title: Neural endoscopic assisted micro-invasive management of Chiari I malformation.
abstract: BACKGROUND
  In order to make posterior fossa decompression for the management of Chiari I malformation simple and less invasive while using direct visualization, a novel solely endoscopic procedure has been employed for the decompression of Chiari malformation type I. The objective of this study was to present neural endoscopic posterior fossa decompression and atlas laminectomy for Chiari type I patients.
  
  
  METHODS
  Twenty-one patients with Chiari type I underwent neural endoscopic posterior fossa decompression and atlas laminectomy. We described the procedure for neural endoscopic posterior fossa decompression and atlas laminectomy. All patients in this series demonstrated cerebellar tonsil herniation below the foramen magnum in addition to syringomyelia. All patients in the reviewed study underwent preoperative MRI as well as 3-month postoperative MRI. Additional follow-up MRI varied but was usually repeated 12 months to 18 months after surgery. Postoperative MRI studies were retrospectively reviewed and compared with preoperative studies.
  
  
  RESULTS
  All patients showed clinical improvements, and none had any complications. Patients with syringomyelia had symptoms entirely disappear. Eleven patients (52.4%) experienced radiographic improvement in syringomyelia (decreased size or resolution) during the follow-up period. Nine patients (42.8%) demonstrated decreased syrinx size and four (19%) demonstrated resolved syrinx. Of the 15 patients with symptomatic syringomyelia, 11 (73.3%) experienced symptomatic improvement. The median time to symptom improvement was four months after surgery. Post surgical MRI examinations indicated complete and sufficient decompression of foramen magnum region.
  
  
  CONCLUSIONS
  Endoscope atlanto-occipital decompression surgery is an innovative, safe and effective surgical procedure. It has similar results compared to traditional surgery, however with the added advantages of being minimal invasive, having fewer complications, decreased influence on stability of occipital bony structure, and a faster recovery as well as reduced hospital stay and expenses.
authors.affiliation: Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.
authors.forename: Kan
authors.initials: K
authors.lastname: Deng
authors.forename: Yong-Ning
authors.initials: YN
authors.lastname: Li
authors.forename: Gui-Lin
authors.initials: GL
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Gao
authors.forename: Zhong
authors.initials: Z
authors.lastname: Yang
authors.forename: Xiao
authors.initials: X
authors.lastname: Di
authors.forename: Ren-Zhi
authors.initials: RZ
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D001139:Arnold-Chiari Malformation / Q000601:surgery*; D002648:Child; D019299:Decompression, Surgical / Q000379:methods; D004724:Endoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D019060:Minimally Invasive Surgical Procedures / Q000379:methods; D012189:Retrospective Studies; D013595:Syringomyelia / Q000601:surgery*