title: Comparison between two surgical techniques for prenatal correction of meningomyelocele in sheep.
abstract: OBJECTIVE
  To compare the classical neurosurgical technique with a new simplified technique for prenatal repair of a myelomeningocele-like defect in sheep.
  
  
  METHODS
  A myelomeningocele-like defect (laminectomy and dural excision) was created in the lumbar region on day 90 of gestation in 9 pregnant sheep. Correction technique was randomized. In Group 1 the defect was corrected using the classic neurosurgical technique of three-layer suture (dura mater, muscle and skin closure) performed by a neurosurgeon. In Group 2, a fetal medicine specialist used a biosynthetic cellulose patch to protect the spinal cord and only the skin was sutured above it. Near term (day 132 of gestation) fetuses were sacrificed for pathological analysis.
  
  
  RESULTS
  There were two miscarriages and one maternal death. In total, six cases were available for pathological analysis, three in each group. In Group 1, there were adherence of the spinal cord to the scar (meningo-neural adhesion) and spinal cord architecture loss with posterior funiculus destruction and no visualization of grey matter. In Group 2, we observed in all cases formation of a neo-dura mater, separating the nervous tissue from adjacent muscles, and preserving the posterior funiculus and grey matter.
  
  
  CONCLUSIONS
  The new simplified technique was better than the classic neurosurgical technique. It preserved the nervous tissue and prevented the adherence of the spinal cord to the scar. This suggests the current technique used for the correction of spina bifida in humans may need to be reassessed.
authors: Universidade de São Paulo, São Paulo, SP, Brazil.
authors: Silvia Rejane Fontoura
authors: SR
authors: Herrera
authors: Ricardo José de Almeida
authors: RJ
authors: Leme
authors: Paulo Roberto
authors: PR
authors: Valente
authors: Elia Garcia
authors: EG
authors: Caldini
authors: Paulo Hilário Nascimento
authors: PH
authors: Saldiva
authors: Denise Araujo Lapa
authors: DA
authors: Pedreira
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004388:Dura Mater / Q000166:cytology / Q000601:surgery; D005260:Female; D046128:Fetal Therapies; D005332:Fetoscopy / Q000379:methods*; D005333:Fetus / Q000601:surgery*; D062069:Inventions; D008591:Meningomyelocele / Q000601:surgery*; D019635:Neurosurgical Procedures / Q000379:methods*; D007752:Obstetric Labor, Premature; D011247:Pregnancy; D012756:Sheep