Ballistic lobar trajectory outcomes in civilian firearm penetrating brain injury.

OBJECTIVE: Penetrating brain injury (PBI) is the most lethal of all firearm injuries, with reported survival rates of less than 20%. The projectile trajectory (PT) has been shown to impact mortality, but the significant lobar tracks have not been defined. The aim of this retrospective case-control study was to test for associations between distinct ballistic trajectories, missile types, and patient outcomes. METHODS: A total of 243 patients who presented with a PBI to the Saint Louis University emergency department from 2008 through 2019 were identified from the hospital registry. Conventional CT scans combined with 3D CT reconstructions and medical records were reviewed for each patient to identify distinct PTs. RESULTS: A total of 65 ballistic lobar trajectories were identified. Multivariable regression models were used, and the results were compared with those in the literature. Penetrating and perforating types of PBI associated with bitemporal (t-statistic = -2.283, p = 0.023) or frontal-to-contralateral parietal (t-statistic = -2.311, p = 0.025) projectile paths were universally found to be fatal. In the group in which the Glasgow Coma Scale (GCS) score at presentation was lower than 8, a favorable penetrating missile trajectory was one that involved a single frontal lobe (adjusted OR 0.02 [95% CI 0.00-0.38], p = 0.022) or parietal lobe (adjusted OR 0.15 [95% CI 0.02-0.97], p = 0.048). Expanding or fragmenting types of projectiles carry higher mortality rates (OR 2.53 [95% CI 1.32-4.83], p < 0.001) than do nondeformable missiles. Patient age was not associated with worse outcomes when controlled by other significant predictive factors. CONCLUSIONS: Patients with penetrating or perforating types of PBI associated with bitemporal or frontal-to-contralateral parietal PTs should be considered as potential donor candidates. Trauma patients with penetrating missile trajectories involving a single frontal or parietal lobe should be considered for early neurosurgical intervention, especially in the circumstances of a low GCS score (< 8). Surgeons should not base their decision-making solely on advanced patient age to defer further treatment. Patients with PBIs caused by nondeformable types of projectiles can survive multiple simultaneous intracranial missile trajectories.

Two-year mortality and functional outcomes in combat-related penetrating brain injury: battlefield through rehabilitation.

OBJECTIVEThere are limited data concerning the long-term functional outcomes of patients with penetrating brain injury. Reports from civilian cohorts are small because of the high reported mortality rates (as high as 90%). Data from military populations suggest a better prognosis for penetrating brain injury, but previous reports are hampered by analyses that exclude the point of injury. The purpose of this study was to provide a description of the long-term functional outcomes of those who sustain a combat-related penetrating brain injury (from the initial point of injury to 24 months afterward).METHODSThis study is a retrospective review of cases of penetrating brain injury in patients who presented to the Role 3 Multinational Medical Unit at Kandahar Airfield, Afghanistan, from January 2010 to March 2013. The primary outcome of interest was Glasgow Outcome Scale (GOS) score at 6, 12, and 24 months from date of injury.RESULTSA total of 908 cases required neurosurgical consultation during the study period, and 80 of these cases involved US service members with penetrating brain injury. The mean admission Glasgow Coma Scale (GCS) score was 8.5 (SD 5.56), and the mean admission Injury Severity Score (ISS) was 26.6 (SD 10.2). The GOS score for the cohort trended toward improvement at each time point (3.6 at 6 months, 3.96 at 24 months, p > 0.05). In subgroup analysis, admission GCS score ≤ 5, gunshot wound as the injury mechanism, admission ISS ≥ 26, and brain herniation on admission CT head were all associated with worse GOS scores at all time points. Excluding those who died, functional improvement occurred regardless of admission GCS score (p < 0.05). The overall mortality rate for the cohort was 21%.CONCLUSIONSGood functional outcomes were achieved in this population of severe penetrating brain injury in those who survived their initial resuscitation. The mortality rate was lower than observed in civilian cohorts.

Early venous thromboembolism chemoprophylaxis in combat-related penetrating brain injury.

OBJECTIVE Traumatic brain injury (TBI) is independently associated with deep vein thrombosis (DVT) and pulmonary embolism (PE). Given the numerous studies of civilian closed-head injury, the Brain Trauma Foundation recommends venous thromboembolism chemoprophylaxis (VTC) after severe TBI. No studies have specifically examined this practice in penetrating brain injury (PBI). Therefore, the authors examined the safety and effectiveness of early VTC after PBI with respect to worsening intracranial hemorrhage and DVT or PE. METHODS The Kandahar Airfield neurosurgery service managed 908 consults between January 2010 and March 2013. Eighty of these were US active duty members with PBI, 13 of whom were excluded from analysis because they presented with frankly nonsurvivable CNS injury or they died during initial resuscitation. This is a retrospective analysis of the remaining 67 patients. RESULTS Thirty-two patients received early VTC and 35 did not. Mean time to the first dose was 24 hours. Fifty-two patients had blast-related PBI and 15 had gunshot wounds (GSWs) to the head. The incidence of worsened intracranial hemorrhage was 16% after early VTC and 17% when it was not given, with the relative risk approaching 1 (RR = 0.91). The incidence of DVT or PE was 12% after early VTC and 17% when it was not given (RR = 0.73), though this difference was not statistically significant. CONCLUSIONS Early VTC was safe with regard to the progression of intracranial hemorrhage in this cohort of combat-related PBI patients. Data in this study suggest that this intervention may have been effective for the prevention of DVT or PE but not statistically significantly so. More research is needed to clarify the safety and efficacy of this practice.

Arterial injuries after penetrating brain injury in civilians: risk factors on admission head computed tomography.

OBJECT: The object of this study was to determine the specific CT findings of the injury profile in penetrating brain injury (PBI) that are risk factors related to intracranial arterial injuries. METHODS: The authors retrospectively evaluated admission head CTs and accompanying digital subtraction angiography (DSA) studies from patients with penetrating trauma to the head in the period between January 2005 and December 2012. Two authors reviewed the CT images to determine the presence or absence of 30 injury profile variables and quantified selected variables. The CT characteristics in patients with and without arterial injuries were compared using univariate analysis, multivariate analysis, and receiver operating characteristic (ROC) curve analysis to determine the respective risk factors, independent predictors, and optimal threshold values for the continuous variables. RESULTS: Fifty-five patients were eligible for study inclusion. The risk factors for an intracranial arterial injury on univariate analysis were an entry wound over the frontobasal-temporal regions, a bihemispheric wound trajectory, a wound trajectory in proximity to the circle of Willis (COW), a subarachnoid hemorrhage (SAH), a higher SAH score, an intraventricular hemorrhage (IVH), and a higher IVH score. A trajectory in proximity to the COW was the best predictor of injury (OR 6.8 and p = 0.005 for all penetrating brain injuries [PBIs]; OR 13.3 and p = 0.001 for gunshot wounds [GSWs]). Significant quantitative variables were higher SAH and IVH scores. An SAH score of 3 (area under the ROC curve [AUC] for all PBIs 0.72; AUC for GSWs 0.71) and an IVH score of 3 (AUC for all PBIs 0.65; AUC for GSWs 0.65) could be used as threshold values to suggest an arterial injury. CONCLUSIONS: The risk factors identified may help radiologists suggest the possibility of arterial injury and prioritize neurointerventional consultation and potential DSA studies.