Extended endoscopic endonasal approach to the anterior cranio-vertebral junction: anatomic study.

OBJECTIVE Our aim in this study was to identify the endoscopic anatomy of the anterior cranio-vertebral junction to be able to perform minimal invasive endoscopic surgical procedures to this region (such as dens resection) safely with better postoperative performance of the patients. MATERIAL AND METHODS Five fresh adult cadavers were studied (n=5). We used Karl Storz 0 and 30 degree, 4mm, 18 cm and 30 cm rod lens rigid endoscope in our dissections. After cadaveric specimen preparation, we approached the anterior cranio-vertebral junction by binostril extended endoscopic endonasal approach. RESULTS The cranio-vertebral junction was located by orientating the endoscope between -10 to +10 degrees. The rhinopharynx was widely exposable after resection of the vomer. The safe lateral limit of this approach was the occipital condyles and foramen lacerum. We could perform odontoid process resection with a pure endoscopic endonasal approach. CONCLUSION Our anatomic study offered the facility to learn the endoscopic anatomy of the anterior cranio-vertebral junction and understand the appropriate approaches to this region. Our approach is appropriate for treatment of some pathologies of this region, with less invasiveness compared to the traditional transoral approach.