Xin Zhang1,2,3, Halima Tabani1,2, Ivan El-Sayed1,2,4, Matthew Russell4, Xuequan Feng1,2, Arnau Benet1,2,4. 1. Department of Neurological Surgery, University of California, San Francisco, San Francisco, California. 2. Skull Base and Cerebrovascular Laboratory, Univer-sity of California, San Francisco, San Francisco, California. 3. Department of Neurosurgery, Beijing Bo'ai Hospital, China Rehabilitation Research Center, Beijing, China. 4. Department of Oto-laryngology Head and Neck Surgery, University of California, San Francisco, San Francisco, California.
Abstract
BACKGROUND: Surgical access to Meckel's Cave (MC) is challenging due to its deep location and surrounding important neurovascular structures. Currently existing endoscopic endonasal (EE) approaches require dissecting near the internal carotid artery (ICA) or require transposition of the pterygopalatine neurovascular bundle. OBJECTIVE: To describe a novel approach to access the anterolateral aspect of the MC using a minimally invasive EE route. METHODS: The EE transmaxillary transinferior orbital fissure approach was simulated in 10 specimens. The approach included an ethmoidectomy followed by an extended medial maxillectomy with transposition of the nasolacrimal duct. The infraorbital fissure was opened, and the infraorbital neurovascular bundle was transposed inferiorly. A quadrilateral space, bound by the maxillary nerve inferomedially, ophthalmic nerve superomedially, infraorbital nerve inferolaterally, and floor of the orbit superolaterally, was exposed. The distances from the foramen rotundum (FR) to the ICA, orbital apex (OA), and infratemporal crest (ITC) and from the OA to the ICA and ITC were measured. RESULTS: The distances obtained were FR-ICA = 19.42 ± 2.03 mm, FR-ITC = 18.76 ± 1.75 mm, FR-OA = 8.54 ± 1.34 mm, OA-ITC = 19.78 ± 2.63 mm, and OA-ICA = 20.64 ± 142 mm. Two imaginary lines defining safety boundaries were observed between the paraclival ICA and OA, and between the OA and ITC (safety lines 1 and 2). CONCLUSION: The reported approach provides a less invasive route compared to contemporary approaches, allowing expanded views and manipulation anteromedial and anterolateral to MC. It may be safer than the existing approaches as it does not require transposition of the ICA, infratemporal fossa, and pterygopalatine fossa, and allows access to tumors located anteriorly on the floor of the middle cranial fossa.
BACKGROUND: Surgical access to Meckel's Cave (MC) is challenging due to its deep location and surrounding important neurovascular structures. Currently existing endoscopic endonasal (EE) approaches require dissecting near the internal carotid artery (ICA) or require transposition of the pterygopalatine neurovascular bundle. OBJECTIVE: To describe a novel approach to access the anterolateral aspect of the MC using a minimally invasive EE route. METHODS: The EE transmaxillary transinferior orbital fissure approach was simulated in 10 specimens. The approach included an ethmoidectomy followed by an extended medial maxillectomy with transposition of the nasolacrimal duct. The infraorbital fissure was opened, and the infraorbital neurovascular bundle was transposed inferiorly. A quadrilateral space, bound by the maxillary nerve inferomedially, ophthalmic nerve superomedially, infraorbital nerve inferolaterally, and floor of the orbit superolaterally, was exposed. The distances from the foramen rotundum (FR) to the ICA, orbital apex (OA), and infratemporal crest (ITC) and from the OA to the ICA and ITC were measured. RESULTS: The distances obtained were FR-ICA = 19.42 ± 2.03 mm, FR-ITC = 18.76 ± 1.75 mm, FR-OA = 8.54 ± 1.34 mm, OA-ITC = 19.78 ± 2.63 mm, and OA-ICA = 20.64 ± 142 mm. Two imaginary lines defining safety boundaries were observed between the paraclival ICA and OA, and between the OA and ITC (safety lines 1 and 2). CONCLUSION: The reported approach provides a less invasive route compared to contemporary approaches, allowing expanded views and manipulation anteromedial and anterolateral to MC. It may be safer than the existing approaches as it does not require transposition of the ICA, infratemporal fossa, and pterygopalatine fossa, and allows access to tumors located anteriorly on the floor of the middle cranial fossa.
Authors: E Suero Molina; J M Revuelta Barbero; C Ewelt; W Stummer; R L Carrau; D M Prevedello Journal: Neurosurg Rev Date: 2020-02-10 Impact factor: 3.042