Endoscopic transnasal resection of anterior cranial fossa meningiomas

The extended transnasal approach, a recent surgical advancements for the ventral skull base, allows excellent midline access to and visibility of the anterior cranial fossa, which was previously thought to be approachable only via a transcranial route. The extended transnasal approach allows early decompression of the optic canals, obviates the need for brain retraction, and reduces neurovascular manipulation.

Between 2004 and 2007, 11 consecutive patients underwent transnasal resection of anterior cranial fossa meningiomas--4 olfactory groove (OGM) and 7 tuberculum sellae (TSM) meningiomas. Age at surgery, sex, symptoms, and imaging studies were reviewed. Tumor size and tumor extension were estimated, and the anteroposterior, vertical, and horizontal diameters were measred on MR images. Medical records, surgical complications, and outcomes of the patients were collected.

A gross-total removal of the lesion was achieved in 10 patients (91%), and in 1 patient with a TSM only a near-total (> 90%) resection was possible. Four patients with preoperative visual function defect had a complete recovery, whereas 3 patients experienced a transient worsening of vision, fully recovered within few days. In 3 patients (2 with TSMs and 1 with an OGM), a postoperative CSF leak occurred, requiring a endoscopic surgery for skull base defect repair. Another patient (a case involving a TSM) developed transient diabetes insipidus. The operative time ranged from 6 to 10 hours in the OGM group and from 4.5 to 9 hours in the TSM group. The mean duration of the hospital stay was 13.5 and 10 days in the OGM and TSM groups, respectively. Six patients (3 with OGMs and 3 with TSMs) required a blood transfusion. Surgery-related death occurred in 1 patient with TSM, in whom the tumor was successfully removed.

The technique offers a minimally invasive route to the midline anterior skull base, allowing the surgeon to avoid using brain retraction and reducing manipulation of the large vessels and optic apparatus; hastens postoperative recovery; and improves patient compliance. Further assessment and refinement are required, particularly because of the potential risk of CSF leakage. Other studies and longer follow-up periods are necessary to ascertain the benefits of the technique.