Role of magnetic resonance imaging in predicting late facial motor function after removal of vestibular schwannomas by the translabyrinthine approach

Abstract

AbstractFacial motor function was assessed in 61 patients 18 months after surgical resection, by the translabyrinthine approach, of vestibular schwannoma involving both the cerebellopontine angle (CPA) and the auditory canal.Pre-operative magnetic resonance imaging (MRI) was performed to measure the maximum extracanalicular diameter of the tumour between the porus and the farthest extension in the CPA on tranverse slices and to calculate extracanalicular tumour volume. Post-operative facial motor function was graded according to the House and Brackmann system.There was a statistically significant relationship between late facial motor function and extracanalicular diameter. The best cut-off point for good and poor results was 20mm. There was no relationship between the tumour volume and the late post-operative facial motor function grade.In this study the best pre-operative radiological predictor of the late facial motor function in patients operated on by the translabyrinthine approach was the maximum diameter measured byMRI.