Combined Transorbital-Endonasal Approach to the Anterior Skull Base

Introduction: Traditional craniofacial approaches to the midline anterior skull base are associated with risks (i.e., loss of olfaction) that, while tolerated for malignancies, could be avoided for benign/less extensive pathology. Keyhole craniotomies are based anterolaterally where view of the midline skull base is hindered by the orbital roof. The orbit could serve as a direct conduit to access select lesions; combined with an endonasal approach, this could allow circumferential exposure of the anterior cranial fossa.

Methods: Either a transpalpebral or transconjunctival incision is performed to expose the supraorbital ridge. A mini-orbitofrontal craniotomy including the orbital roof is performed; after which, surgery proceeds under microscope or endoscope illumination. Concurrently, an endonasal endoscopic approach aids in resection of intranasal tumor and/or repair of any anterior cranial fossa defect. Dural defects are repaired with fascia lata.

Results: Six patients (ages 20-58 years) underwent combined transorbital-endonasal surgery for: esthesioneuroblastoma, mucocele, CSF leak. In all patients, surgery was considered successful (gross total resection/negative margins or no CSF leak recurrence). No cosmetic or orbital complications (including corneal abrasion and lacrimal duct injury) were noted.

Conclusions: A transorbital approach can access midline pathology and lateral anterior cranial fossa not accessible endonasally; it further allows for direct visualization of dural/intracranial pathology involvement. The combined transorbital-endonasal approach is a two-surgeon/four-handed technique to circumferentially access the anterior cranial fossa from transcranial and transnasal trajectories in a minimally invasive fashion. For select lesions, this technique is an efficient and safe alternative to traditional approaches (e.g., bifrontal craniotomy).