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

Objectives: To identify radiological predictors of contralateral extradural haematoma (CEDH) in patients undergoing evacuation of acute subdural haematoma (ASDH).
Design: Retrospective case-control study.
Subjects: 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.
Materials and Methods: 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).
Results: 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.
Conclusions: 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.