Introduction: Chiari malformation type I (CMI) exhibit an incidence of approximately 1 in 1000 births but often poses a significant diagnostic and treatment challenge for neurosurgeons. Although treatment outcomes are favorable, controversy remains as to the ideal surgical treatment paradigm. Recent experiences and data suggest that bony decompression alone without duraplasty is favored due to the lower incidence of pseudomeningocele and aseptic meningitis. We believe that technical nuisances such as linear dural opening and use of autologous pericranium duraplasty maximize favorable outcome without significant concern of pseudomeningocele and/or aseptic meningitis.

Methods: We retrospectively reviewed 50 CMI patients surgically treated and followed by senior author. We report long-term (>1 year) outcome and complication rate. We also discuss the current literature and controversies surrounding Chiari treatment paradigms.

Results: The female to male ratio was approximately 3:1 (37 females and 13 males) and median age was 22. Primary outcomes of significant improvement of exertion-headache and/or spinal syringomyelia were achieved in 96% (48/50) of patients at 1 year. Two patients developed pseudomeningoceles but only one required surgical re-exploration and repair while the other patient was asymptomatic and resolved at 1 year. No return ER visit or readmission for post-operative aseptic meningitis was seen.

Conclusions: The ideal surgical approach for CMI has yet to be elucidated. Suboccipital decompression and C1 laminectomy alone offers some advantages but it may miss 4th ventricular outlet obstructions such as arachnoid veils requiring re-operation in up to 10% of cases. Furthermore, it prevents direct tonsilar manipulation. Techniques allowing for simpler and more watertight duraplasty closure may off set risks of pseudomeningocele and aseptic meningitis. For symptomatic CMI patients, suboccipital craniectomy with linear autologous duraplasty is a safe and viable surgical treatment option that can provide excellent outcome without increased risk of surgery-related complications.

Patient Care: By providing our experience and outcomes with linear autologous duraplasty for posterior fossa decompression, other neurosurgeons have the opportunity to add this to their armamentarium of Chairi

Learning Objectives: 1) Understand potential surgical advantages of linear, autologous duraplasty 2) Review various treatment options for CIM 3) Identify an effective treatment for posterior fossa decompression in CIM patients

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