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CC BY-NC-ND 4.0 · Asian J Neurosurg
DOI: 10.1055/s-0045-1813217
Research Article

The Impact of Foramen Magnum Decompression With versus Without Duraplasty on Symptom Improvement and Syrinx Reduction in Chiari 1 Malformation Patients

Authors

  • Sung-Min Jun 

    1   Department of Neurosurgery, Waikato Hospital, Waikato District Health Board, Hamilton, New Zealand

  • Sang Ho Kim

    2   Department of Surgery, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand

  • Sameer Bhat

    2   Department of Surgery, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand

  • Daniel Joseph

    1   Department of Neurosurgery, Waikato Hospital, Waikato District Health Board, Hamilton, New Zealand

  • Heta Leinonen

    1   Department of Neurosurgery, Waikato Hospital, Waikato District Health Board, Hamilton, New Zealand

  • Peter Yee Chiung Gan

    1   Department of Neurosurgery, Waikato Hospital, Waikato District Health Board, Hamilton, New Zealand
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Abstract

Introduction

Surgical decompression is considered the gold standard of treatment for patients with Chiari 1 malformation who are symptomatic or with syrinx. Currently, foramen magnum decompression with duraplasty (FMDD) and without duraplasty (FMD) are the two most commonly used techniques. This retrospective analysis aims to compare clinical improvement and syrinx reduction in patients undergoing FMDD versus FMD.

Materials and Methods

Clinical and radiological assessments were conducted pre- and postoperatively. Patient data was collected from electronic records and analyzed using univariate and multivariate regression analysis in R.

Results

Fifty-eight patients underwent FMDD and 38 patients underwent FMD. No difference in likelihood for symptom improvement (adjusted odds ratio [aOR] 0.96, p = 0.95) or syrinx reduction (aOR 1.69, p = 0.62) was seen between FMD and FMDD. Headaches were associated with increased likelihood for symptom improvement (aOR 4.83, p = 0.03), while unsteadiness (aOR 0.18, p = 0.03) and neck pain had lower likelihood for overall symptom improvement (aOR 0.23, p = 0.03). The presence of limb symptoms (aOR 16.45, p = 0.03) was associated with a higher likelihood while older age (aOR 0.95, p = 0.03) and male sex (aOR 0.04, p = 0.02) had lower likelihood for syrinx reduction. FMD was associated with a shorter length of stay (mean difference 1.94, p = 0.00).

Conclusion

No differences in overall symptom improvement or syrinx reduction were seen between patients undergoing FMD and FMDD. However, patients undergoing FMDD had longer lengths of stay in hospital. The lack of difference in symptom improvement and syrinx reduction may promote FMD as a better surgical technique. Furthermore, the role for individual symptoms in predicting symptom improvement and syrinx reduction was demonstrated. Larger studies will be required to validate which technique is better suited for patients with Chiari 1 malformations and to investigate the role of symptoms in predicting outcomes.

Keywords

Chiari 1 malformation - duraplasty - foramen magnum decompression - posterior fossa decompression - syringomyelia

Note

This manuscript was presented as an oral presentation at the Society of British Neurosurgical Surgeons Autumn Meeting, Birmingham, on Thursday, September 26, 2024.


Authors' Contributions

SM. J. was responsible for data collection, data analysis, and manuscript preparation and served as the primary author. SH. K. contributed to manuscript preparation. D.J. assisted with data collection, while S.B. performed the statistical analysis. H.L. contributed to the design and execution of the analysis, assisted with data interpretation, and reviewed the manuscript. P.G. conceived and designed the analysis, reviewed the manuscript, and served as the corresponding author.


Ethical Approval

This research project was review and given locality/ethical approval by the Health New Zealand | Te Whatu Ora Waikato Hospital Research Office (Project number: RD024049).




Publication History

Article published online:
09 December 2025

© 2025. Asian Congress of Neurological Surgeons. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

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