ABSTRACT
Objectives:
Chiari malformations (CM) are common, highly variable, congenital problems of the craniovertebral junction and hindbrain. The term complex Chiari is used to describe cases that do not benefit from simple posterior fossa decompression and require occipitocervical fusion or odontoidectomy. Our series and medical literature are reviewed to discuss some cases of failed CM surgery that worsened after decompression.
Materials and Methods:
Patients diagnosed with CM and operated between 2010 and 2020 were examined. In addition, a bibliography-based research was conducted using the Medline, PubMed and Science databases. Three sample cases of unsuccessful Chiari surgery are presented at random to discuss possible misdiagnosis, clinical problems, and surgical interventions.
Results:
Detailed data of 60 patients diagnosed with CM and operated on were analyzed. The patient series consisted of 37 women (61.7%) and 23 men (38.3%). On radiological examinations, 95% of the patients had a mean cerebellar tonsil herniation of 11 mm (median 11 mm; 5-25; ±4.63). Basilar Invagination was present in 5 patients (8.33%), tethered spinal cord malformation in 1 patient (1.67%), spina bifida in 1 patient (1.67%), and spinal arachnoid cyst in 1 patient (1.67%).
Conclusion:
For successful surgical treatment of CM, preoperative radiological evaluation and determining the relationship between findings and clinical symptoms are as important as surgical treatment itself.
Keywords: Chiari Malformations, Complex Chiari, Craniovertebral Junction, Failed Chiari, Occipitocervical Fusion
References
1
Bollo RJ, Riva-Cambrin J, Brockmeyer MM, et al. Complex Chiari malformations in children: an analysis of preoperative risk factors for occipitocervical fusion. J Neurosurg Pediatr. 2012;10:134-141.
2
Brockmeyer DL. The complex Chiari: issues and management strategies. Neurol Sci. 32(Suppl 3):345-347.
3
Klekamp J. Neurological deterioration after foramen magnum decompression for Chiari malformation Type I: old or new pathology? J Neurosurg Pediatr. 2012;10:538-547.
4
Naftel RP, Tubbs RS, Menendez JY, et al. Worsening or development of syringomyelia following Chiari I decompression: case report. Clinical article. J Neurosurg Pediatr. 2013;12:351-356.
5
Greenberg AD, Scoville WB, Davey LM. Transoral decompression of atlanto-axial dislocation due to odontoid hypoplasia. Report of two cases. J Neurosurg. 1968;28:266-269.
6
Menezes AH, VanGilder JC, Graf CJ, et al. Craniocervical abnormalities. A comprehensive surgical approach. J Neurosurg. 1980;53:444-455.
7
Tubbs RS, Iskandar BJ, Bartolucci AA, et al. A critical analysis of the Chiari 1.5 malformation. J Neurosurg. 2004;101(Suppl 2):179-183.
8
Schuster JM, Zhang F, Norvell DC, et al. Persistent/Recurrent syringomyelia after Chiari decompressionnatural history and management strategies: a systematic review. Evid Based Spine Care J. 2013;4:116-125.
9
Goldstein HE, Anderson RCE. Craniovertebral junction instability in the setting of Chiari I malformation. Neurosurg Clin N Am. 2015;26:561-569.
10
Martin BA, Kalata W, Shaffer N, et al. Hydrodynamic and longitudinal impedance analysis of cerebrospinal fluid dynamics at the craniovertebral junction in type I Chiari malformation. PLoS One. 2013;8:e75335.
11
Achawal AGS. The surgical treatment of Chiari malformation associated with atlantoaxial dislocation. Br J Neurosurg. 1995;9:67-72.
12
Goel A. A review of a new clinical entity of “central atlantoaxial instability”: expanding horizons of craniovertebral junction surgery. Neurospine. 2019;16:186-194.
13
Goel A, Dhar A, Shah A. Central or axial atlantoaxial dislocation as a cause of cervical myelopathy: a report of outcome of 5 cases treated by atlantoaxial stabilization. World Neurosurg. 2019;121:908-916.
14
Goel A, Bhatjiwale M, Desai K. Basilar invagination: a study based on 190 surgically treated cases. J Neurol Surg. 1998;88:962-968.
15
Goel A. Treatment of basilar invagination by atlantoaxial joint distraction and direct lateral mass fixation. J Neurosurg Spine. 2004;1:281-286.
16
Goel A. Is Chiari malformation nature’s protective “air-bag”? Is its presence diagnostic of atlantoaxial instability? J Craniovertebr Junction Spine. 2014;5:107-109.
