Outcomes in children undergoing posterior fossa decompression and duraplasty with and without tonsillar reduction for Chiari malformation type I and syringomyelia: a pilot prospective multicenter cohort study

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OBJECTIVE

Despite significant advances in diagnostic and surgical techniques, the surgical management of Chiari malformation type I (CM-I) with associated syringomyelia remains controversial, and the type of surgery performed is surgeon dependent. This study’s goal was to determine the feasibility of a prospective, multicenter, cohort study for CM-I/syringomyelia patients and to provide pilot data that compare posterior fossa decompression and duraplasty (PFDD) with and without tonsillar reduction.

METHODS

Participating centers prospectively enrolled children suffering from both CM-I and syringomyelia who were scheduled to undergo surgical decompression. Clinical data were entered into a database preoperatively and at 1–2 weeks, 3–6 months, and 1 year postoperatively. MR images were evaluated by 3 independent, blinded teams of neurosurgeons and neuroradiologists. The primary endpoint was improvement or resolution of the syrinx.

RESULTS

Eight clinical sites were chosen based on the results of a published questionnaire intended to remove geographic and surgeon bias. Data from 68 patients were analyzed after exclusions, and complete clinical and imaging records were obtained for 55 and 58 individuals, respectively. There was strong agreement among the 3 radiology teams, and there was no difference in patient demographics among sites, surgeons, or surgery types. Tonsillar reduction was not associated with > 50% syrinx improvement (RR = 1.22, p = 0.39) or any syrinx improvement (RR = 1.00, p = 0.99). There were no surgical complications.

CONCLUSIONS

This study demonstrated the feasibility of a prospective, multicenter surgical trial in CM-I/syringomyelia and provides pilot data indicating no discernible difference in 1-year outcomes between PFDD with and without tonsillar reduction, with power calculations for larger future studies. In addition, the study revealed important technical factors to consider when setting up future trials. The long-term sequelae of tonsillar reduction have not been addressed and would be an important consideration in future investigations.

ABBREVIATIONS ASAP = American Syringomyelia and Chiari Alliance Project; CM-I = Chiari malformation type I; PFD = posterior fossa decompression; PFDD = PFD and duraplasty; PFDD-T = PFDD with tonsillar reduction.
Article Information

Contributor Notes

Correspondence Bermans J. Iskandar: University of Wisconsin Hospitals and Clinics, Madison, WI. iskandar@neurosurgery.wisc.edu.INCLUDE WHEN CITING Published online October 18, 2019; DOI: 10.3171/2019.8.PEDS19154.

J.K. and C.S.G share first authorship, and T.M.G. and B.J.I. share senior authorship of this work.

Disclosures The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.
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References
  • 1

    Asgari SEngelhorn TBschor MSandalcioglu IEStolke D: Surgical prognosis in hindbrain related syringomyelia. Acta Neurol Scand 107:12212003

    • Search Google Scholar
    • Export Citation
  • 2

    Bao CSLiu LWang BXia XGGu YJLi DJ: Craniocervical decompression with duraplasty and cerebellar tonsillectomy as treatment for Chiari malformation-I complicated with syringomyelia. Genet Mol Res 14:9529602015

    • Search Google Scholar
    • Export Citation
  • 3

    Beecher JSLiu YQi XBolognese PA: Minimally invasive subpial tonsillectomy for Chiari I decompression. Acta Neurochir (Wien) 158:180718112016

    • Search Google Scholar
    • Export Citation
  • 4

    Bertrand G: Chapter 26. Dynamic factors in the evolution of syringomyelia and syringobulbia. Clin Neurosurg 20:3223331973

  • 5

    Chotai SMedhkour A: Surgical outcomes after posterior fossa decompression with and without duraplasty in Chiari malformation-I. Clin Neurol Neurosurg 125:1821882014

    • Search Google Scholar
    • Export Citation
  • 6

    Donoghoe MWMarschner IC: logbin: An R package for relative risk regression using the log-binomial model. J Stat Softw 86:1222018

  • 7

    Durham SRFjeld-Olenec K: Comparison of posterior fossa decompression with and without duraplasty for the surgical treatment of Chiari malformation Type I in pediatric patients: a meta-analysis. J Neurosurg Pediatr 2:42492008

    • Search Google Scholar
    • Export Citation
  • 8

    Ellenbogen RGArmonda RAShaw DWWinn HR: Toward a rational treatment of Chiari I malformation and syringomyelia. Neurosurg Focus 8(3):E62000

    • Search Google Scholar
    • Export Citation
  • 9

    Fischer EG: Posterior fossa decompression for Chiari I deformity, including resection of the cerebellar tonsils. Childs Nerv Syst 11:6256291995

    • Search Google Scholar
    • Export Citation
  • 10

    Friede RLRoessmann U: Chronic tonsillar herniation: an attempt at classifying chronic hernitations at the foramen magnum. Acta Neuropathol 34:2192351976

    • Search Google Scholar
    • Export Citation
  • 11

    Greenlee JDDonovan KAHasan DMMenezes AH: Chiari I malformation in the very young child: the spectrum of presentations and experience in 31 children under age 6 years. Pediatrics 110:121212192002

