Tailoring the Retroauricular Distal Cervical Transtemporal Approach to Jugular Foramen Lesions: Surgical Triangles, Anatomical Classification, and Review of 30 Cases

Introduction: Lesions of the jugular foramen occupy a deep location at the junction between the distal cervical and lateral skull base regions, and exhibit complex neurovascular relationships. Given their rarity and the increasing use of radiosurgery, neurosurgeons are becoming less experienced with their surgical management. Anatomical factors are crucial in designing the approach to achieve a maximal safe resection.

Methods: Six cadaveric heads (12 sides) were dissected using a combined postauricular infralabyrinthine and distal transcervical approach with additional anterior transstyloid and posterior far lateral exposures. Contiguous surgical triangles were measured and their contents analyzed. Thirty patients were treated surgically for 31 lesions involving the jugular foramen region at our institution between 2000 and 2016 through different variations of the retro-auricular distal cervical transtemporal approach. Preoperative imaging and intraoperative findings were reviewed.

Results: The anatomy of the following triangles was reviewed in detail: carotid, stylodigastric, jugular, condylar, suboccipital, deep condylar, mastoid, suprajugular, suprahypoglossal (infrajugular), and infrahypoglossal. Their borders and surface areas were measured. These triangles partition this region into adjacent anatomical compartments, allowing us to unlock the jugular foramen region in a stepwise fashion that is tailored to the pathology. Retrospectively reviewed tumors included 13 schwannomas (8 hypoglossal, 2 vagal, 2 glossopharyngeal and one accessory), 7 glomus jugulare/vagale, 7 meningiomas, 1 chondrosarcoma, 1 adenocystic carcinoma, 1 plasmacytoma of the occipitocervical joint and 1 sarcoid lesion. Extracranial tumors (type 1) were approached through the carotid triangle. For more distal lesions and/or those displacing the internal carotid artery postero-laterally, the stylodigastric triangle was opened. Intradural tumors (type 2) were approached through the presigmoid, retrosigmoid, or lateral suboccipital corridors. Intraosseous tumors (type 3) were accessed through the jugular triangle, and through the condylar triangle whenever the occipital condyle was involved. Dumbbell-shaped tumors (type 4) required either combined or staged procedures through variations of the retro-auricular approach.

Conclusion: Lesions of the jugular foramen can be safely resected through a retro-auricular distal cervical lateral skull base approach. The approach can be customized to the anatomical location and extension of the tumor, by tailoring the incision and the involved osteo-muscular triangles.