Introduction: Surgical treatment of Chiari I malformation continues to have a relatively high recurrence rate. Although more invasive, resection of the cerebellar tonsils may improve outcome in selected cases.
Methods: We reviewed 104 children surgically treated for Chiari I Malformations between 1995 and 2012. Surgical indications were the presence of symptoms or an expansile syrinx. Procedures were classified into 3 groups: foramen magnum decompression by bone removal and duraplasty with or without arachnoid dissection (SOC), SOC with bilateral coagulation of tonsils (SOC+TC), and SOC with subpial resection of the cerebellar tonsils (SOC+TR). The extent of surgery was determined by the pre-operative appearance of the relationship of the posterior fossa to its contents.
Results: Mean age was 7.2 ± 5.1 years. Forty-two patients (39%) had syringomyelia upon presentation. SOC was performed in 18 patients (16.8%), SOC+TC in 23 (21.5%), and SOC+TR in 63 (58.8%). Mean follow up was 34 ± 36.4 months and ranged from 6 months to 12 years. Eighty patients clinically improved (77%) and 24 were unchanged (23%). Syringomyelia improved in 91% of the patients that underwent SOC+TR (21/23), 87.5% in SOC+TC (7/8) and 62.5% (5/8) in SOC. There was no mortality. Complications occurred in 8 patients (7.4%); 2 in the SOC group (11%), 3 from SOC+TC (13%) and 3 from SOC+TR (4.8%). There was no vascular or neural injury secondary to tonsil manipulation. Three (2.9%) patients were re-operated because of persistent symptoms (1) or syrinx (2). There was no recurrence.
Conclusions: Surgical treatment of Chiari I malformation in children with SOC + TR provide excellent long term decompression of the cervicomedullary junction without an increase in surgical morbidity.
Patient Care: It will bring to the attention of the neurosurgical community the fact that suboccipital decompression with tonsil resection is a safe and effective modality in the treatment of children with Chiari I malformation.
Learning Objectives: By the conclusion of this section, participants should be able to consider suboccipital decompression with tonsil resection as an effective and safe modality in the treatment of children with Chiari I malformation.