Posterior Fossa Decompression With or Without Duraplasty for Chiari Type I Malformation With Syringomyelia

Study Overview
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Brief Summary
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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.

Detailed Description
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Participants with Chiari Malformation type I and syringomyelia will be randomized to either have a posterior fossa decompression done with or without duraplasty. The participant will then return to the neurosurgeon's office at the following time points which are consistent with standard of care practice: < 6 weeks, 3-6 months, and 12 months. At these visits, the clinician will complete a physical exam and the participant will report on the prognosis of symptoms and complete two quality of life questionnaires. A brain and cervical spine MRI will be performed 12 months after the decompression.

Official Title
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Posterior Fossa Decompression With or Without Duraplasty for Chiari Type I Malformation With Syringomyelia

Conditions
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Arnold-Chiari Malformation, Type 1, Chiari Malformation Type I, Type I Arnold-Chiari Malformation, Syringomyelia

Intervention / Treatment
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* Procedure: Posterior fossa decompression
* Procedure: Dural Augmentation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≤21 years old Chiari malformation type I ≥5 mm tonsillar ectopia Syrinx between 3 mm and 6 mm Chiari Severity Index (CSI) classification 1 MRI of the brain and cervical and thoracic spine are required prior to surgery and must be available to be shared with the Data Coordinating Center Exclusion Criteria: CSI-2 or CSI-3 classification Syrinx <3 mm and/or ≥6 mm Neuro-imaging demonstrating basilar invagination Clival canal angle <120° (signs of severe craniovertebral junction disease) Chiari Malformation I + syringomyelia 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

Ages Eligible for Study
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Maximum Age: 21 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Posterior fossa decompression surgery<br>The bone is surgically removed from the suboccipital region of the skull and Cervical 1 lamina so the constricting epidural band can be resected | Procedure: Posterior fossa decompression<br>* Planned areas of bone removal from the suboccipital region of the skull and cervical l1 lamina. Then, the constricting epidural band at the level of the foramen magnum is resected.<br>* Other names: Extradural posterior decompression;|
| Experimental: Dural augmentation surgery<br>The bone is removed from the suboccipital region of the skull and Cervical 1 lamina so the constricting epidural band can be resected. Then, the dura is opened. Microsurgical dissection is performed and the dura is sewn closed. | Procedure: Dural Augmentation<br>* The dura is opened sharply, exposing the cerebellar tonsils, brainstem, and upper spinal cord. After microsurgical dissection, the dura is sewn closed with a dural graft.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The number of participants with complications such as cerebrospinal fluid (CSF) leaks, pseudomeningoceles, infections, aseptic meningitis, hydrocephalus, and revisions. |  | 6 months from decompression | 
| The number of participants with complications such as cerebrospinal fluid (CSF) leaks, pseudomeningoceles, infections, aseptic meningitis, hydrocephalus, and revisions. |  | 12 months from decompression | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Compare the change in size of syrinx before and after decompression. | Syrinx size will be measured with radiographic imaging pre-operatively and 12 months post-operatively. | 12 months |