Surgical outcomes by sectioning a filum terminale in patients with terminal syringomyelia

Although terminal syringomyelia suggests a tethered spinal cord, a consensus has still not been established for surgical indications, when there are no associated abnormalities or only minor associated abnormalities. We analyzed surgical outcomes of sectioning a filum terminale in patients with terminal syringomyelia to elucidate the significance of untethering surgery.

Fifty-seven pediatric patients with terminal syringomyelia who underwent untethering via sectioning the filum terminale between 2007 and 2018 were retrospectively analyzed. Postoperative outcomes of symptoms and MRI findings were evaluated.

Of 57 patients, 40 had other associated abnormalities (25 with filar lipoma and 29 with low conus medullaris) that could be responsible for tethered cord. Nineteen patients had symptoms. The mean age at the time of surgery was 18 months (3-96 months). The mean follow-up period was 3.3 years (1-9 years). Preoperative symptoms improved in 9 patients (47%) after surgery. At 1 year after the surgery, the size of syringomyelia decreased in 19 (33%), increased in 4 (8%), and did not change in 34 (69%) patients. Of 28 patients who were followed up for more than 3 years, the size decreased in 17 (61%), increased in 1 (4%), and did not change in 10 (35%).

When untethering was performed by sectioning a filum terminale, the size of terminal syringomyelia decreased in more than half of patients in the long term. Sectioning the filum terminale demonstrated the possibility of radiological and clinical improvement in patients with terminal syringomyelia.