Endoscopic Endonasal Interdural Posterior Clinoidectomy: A Key Step to Achieve Complete Resection in Clival Chordomas

Introduction: Skull base chordomas are relatively rare malignant tumors with locally aggressive behavior. Surgical removal is the gold-standard of treatment and the extent of resection is the best prognostic factor. The challenging location of posterior clinoids behind the pituitary gland results in them not being resected very often and hence, potentially leaving residual in chordomas with upper clival extension. Favorable endocrinological outcomes and technical nuances of the interdural pituitary transposition have been described, but its routine use has not spread. The purpose of this study was to understand the role of endonasal transcavernous posterior clinoidectomy approach with pituitary transposition for the treatment of clival chordomas.

Methods: All patients with skull base chordomas who underwent endoscopic endonasal posterior clinoidectomy with interdural pituitary transposition and had posterior clinoid(s) identified in surgical pathology reports between January 2012 and February 2018 were included and retrospectively analyzed. Surgical pathology reports of the posterior clinoid(s) and the radiographic location of the tumor on preoperative neuroimaging (CT and MRI) were reviewed.

Results: Thirty-three patients underwent endonasal transcavernous posterior clinoidectomy approach with pituitary transposition during the period reviewed. 23 (69.7%) patients had tumor documented by pathology in the posterior clinoid. Bilateral involvement was found in 39.1% of cases (9/23 patients). The radiographic analysis showed that upper clivus (96%) and the petroclival region (65%) were the most common locations of chordomas associated with posterior clinoid tumor involvement. Complete resection was achieved in 22/23 cases (95.7%). There was only one recurrence in this group of patients with a mean follow-up period of 18 months (6–64 months).

Conclusion: These results confirm the importance of posterior clinoid resection to achieve as much tumor removal as possible in chordoma surgery. Hence, the endoscopic endonasal interdural pituitary transposition and posterior clinoidectomy should be performed routinely in chordomas with involvement of the upper clivus or petroclival region.

No conflict of interest has been declared by the author(s).