17
Goel A. Is atlantoaxial instability the cause of Chiari malformation? Outcome analysis of 65 patients treated by atlantoaxial fixation. J Neurosurg Spine. 2015;22:116-127.
18
Goel A, Jain S, Shah A. Radiological evaluation of 510 cases of basilar invagination with evidence of atlantoaxial instability (Group A Basilar Invagination). World Neurosurg. 2018;110:533-543.
19
Goel A, Sathe P, Shah A. Atlantoaxial fixation for basilar invagination without obvious atlantoaxial instability (Group B Basilar Invagination): outcome analysis of 63 surgically treated cases. World Neurosurg. 2017;99:164-170.
20
Goel A. Facetal alignment: basis of an alternative Goel’s classification of basilar invagination. J Craniovertebr Junction Spine. 2014;5:59-64.
21
Goel A. Goel’s classification of atlantoaxial “facetal” dislocation. J Craniovertebr Junction Spine. 2014;5:3-8.
22
Chiari H. Ueber verinderungenDes Kleinhirns, Des pons und der medulla oblongata in Folge yon congenitalerhydrocephalieDesgrosshirns. Denschr Akad Wiss Wien; 1895. p. 71-116.
23
Gardner WJ. Anatomic features common to the Arnold-Chiari and the Dandy-Walker malformations suggest a common origin. Cleve Clin Q. 1959;26:206-222.
24
Williams B. Pathogenesis of syringomyelia. Acta Neurochir (Wien). 1993;123:159-165.
25
Mathijssen IM. Guideline for care of patients with the diagnoses of craniosynostosis: working group on craniosynostosis. J Craniofac Surg. 2015;26:1735-1807.
26
Brito JNPO, Santos BAD, Nascimento IF, et al: Basilar invagination associated with Chiari malformation type I: A literature review. Clinics (Sao Paulo). 2019;74:e653.
27
Milhorat TH, Chou MW, Trinidad EM, et al. Chiari I malformation redefined: clinical and radiographic findings for 364 symptomatic patients. Neurosurgery. 1999;44:1005-1017.
28
Caetano de Barros M, Farias W, Ataíde L, et al. Basilar impression and Arnold-Chiari malformation. A study of 66 cases. J Neurol Neurosurg Psychiatry. 1968;31:596-605.
29
Gonçalves da Silva JA, Gonçalves da Silva CE, de Farias Brito JC, et al. Impressão basilar e malformação de Arnold-Chiari. Considerações técnico-cirúrgicas a propósito de 13 casos [The basilar impression and the Arnold-Chiari malformation. Techno-surgical considerations apropos of 13 cases]. Arq Neuropsiquiatr. 1978;36:27-31.
30
Chatterjee S, Shivhare P, Verma SG. Chiari malformation and atlantoaxial instability: problems of co-existence. Childs Nerv Syst. 2019;35:1755-1761.
31
Klekamp J. Chiari I malformation with and without basilar invagination: a comparative study. Neurosurg Focus. 2015;38:12.
32
Hankinson TC, Klimo P, Feldstein NA, et al. Chiari malformations, syringohydromyelia and scoliosis. Neurosurg Clin N Am. 2007;18:549-568.
33
Moore HE, Moore KR. Magnetic resonance imaging features of complex Chiari malformation variant of Chiari 1 malformation. Pediatr Radiol. 2014;44:1403-1411.
34
Klekamp J. Surgical treatment of Chiari I malformation-analysis of intraoperative findings, complications, and outcome for 371 foramen magnum decompressions. Neurosurgery. 2012;71:365-368.
35
Sindgikar P, Das KK, Sardhara J, et al. Craniovertebral junction anomalies: when is resurgery required? Neurol India. 2016;64:1220-1232.
36
Perrini P, Anania Y, Cagnazzo F, et al. Radiological outcome after surgical treatment of syringomyelia-Chiari I complex in adults: a systematic review and meta-analysis. Neurosurg Rev. 2021;44:177-187.
37
Lin W, Duan G, Xie J, et al. Comparison of Results Between Posterior Fossa Decompression with and without Duraplasty for the Surgical Treatment of Chiari Malformation Type I: A Systematic Review and Meta-Analysis. World Neurosurg. 2018;110:460-474.
38
Chauvet D, Carpentier A, George B. Dura splitting decompression in Chiari type 1 malformation: clinical experience and radiological findings. Neurosurg Rev. 2009;32:465-470.
39
Kim IK, Wang KC, Kim IO, et al. Chiari 1.5 malformation: an advanced form of Chiari I malformation. J Korean Neurosurg Soc. 2010;48:375-379.
