tests, the same behind the armor blunt trauma displacement limit is used for both soft and hard body armor evaluations and design considerations. Because the human thoraco-abdominal contents are heterogeneous, have different skeletal coverage, and have different functional requirements, the same level of penetration limit does not imply the same level of protection. It is important to determine the regional responses of different thoraco-abdominal organs to better describe human tolerance and improve the current behind armor blunt trauma standard. The purpose of this study was to report on the methods, procedures, and data collected from swine. MATERIALS AND METHODS: Live swine tests were conducted after obtaining approvals from the local institution and the Army Care and Use Review Office of the U.S. Department of Defense. Trachea tubes and an intravenous line were introduced before administering anesthesia. Pressure transducers were inserted into the lungs and aorta. An indenter simulating the backface deformation profiles produced by body armor from military-relevant ballistics to human cadavers was used to deliver impact loading to the liver region. A triaxial accelerometer was included in the indenter design. The animals were monitored for 6 hours, necropsies were performed, and injuries were identified. Biomechanical data of the energy, velocity, deflection, viscous criterion, force, and impulse variables were obtained for each test. RESULTS: Peak accelerations, velocities, deflections, forces, impulse, and energies ranged from 897 to 5,808 g, 21 to 59 m/s, 1.96 to 8.87 cm, 2.3 to 13.1 kN, 1.1 to 7.1 Ns, and 58 to 387 J, respectively. The peak viscous criterion ranged from 0.8 to 5.8 m/s. All animals survived the 6-hour survival period. Three animals responded with liver lacerations while the remaining 4 did not have any injuries. CONCLUSION: The experimental design based on parallel tests with whole body human cadavers and cadaver swine was found to be successful in delivering controlled impacts to the liver region of live swine and reproducing liver injuries. Previously used biomechanical measures as potential candidates for injury criteria development were obtained. Using this proven model, tests with additional samples are needed to develop injury risk curves for liver impacts and obtain regional (liver) injury criteria.

Three-Dimensional-Digital Image Correlation Methodology for Kinematic Measurements of Non-Penetrating Blunt Impacts.

Blunt force trauma remains a serious threat to many populations and is commonly seen in motor vehicle crashes, sports, and military environments. Effective design of helmets and protective armor should consider biomechanical tolerances of organs in which they intend to protect and require accurate measurements of deformation as a primary injury metric during impact. To overcome challenges found in velocity and displacement measurements during blunt impact using an integrated accelerometer and two-dimensional (2D) high-speed video, three-dimensional (3D) digital image correlation (DIC) measurements were taken and compared to the accepted techniques. A semispherical impactor was launched at impact velocities from 14 to 20 m/s into synthetic ballistic gelatin to simulate blunt impacts observed in behind armor blunt trauma (BABT), falls, and sports impacts. Repeated measures Analysis of Variance resulted in no significant differences in maximum displacement (p = 0.10), time of maximum displacement (p = 0.21), impact velocity (p = 0.13), and rebound velocity (p = 0.21) between methods. The 3D-DIC measurements demonstrated equal or improved percent difference and low root-mean-square deviation compared to the accepted measurement techniques. Therefore, 3D-DIC may be utilized in BABT and other blunt impact applications for accurate 3D kinematic measurements, especially when an accelerometer or 2D lateral camera analysis is impractical or susceptible to error.

Outcomes of thoracic endovascular aortic repair in patients with concomitant blunt thoracic aortic injury and traumatic brain injury from the Aortic Trauma Foundation global registry.

