Trans-base and trans-vault low-velocity penetrating brain injury: A retrospective comparative study of characteristics, treatment, and outcomes

PURPOSE: Low-velocity penetrating brain injury (LVPBI) caused by foreign bodies can pose life-threatening emergencies. Their complexity and lack of validated classification data have prevented standardization of clinical management. We aimed to compare the trans-base and trans-vault phenotypes of LVPBI to help provide guidance for clinical decision-making of such injury type. METHODS: A retrospective study on LVPBI patients managed at our institution from November 2013 to March 2020 was conducted. We included LVPBI patients admitted for the first time for surgery, and excluded those with multiple injuries, gunshot wounds, pregnancy, severe blunt head trauma, etc. Patients were categorized into trans-base and trans-vault LVPBI groups based on the penetration pathway. Discharged patients were followed up by outpatient visit or telephone. The data were entered into the Electronic Medical Record system by clinicians, and subsequently derived by researchers. The demography and injury characteristics, treatment protocols, complications, and outcomes were analyzed and compared between the two groups. A t-test was used for analysis of normally distributed data, and a Mann-Whitney U test for non-parametric data. A generalized linear model was further established to determine whether the factors length of stay and performance scale score were influenced by each factor. RESULTS: A total of 27 LVPBI patients were included in this analysis, comprised of 13 (48.1%) trans-base cases and 14 (51.9%) trans-vault cases. Statistical analyses suggested that trans-base LVPBI was correlated with deeper wounds; while the trans-vault phenotype was correlated with injury by metal foreign bodies. There was no difference in Glasgow Coma Scale score and the risk of intracranial hemorrhage between the two groups. Surgical approaches in the trans-base LVPBI group included subfrontal (n = 5, 38.5%), subtemporal (n = 5, 38.5%), lateral fissure (n = 2, 15.4%), and distal lateral (n = 1, 7.7%). All patients in the trans-vault group underwent a brain convex approach using the foreign body as reference (n = 14, 100%). Moreover, the two groups differed in application prerequisites for intracranial pressure monitoring and vessel-related treatment. Trans-base LVPBI was associated with higher rates of cranial nerve and major vessel injuries; in contrast, trans-vault LVPBI was associated with lower functional outcome scores. CONCLUSION: Our findings suggest that trans-base and trans-vault LVPBIs differ in terms of characteristics, treatment, and outcomes. Further understanding of these differences may help guide clinical decisions and contribute to a better management of LVPBIs.