Objective: We review a description of the surgeries performed at the occipito- Atlanto-Axial segment in order to present the experience of the lesions diagnosed and managed at this level that required anterior decompression. An odontoidectomía was performed due to the irreducible nature of the lesion and/or because the mechanism of compression in the front, which were not susceptible to posterior approach.

Patients and methods: We report six cases in which, was used an trans oral technique to deal with the upper cervical spine segment. The cases were: four cases of rheumatoid arthritis and 2 cases of basilar impression. We described the clinical picture and the surgical technique used. Then we described the techniques used for posterior stabilization in each case.

Results: The first patient operated corresponded to a basilar impression and had dehiscence of the uvula and 1 patient (case 4) died a month after surgery due to nosocomial pneumonia and one pending fixation. The remaining patients were showed clinical improvement of symptoms and good consolidation later.

Conclusions: The trans-oral decompression surgery should be indicated in irreducible injuries and lesions where the compression is above, is recommended in other aetiologies abnormalities of bone, soft tissue or vascular. Transoral decompression - Atlanto axial instability - posterior fixation.