The choice of surgical procedure for decompression of Chiari I malformations is often influenced by the presence of syringomyelia. The goal of this study was to determine if syringomyelia and/or scoliosis are influenced by dural opening versus nondural opening suboccipital decompressive (SOD) procedures.
A retrospective review of 54 pediatric patients over a 13-year period presenting with Chiari I malformation and syringomyelia at time of diagnosis is presented. Between 1994 and 2002 nearly all patients underwent SOD with duraplasty (n = 26), while between 2003 and 2007 nearly all patients underwent SOD without dural opening (n = 28). Sixteen of 26 patients who underwent duraplasty presented with scoliosis while 8 of 28 patients without duraplasty had scoliosis. All of the patients had a complete spinal cord MRI before and after surgery.
MRI studies clearly demonstrated a greater degree of resolution of the syrinx in the duraplasty group. However, the degree of resolution of the syrinx did not correlate with clinical outcome (that is, improvement of symptoms or progression of scoliosis). Progression of scoliosis was rare in either group.
While much controversy exists as to the best method of decompression in patients with Chiari I malformations, it does not appear from this study that dural opening influences the clinical progression of syringomyelia or scoliosis.