Posterior Fossa Decompression with or without Duraplasty for Chiari Type I Malformation with Syringomyelia


About this study

The purpose of this study is to determine whether a posterior fossa decompression or a posterior fossa decompression with duraplasty results in better patient outcomes with fewer complications and improved quality of life in those who have Chiari malformation type I and syringomyelia.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  • Age ≤21 years old
  • Chiari malformation type I with ≥5 mm tonsillar ectopia
  • Syrinx diameter (recorded as the greatest antero-posterior or transverse diameter) 3-9 mm
  • MRI of the brain and cervical and thoracic spine are required prior to surgery and available to be shared with the DCC

Exclusion Criteria:

  • Syrinx <3 mm and/or ≥10 mm
  • Neuro-imaging demonstrating basilar invagination (position of the superior tip of dens  ≥5 mm above Chamberlain’s line)
  • Neuro-imaging demonstrating clival canal angle <120°
  • Prior PFD, PFDD, or other surgery at the craniovertebral junction
  • CM+SM secondary to other pathology (e.g. a tumor)
  • Unable to share pre-decompression MRI of the brain and cervical and thoracic spine
  • Patients who do not wish to participate

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

David Daniels, M.D., Ph.D.

Contact us for the latest status

Contact information:

Adam Loudermilk

(507) 422-0718

More information


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