Radiological prediction of contralateral extradural haematoma following evacuation of traumatic acute subdural haematoma.

To identify radiological predictors of contralateral extradural haematoma (CEDH) in patients undergoing evacuation of acute subdural haematoma (ASDH). Retrospective case-control study. Patients requiring evacuation of traumatic ASDH via craniotomy/craniectomy with contralateral skull fracture were analysed in two groups: those who developed CEDH postoperatively and those who did not. Retrospective analysis of severe traumatic brain injury admissions over 24 months (2017-2019) at a major trauma centre. Pre- and post-operative CT scans were reviewed by a Consultant Neuroradiologist for initial fracture haematoma (FH) and specific contralateral skull fracture features (CLFF) comprising: complex petrous fracture, suture diastasis and fractures involving foramen spinosum or middle meningeal groove (MMG). 35 patients had ASDH evacuation (age: 11-74); 7 with craniotomy, 28 with craniectomy. 9/35 developed CEDH of whom 7 underwent bilateral craniotomy/craniectomy. 8/9 with CEDH had FH, 6/26 of those without CEDH had FH. All patients with CEDH had CLFF. 6/9 had >1 CLFF. CLFF was identified in 9/26 patients without CEDH and only 3/26 non-CEDH had >1 CLFF. Analysis using univariate logistic regression identified statistically significant factors for the development of CEDH which were: younger age, FH on initial CT, increasing number of CLFF and MMG involvement alone. After multivariate analysis, only younger age and FH were significant. FH and CLFF on CT enable prediction of CEDH in patients undergoing evacuation of traumatic ASDH. These features raise a high index of suspicion for this complication and may expedite investigation and management for CEDH.