Revision surgery after inappropriate posterior fossa decompression for craniocervical junction malformation [Kranioservikal bileşke malformasyonlari{dotless}nda uygunsuz posterior fossa dekompresyonu sonrasi{dotless} revizyon]

Background: a variety of treatment options have been described for craniocervical junction malformation. the authors described a revision surgical technique with intraoperative ct navigation system for treatment of craniocervical junction malformation associated with inappropriate excessive posterior fossa decompression. methods: the 12 patients with chiari i malformation,basilar invagination,and syringomyelia,which were performed extensive posterior fossa decompression in other institutions received the revision surgery from april 2009 to march 2012.clinical presentation,diagnose,treatment,therapeutic outcome and follow-up results of the patients were retrospectively studied. results: 8 patients were performed the posterior fixation and fusion in a reduced position. 3 patients with irreducible craniovertebral junction were only performed the posterior occipitocervical fixation,whereas 1 patient was performed the posterior occipitocervical fixation,and a transoral odontoidectomy was performed as the second procedure. the postoperative stability of the region and decompression of the brainstem was confirmed radiologically,and the 11 patients were relieved of their symptoms. at 9-24 months of follow-up,respectively,solid bone fusion was observed between the occipital bone and axis in all patients. conclusions: an excessive large posterior fossa and upper cervical canal decompression should be avoided for basilar invagination associated with chiari i malformation. the revision occipitocervical fixation and fusion with the intraoperative ct and neuronavigation for treatment of craniocervical junction malformation with inappropriate excessive posterior fossa decompression can be successfully performed. ventral decompression via the transoral route should be considered in the patients whose clinical symptoms had not been improved after the posterior decompression and fixation.