title: Bladder changes after several coverage modalities in the surgically induced model of myelomeningocele in lambs.
abstract: OBJECTIVE
  To assess the presence of early bladder abnormalities in a prenatally corrected and uncorrected animal model of Myelomeningocele (MMC).
  
  
  METHODS
  A MMC-like lesion was surgically created in 18 fetal lambs between the 60th and the 80th day of gestation. Eight of them did not undergo fetal repair (group A), three were repaired with an open two-layer closure (group B), three using BioGlue® (groupC) and four fetoscopically (group D). At term, bladders were examined macroscopically and histopathological changes were assessed using H-E and Masson Trichrome.
  
  
  RESULTS
  Five animals in group A (5/8, 62%), two in group B (2/3, 66%), one in group C (1/3, 33%) and one in group D (1/4, 25%) survived. Macroscopically bladders in group A were severely dilated and showed thinner walls. Microscopically they showed a thin layer of colagenous tissue (Blue layer. BL) lying immediately subjacent to the urothelium. The muscular layers were thinner. Non compliant pattern with thick wall and low capacity was also found in the non corrected model. Group B and the control showed preservation of muscular layers and absence of BL. Groups C and D presented BL but also preservation of muscular layers.
  
  
  CONCLUSIONS
  Bladder changes in a surgically-induced model of MMC can be described using histopathological data. Both extremes of bladder changes can be observed in the model. These changes were completely prevented with open fetal surgery and partially with other coverage modalities.
authors.affiliation: Departamento de Urología Pediátrica, Hospital Universitario La Paz, Madrid, España. Electronic address: lauraburgos33@hotmail.com.
authors.forename: L
authors.initials: L
authors.lastname: Burgos
authors.affiliation: Departamento de Cirugía Pediátrica, Hospital Universitario La Paz, Madrid, España.
authors.forename: J L
authors.initials: JL
authors.lastname: Encinas
authors.affiliation: Departamento de Anatomía Patológica, Hospital Universitario La Paz, Madrid, España.
authors.forename: M Á
authors.initials: MÁ
authors.lastname: García-Cabezas
authors.affiliation: Cirugía Pediátrica, Unidad de Cirugía Fetal y Neonatal, Hospital Vall d'Hebrón, Barcelona, España.
authors.forename: J L
authors.initials: JL
authors.lastname: Peiró
authors.affiliation: Departamento de Cirugía Pediátrica, Hospital Universitario La Paz, Madrid, España.
authors.forename: M
authors.initials: M
authors.lastname: López-Santamaría
authors.affiliation: Departamento de Urología Pediátrica, Hospital Universitario La Paz, Madrid, España.
authors.forename: E
authors.initials: E
authors.lastname: Jaureguízar
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005333:Fetus; D008591:Meningomyelocele; D012756:Sheep; D013514:Surgical Procedures, Operative / Q000379:methods; D001743:Urinary Bladder / Q000473:pathology*
keywords: Bladder; Blue layer; Capa azul; Cobertura; Coverage; Fetal; Histopathology; Histopatología; Mielomeningocele; Myelomeningocele; Ovega; Sheep; Vejiga