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Completed

NCT Number: NCT06079125

PFDD Versus PFDRT in Chiari Decompression Surgery

The purpose of this study is to determine whether a posterior fossa decompression and duraplasty with or without tonsil manipulation results in better patient outcomes with fewer complications and improved quality of life in those who have Chiari malformation type I and syringomyelia.

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Key information

Conditions

Chiari Malformation Type I Arnold-Chiari Malformation Central Nervous System Diseases Congenital Abnormalities Congenital, Hereditary, and Neonatal Diseases and Abnormalities Nervous System Diseases Nervous System Malformations Neural Tube Defects Spinal Cord Diseases Syringomyelia Tonsillectomy

Age range

14 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Fengzeng Jian

Beijing, Beijing Municipality, 100053, China

About this study

Participants with Chiari Malformation type I and syringomyelia will be randomized to either have a posterior fossa decompression and duraplasty with or without tonsil manipulation. The participant will then return to the neurosurgeon's office at the following time points which are consistent with standard of care practice: 3-6 months, 12 and 24 months. At these visits, the clinician will complete a physical exam and the participant will report on the prognosis of symptoms and complete questionnaires. A spine MRI will be performed 3-6 months, 12 and 24 months after the surgery.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age ≥14 years old
  • Chiari malformation type I ≥5 mm tonsillar ectopia
  • a syrinx with a width > 50% of the cross-sectional diameter of the spinal cord , and a length of at least 2 cervical and/or thoracic vertebral segments.
  • 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

  • included one or more of the following preexisting conditions: hydrocephalus; tumor; brain trauma; stroke; meningitis; abscess;
  • other congenital anomalies of the brain or skull base; vertebral anomalies (i.e., Klippel-Feil, atlas assimilation, etc.);
  • degenerative or demyelinating disease;
  • CM-I without syringomyelia;
  • syringomyelia with cerebellar tonsils in a normal position;
  • fibromyalgia;
  • chronic fatigue syndrome;
  • prior posterior fossa surgery.
  • Unable to share pre-decompression MRI of the brain and spine Patients who do not wish to participate

Treatment and study plan

Posterior fossa decompression with duraplasty

Procedure

In brief, a midline incision was made from the inion to the C2 level. A piece of autologous fascia was harvested from the muscular fascia layer. Paraspinal muscles were dissected to expose the occipital bone, posterior arch of the atlas and axis, spinous process, and lamina. The inferior portion of the occipital bone and approximately 2 cm of the posterior arch of C1 were removed, achieving bony decompression (approximately 2.5-3 × 2.5-3 cm). Once the dura was exposed, the atlanto-occipital membrane was coagulated and dissected off the dura. The dura was then incised in a Y-shaped fashion, with care taken to preserve the underlying arachnoid. Watertight duraplasty was performed using the autologous fascia. The wound was closed in anatomical layers.

PFDD with tonsillar resection/reduction

Procedure

Briefly, a midline incision approximately 3-4 cm posterior to the foramen magnum is made. The incision is deepened layer by layer along the midline to reach the occipital bone, exposing the posterior margin of the foramen magnum and part of the occipital squama. The posterior edge of the foramen magnum is opened, and part of the occipital squama is removed up to the junction of the cerebellar vermis and cerebellar tonsils. The occipitoatlantal fascia is exposed and dissected. The dura mater and arachnoid mater are incised longitudinally and suspended bilaterally to provide a clear surgical field. The primary objectives of resection were: ensuring no significant obstruction of CSF circulation at the foramen magnum and the foramen of Magendie under natural conditions. Preventing occlusion of the foramen of Magendie caused by herniated cerebellar tonsils or any membranous structures under natural conditions. The dura is closed in situ.

Primary outcomes

  1. improvement or resolution of the syrinx,

    Time frame: 3-6, 12 and 24 months

    defined as > 50% improvement in length, maximal cross-sectional diameter, or both.

Secondary outcomes

  1. complication rates

    Time frame: 12 months

    Reoperation,Wound infection,Aseptic meningitis,CSF fistula,Subcutaneous hydrops,Other complications

  2. Chicago Chiari Outcome Scale (CCOS) scale

    Time frame: 12 months

    for evaluating the spinal cord function after chiari decompression surgery, Each item is scored on a scale from 1 to 4, with 4 representing the best possible functional status.

  3. visual analog scale (VAS)

    Time frame: 12 months

    degree of the pain, 1-10, higher scores mean a worse outcome

  4. Japanese Orthopaedic Association (JOA) scale

    Time frame: 12 months

    Motor function， sensory， bladder function；for evaluating the spinal cord function；0-17， higher scores mean a better outcome

  5. blood loss

    Time frame: 12 months

    blood loss

  6. hospital stay

    Time frame: 12 months

    hospital stay

  7. cost for the hospitalisation.

    Time frame: 12 months

    cost for the hospitalisation.

Sponsors and collaborators

Lead sponsor

Xuanwu Hospital, Beijing

Other

Collaborators

  • Beijing Jiangong Hospital
  • The First Hospital of Hebei Medical University

Registry information

Official study title

Type of Surgical Intervention for Chiari Malformation-syringomyelia: a Multicenter Randomized Controlled Study

Important dates

Study start
2024
Primary completion
2026
Study completion
2026
First posted
Oct 12, 2023
Registry last updated
Feb 17, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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