BACKGROUND: Traumatic brain injury (TBI) and blunt thoracic aortic injury (BTAI) are the top two leading causes of death after blunt force trauma. Patients presenting with concomitant BTAI and TBI pose a specific challenge with respect to management strategy, because the optimal hemodynamic parameters are conflicting between the two pathologies. Early thoracic endovascular aortic repair (TEVAR) is often performed, even for minimal aortic injuries, to allow for the higher blood pressure parameters required for TBI management. However, the optimal timing of TEVAR for the treatment of BTAI in patients with concomitant TBI remains an active matter of controversy. METHODS: The Aortic Trauma Foundation international prospective multicenter registry was used to identify all patients who had undergone TEVAR for BTAI in the setting of TBI from 2015 to 2020. The primary outcomes included delayed ischemic or hemorrhagic stroke, in-hospital mortality, and aortic-related mortality. The outcomes were examined among patients who had undergone TEVAR at emergent (<6 vs ≥6 hours) or urgent (<24 vs ≥24 hours) intervals. RESULTS: A total of 100 patients (median age, 43 years; 79% men; median injury severity score, 41) with BTAI (Society for Vascular Surgery BTAI grade 1, 3%; grade 2, 10%; grade 3, 78%; grade 4, 9%) and concomitant TBI who had undergone TEVAR were identified. Emergent repair was performed for 51 patients (51%). Comparing emergent repair (<6 hours) to urgent repair (≥6 hours), no difference was found in delayed cerebral ischemic events (2.0% vs 4.1%; P = .614), in-hospital mortality (15.7% vs 22.4%; P = .389), or aortic-related mortality (2.0% vs 2.0%; P = .996) and no patient had experienced delayed hemorrhagic stroke. Likewise, repairs conducted in an urgent (<24 hours) setting showed no differences compared with those completed in an emergent (≥24 hours) setting regarding delayed ischemic stroke (2.6% vs 4.3%; P = .548), in-hospital mortality (18.2% vs 21.7%; P = .764), or aortic-related mortality (1.3% vs 4.3%; P = .654), and no patient had experienced delayed hemorrhagic stroke. CONCLUSIONS: In contrast to prior retrospective efforts, results from the Aortic Trauma Foundation international prospective multicenter registry have demonstrated that neither emergent nor urgent TEVAR for patients with concomitant BTAI and TBI was associated with delayed stroke, in-hospital mortality, or aortic-related mortality. In these patients, the timing of TEVAR did not have an effect on the outcomes. Therefore, the decision to intervene should be guided by individual patient factors rather than surgical timing.

Stretch-Induced Intimal Failure in Isolated Cerebral Arteries as a Function of Development.

Recent clinical studies have shown that traumatic brain injury is a significant risk factor for stroke. Motivated to better understand possible mechanisms of this association, we studied subfailure disruption of the intima in overstretched sheep cerebral arteries, as this has been implicated in the increased risk of stroke following blunt cerebrovascular injury. Middle cerebral arteries from four age groups (ranging from fetal to adult) were stretched axially to failure, and intimal disruption was captured with a video camera. All vessels demonstrated intimal disruption prior to catastrophic failure, with nearly all incurring disruption at stretch values well below those at ultimate stress (means of 1.56 and 1.73, respectively); the lowest stretch associated with intimal disruption was 1.29. The threshold of intimal failure was independent of age. Additional analysis showed that disruption included failure of both the endothelium and internal elastic lamina. Although our experiments were conducted at quasi-static rates, the results likely have important implications for vessel function following trauma. Future work should seek to identify subfailure disruption of the cerebrovasculature in head trauma.

Geometric, Biomechanic and Haemodynamic Aortic Abnormalities Assessed by 4D Flow Cardiovascular Magnetic Resonance in Patients Treated by TEVAR Following Blunt Traumatic Thoracic Aortic Injury.

OBJECTIVE: Thoracic endovascular aortic repair (TEVAR) is widely used for the treatment of patients with blunt traumatic thoracic aortic injury (BTAI). However, aortic haemodynamic and biomechanical implications of this intervention are poorly investigated. This study aimed to assess whether patients treated by TEVAR following BTAI have thoracic aortic abnormalities in geometry, stiffness, and haemodynamics. METHODS: Patients with BTAI treated by TEVAR at Vall d'Hebron Hospital between 1999 and 2019 were compared with propensity score matched healthy volunteers (HVs). All subjects underwent cardiovascular magnetic resonance (CMR) comprising a 4D flow CMR sequence. Spatially resolved aortic diameter, length, volume, and curvature were assessed. Pulse wave velocity, distensibility, and longitudinal strain (all measurements of aortic stiffness) were determined regionally. Moreover, advanced haemodynamic descriptors were quantified: systolic flow reversal ratio (SFRR), quantifying backward flow during systole, and in plane rotational flow (IRF), measuring in plane strength of helical flow. RESULTS: Twenty-six BTAI patients treated by TEVAR were included and matched with 26 HVs. They did not differ in terms of age, sex, and body surface area. Patients with TEVAR had a larger and longer ascending aorta (AAo) and marked abnormalities in local curvature. Aortic stiffness was greater in the aortic segments proximal and distal to TEVAR compared with controls. Moreover, TEVAR patients presented strongly altered flow dynamics compared with controls: a reduced IRF from the distal AAo to the proximal descending aorta and an increased SFRR in the whole thoracic aorta. These differences persisted adjusting for cardiovascular risk factors and were independent of time elapsed since TEVAR implantation. CONCLUSION: At long term follow up, previously healthy patients who underwent TEVAR implantation following BTAI had increased diameter, length and volume of the ascending aorta, and increased aortic stiffness and abnormal flow patterns in the whole thoracic aorta compared with matched controls. Further studies should address whether these alterations have clinical implications.

