Experience With the Endoscopic Contralateral Transmaxillary Approach to the Petroclival Skull Base.

OBJECTIVES/HYPOTHESIS: The contralateral transmaxillary (CTM) approach is a new surgical approach that improves the surgical trajectory relative to the petrous segment of the internal carotid artery (ICA). Here, we present our clinical experience with the CTM approach to the petroclival region of the skull base. STUDY DESIGN: Retrospective review. METHODS: A retrospective review of 29 patients who underwent a CTM approach for skull base pathology from 2015 to 2020 was performed. Assessment of gross total resection (GTR) was based on postoperative imaging. RESULTS: The male:female ratio was 15:14, with an average age of 52 years (range = 19-78 years). Diagnoses included: 12 chondrosarcomas, 11 chordomas, two meningiomas, one schwannoma, one metastasis, one petrous apicitis, and one arachnoid cyst. CTM was performed in addition to a transclival approach and ipsilateral transpterygoid approach in all patients. Reconstruction of surgical defects included a vascularized flap in all but two patients: 24 nasoseptal flaps and three lateral nasal wall flaps. The reconstructive flap was on the same side as the CTM approach in 22 of 28 (79%) patients. There were no ICA injuries. In a subset of patients with chondromatous tumors, GTR of the targeted area was achieved in 16 of 22 (73%) evaluable chondromatous tumors. With a median follow-up of 13 months, 64% of these patients are without disease or dead of other causes; the remainder are alive with disease. CONCLUSIONS: The CTM approach improves the degree of resection of skull base tumors involving the petroclival region using an endoscopic endonasal approach and may minimize risk to the ICA. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:294-298, 2021.

Endoscope-assisted contralateral transmaxillary approach to the clivus and the hypoglossal canal: technical case report.

Clival lesions are still considered surgically complex due to their anatomical location. Critical structures, such as the internal carotid arteries (ICAs), cavernous sinuses, cranial nerves, and brainstem, may be encased within the lesion. Although advances in endoscopic endonasal approaches have provided new routes to these lesions, exposure and resection of clival tumors through the endonasal route remain a technical challenge. Here, the authors report a left-sided endoscopic transmaxillary approach to access the right aspect of the clivus and the hypoglossal canal.A 35-year-old woman presented with progressive right 6th cranial nerve palsy. MRI revealed a contrast-enhancing right petroclival chondrosarcoma that involved Meckel's cave and extended into the right hypoglossal canal. An endoscopic-contralateral-transmaxillary approach through a left sublabial incision was used to access the right petroclival region and right hypoglossal canal. A left maxillary osteoplastic flap was elevated to expose the left maxillary sinus. This was followed by a left medial maxillectomy, gaining access to the left posterior nasal cavity. The posterior third of the left inferior turbinate and nasal septum were removed to access the right side of the petroclival region. Near-total resection was achieved without any vascular or neurological complications. A thin shell of residual tumor was left behind due to involvement of vital structures, such as the ICA, and further treated with proton-beam radiotherapy.The endoscopic-contralateral-transmaxillary approach provides a direct surgical corridor and good lateral visualization of the skull base vasculature. This approach allows wide maneuverability around the ICA and hypoglossal canal, which, in this case, allowed maximal tumor resection with full preservation of neurological function.

Abordaje transmaxilar segmentado para resección de tumores del clivus: Reporte de un caso / Segmented trans-maxillary approach for clivus tumor resection: Case report

La compleja anatomía de las estructuras vitales de la base del cráneo dificulta mucho la resección quirúrgica de los tumores que afectan esta zona. El problema fundamental de los tumores que afectan a la base del cráneo es elegir el abordaje ideal. El desarrollo inicial de la cirugía de la base del cráneo fue producto de la colaboración entre la otorrinolaringología y la neurocirugía; la participación del cirujano maxilofacial ha sido un fenómeno relativamente reciente. En este caso se presenta un abordaje transmaxilar para acceso al clivus y eliminar el tumor.

The complex anatomy exhibited by the vital structures of the skull base hinders surgical resection of tumors present in that area. The main problem when facing tumors lodged in the skull base resides in choosing the most suitable approach. The initial development of skull base surgery was a product of the collaboration between otorhinolaryngology and neurosurgery techniques. The participation of maxillofacial surgeons in these events has been a relatively recent endeavor. In the present instance a case of trans-maxillary approach to access clivus and remove a tumor was presented.