Isolated severe traumatic brain injuries sustained during combat operations: demographics, mortality outcomes, and lessons to be learned from contrasts to civilian counterparts.

BACKGROUND: Severe traumatic brain injuries occurring in the context of modern military conflict are entities about which little has been reported. We reviewed the epidemiology of these injuries from the Joint Trauma Theater Registry (JTTR), contrasting these results with civilian counterparts from the National Trauma Databank (NTDB).
METHODS: Isolated severe brain injuries (defined as head abbreviated injury scale [AIS] ≥3 and no other body region AIS>2) were queried from the JTTR over a period from 2003 to 2007. The demographics and outcomes of these injuries were reviewed. These results were then contrasted to findings of similar patients, age 18 years to 55 years, over the same period from the NTDB using propensity score matching derived from age, gender, systolic blood pressure, Glasgow Coma Scale, and AIS.
RESULTS: JTTR review identified 604 patients meeting study criteria, with a mean age of 25.7 years. Glasgow Coma Scale was ≤8 in 27.8%, and 98.0% were men. Hypotension at presentation was noted in 5.5%. Blast (61.9%) and gunshot wound (19.5%) mechanisms accounted for the majority of combat injuries. Intracranial pressure monitoring was used in 15.2%, and 27.0% underwent some form of operative cranial decompression, lobectomy, or debridement. When compared with matched civilian NTDB counterparts, JTTR patients were significantly more likely to undergo intracranial pressure monitoring (13.8% vs. 1.7%; p<0.001) and operative neurosurgical intervention (21.5% vs. 7.2%; p<0.001). Mortality was also significantly better among military casualties overall (7.7% vs. 21.0%; p<0.001; odds ratio, 0.32 [0.16-0.61]) and particularly after penetrating mechanisms of injury (5.6% vs. 47.9%; p<0.001; odds ratio, 0.07 [0.02-0.20]) compared with propensity score-matched NTDB counterparts.
CONCLUSION: Patients sustaining severe traumatic brain injury during military operations represent a unique population. Comparison with civilian counterparts has inherent limitations but reveals higher rates of neurosurgical intervention performed after penetrating injuries and a corresponding improvement in survival. Many factors likely contribute to these findings, which highlight the need for additional research on the optimal management of penetrating brain injury.