Screening performance of the chest X-ray in adult blunt trauma evaluation: Is it effective and what does it miss?

BACKGROUND: Although chest x-ray (CXR) is often used as a screening tool for thoracic injury in adult blunt trauma assessment, its screening performance is unclear. Using chest CT as the referent standard, we sought to determine the screening performance of CXR for injury. METHODS: We analyzed data from the NEXUS Chest CT study, in which we prospectively enrolled blunt trauma patients older than 14 years who received chest imaging as part of their evaluation at nine level I trauma centers. For this analysis, we included patients who had both CXR and chest CT. We used CT as the referent standard and categorized injuries as clinically major or minor according to an a priori expert panel classification. RESULTS: Of 11,477 patients enrolled, 4501 had both CXR and chest CT; 1496 (33.2%) were found to have injury, of which 256 (17%) were classified as major injury. CXR missed injuries in 818 patients (54.7%), of which 63 (7.7%) were classified as major injuries. For injuries of major clinical significance, CXR had a sensitivity of 75.4% (95% confidence interval [CI] 69.6-80.4%), specificity of 86.2% (95% CI 85.1-87.2%), negative predictive value of 98.3 (95%CI 97.9-98.6%), and positive predictive value of 24.7 (95%CI 22.9-26.7%). For any injury CXR had a sensitivity of 45.3% (95% CI 42.8-47.9%), specificity of 96.6% (95% CI 95.9-97.2%), negative predictive value of 78% (95% CI 77.2-78.8%), and positive predictive value of 86.9% (95% CI 84.5-89.0%). The most common missed major injuries were pneumothorax (30/185; 16.2%), spinal fractures (19/39; 48.7%), and hemothorax (8/70; 11.4%). The most common missed minor injuries were rib fractures (381/836; 45.6%), pulmonary contusion (203/462; 43.9%), and sternal fractures (153/229; 66.8%). CONCLUSIONS: When used alone, without other trauma screening criteria, CXR has poor screening performance for blunt thoracic injury.

POSTERIOR SEGMENT INJURIES IN OPERATION IRAQI FREEDOM AND OPERATION ENDURING FREEDOM: 2001 to 2011.

BACKGROUND/PURPOSE: To characterize the nature of posterior segment ocular injuries in combat trauma. METHODS: Eyes in the Walter Reed Ocular Trauma Database were evaluated for the presence of posterior segment injury. Final visual outcomes in open-globe versus closed-globe injuries and by zone of injury and the types of posterior segment injuries in open-globe versus closed-globe injuries were assessed. RESULTS: Four hundred fifty-two of 890 eyes (50.8%) had at least one posterior segment injury. The mechanism of injury was most commonly an improvised explosive device in 280 (62.0%) eyes. Sixty-one patients (13.5%) had a Zone I injury, 50 (11.1%) a Zone II injury, and 341 (75.4%) a Zone III injury. Patients with Zone I injuries were more likely to have a final visual acuity of 20/200 or better compared with patients with either a Zone II (P < 0.001) or Zone III injury (P = 0.007). Eyes with a closed-globe injury were more likely to have a final visual acuity of 20/200 or better compared with those with an open-globe injury (P < 0.001). Furthermore, closed-globe injury compared with open-globe injury had a lower risk of vitreous hemorrhage (odds ratio 0.32, P < 0.001), proliferative vitreoretinopathy (odds ratio 0.14, P < 0.001), and retinal detachment (odds ratio 0.18, P < 0.001) but a higher risk of chorioretinal rupture (odds ratio 2.82, P < 0.001) and macular hole (odds ratio 3.46, P = 0.004). CONCLUSION: Patients with combat ophthalmic trauma had similar posterior segment injury patterns to civilian trauma in open-globe versus closed-globe injuries. Zone II and III injuries were associated with a worse visual prognosis.

