title: Fetal surgery for repair of myelomeningocele allows normal development of anal sphincter muscles in sheep.
abstract: One major problem for patients with myelomeningocele (MMC) is fecal incontinence. To prevent this problem, fetal surgery for repair of MMC has been recently undertaken. The strategy behind this surgery is to allow normal development of anal sphincter muscles. The purpose of this study was to determine whether fetal surgery for repair of MMC allows normal development of anal sphincter muscles. Myelomeningocele was surgically created in fetal sheep at 75 days of gestation. At 100 days of gestation, fetal surgery for repair of the MMC lesion was performed. Three repair methods were used: standard neurosurgical repair (4 fetal sheep), covering the MMC lesion with Alloderm (2 fetal sheep), and covering the MMC lesion with Gore-Tex (2 fetal sheep). After the sheep were delivered (140 days of gestation), external and internal anal sphincter muscles were analyzed histopathologically. In control fetal sheep (not repaired) anal sphincter muscles did not develop normally. In contrast, in fetal sheep that underwent repair of the MMC, the external and internal anal sphincter muscles developed normally. Histopathologically, in the external sphincter muscles, muscle fibers were dense. In the internal sphincter muscles, endomysial spaces were small, myofibrils were numerous, and fascicular units were larger than those in unrepaired fetal sheep. There was no difference in muscle development for the repair methods. Fetal surgery for repair of MMC allows normal development of anal sphincter muscles.
authors.affiliation: Division of Pediatric Surgery and Fetal Treatment Center, Department of Surgery, University of California, San Francisco, CA, USA. jyoji@jikei.ac.jp
authors.forename: Jyoji
authors.initials: J
authors.lastname: Yoshizawa
authors.forename: Lourenco
authors.initials: L
authors.lastname: Sbragia
authors.forename: Bettina W
authors.initials: BW
authors.lastname: Paek
authors.forename: Roman M
authors.initials: RM
authors.lastname: Sydorak
authors.forename: Yoji
authors.initials: Y
authors.lastname: Yamazaki
authors.forename: Michael R
authors.initials: MR
authors.lastname: Harrison
authors.forename: Diana L
authors.initials: DL
authors.lastname: Farmer
mesh_terms: D001003:Anal Canal / Q000196:embryology* / Q000473:pathology; D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use; D003094:Collagen / Q000627:therapeutic use; D005333:Fetus / Q000601:surgery*; D005865:Gestational Age; D008567:Membranes, Artificial; D008591:Meningomyelocele / Q000196:embryology / Q000601:surgery*; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D009210:Myofibrils / Q000473:pathology; D019635:Neurosurgical Procedures; D038081:Organogenesis / Q000502:physiology*; D011138:Polytetrafluoroethylene / Q000627:therapeutic use; D012756:Sheep; D017768:Skin, Artificial
chemical_list: C440568:Alloderm; D001672:Biocompatible Materials; D008567:Membranes, Artificial; D011138:Polytetrafluoroethylene; D003094:Collagen