Minimally Invasive Decompression for Chiari I Malformation: A Systematic Review and Meta-Analysis.
Patrick Pema1, Daniel Monahan2, Shiv Patel2
1Neurosurgery, Hackensack Meridian Jersey Shore University Medical Center, Neptune, USA.
Cureus
|September 2, 2025
Summary
Minimally invasive foramen magnum decompression (MID) effectively treats Chiari I malformation (CIM), showing significant syringomyelia improvement and favorable complication rates compared to open surgery.
Area of Science:
- Neurosurgery
- Minimally Invasive Surgery
- Cerebellar Malformations
Background:
- Chiari I malformation (CIM) involves cerebellar tonsil herniation into the foramen magnum.
- Traditional treatment is open foramen magnum decompression.
- Minimally invasive foramen magnum decompression (MID) is an alternative surgical approach.
Purpose of the Study:
- To compare outcomes between traditional open and minimally invasive foramen magnum decompression (MID) for symptomatic Chiari I malformation.
- To elucidate differences in efficacy and complication rates.
Main Methods:
- Systematic literature search of PubMed for studies on MID in symptomatic CIM patients.
- Inclusion criteria: symptomatic patients, MID surgical intervention, explicit complication reporting.
- Meta-analysis of 10 studies reporting on 200 patients, analyzing operative time, neurological outcomes, and complications.
Main Results:
- Average syringomyelia improvement rate of 84% following MID.
- Meta-analysis of complication rates showed moderate heterogeneity (I² = 61%), with overall rates of 0.16 (common) and 0.12 (random effects).
- Neurological assessment scales (VAS, KPS, mJOA, CCOS) indicated functional improvement; dural tear was the most common complication (8 occurrences).
Conclusions:
- Minimally invasive foramen magnum decompression (MID) is an effective treatment for symptomatic Chiari I malformation (CIM).
- MID demonstrates favorable complication rates, potentially superior to open surgery.
- The technique is as efficacious as open surgery, with significant patient functional improvement and syringomyelia resolution.
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