Suboccipital decompression during posterior cranial vault remodeling for selected cases of Chiari malformations associated with craniosynostosis

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>The optimal management of Chiari malformations in the setting of craniosynostosis is not well established. In this report the authors describe their outcomes with the combined technique of simultaneous suboccipital decompression (SOD) during posterior cranial vault remodeling (PCVR).</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>A retrospective review was performed of all patients undergoing PCVR and simultaneous SOD. Demographic data, diagnosis, imaging studies, operative intervention, and clinical follow-up were evaluated.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Thirty-four patients were identified as having undergone a simultaneous PCVR/SOD for Chiari malformation associated with craniosynostosis. Eighty-eight percent of these patients had syndromic, multisutural craniosynostosis, and the remaining patients had unilateral lambdoid craniosynostosis. There were no postoperative complications as a direct result from this combined procedure. Two patients required a subsequent direct approach for decompression of the Chiari malformation. The interval between these subsequent surgeries was 3 years and 19 months.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Chiari malformations are commonly associated with syndromic, complex craniosynostosis and isolated lambdoid craniosynostosis. In appropriately selected patients, a combined posterior cranial vault enlargement and SOD of the foramen magnum is associated with a low complication rate and appears to be an effective procedure.</jats:p></jats:sec>

Lambdoid Craniosynostosis

“…Performance of a suboccipital decompression during posterior remodeling procedures has been shown to provide radiographic improvement of tonsillar herniation in 70 percent of asymptomatic patients (with stability in the remaining 30 percent) without adding any additional morbidity. 9 We believe that this additional step has the potential to prevent the development of a symptomatic Chiari deformation, and the need for later surgical intervention, by preventing future cord compression. Thus far, of the 17 patients undergoing simultaneous suboccipital decompressions in this series, none have required any additional treatment related to the development of either a symptomatic Chiari deformation or a syrinx.…”

“…2 and 3). 9 All patients were followed with magnetic resonance imaging scans postoperatively, with increasing time lags based on age, until skeletal maturity. The need for secondary operative intervention was determined by either the development of a symptomatic Chiari I deformation or a significant recurrence of the presenting deformity.…”

Upward Translation of Cerebellar Tonsils following Surgical Expansion of Supratentorial Cranial Vault: A Unified Biomechanical Explanation of Chiari Type I

“…The near universal treatment of symptomatic Chiari I, in the absence of other identified causative pathology such as mass within the posterior fossa [3,5,8,9,10,11,12,13,14,15,16,17,18,19,58,59] or hydrocephalus [52], is the surgical provision of more space across the cervicomedullary region. When the root cause of Chiari I deformity is supratentorial craniocerebral disproportion or hydrocephalus, cervicomedullary decompression does not address the pathological downward force vector but simply provides additional space for transforaminal herniation and this can be lethal [60].…”

“…Chiari type I is occasionally referred to as a malformation but is, more correctly, a deformation of normal cerebellar tissue. The entity has puzzling aspects, as evidenced by the diversity of putative pathophysiologies [3,4,5,6,7,8], advocated surgical approaches [3,5,8,9,10,11,12,13,14,15,16,17,18,19], nonsurgical approaches [8], and outcomes [9,15,20,21,22]. Chiari type I deformity may be present at birth or can first appear later in life, including adulthood, and it can be reversed.…”

A unifying theory for the multifactorial origin of cerebellar tonsillar herniation and hydrocephalus in osteopetrosis

“…52,58 The association between craniosynostosis and CTH has been well recognized, 8,17,34,50 and most believe that these hindbrain malformations are an acquired defect occurring sometime during the postnatal period as a result of premature fusion of the cranial sutures. 52,58 The association between craniosynostosis and CTH has been well recognized, 8,17,34,50 and most believe that these hindbrain malformations are an acquired defect occurring sometime during the postnatal period as a result of premature fusion of the cranial sutures.…”