Management of Chiari I malformation in children: effectiveness of intra-operative ultrasound for tailoring foramen magnum decompression

Childs Nerv Syst. 2015 Aug;31(8):1371-6. doi: 10.1007/s00381-015-2699-1. Epub 2015 Apr 15.


Purpose: Patients with Chiari I malformation (CM-1) commonly undergo foramen magnum decompression (FMD). However, there is no consensus on how this should be achieved. An approach would be to rationalize surgical steps based on pre-operative imaging and intra-operative findings. The aim of this study is to assess the usefulness of intra-operative ultrasound scanning (IOUS) in tailoring foramen magnum decompression in children with CM-1 and whether the use of IOUS is effective in reducing the risk of complications without increasing the need for re-operation.

Method: We performed a retrospective study. IOUS was utilized during FMD: a subjective assessment was made on whether there was adequate cerebellar tonsillar and/or CSF pulsation following suboccipital craniectomy. If there was adequate pulsation, the dura was not opened. Additional data were collected including age and gender of patients, presence of pre-operative syringomyelia, intra-operative ultrasound findings, length of follow-up, complications and radiological and clinical outcome. The statistical analysis was performed with XLStat®(Addinsoft SARL™, France).

Results: Nineteen patients underwent FMD from June 2011 to December 2012. The mean age was 10.5 years; there were nine females and ten males. Eleven patients had syringomyelia at diagnosis. Based on IOUS, eight patients underwent dural decompression and 11 patients bony decompression only. One patient had a post-operative pseudomeningocoele and two patients required re-operation. There was no significant statistical difference between the two groups regarding post-operative improvement in the syrinx.

Conclusion: We found that tailoring FMD for patients with CM-1 using intra-operative findings using ultrasound scan was useful in avoiding unnecessary manoeuvres, while not compromising on the outcome.

MeSH terms

  • Adolescent
  • Arnold-Chiari Malformation / diagnostic imaging*
  • Arnold-Chiari Malformation / surgery*
  • Child
  • Child, Preschool
  • Decompressive Craniectomy / methods*
  • Female
  • Foramen Magnum / surgery*
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Retrospective Studies
  • Ultrasonography