Transnasal endoscopic odontoidectomy after occipito-cervical fusion during the same operative setting-technical note

Recently, a purely transnasal endoscopic approach (TNEA) for decompression of the anterior cranio-cervical junction has been described. At present, there is only a limited number of patients having been operated on in a few specialized centers. The possibilities, safety, and limits of this approach are still under investigation. The relationship between TNEA and occipito-cervical fusion, especially, which may typically be considered in this kind of pathologies, should be further elucidated. So far, the feasibility of TNEA after previous occipito-cervical fusion has only been reported for a single case. In that case, there was a posterior atlanto-axial subluxation and basilar invagination. In the present paper, another example of a surgical procedure of TNEA after previous posterior fusion during the same operative setting is given. It differs from the other case concerning the pathophysiology. In fact, here, there was anterior atlanto-axial subluxation and no basilar invagination. The possibilities and limits of this novel approach are thoroughly discussed. Special interest is given to the problem of CCJ instability and previous occipito-cervical fusion. Technical hints and pitfalls are described in detail.