Endoscope-assisted microsurgical resection of skull base meningiomas

Abstract

This study aims to determine the value of endoscope assistance in the microsurgical resection of skull base meningiomas. Fourty-six patients harboring a skull base meningioma underwent an endoscope-assisted microsurgical resection. In 30 patients (65%), tumor parts which could not be visualized under the microscope were detected with the endoscope. In 26 patients (56%), these tumor remnants were removed under endoscopic view. Gross total resection was achieved in 35 patients (76%) and near-total resection in 11 (24%). There was no surgical mortality. The major complication was new cranial nerve deficit. The application of endoscopes was most useful in the small supraorbital craniotomies to look under the ipsilateral optic nerve and internal carotid artery as well as to visualize the diaphragm sellae and olfactory groove. In the retrosigmoid craniotomies, the endoscope was beneficial to inspect the internal auditory canal, to look into Meckel's cave, or to inspect areas hidden behind the jugular tubercle and tentorial edge. There was no obvious complication related to the application of the endoscope. Endoscope assistance is particularly of value when skull base meningiomas are to be removed via small craniotomies to inspect blind corners which cannot be visualized in a straight line with the microscope. In addition, there is a benefit of using endoscopes with various angles of view in standard craniotomies and skull base approaches to look around bony and dural corners or to look behind neurovascular structures, by which the amount of skull base drilling and retraction to expose the tumor can be reduced.

Tumors of the anterior skull base

“…CSF leaks, however, were higher in patients recovering from endoscopic surgery [68]. Interestingly, one study reviewing skull-based meningiomas notes that the use of the endoscope allowed further visualization of tumor that a microscope could not see in 65% of patients [19]. A literature review comparing only open transcranial versus transphenoidal craniopharyngiomas showed that the endoscopic study had greater rate of total resection and improved postoperative visual outcome [69].…”

“…Treatment options include monitoring small slow-growing lesions, radiation or surgical resection. The most common surgical complication is cranial nerve palsies [19].…”

Transcranial endoscope-assisted skull base surgery – posterior fossa

“…When using small craniotomies, which allow only a nearly coaxial vision, the endoscope is mandatory to inspect any corner of the surgical field [ 19 ].…”

The combined microscopic-endoscopic technique for radical resection of cerebellopontine angle tumors

“…2,3,26 Endoscopic techniques for cer-ebellopontine angle (CPA) surgery have been well studied and applied to tumor resection, vascular decompression, and aneurysm surgery. 5,8,10,[17][18][19]22,23,28,32,[34][35][36]39,40,42 The advantages have been emphasized in the context of minimally invasive craniotomies, 4,13,15,31 increasing visualization of hidden anatomy, and inspecting around corners. 6,7,14,23,33,43, abbreviations CPA = cerebellopontine angle; EVTR = endoscopically verified total resection.…”