Introduction: Historically C1-C2 juntion, dens process and the CVJ have been usually approached through different routes including: transoral – transpharyngeal , transmandibular – retropharyngeal and anterior cervical approaches. This has change over the last years with the development of the expanded endoscopic endonasal approaches. We present our experience with 12 consecutive cases of C1-C2 instability that required 360 dregree surgery. 5 cases a endonasal endoscopic odontoidectomy was done and compare them with seven regular transoral (TO) cases

Methods: 12 consecutive cases were documented and diagnosticated with CVJ instability with or without basilar invagination (BI) in Mexico City from 2009 to January 2013. Five cases onset with more than 5mm BI (AVG 11mm) were operated through an endonasal endoscopic approach for the odontoidectomy using a 18cm x 4mm Karl Storz rigid endoscope attached to a High definition camera. Seven cases with non reducible C1-C2 luxation and BI were operated through a traditional TO approach. All cases were fused using a posterior construct with laterall masses screws in the same procedure, just after the odontoidectomy was performed. One case was previously fused (Occiput – C4 fusion). All cases were operated by one neurosurgeon

Results: In the TO group two pacients presented postoperative disphonia, one disphagia and one CFS leak, non complication were reported on the endoscopic group. Endoscopic approach requieres a larger surgical time (AVG 238 min Vs transoral 141min), but with fewer postop days of hospital stay (AVG 2.8 days Vs 6.5 days). Technically endoasal ensocopic approch to the odontoid process is more demanding and more time consuming.

Conclusions: Endonasal endoscopic odontoidectomy is a safe and well tolerated procedure. No complications were documented in these five cases, and should be considered if BI is present. Further studies are needed.

Patient Care: Expanded endonasal approach continues to develop, patients can beneift form this procedure since it is best tolerated.

Learning Objectives: We present our experience with 12 consecutive cases of C1-C2 instability that required 360 dregree surgery. 5 cases a endonasal endoscopic odontoidectomy was done and compare them with seven regular transoral (TO) cases

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