Clinical Outcomes following Endoscopic Endonasal Surgery for Anterior Cranial Base Meningiomas

Objective The endonasal endoscopic approach has been used increasingly for disease processes of the skull base; however, guidelines for endoscopic intervention are evolving and experience often limited. We sought to analyze tumor characteristics, clinical outcomes, and complications with endoscopic endonasal resection of meningiomas arising from the anterior cranial base.

Method Patients who underwent an endoscopic endonasal approach for primary and recurrent meningiomas of the anterior cranial base between April 2008 and July 2017 were retrospectively reviewed and clinical outcomes recorded.

Results Twenty-four patients with a mean age of 55.7 years and mean follow-up time of 34.6 months underwent endoscopic endonasal approaches for resection of primary or recurrent anterior cranial base meningiomas, often for WHO Grade I tumors (83.3%). There were 6 males and 18 females. Patients most frequently presented with visual changes and had tumors located in the tuberculum sella (22%) and planum sphenoidale (9%) or both (61%). Nineteen of the 24 patients underwent primary endoscopic surgery. In 10 of these, surgical and radiographic gross total tumor resection was achieved when tumors were centered in the tuberculum sellae or planum sphenoidale. The other five patients had endoscopic approaches for recurrent tumors treated previously by endoscopic or open approach (four) or a staged combined approach (one). Neither tumor size, optic canal involvement, nor primary site was limitations to gross total resection. Cavernous sinus and internal carotid artery involvement were predictive of subtotal resection (p < 0.05). While intraoperative cerebrospinal fluid (CSF) leak was frequently encountered (73.7%) only two patients experienced postoperative CSF leaks, both of which required return to the operating room for repair. Two patients each experienced hyponatremia requiring readmission and postoperative cranial nerve neuropathies (cranial nerve VI and cranial nerve II, respectively). Stable or disease-free status was achieved in 81% of patients with at least 1 year of clinical follow-up.

Conclusion The endoscopic endonasal approach for meningiomas of the midline anterior cranial base represents an excellent technique to achieve local disease control while avoiding craniotomy and cerebral retraction. Following an endonasal approach, complication rates remain low, with postoperative CSF leak and hyponatremia being most commonly encountered, yet overall infrequent.