Surgical outcome of Chiari i malformation in children: Clinico-radiological factors and technical aspects

Purpose: The optimal treatment for Chiari I malformation in children is still under debate. The aim of this study was to evaluate the surgical outcome of the pediatric Chiari I malformation, focusing on clinico-radiological factors and technical aspects. Methods: Fifty-six patients with Chiari I malformation who received surgery at Seoul National University Children's Hospital were included. The mean age was 7.9 years. The patients were divided into three groups: group I (n∈=∈8) with hydrocephalus, group II (n∈=∈11) without syrinx, and group III (n∈=∈37) with syrinx. Group I received shunting operation initially, and others received foramen magnum decompression (FMD). Group III was further subdivided: group IIIa (n∈=∈9), minimal intradural manipulation, and group IIIb (n∈=∈27), active intradural manipulation. The outcomes were compared between the groups. The mean follow-up period was 75.9 months. Results: In group I, symptoms were resolved or had improved in most patients, with only one patient received additional FMD. Symptoms resolved or improved in 10 (91 %) and 25 cases (84 %) in groups II and III, respectively. Syrinx was markedly decreased in 31 cases (86 %) in group III. FMD was less effective for scoliosis (improved or stabilized in 57 %). The persistence of syrinx was related with an aggravation of scoliosis. The outcomes between group IIIa and IIIb showed no significant difference. Conclusions: In most pediatric Chiari I patients with hydrocephalus, a shunting operation was sufficient. FMD showed high efficacy in treating patients without hydrocephalus. The extent of the intradural procedure did not have a significant effect on the clinical outcome.