gms | German Medical Science

Objective: Endoscopic endonasal approach is now a safe surgical technique for the treatment of craniovertebral junction malformation. The biomechanical consequences of the traditional odontoidectomy led to the necessity for a cervical spine stabilization. Preserving the inferior portion of C1 anterior arch should prevent instability. The most fascinating potential of 3D vision is the ability to control the anatomical structures that are present but not usually and easily visible, and this is important for the preservation of C1 anterior arch.

Method: 12 patients affected by severe ventral compression secondary to craniovertebral junction malformation underwent an endoscopic endonasal resection of the odontoid tip between September 2010 and November 2013. Each patient was studied with cervical column radiography, with projection in flexion end extension in addition to normal radiograms, brain and cervical column CT and MRI scan. 8 patients were affected by complex occipital-cervical junction malformation, 2 patients had Chiari I malformation, 1 patient was affected by chondrosarcoma of odontoid tip and one patient had periodontoid rheumatoid pannus. A contribution to decrease the post-operative risk of spinal instability is the preservation of the superior part of the anterior C1 arch.

Results: Complete odontoidectomy was performed in all 12 patients. Preservation of C1 anterior arch was possible in 5 cases. 4 patients, where the anterior arch of C1 was not preserved, underwent a posterior fixation because of vertebral instability. The other 3 cases were affected by complex CVJ malformation with atlanto-occipital assimilation. Only one patient (first of the series) developed surgical site infection, successfully treated with antimicrobial drug. No patient developed CSF leak. All patients underwent a cervical spine XRay, with flexion end extension projections and cervical spine MRI and CT scan 3 months after surgery. Neuroimaging confirmed that a good decompression was achieved and an improvement of myelopathy in every patient treated.

Conclusions: In craniovertebral malformation endoscopic endonasal approach offer direct access to the lesion, reduces working distance, and the rostro-caudal approach allows preservation of C1 anterior arch. 3D Stereoscopic vision with depth perception do a better visualisation of morphology and anatomical relationships between structures. 3D technology improves hand-eye coordination. The 3D improved and reduced the learning curve for novice surgeons.