Background Extended endoscopic endonasal approaches (EEA) are increasingly being used to address
different types of anterior cranio-vertebral junction (aCVJ) diseases, including rheumatoid
arthritis-related bulbo-medullary compression, basilar invagination in complex CVJ
malformations and non-healed odontoid type II fractures. EEA, eventually supplemented
by a variety of anterior endoscopic C1−C2 screw fixation and how these new techniques
may help in extending indications or in implementing the conventional techniques,
by combined approaches, in aCVJ lesions which require surgical treatment are illustrated
and discussed.
Methods From 2009 to July 2017, a total of 36 patients affected by aCVJ disorders underwent
EEA alone or combined with conventional surgical approaches at our institution. A
combined classical anterior transcervical and endoscopic endonasal C1−C2 screw fixation
approach for nonunion of odontoid fractures was used in 12 cases. A fully endoscopic
endonasal decompression and C1−C2 fusion was used in five patients affected by complex
cranio-vertebral malformations. EEA was also used in 19 patients with irreducible
bulbo-medullary junction compression due to a migrated odontoid process and/or retro-periodontoid
inflammatory process. Endoscopic endonasal odontoidectomy was performed always sparing
the anterior C1 arch, to preserve spine stability or to be used as pivot point for
anterior C1−C2 screw fixation and fusion if needed. All patients were followed up
by diversified imaging modalities (MRI, CT scan, and dynamic X-ray examinations).
Results An improvement of at least one point in Ranawat or Nurick scales was observed in
all cases. Radiologically adequate bulbo-medullary decompression was always achieved.
Only two patients developed delayed spine instability, requiring posterior occipito-cervical
fixation. Clear bone fusion was always observed when anterior endoscopic C1−C2 screw
fixation was used. Two patients had a CSF leaks and two patients suffered from a dehiscence
of the mucosal incision with secondary healing confirmed at regular endoscopic outpatient
follow-up.
Conclusion The extended transnasal fully endoscopic technique may represent a valid alternative
approach to conventional open transcervical, posterolateral, or transoral approaches
classically used for aCVJ lesions. The potential advantages over the standard and
transoral approaches include less invasiveness, wider and straightforward working
angle, enhanced chances of preserving anterior C1 arch, with the possibility for both
decompression plus anterior endoscopic C1−C2 fixation/fusion to reduce the risk of
cranial settling and the need of posterior C1−C2 or occipito-cervical fusion for spine
instability.
