THE SURGICAL ANATOMY OF TRANSORAL APPROACH

Objective: The aim of this study is to obtain summarized description of the surgical anatomy of Transoral Approach (TOA) and to show the relationship between the important bony and ligamentous anatomical structures.Material and Methods: To demonstrate the TOA, ten cadaveric head specimens filled with microfil were dissected. Metric measurements between the important anatomical structures were performed in twenty head specimens. Extended indications of the approach were discussed.Results: In all specimens the TOA was successfully demonstrated. The Transoral Transpalatal Approach (TOTPA) is performed as a modification of TOA with the resection of the hard palate to reach the skull base. Some of the important metric measurements were as follows: 8.2 ± 0.2 cm between teeth and odontoid process; height of odontoid process: 2.4 ± 0.1 cm; height of arcus of C1 : 1.1 ± 0.1 cm; intercondylar distance: 2.2 ± 0.1 cm. The longest distance of the approach was with 11.2 ± 0.2 cm between the teeth and the vertebral arteries.Conclusion: The TOA is a useful procedure for ventral and ventrolateral extradural and intradural lesions of craniovertebral junction. For a proper exposure the surgical anatomy of the region should be well known. For intradural approaches, specially designed instruments should be used.Key Words: Craniovertebral junction, Surgical anatomy, Transoral approach

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