Abstract

Introduction: is a malformation of the skull. It consists of a downward displacement of the cerebellar tonsils through the foramen magnum sometimes causing non-communicating hydrocephalus.

Objectives: to assess the value of the surgical management by posterior fossa bony decompression and cautious durotomy, shrinkage of tonsils and duroplasty with fascia lata graft in the clinical and radiological improvement of patients with Chiari malformation type 1.

Patients & Methods: This is a prospective study included 20 patients with Chiari malformation type I, operated through posterior fossa craniectomy, durotomy in Y-shaped manner, shrinkage of cerebellar tonsils by bipolar electrocautry, duroplasty by fascia lata graft and water tight closure. All patients underwent evaluation clinically and radiologically by CT scanning and MRI brain preoperatively and 3 months after surgery to assess the improvement.

Results: The mean age was 41.5 years ranging from 18 to 65 years. There was a female predominance as the females represented (60%) and males (40%). The most common clinical findings presented at diagnosis were headache in 20 patients, neck pain in 18 patients, 12 patients reported good outcome, 4 fair, 4 poor, 10 patients showed marked reduction in syrinx size, 2 mild reduction, 8 no change, 16 patients showed normal level of tonsils postoperatively, and 4 patients were within 5 mm below foramen magnum.

Conclusion: Posterior fossa bony decompression and cautious durotomy, shrinkage of tonsils and duroplasty with fascia lata graft has good clinical and radiological outcome. Watertight closure of dura is recommended to avoid CSF leak and wound infection.

Keywords: Small posterior fossa; Osseous decompression; Dural graft; Syringomyelia