title: High long-term symptomatic recurrence rates after Chiari-1 decompression without dural opening: a single center experience.
abstract: OBJECTIVE
  We evaluated long-term outcomes of posterior fossa decompression (PFD) without duroplasty in consecutive patients with newly diagnosed Chiari-1 malformation.
  
  
  METHODS
  We searched the institutional database for all adult patients who underwent Chiari decompression between 1995 and 2007. PFD was offered to all consecutive patients with Chairi-1 malformation during this time period. We excluded patients who underwent re-exploration after initial Chiari-1 decompression elsewhere. Besides the demographic variables, presenting symptoms, neurological and radiographic findings the clinical records were studied for long-term outcomes specifically symptomatic improvement. We defined symptomatic improvement as resolution of all presenting symptoms including pain and/or neurological deficits at the last follow-up. The factors associated with symptom recurrence were also analyzed.
  
  
  RESULTS
  We identified 47 patients who underwent PFD for Chiari-1 malformation. Syringomyelia was noted in 36.2% of patients and the mean tonsilar herniation was 12.6mm. At a mean follow-up of 9.3 years, the symptomatic improvement rate was 60.6%. There were no operative complications. Repeat posterior fossa decompression was required for 31.9% patients with symptomatic recurrence at an average of 2.6 years after initial decompression. Fibrotic thickening overlying the dura mater was observed in one-third of these patients.
  
  
  CONCLUSIONS
  This case series reports low complication but high long-term symptomatic recurrence rates adults with symptomatic Chiari-1 malformation undergoing PFD.
authors: Division of Neurosurgery, Department of Neuroscience, Medical University of South Carolina, Charleston, USA. Electronic address: vibhor.krishna@uhn.ca.
authors: Vibhor
authors: V
authors: Krishna
authors: Division of Neurosurgery, Department of Neuroscience, Medical University of South Carolina, Charleston, USA.
authors: Marc
authors: M
authors: McLawhorn
authors: Division of Neurosurgery, Department of Neuroscience, Medical University of South Carolina, Charleston, USA.
authors: Libby
authors: L
authors: Kosnik-Infinger
authors: Division of Neurosurgery, Department of Neuroscience, Medical University of South Carolina, Charleston, USA.
authors: Sunil
authors: S
authors: Patel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001139:Arnold-Chiari Malformation / Q000453:epidemiology / Q000601:surgery*; D003627:Data Interpretation, Statistical; D004388:Dura Mater / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D019635:Neurosurgical Procedures / Q000379:methods*; D012008:Recurrence; D012307:Risk Factors; D016896:Treatment Outcome; D055815:Young Adult
keywords: Chiari decompression; Chiari decompression without duroplasty; Chiari malformation