gms | German Medical Science

Objective: Meningiomas involving the anterior visual system may originate from different anatomical sites of the anterior or middle fossa. Some of these tumors may also additionally invade the optic canal. Microsurgical resection of the intracanalicular part of the tumor is crucial in order to achieve satisfactory postoperative visual outcome. We report our experience of endoscopic visualization of the optic canal in order to identify remnant intracanalicular tumors.

Method: There were 126 patients with skullbase meningiomas involving the anterior optic system. Patients were operated through the frontolateral or pterional approach using microsurgical technique between January 2006 and August 2014. In 26 patients, the endoscope was used additionally in order to evaluate, whether any intracanalicular tumor remnants could be identified although the microscopic view assumed complete intracanalicular resection of the tumor.

Results: Among 26 patients, who underwent endoscope assisted microsurgery, there were 14 tuberculum sellae meningiomas and 12 planum sphenoidale meningiomas. In 16 patients, tumor involvement of the optic canal was suspected on preoperative MRI imaging. Intraoperatively, optic canal involvement was observed under the operating microscope in all 26 patients. Tumors were resected using the surgical microscope until complete tumor removal was assumed by the surgeon including the intracanalicular tumor portion. The endoscope with 0° and 30° angled view was used thereafter. Intracanalicular tumor remnants were identified in 6 patients, which led to subsequent surgical dissection in order to completely remove the tumor in the optic canal.

Conclusions: Additional endoscopic visualization of the optic canal through a standard frontolateral or pterional approach allowed identification of otherwise microscopically dismissed intracanalicular tumor remnants. Endoscopic assisted surgery enhanced radicality of tumor resection in meningiomas involving the optic canal.