Outcomes for the Surgical Management of Chiari I and Chiari II Malformations

Abstract

An up-to-date, evidence-based review of the neurosurgical literature reveals that clinical outcomes following the operative management of Chiari I and II malformations (CM I and CM II) have improved dramatically since these congenital disorders were first recognized as surgical diseases. A detailed assessment of major measurable postoperative parameters—including improvement in clinical signs and symptoms, resolution of syringomyelia, and progression of scoliosis—proves these procedures to be safe and effective when performed in a timely manner by an experienced neurosurgeon. Patients with CM I routinely report a significant reduction in headache, neck pain, apnea, and syrinx-related symptoms and encounter low rates of complication or reoperation after posterior fossa decompression using a bone-only or intradural approach. Neonates and infants with CM II have higher rates of symptomatic improvement and reversal of impairment when an operative intervention is made at the first sign of brain stem dysfunction. The current trend of less invasive bone-only surgical approaches, if shown in larger prospective trials to be superior to traditional decompressions with dural opening, will only add to the modern-day neurosurgeon’s ability to achieve excellent clinical outcomes with minimal risk in the treatment of patients with Chiari I and II malformations.