The Surgical Management Of Skull Base Chordomas

Chordomas are rare malignant bone tumors,believed to arise from vestigial or ectopic notochordal tissue,However, recent studies suggest the possibility that chordomas arise from benign notochordal cell tumors.They were considered as mali- gnant tumors, with local invasiveness, a tendency for recurrence, and, in rare circumstances, the potential to metastasize. The most common locations include the sacrococcygeal region and skull base. The management of the skull base chordomas is particularly challenging as they lie adjacent to vital anatomic structures.Traditionally the management of skull base chordomas has been a formidable challenge for neurosurgeons,it's risky to acc- ess the locations via intracranial or cranial-facial,and cranial- facial defects are common. Trans-extracranial to access to the skull base has been paied much more attention to with the study of the skull base structure and the development of the medical equipments ,especially the development of the Otorhinolaryngo- lgy-Head and Neck Surgery.The nasal endoscopic surgery make it possible to diminish the surgical trauma and structure defect, even enlarge the visual field of operation,besides,the resection of tumor would be completely,and avoid the damage of the important structures.Because of the diversification of tumors and the complex- ity of the cranial base structures,the chordomas could be divided into different categories,according to the diffusion types of tumor,clinical manifestation or the locations,many surgical access were adopted to management chordomas according to the different categories and the special conditions.sometimes it's necessary for surgeons to adopt two or more accesses to resect the tumor completely.recently,the main accesses contains: trans- oral approach,transsuperior maxillary bone-sphenoid bone app- roach,Le Fort I and enlarged Le Fort I approach,transcondylus approach,transtemporal approach,transsuperior maxillary bone turnover approach and with the guiding of the nasal endoscopic operation,and so on.with the development and the maturity of Nasal Endoscopic Surgery(NES),the use of the NES will be ext- ensively and superiority of it will be showed in the managem- ent of chordoma.Surgical resection followed by radiation therapy is the rational choice for the patients suffered from chordomas. Chord- omas were considered relatively resistant to conventional radio- therapy,so it's neccesary to increase the dose of radiotherapy. with the development of radiation therapy and the maturity of surgical technical day by day,the local control muse be impro- ved,the relapse rate must be diminished,besides,the quality of life must be improved.