Management opinions from different centers (Rio de Janeiro).

Introduction: The surgical treatment of Chiari type 1 (CM1) malformation is controversial and depends largely on the preference of the surgeon. The evolution of neuroimaging resulted in an increased number of asymptomatic patients incidentally diagnosed.

Purpose: To study retrospectively a population of 24 symptomatic patients with CM1 operated between 1999 and 2017 in which intraoperative ultrasonography (IOUS)-assisted posterior fossa-C1 decompression was used to decide whether the dura mater should be opened (CVD+) or not (CVD).

Results: Most of the patients complained of headache or neck pain, 15 had hydrosyringomyelia and 14 had some spinal cord involvement. Patients were categorized in improved, unchanged, or worse according the preoperative signs and symptoms. Overall, 19 patients improved, 3 deteriorated, and 2 remained unchanged. Among these, 4 out 5 had syringohydromyelia.

Conclusions: IOUS-assisted posterior fossa-C1 decompression is our preferred option to treat CM1. Children submitted to intradural procedures, initially or subsequently, had increased postoperative complications. CSF fistula or pseudomeningocele was the major cause of complication. The final result seems to correlate with the preoperative neurological status.