%0 Journal Article %T Olfactory Preservation in Craniofacial Resection of Tumor Invading Hemianterior Skull Base: Operative Video. %A Kobayashi K %A Miyakita Y %A Matsumoto F %A Omura G %A Matsumura S %A Ikeda A %A Eguchi K %A Ito A %A Narita Y %A Akazawa S %A Yoshimoto S %J J Neurol Surg B Skull Base %V 83 %N 0 %D Aug 2022 %M 36068901 %F 1.407 %R 10.1055/s-0041-1727123 %X In traditional craniofacial resection of tumors invading the anterior skull base, the bilateral olfactory apparatus is resected. Recently, transnasal endoscopy has been used for olfactory preservation in resections of unilateral low-grade malignancies. However, for tumors that invade the orbita or for high-grade malignancies, the transnasal endoscopic skull base surgery has been controversial. This video demonstrates the surgical techniques of olfactory preservation during craniofacial resection of a high-grade malignancy invading the hemianterior skull base and orbita. We present the case of a 32-year-old woman with osteosarcoma in the right ethmoid sinus. The tumor invaded the ipsilateral cribriform plate, dura menta, and orbital periosteum; however, the nasal septum and crista galli were intact ( Fig. 1A, B ). Because the tumor was a high-grade malignancy and the orbita had been invaded, we performed craniofacial resection instead of endoscopic resection ( Fig. C2A ). We drilled into the right side of the crista galli, midline of the cribriform plate, and perpendicular plate of the ethmoid bone via craniotomy. As a result, we accessed the nasal cavity directly ( Fig. 2B ). To preserve the nasal septum, we detached the remaining right septal mucosa through the transfacial approach ( Fig. 2C ). Because of the high risk of cerebrospinal fluid leakage as a result of previous irradiation, we performed vascularized free flap reconstruction of the skull base instead of pericranial flap. Postoperative computed tomography revealed no evidence of tumor ( Fig. 1C, D ). The patient's sense of smell returned after 1 postoperative day, and she was discharged on the postoperative day 14. The link to the video can be found at: https://youtu.be/XzPABYwzkjs .