Microsurgical Endoscopic-Assisted Odontoidectomy in Extreme Form of Basilar Invagination via a Transoral Epipharyngeal Approach without Palatotomy

Objective: Transoral odontoidectomy in the treatment of basilar invagination is surgically challenging. Incision of the soft palate significantly increases rostral exposure of the clivus but is associated with a high incidence of speech and swallowing difficulties after surgery. We present a patient suffering from severe compression of the medulla oblongata due to an extreme form of basilar invagination treated successfully with dens resection via a transoral nasopharyngeal approach without palatotomy.

Methods: Microsurgical endoscopic-assisted odontoidectomy through a transoral epipharyngeal approach was performed with subsequent cranio-cervical stabilization in a 21-year-old patient suffering from progressive myelopathy due to compression of the medulla oblongata and associated progressive syringomyelia.

Results: The 21-year-old man was initially treated by suboccipital craniotomy in another institution. Despite posterior decompression he subsequently developed progressive ataxia, bulbar speech and weakness of the extremities due to severe compression of the medulla oblongata by the high and dorsally migrated dens. In addition, one year after dorsal decompression he developed cervico-thoracic syringomyelia. Resection of the dens was successfully accomplished via a microsurgical transoral epipharyngeal endoscopic-assisted odontoidectomy without palatal incision. One week after odontoidectomy posterior cranio-cervical stabilization was performed. Preoperative symptoms and signs particularly bulbar speech and limb weakness improved significantly. On MR imaging performed one month after surgery syringomyelia had completely resolved.

Conclusion: A palatotomy is rarely required even for the treatment of severe forms of basilar invagination.