"Do You Need a Doctor's Note?" Factors Leading to Delayed Return to Work after Blunt Chest Trauma.

BACKGROUND: Blunt chest trauma is associated with significant morbidity, but the long-term functional status for these patients is less well-known. Return to work (RTW) is a benchmark for functional recovery in trauma patients, but minimal data exist regarding RTW following blunt chest trauma. MATERIALS AND METHODS: Patients ≥ 18 y old admitted to a Level 1 trauma center following blunt chest trauma with ≥ 3 rib fractures and length of stay (LOS) ≥ 3 d were included. An electronic survey assessing RTW was administered to patients after discharge. Patients were stratified as having delayed RTW (> 3 mo after discharge) or self-reported worse activities-of-daily-living (ADL) function after injury. Patient demographics, outcomes, and injury characteristics were compared between groups. RESULTS: Median time to RTW was 3 mo (IQR 2,5). Patients with delayed RTW had higher odds of having more rib fractures than those with RTW ≤ 3 mo (median 10 versus 7; OR:1.24, 95%CI:1.04,1.48) as well as a longer LOS (median 13 versus 7 d; OR:1.15, 95% CI:1.04,1.30). Patients with stable ADL after trauma returned to work earlier than those reporting worse ADL (median 2 versus 3.5 mo, P < 0.01). 23.6% of respondents took longer than 5 mo to return to independent functioning, and 50% of respondents' report limitations in daily activities due to physical health after discharge. CONCLUSIONS: The significant proportion of patients with poor physical health and functional status suggests ongoing burden of injury after discharge. Patients with longer LOS and greater number of rib fractures may be at highest risk for delayed RTW after injury.

Blunt trauma to abdominal solid organs: an experience of non-operative management at a rural hospital in Zambia.

INTRODUCTION: although non-operative management of patients with blunt trauma to abdominal solid organs has become standard care, the role of peripheral hospitals remains poorly defined. This study reviews treatment and outcomes in patients with liver and spleen injuries at a regional hospital over a 10-year period. METHODS: a retrospective review of prospectively collected data was performed and supplemented by case notes retrieval. All patients with solid visceral injuries managed between 2009 and 2019 at a rural surgical hospital in Zambia were included. On admission, the patients were offered either urgent laparotomy or non-operative management (NOM) depending on their haemodynamic status. Continuous variables were expressed as median and mean ± standard deviation; categorical data were expressed as percentages. Statistical evaluation of data was performed by two-sample t-test. Statistical significance was assigned at p<0.05. RESULTS: fourty-three patients were included. The majority of victims sustained isolated spleen or liver injury. Twenty-three patients were urgently operated due to haemodynamic instability. Splenectomy performed in 17 patients, liver laceration sutured in 5 patients. One patient underwent concomitant splenectomy and liver repair. Conservative management was attempted in 20 (47%) patients and was successful in 18 (42%). In two patients NOM failed and splenectomy was performed urgently. Two patients died postoperatively. There were no deaths in NOM group. CONCLUSION: NOM of patients with injury to solid abdominal organs could be safely initiated in rural hospitals provided there is uninterrupted monitoring of patients' condition, well-trained staff and unrestricted access to the operating theatre (OT).

A New Understanding for Preoperative Management in a Patient with Blunt Brachiocephalic Trunk Injury.

