Choice Of Operation Methods For Chiari Ⅰ Malformation

Objective: To investigate the Chiari malformation typeâ… clinical features, imaging features, preoperative evaluation and the indications for various surgical procedures.Methods: During May 1999 ~ October 2008, our group had treated 25 cases of Chiari malformation typeâ… patients by surgery. All these patients were examined by head MRI and/or with an additional whole spinal cord MRI to get a clear diagnosis which could confirmed the location of cerebellar tonsillar tips below the foramen magnum and whether complicated with hydrocephalus and/or syringomyelia. All patients took the head plain X-ray films or CT three-dimensional reconstruction(3 positions: over flexion position, over extension position and normal positon) in order to exclude some other complications, craniocervial junction bone abnor- mality, such as basilar invagination, atlantoaxial malformation and scoliosis,etc.. After diagnosis, design of the operation plan must be individualization. Include posterior fossa decompression, dural plasty, Torkildsen shunt, exploratory surgery of the opening of spinal cord central canal, transoral approach decompression and occipitocervical fusion procedure.Results: 13 of the 25 patients were treated with posterior fossa decompression + dural plasty, 4 patients were underwent procedure post- erior fossa decompression + partial resection of the cerebellar tonsil + dural plasty, 3 patients were underwent procedure posterior fossa decompression + dural plasty + exploratory surgery of the opening of spinal cord central canal; 3 patient were treated with posterior fossa decom- pression + dural plasty + Torkildsen shunt; 2 patients were treated with transoral approach + posterior fossa decompression + dural plasty + occipitocervical fusion. 1 cases,deteriorated rapidly and death. 22 patients had a improvement postoperative,1 patient without alleviation, deterioration in 1 case.Conclusion: Surgical methods for Chiari malformation typeâ… must be individualized for each case. Trying to achieve decompression through one surgery could avoid further symptoms aggravation and maintain the stability of craniocervical junction at the same time.