Institutional Review and Identification of Indications for Endoscopic Expanded Endonasal versus Craniotomy Approach to Anterior Skull Base Meningiomas

Introduction: Several microsurgical transcranial approaches have been used for resection of anterior cranial fossa meningiomas. However, debate continues as to whether these approaches may be more prone to injury of the optic apparatus or its blood supply. The definitive indications for using the endoscopic expanded endonasal (EEE) approach are not yet clear. We report our experience of the EEE approach for tuberculum sellae and olfactory groove meningiomas using the endoscope as the sole means of visualization (i.e., “pure” endoscopic). In addition, we reviewed and pooled the available literature regarding the use of the pure EEE approach for these lesions.

Methods: Following local research ethics board approval, a prospectively maintained database of all surgical cases between May 2006 and August 2012 was retrospectively reviewed. Twenty-four patients were identified who had pure EEE surgery performed by ZG and FG. This group had a median age of 66 years at the time of surgery (range, 37-88 years). The follow-up period ranged from 3 to 48 months (median, 11 months). A PubMed literature search was performed and articles were retrieved and reviewed for patients undergoing pure EEE approaches, in addition to all references therein being assessed for further relevant cases. Single case reports were excluded. Inclusion criteria were: (1) data presented in a disaggregated fashion, (2) patients clearly identifiable as having undergone pure EEE for tuberculum sellae or olfactory groove meningioma, and (3) minimum outcome data included tumor resection rates and postoperative CSF leak incidences.

Results: At the time of abstract submission, the majority of patients had a gross total resection (Simpson grades I and II). There was no perioperative mortality. Postoperative cerebrospinal fluid (CSF) leaks occurred in two patients (rate of 8%), one of whom also had a CSF infection. Four required a lumbar drain. Results of literature search will be presented in table format.

Conclusion: A pure EEE approach for anterior cranial fossa meningiomas can be safely used by surgeons who are appropriately experienced in endoscopic endonasal procedures. CSF leakage remains the most significant complication of this technique, although it is felt likely that, with widespread use of the pedicled nasoseptal flap, leak rates should improve. In addition, with longer follow-up, the recurrence rates via an endoscopic expanded endonasal approach will be better delineated.