We report a case of a 24-year-old male patient with blunt brachiocephalic trunk injury, who was given low-dose dexmedetomidine (DEX) for 2 weeks to help smoothly pass the preparation period before the recanalization operation. Because the patient's vital signs were stable after the injury, the surgeon did not perform emergency surgery. Taking into account the characteristics of blunt brachiocephalic trunk injury, it is necessary to avoid damage to or even rupture of brachiocephalic trunk resulting from irritability and high blood pressure. Patients should be sedated to avoid hemodynamic fluctuations that may be caused by cerebral ischemia and restlessness, and based on the patient's neurological symptoms, prevention or treatment of perioperative neurocognitive disorders (PNDs) cannot be ignored. Therefore, the choice of drugs for bridging the preoperative preparation stage is crucial. DEX is an α2-adrenergic receptor agonist with antianxiety, analgesic, and sedative effects. It can also stabilize hemodynamics, regulate neuroinflammation, and provide neuroprotection. Instead of using either ß-adrenergic receptor antagonists or sedatives, the patient received only low-dose DEX during preoperative preparation. DEX achieved the effects of ß-adrenergic receptor blockers, vasodilators, and other sedatives, and it also had certain benefits for the patient's PND. In short, based on our understanding of the relevant physiological factors, risk factors of brachiocephalic trunk injury, and the effects of DEX, low-dose DEX provides a good option for preoperative management in a patient with blunt brachiocephalic trunk injury.

Reevaluating the Need for Routine Coverage of the Left Subclavian Artery in Thoracic Blunt Aortic Injury.

BACKGROUND: Thoracic endovascular aortic repair (TEVAR) is the treatment of choice for thoracic blunt aortic injury (TBAI). A 20 mm proximal seal zone is recommended based on aneurysmal disease literature which often results in coverage of the left subclavian artery (LSA). The aim of this study was to analyze our experience with TEVAR for TBAI and evaluate whether 20 mm is required to achieve successful remodeling. METHODS: This is a single-center, retrospective study of all consecutive patients who received a TEVAR for treatment of moderate and severe TBAI between April 2014 and November 2018. Three-dimensional software reconstruction was used for computed tomography (CT) scan centerline measurements. Outcomes included technical success, need for reinterventions, and immediate and long-term aortic-related complications. RESULTS: Sixty-one patients underwent TEVAR for TBAI during the study period. Twenty-eight (46%) patients underwent LSA coverage with an average distance from the LSA to the injury of 6.4 mm (0-15.1 mm). Of the 33 (54%) patients who did not undergo coverage of the LSA, 22 patients (66%) had less than 20 mm of proximal seal zone. The mean distance from the LSA to injury in this group was 16.6 mm (7.9-29.5 mm). None of the patients with LSA coverage developed ischemic symptoms, and an average decrease in left arm systolic blood pressure of 24.8 mm Hg (0-62 mm Hg) was noted versus the right arm. There was no aortic-related mortality in either group. Follow-up CT scans revealed excellent remodeling. CONCLUSIONS: Immediate outcomes of TEVAR for TBAI with LSA coverage are well tolerated; however, the long-term sequela of LSA coverage is unknown. Exclusion of the injury and excellent remodeling appear to occur with less than 20 mm of proximal seal, and perhaps more attention should be made to preservation of the LSA.

The importance of modeling the human cerebral vasculature in blunt trauma.

BACKGROUND: Multiple studies describing human head finite element (FE) models have established the importance of including the major cerebral vasculature to improve the accuracy of the model predictions. However, a more detailed network of cerebral vasculature, including the major veins and arteries as well as their branch vessels, can further enhance the model-predicted biomechanical responses and help identify correlates to observed blunt-induced brain injury. METHODS: We used an anatomically accurate three-dimensional geometry of a 50th percentile U.S. male head that included the skin, eyes, sinuses, spine, skull, brain, meninges, and a detailed network of cerebral vasculature to develop a high-fidelity model. We performed blunt trauma simulations and determined the intracranial pressure (ICP), the relative displacement (RD), the von Mises stress, and the maximum principal strain. We validated our detailed-vasculature model by comparing the model-predicted ICP and RD values with experimental measurements. To quantify the influence of including a more comprehensive network of brain vessels, we compared the biomechanical responses of our detailed-vasculature model with those of a reduced-vasculature model and a no-vasculature model. RESULTS: For an inclined frontal impact, the predicted ICP matched well with the experimental results in the fossa, frontal, parietal, and occipital lobes, with peak-pressure differences ranging from 2.4% to 9.4%. For a normal frontal impact, the predicted ICP matched the experimental results in the frontal lobe and lateral ventricle, with peak-pressure discrepancies equivalent to 1.9% and 22.3%, respectively. For an offset parietal impact, the model-predicted RD matched well with the experimental measurements, with peak RD differences of 27% and 24% in the right and left cerebral hemispheres, respectively. Incorporating the detailed cerebral vasculature did not influence the ICP but redistributed the brain-tissue stresses and strains by as much as 30%. In addition, our detailed-vasculature model predicted strain reductions by as much as 28% when compared to current reduced-vasculature FE models that only include the major cerebral vessels. CONCLUSIONS: Our study highlights the importance of including a detailed representation of the cerebral vasculature in FE models to more accurately estimate the biomechanical responses of the human brain to blunt impact.