    • Search Google Scholar
    • Export Citation
  • 12

    Guyotat JBret PJouanneau ERicci ACLapras C: Syringomyelia associated with type I Chiari malformation. A 21-year retrospective study on 75 cases treated by foramen magnum decompression with a special emphasis on the value of tonsils resection. Acta Neurochir (Wien) 140:7457541998

    • Search Google Scholar
    • Export Citation
  • 13

    Herculano-Houzel S: The human brain in numbers: a linearly scaled-up primate brain. Front Hum Neurosci 3:312009

  • 14

    Kennedy BCNelp TBKelly KMPhan MQBruce SSMcDowell MM: Delayed resolution of syrinx after posterior fossa decompression without dural opening in children with Chiari malformation Type I. J Neurosurg Pediatr 16:5996062015

    • Search Google Scholar
    • Export Citation
  • 15

    Klekamp J: Neurological deterioration after foramen magnum decompression for Chiari malformation type I: old or new pathology? J Neurosurg Pediatr 10:5385472012

    • Search Google Scholar
    • Export Citation
  • 16

    Klekamp JBatzdorf USamii MBothe HW: The surgical treatment of Chiari I malformation. Acta Neurochir (Wien) 138:7888011996

  • 17

    Krishna VMcLawhorn MKosnik-Infinger LPatel S: High long-term symptomatic recurrence rates after Chiari-1 decompression without dural opening: a single center experience. Clin Neurol Neurosurg 118:53582014

    • Search Google Scholar
    • Export Citation
  • 18

    Lazareff JAGalarza MGravori TSpinks TJ: Tonsillectomy without craniectomy for the management of infantile Chiari I malformation. J Neurosurg 97:101810222002

    • Search Google Scholar
    • Export Citation
  • 19

    Milhorat THChou MWTrinidad EMKula RWMandell MWolpert C: Chiari I malformation redefined: clinical and radiographic findings for 364 symptomatic patients. Neurosurgery 44:100510171999

    • Search Google Scholar
    • Export Citation
  • 20

    Pueyrredon FSpaho NArroyave IVinters HLazareff J: Histological findings in cerebellar tonsils of patients with Chiari type I malformation. Childs Nerv Syst 23:4274292007

    • Search Google Scholar
    • Export Citation
  • 21

    Rocque BGGeorge TMKestle JIskandar BJ: Treatment practices for Chiari malformation type I with syringomyelia: results of a survey of the American Society of Pediatric Neurosurgeons. J Neurosurg Pediatr 8:4304372011

    • Search Google Scholar
    • Export Citation
  • 22

    Sakaki TTsunoda SMorimoto TUtsumi S: Is Chiari I malformation in the aged initiated by mechanical factors? Report of three cases. Neurol Med Chir (Tokyo) 30:3243281990

    • Search Google Scholar
    • Export Citation
  • 23

    Stanko KMLee YMRios JWu ASobrinho GWWeingart JD: Improvement of syrinx resolution after tonsillar cautery in pediatric patients with Chiari Type I malformation. J Neurosurg Pediatr 17:1741812016

    • Search Google Scholar
    • Export Citation
  • 24

    Strahle JMuraszko KMKapurch JBapuraj JRGarton HJMaher CO: Chiari malformation Type I and syrinx in children undergoing magnetic resonance imaging. J Neurosurg Pediatr 8:2052132011

    • Search Google Scholar
    • Export Citation
  • 25

    Strahle JSmith BWMartinez MBapuraj JRMuraszko KMGarton HJ: The association between Chiari malformation Type I, spinal syrinx, and scoliosis. J Neurosurg Pediatr 15:6076112015

    • Search Google Scholar
    • Export Citation
  • 26

    Tubbs RS: Definitions and anatomic considerations in Chiari I malformation and associated syringomyelia. Neurosurg Clin N Am 26:4874932015

    • Search Google Scholar
    • Export Citation
  • 27

    Tubbs RSBeckman JNaftel RPChern JJWellons JC IIIRozzelle CJ: Institutional experience with 500 cases of surgically treated pediatric Chiari malformation Type I. J Neurosurg Pediatr 7:2482562011

    • Search Google Scholar
    • Export Citation
  • 28

    Vanaclocha VSaiz-Sapena NGarcia-Casasola MC: Surgical technique for cranio-cervical decompression in syringomyelia associated with Chiari type I malformation. Acta Neurochir (Wien) 139:5295401997

    • Search Google Scholar
    • Export Citation
  • 29

    Welch KShillito JStrand RFischer EGWinston KR: Chiari I “malformations”—an acquired disorder? J Neurosurg 55:6046091981

    • Search Google Scholar
    • Export Citation
  • 30

    Wetjen NMHeiss JDOldfield EH: Time course of syringomyelia resolution following decompression of Chiari malformation Type I. J Neurosurg Pediatr 1:1181232008

    • Search Google Scholar
    • Export Citation
  • 31

    Williams B: Surgery for hindbrain related syringomyelia. Adv Tech Stand Neurosurg 20:1071641993

  • 32

    Woodward M: Epidemiology Study Design and Data Analysis. Boca Raton: Chapman & Hall/CRC2005

  • 33

    Wu TZhu ZJiang JZheng XSun XQian B: Syrinx resolution after posterior fossa decompression in patients with scoliosis secondary to Chiari malformation type I. Eur Spine J 21:114311502012

    • Search Google Scholar
    • Export Citation
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