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Surgical Management of Chiari 1.5 in Children: A Truly Different Disease?
Ignazio G Vetrano1,2, Arianna Barbotti1, Tommaso Francesco Galbiati1
1Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy.
Insights
Chiari 1.5 malformation (CM1.5) in children often presents with craniovertebral junction anomalies. Posterior fossa decompression with duraplasty is effective, though some patients require tonsil resection due to severe crowding.
Area of Science:
- Neurosurgery
- Pediatric Neurology
- Craniovertebral Junction Anomalies
Background:
- Chiari 1.5 malformation (CM1.5) may have a more aggressive course and higher association with craniovertebral junction (CVJ) anomalies.
- Optimal management for CM1.5 remains unclear due to limited specific data.
- This study investigates the characteristics and outcomes of pediatric CM1.5 patients.
Purpose of the Study:
- To elucidate the peculiar characteristics of Chiari 1.5 malformation in pediatric patients.
- To evaluate the management and outcomes of CM1.5 treated with posterior fossa decompression and duraplasty.
- To identify factors influencing surgical outcomes in this specific patient subgroup.
Main Methods:
- Retrospective analysis of 33 pediatric patients diagnosed with Chiari 1.5 malformation.
- All patients underwent posterior fossa decompression and duraplasty (PFDD) between 2006 and 2021.
- Evaluation of clinical presentation, CVJ anomalies, surgical procedures, and outcomes.
Main Results:
- Headache was the most common symptom (100%), followed by syringomyelia (58%).
- Over 60% of patients had associated CVJ anomalies, though most did not require fusion.
- Posterior fossa decompression and duraplasty led to headache resolution in 84% of cases; 58% required tonsil resection/coagulation.
- Tonsil resection/coagulation was more frequently needed in CM1.5 patients due to severe crowding.
Conclusions:
- Pediatric Chiari 1.5 malformation is frequently associated with CVJ anomalies.
- Posterior fossa decompression and duraplasty is an effective treatment for symptomatic CM1.5.
- Increased tonsil crowding in CM1.5 necessitates a higher rate of tonsil resection or coagulation compared to other Chiari malformations.
Abstract:
Background: In patients with Chiari 1.5 malformation (CM1.5), a more aggressive disease course and an increased association with craniovertebral junction (CVJ) anomalies has been suggested. The best management of this subgroup of patients is not clearly defined, also due to the lack of specific series elucidating this anomaly's peculiar characteristics. Methods: We evaluated a series of 33 patients (25 females, 8 males; mean age at surgery: 13 years) fulfilling the criteria for Chiari 1.5 diagnosis who underwent posterior fossa decompression and duraplasty (PFDD) between 2006 and 2021. Results: Headache was present in all children, five presented central apnea, five had dysphagia, and three had rhinolalia. Syringomyelia was present in 19 (58%) children. Twenty patients (61%) showed various CVJ anomalies, but only one child presented instability requiring arthrodesis. The mean tonsil displacement below the foramen magnum was 19.9 mm (range: 12-30), without significant correlation with the severity of symptoms. Syringomyelia recurred or was unchanged in three patients, and one needed C1-C2 fixation. The headache disappeared in 28 children (84%). Arachnoid opening and tonsil coagulation or resection was necessary for 19 children (58%). Conclusions: In our pediatric CM series, the need for tonsil resection or coagulation was higher in CM1.5 children due to a more severe crowding.