Mean arterial pressure maintenance following spinal cord injury: Does meeting the target matter?

INTRODUCTION: Neurosurgical guidelines recommend maintaining mean arterial pressure (MAP) between 85 and 90 mm Hg following acute spinal cord injury (SCI). In our hospital, SCI patients receive orders for MAP targeting for 72 hours following admission, but it is unclear how often the patient's MAP meets the target and whether or not this affects outcome. We hypothesized that the proportion of MAP measurements ≥85 mm Hg would be associated with neurologic recovery. METHODS: Spinal cord injury patients with blunt mechanism of injury admitted between 2014 and 2019 were identified from the registry of a level 1 trauma center. Proportion of MAP values ≥85 mm Hg was calculated for each patient. Neurologic improvement, as measured by positive change in American Spinal Injury Association (ASIA) impairment scale by ≥1 level from admission to discharge was evaluated with respect to proportion of elevated MAP values. RESULTS: A total of 136 SCI patients were evaluated. Average proportion of elevated MAP values was 75%. Admission ASIA grades were as follows: A, 30 (22.1%); B, 20 (14.7%); C, 28 (20.6%); and D, 58 (42.6%). One hundred six patients (77.9%) required vasopressors to elevate MAP (ASIA A, 86.7%; B, 95.0%; C, 92.9%; D, 60.3%). Forty patients (29.4%) were observed to have improvement in ASIA grade by discharge (admission ASIA A, 15%; B, 33%; C, 40%; D, 13%). The proportion of elevated MAP values was higher for patients with neurologic improvement (0.81 ± 0.15 vs. 0.72 ± 0.25, p = 0.014). Multivariate modeling demonstrated a significant association between proportion of elevated MAP values and neurologic improvement (p = 0.028). An interaction revealed this association to be moderated by vasopressor dose (p = 0.032). CONCLUSION: The proportion of MAP measurements ≥85 mm Hg was determined to be an independent predictor of neurologic improvement. Increased vigilance regarding MAP maintenance above 85 mm Hg is warranted to optimize neurologic recovery following SCI. LEVEL OF EVIDENCE: Therapeutic/care management, level IV.

Evaluation of Densitometric Analysis for Early Detection of Corneal Blood Staining in Hyphema.

PURPOSE: To investigate the possibility of detecting presumed corneal blood staining after traumatic hyphema with corneal densitometry and to evaluate corneal transparency after hyphema resolution. METHODS: Twenty-eight patients with uniocular nonpenetrating ocular trauma with hyphema were included in the study. Corneal densitometry measurements were performed at the first week and the first month after full resolution of blood in the anterior chamber and discontinuation of medication. The uninjured eyes were accepted as the control group. RESULTS: The corneal densitometry values at all zones of the posterior layer in the study eyes were significantly higher at the first week compared with the first month (P < 0.05 for all). Comparison of the corneal densitometry values of the study eyes at the first week with the fellow eyes showed significantly higher values at all zones of the posterior corneal layer (P < 0.05 for all). Comparison of the study eyes at the first month with the fellow eyes was significantly higher at the posterior 0- to 2-, 2- to 6-, and 6- to 10-mm zones (P = 0.030, P = 0.044, and P = 0.035, respectively). Although corneal densitometry values at the posterior 10- to 12-mm and posterior total zones were higher at the first month compared with those of the fellow eyes, these differences were not statistically significant (P = 0.197 and P = 0.085, respectively). CONCLUSIONS: Corneal densitometry at all zones of the posterior corneal layer significantly changed after traumatic hyphema. Corneal densitometry analysis could be used in clinically normal cases for possible early corneal blood staining detection.

Thoracic Aortic Dilation after Endovascular Repair of Blunt Traumatic Aortic Injury.

