title: Embryopathogenetic surgicoanatomical classification of dysraphism and surgical outcome of spinal lipoma: a nationwide multicenter cooperative study in Japan.
abstract: OBJECTIVE
  The natural history of asymptomatic spinal lipoma in infancy remains unclear, and the indication for the prophylactic untethering operation is still debatable. To address this question, a multicenter cooperative study for the treatment of spinal lipoma was performed by the 7 most active institutions in neurosurgical care for spina bifida in Japan between 2001 and 2005.
  
  
  METHODS
  Patients were classified using the embryopathogenetic surgicoanatomical classification. Their neurosurgical postoperative course was analyzed using the Spina Bifida Neurological Scale. Among 261 patients, 159 were asymptomatic and 102 were symptomatic.
  
  
  RESULTS
  Of the 136 patients for whom prophylactic surgeries were performed, 135 remained asymptomatic and only 1 (0.4%) of the 261 patients presented with mild sensory disturbance. Mild foot deformity was identified in 1 (4.3%) of 23 conservatively observed patients. Of 100 symptomatic patients, deterioration after surgery was seen in 6%, and improvement in 44%. Complete resolution of symptoms was seen in only 14.2%. Filar types for patients > 3 years old improved in Spina Bifida Neurological Scale scores from 12.3 to 14.0. The mean age of symptomatic patients with lipomyelomeningocele was the youngest of all (1.3 years), which indicates lipomyelomeningocele may deteriorate in early infancy. Improvements from surgery were seen for all types of lipoma except the caudal type, presenting at an older mean age (15 years).
  
  
  CONCLUSIONS
  A low rate of postsurgical worsening indicates that surgeries for asymptomatic and symptomatic lipomas are safe. Surgeries done after the onset of symptoms seldom cure the patients. These two results support early untethering for any kind of lipoma; however, further study of the natural history is required.
authors.affiliation: Division of Pediatric Neurosurgery, Department of Neurosurgery, The Jikei University Hospital Women's and Children's Medical Center, Juntendo University, Tokyo, Japan. prof.oi@jikei.ac.jp
authors.forename: Shizuo
authors.initials: S
authors.lastname: Oi
authors.forename: Sadahiro
authors.initials: S
authors.lastname: Nomura
authors.forename: Masato
authors.initials: M
authors.lastname: Nagasaka
authors.forename: Hajime
authors.initials: H
authors.lastname: Arai
authors.forename: Reizo
authors.initials: R
authors.lastname: Shirane
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yamanouchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nishimoto
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Date
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D000013:Congenital Abnormalities / Q000145:classification / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007223:Infant; D007564:Japan; D008067:Lipoma / Q000150:complications / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000002:abnormalities* / Q000473:pathology* / Q000601:surgery; D008297:Male; D019635:Neurosurgical Procedures / Q000009:adverse effects / Q000379:methods; D020127:Recovery of Function; D012720:Severity of Illness Index; D016135:Spinal Dysraphism / Q000145:classification / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D013125:Spinal Neoplasms / Q000150:complications / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome