Fourth ventricle stent placement for treatment of recurrent syringomyelia in patients with type I Chiari malformations

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In patients with syringomyelia and type I Chiari malformation (CM-I) who have required reoperation because of persistent, recurrent, or expanding syrinx, the senior author placed a stent from the fourth ventricle to the cervical subarachnoid space in hopes of promoting circulation of CSF out of the ventricle and away from the central canal of the spinal cord. This study was undertaken to determine the long-term success of this operative stratagem in eliminating the syrinx, as well as to document the complications that occurred following stent placement. The technique utilized for placement of fourth ventricle stents is presented.


The surgical database of the senior author was reviewed to identify all patients who underwent stent placement at a reexploration of a suboccipital decompression for a CM-I conducted for a recurrent or ineffectively treated syringomyelia. The clinical and radiological data of these patients were analyzed to determine long-term efficacy and complications of the procedure.


Fourteen patients (average age 10.7 ± 5.2 years, range 2.6–20.1 years) were identified who met these inclusion criteria. They each presented with recurrent, residual, or expanding syringomyelia following a prior decompression for a CM-I. The reoperation with stent placement was complicated by late stent dislodgement and recurrence or persistence of the syrinx in 2 patients (14%) and by neurological deficit in 1 patient (7%). There was 1 perioperative CSF leak (7%). In 1 other patient (7%), the stent dislodged after surgery but required no further intervention, as the syrinx remained collapsed. Two patients (14%) required late reoperation for stent replacement when syrinxes recurred. At the most recent imaging follow-up, the stent was positioned appropriately in 12 patients (86%; average follow-up 6.9 years, range 0.5–18.1 years), and the recurrent or residual syrinx was eliminated or reduced in size by 75% or greater in 13 patients (93%).


The placement of a stent from the fourth ventricle to the cervical subarachnoid space was a highly effective treatment for patients with recurrent, residual, or expanding syringomyelia following an initial decompression of an associated CM-I. The sole neurological complication in this series was related to lysis of arachnoid scar rather than stent placement itself, but inability to maintain fixation of the stent in situ led to further surgery to replace the stent in 2 patients.

ABBREVIATIONS BCH = Boston Children’s Hospital; CM = Chiari malformation; CM-I = type I CM; VP = ventriculoperitoneal.

Article Information

Correspondence R. Michael Scott: Boston Children’s Hospital, Boston, MA.

INCLUDE WHEN CITING Published online October 19, 2018; DOI: 10.3171/2018.7.PEDS18312.

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

© AANS, except where prohibited by US copyright law.



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    Patient exclusion flowchart.

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    Case 4. This 12-year-old girl initially presented with scoliosis associated with a large syrinx and CM-I. Six months later her scoliosis had worsened and MRI revealed an enlarging, holocord syrinx (left). At reoperation, a veil of arachnoid was found at the foramen of Magendie and a stent was placed from the fourth ventricle to the cervical subarachnoid space. Follow-up MRI 13.6 years after stent placement (right) showed the stent in position (arrow) and stable decompression of the syrinx. Figure is available in color online only.

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    Case 6. This 9-year-old boy presented with ventriculomegaly and a large syrinx. Following CM-I decompression, his ventricular system and syrinx became reduced in size, but MRI 5 years later (left) revealed syrinx recurrence. At reoperation, the foramen of Magendie was noted to be scarred shut. The scar was lysed and a stent was placed. MRI 6 months after reoperation (right) showed almost complete decompression of the syrinx. His neurological examination 3.5 years after reoperation was normal, but no further follow-up imaging was obtained and the patient was lost to follow-up.

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    Case 7. This 14-year-old girl was operated on at an outside hospital for CM-I and minimal dilation of the central canal. Six years later, she presented there again with a large syrinx. Reoperation was complicated by wound abscess and meningitis, and postoperative MRI revealed a persisting and enlarging syrinx (left). At her third operation 3 months later at BCH, an extensive scar in the dorsal subarachnoid space and at the foramen of Magendie was encountered and lysed, and a stent was placed. Postoperatively, the patient suffered a unilateral partial dorsal column deficit believed to be from superficial devascularization when the dense scar was lysed. MRI 4.8 years after stent placement (right) revealed almost complete decompression of her syrinx and the stent in good position. A mild, right, upper extremity dorsal column and lateral spinothalamic tract deficit persisted at last clinical follow-up 3.5 years postoperatively.

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    Case 8. This 11-year-old girl initially presented with scoliosis, a CM-I, and syringomyelia. One year after surgery at an outside institution, MRI (left) demonstrated an enlarged holocord syrinx. At reoperation at BCH, dense arachnoid bands and an occlusive web over the foramen of Magendie were found; the adhesions and webs were lysed, and a stent was placed. MRI 6.1 years following stent placement (right) demonstrated complete collapse of the syrinx and a stent (arrow) in stable position. Figure is available in color online only.

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    Case 10. This 3.5-year-old girl presented with severe brief headaches and MRI demonstrating a CM-I with tonsils at the C2–3 level. At her initial surgery at BCH, the tonsils were coagulated and shriveled as part of the decompression. At age 6, the headaches recurred and MRI (left) showed a new syrinx with apparent outflow obstruction of the distal fourth ventricle. At reoperation at BCH, a web of arachnoid occluded the distal fourth ventricle and a stent was placed. MRI 5.5 years after stent placement (right) demonstrated collapse of the syrinx and the stent (arrow) in good position. Figure is available in color online only.



Cinalli GRenier DSebag GSainte-Rose CArnaud EPierre-Kahn A: Chronic tonsillar herniation in Crouzon’s and Apert’s syndromes: the role of premature synostosis of the lambdoid suture. J Neurosurg 83:5755821995


Dyste GNMenezes AHVanGilder JC: Symptomatic Chiari malformations. An analysis of presentation, management, and long-term outcome. J Neurosurg 71:1591681989


Sacco DScott RM: Reoperation for Chiari malformations. Pediatr Neurosurg 39:1711782003


Strahle JMuraszko KMBuchman SRKapurch JGarton HJMaher CO: Chiari malformation associated with craniosynostosis. Neurosurg Focus 31(3):E22011


Venes JLBlack KLLatack JT: Preoperative evaluation and surgical management of the Arnold-Chiari II malformation. J Neurosurg 64:3633701986




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