Septal Transposition: A Novel Technique for Preservation of the Nasal Septum during Endoscopic Endonasal Resection of Olfactory Groove Meningiomas

Introduction: Endonasal resection of olfactory groove meningiomas may be indicated in select cases. The endoscopic approach requires resection of the superior nasal septum for access resulting in a large septal perforation. We describe an approach to the anterior cranial base that best preserves the normal nasal anatomy in a patient with an olfactory groove meningioma. Septal transposition allows for a wide exposure of the anterior cranial base, preserves a nasal septal flap, and eliminates a septal perforation.

Case Report: A 39- year-old woman presented with anosmia and a progressively enlarging olfactory groove meningioma on serial imaging. An endoscopic endonasal resection of the tumor was performed. A nasoseptal flap was raised on the left side in the standard fashion. As opposed to performing a large superior septectomy, a superior and an inferior tunnel was made raising the mucoperichondrium in narrow (10 mm) bands along the superior and inferior septum on the right side. Endoscopic scissors were then placed through these tunnels and used to detach the septum superiorly and inferiorly. This allowed the septum to be detached from the anterior skull base but remain adherent to the septal mucoperichondrium in the central portion. Thus, the septum with its attached mucoperichondrium was transposed off the maxillary crest and pushed into the right nasal corridor, remaining out of the surgical field. This was accomplished without destroying septal bone, cartilage, or mucosa. Once the tumor resection was completed, the septum and a fully intact mucoperichondrium were returned to the midline. On outpatient follow-up, nasal endoscopy the right side of the nasal cavity had completely normal anatomy without septal perforation, and the left side had an intact mucosalized septum. There was no cerebrospinal fluid leakage, and the left-sided nasoseptal flap was well healed and adherent to the cranial base.

Conclusion: In select cases, it is possible to maximally preserve the nasal septum when approaching anterior cranial base tumors such as olfactory groove meningiomas. The septal transposition is a useful technique that allows a wide exposure of the anterior cranial base with preservation of the normal nasal anatomy and avoidance of a large septal perforation.