Dura splitting decompression in Chiari type 1 malformation: clinical experience and radiological findings

To restore the cerebrospinal fluid (CSF) flow at the craniocervical junction in Chiari I malformation (CM-I), most surgeons practice a suboccipital craniectomy with duraplasty. To reduce the risk of CSF leak, a dura splitting decompression is created removing only the dural outer layer. We report on a series of 11 patients with CM-I (five with syringomyelia) operated on between 2000 and 2007 using this technique. Neurological examination and cerebro-spinal MRI scan were performed before and after surgery. Symptoms improved completely in six patients. Headaches and cervicalgias disappeared for all patients. Dizziness and paresthesia in the upper limb remained unchanged for three and two patients, respectively. We observed no complications such as CSF leak, meningocele, or meningitis. Postoperative MRI scan showed a significant craniocervical decompression in ten patients. Four patients had a new cisterna magna. Two syringomyelias completely disappeared, two decreased, and one was stable. Dural splitting can be practiced to treat CM-I. Clinical results are similar to the other techniques with less complications. Radiological findings show satisfying posterior fossa decompression.