Introduction: Historically, the transoral-transpharyngeal approach has been used to access the anterior craniovertebral junction (CVJ). More recently, the endoscopic endonasal approach (EEA) has emerged as a viable option for addressing lesions from the lower clivus and foramen magnum to the odontoid process. The EEA allows direct access to the CVJ, providing management options for both extradural and intradural pathologies. We propose a projection system based on the palatine line, using linear coordinates from outer to inner anatomical landmarks, to guide access to the craniovertebral region.
Methods: To establish an anatomic-radiological coordinate projection system, fifty CT scans in bone window settings were analyzed, focusing on the palatine line as a projection guide to the CVJ. This system was validated through six surgical cases using radiological imaging to assess the line’s accuracy and clinical applicability.
Results: In all CT scans, the palatine line consistently projected from the lower clivus to the anterior arch of C1 and C2, with the pharyngeal tubercle and anterior edge of the foramen magnum identified as key landmarks. Surgical cases showed close correlation with CT measurements, and all patients demonstrated stable post-surgical outcomes, including proper extubation, orientation, and movement of all extremities.
Conclusion : The palatine line, may provide a useful and reliable projection-coordinate line, to safely localize and access the craniovertebral junction. Although radiological studies were used as a means to consistently to mark and identify this coordinate, the palatine line may be especially useful in the absence of a navigation system in the operating room. Further surgical cases may be needed to assess efficacy and presence or absence of inter-operator variability.
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