Endoscopic endonasal resection of medial orbital lesions with intraoperative MRI.

BACKGROUND: Various approaches have been described and used for operating on lesions in the orbit. The approach selection is based on the pathology in the orbit and its exact location. This study was performed to evaluate the endoscopic endonasal approach (EEA) for orbital lesions and application of intraoperative MRI (iMRI).

METHODS: Since 2006, the present authors have performed 614 endoscopic endonasal procedures. iMRI was used in 409 of these cases. Three orbital lesions approached via the endonasal route with a minimum follow-up of 1 year were analysed.

RESULTS: EEA was used in one case of intraconal cavernoma, one extraconal cavernoma and one solitary fibrous tumour in the orbit. The lesion was located medially to the optic nerve in all cases. Radical resection was achieved and the patient's vision was improved in two cases with a preoperative visual field deficit. iMRI was useful in two cases. In one case intraoperative MRI helped to find an intraconal lesion; in the other case iMRI led to evacuation of haemostatic material and blood, which was causing compression in the orbit.

CONCLUSIONS: The EEA should be considered whenever a lesion in the orbit is located medially to the optic nerve. Excellent results were achieved. iMRI proved useful in selected cases.