Background
Hemorrhage progression following traumatic brain injury (TBI) is not fully understood, and preventing it would be a potential therapeutic opportunity in TBI management. The aim of this study was to determine how non-operated hemorrhagic lesions progress following TBI, and how this affects outcome.
Methods
This was a retrospective observational cohort study of adult patients (≥ 15 years) with moderate-to-severe TBI. Hemorrhage volumes were calculated from computed tomography (CT) scans using semi-automated volumetric segmentation.
Results
In total, 643 patients were included, with a median Glasgow Coma Scale of 7. Contusions were the most common form of traumatic intracranial hemorrhage. The mean total lesion volume on the first CT scan was 4.29 ml, and the mean lesion progression volume (LPV), i.e. the increase in volume from first CT scan until the lesion had stopped progressing, was 3.85 ml. Contusions showed a significantly larger LPV than SDH and EDH (p < 0.001). The median lesion progression time (LPT), i.e. the time from injury until all lesions had stopped progressing, was 5.98 hours, with contusions progressing for a longer time than tSAH, SDH and EDH (p < 0.001). Hemorrhage progression also slowed exponentially over time, with almost no further expansion occurring 24 hours after trauma. In multivariable regression analysis, LPV was independently associated with 12-month Glasgow Outcome Score after adjusting for known TBI outcome predictors (p < 0.001).
Conclusions
Contusions were the most common form of traumatic intracranial hemorrhage, and exhibited both a larger LPV and longer LPT than extra-axial hematomas. Regression analysis indicated that LPV was independently related to, and possibly a driver of, unfavorable outcome. Interventions to prevent lesion progression are therefore likely to improve outcome in TBI patients. Moreover, this study suggests a wider window of opportunity to prevent lesion progression than what has previously been suggested.