BACKGROUND: Thoracic endovascular aneurysm repair (TEVAR) has become the current standard of care for emergent treatment of traumatic blunt thoracic aortic injuries (BTAI). Although aortic dilation (AD) of the infrarenal neck after EVAR for aortic aneurysms has been studied, changes in aortic diameter after TEVAR for BTAI is not well understood. This study aims to characterize changes in thoracic aortic diameter after stent-graft placement in the setting of nonaneurysmal traumatic aortic injury. METHODS: A single-center, retrospective review was performed involving patients presenting with BTAI treated with TEVAR. Only patients with at least 12 months follow-up were included. Aortic diameter, defined as the outer-to-outer diameter on 3D center-line imaging, was measured at six locations along the proximal and mid thoracic aorta. The first postoperative CT (≤1 month) served as a baseline from which interval measurements were compared. RESULTS: Twenty patients with BTAI treated from 2011 to 2017 had adequate imaging available for review and were included in this study cohort. Median follow-up time was 46.8 (12-80, range) months. At the latest follow-up, AD occurred at all measured locations within the endograft, starting from the proximal graft edge (0.62 ± 0.69 mm, P = 0.027) to the distal graft edge (1.21 ± 1.28 mm, P = 0.003). AD was most pronounced in the distal graft segment 2 cm proximal to the distal graft edge, with a mean AD of 1.32 ± 1.59 mm (+5.3%, P < 0.001). At this location, AD was found to increase in a linear manner with an estimated rate of 0.67 ± 0.20 mm/year (P = 0.006). The native aorta proximal and distal to the endograft was not found to significantly dilate during follow-up (P = 0.280-0.897). Seventy percent of the patients were found to have AD >5%. The amount of AD was not found to be associated with either graft oversizing (P = 0.151) or age (P = 0.340). There were no cases of graft migration, erosion, or endoleak. CONCLUSIONS: AD is a common benign finding after TEVAR for BTAI. AD is most pronounced at the near the distal end of the stent graft. In late-term follow-up, there are no known associated complications related to AD.

Combined head and abdominal blunt trauma in the hemodynamically unstable patient: What takes priority?

BACKGROUND: The management of hypotensive patients with severe combined head and abdominal trauma is challenging, regarding the need, timing, and sequence of craniotomy or laparotomy. The purpose of the present study was to determine whether rare situations requiring craniotomy prior to laparotomy can be identified on admission with simple clinical parameters. We hypothesized that hypotension is rarely associated with the need of a combined procedure, especially in patients with mildly depressed consciousness. METHODS: National Trauma Data Bank study, including adult blunt trauma patients with combined severe head (Abbreviated Injury Scale score, ≥ 3) and abdominal injury (Abbreviated Injury Scale score, ≥ 3). Data collection included demographic and clinical characteristics, laparotomy, and craniotomy within 24 hours of admission, types of intracranial pathologies, survival, and hospital stay. Multivariate regression analysis was used to determine factors predictive for the need of both operative procedures. RESULTS: Of 25,585 patients with severe combined head and abdominal trauma, 8,744 (34.2%) needed only laparotomy, 534 (2.1%) only craniotomy, and 394 (1.5%) required both procedures within 24 hours of admission. In the subgroup of 4,667 hypotensive patients, 2,421 (51.9%) underwent only laparotomy, 54 (1.2%) only craniotomy, and 79 (1.7%) both procedures within 24 hours of admission. Only 5 (0.7%) of 711 hypotensive patients with Glasgow Coma Scale (GCS) score above 8 who required a laparotomy also needed a craniotomy. Among clinical parameters available on patient's arrival, GCS score of 7 to 8 was independently associated with the highest need for craniotomy in hypotensive patients requiring laparotomy (odds ratio, 7.94; p = 0.004). CONCLUSION: The need for craniotomy in patients with severe combined head and abdominal injury requiring exploratory laparotomy is very low. In hypotensive patients requiring laparotomy, GCS score of 7 to 8 was an independent predictor of the need for craniotomy. In hemodynamically unstable patients with a GCS score greater than 8, it may be safer to proceed with a laparotomy first and address the head with a computed tomography scan at a later stage. LEVEL OF EVIDENCE: Therapeutic, Level IV.