Endoscopic endonasal translacerum approach for resection of petroclival chondrosarcoma

Petroclival chondrosarcomas are a formidable surgical challenge given the close relationship to critical neurovascular structures. The endoscopic endonasal approach can be utilized for many petroclival chondrosarcomas. However, tumors that extend to the inferior petrous apex require working behind the internal carotid artery (ICA). We present a case of a 33-year-old with a 1-year history of complete abducens palsy, with imaging showing an enhancing mass centered at the left petroclival fissure and inferior petrous apex behind the paraclival carotid artery and extending down into the nasopharynx abutting the cervical ICA. In this video, we describe the surgical steps of the endoscopic endonasal translacerum approach with ICA skeletonization and mobilization. We also highlight the relevant surgical anatomy with anatomical dissections to supplement the surgical video. The patient did well without complications. Postoperative MRI demonstrated complete resection and pathology revealed grade II chondrosarcoma. He underwent adjuvant proton beam radiotherapy. The video can be found here: https://youtu.be/80QXALJW9ME.