THE CHIARI-II MALFORMATION - A SURGICAL SERIES

Thirty patients between the ages of 7 months and 24 years were treated surgically for symptomatic Chiari II malformation at the Arkansas Chi ldren's Hospital. All patients underwent at least bony decompression o f the malformation. Assessments of the patients' conditions were made at 6 weeks and 1 year after surgery, and complications of surgery were noted. For a majority of the patients, the presenting symptoms were r esolved following treatment (74% at 6 weeks and 80% at 1 year). Partia l resolution occurred in several of the patients (17% at 6 weeks and 1 4% at 1 year). A small number remained the same at 6 weeks (6%) and at 1 year (3%), while 1 patient was worse after surgery. Ten of the pati ents with complete resolution in the short term required repeat surger y an average of 49 months after their original operation, after which they again attained complete resolution of their symptoms. Scales for clinical, radiographic and operative grading of the patients' conditio ns as mild, moderate or severe were devised, and these were employed t o characterize the condition of each patient. Patients in each grading category had good results, with rates of complete symptomatic resolut ion ranging from 67 to 100%. Severity in each category was found to be well correlated with eventual recurrence of symptoms and need for reo peration.