Endoscopic Endonasal Odontoidectomy in Patients with Basilar Invagination: Technical Description and Analysis of 5 Cases

Introduction: The basilar invagination is usually understood as a subluxation of the axis that occurs in the context of other changes to cranio-vertebral junction such as: short and retroverted clivus and Chiari malformation. The transoral corridor can be considered as the standard access for odontoidectomies, whereas the use of the endonasal route has been gaining notoriety in recent years, with the development of endoscopic techniques. The literature is still scarce in relation to the use of endonasal endoscopy in patients with basilar invagination.

Objective: The present presentation describes the technical features of endoscopic endonasal odontoidectomy (EEO) in a patient group with a pathology that deforms most of the anatomical parameters of the cranio-vertebral junction.

Methods: We retrospectively analyzed the surgical findings and the associated complications of the patients submitted to EEO for BI.

Results: There were 5 patients submitted to EEO. All the patients showed satisfactory clinical improvement. No patient evolved with infection related with the procedure. From a radiological point of view, the axis was completed resected in three patients. All cases were submitted to the posterior occipocervical fixation in second time.

Conclusion: The present technique is a viable alternative to anterior decompression of the craniovetebral junction in patients with B, but the structural anomalies associated with the disease make the surgical field too deep and difficult to identify anatomical landmarks.

Keywords: Arnold-Chiari Malformation; Basilar invagination; Endoscopic endonasal odontoidectomy.