Advertisement

Endoscopic coverage of fetal open myelomeningocele in utero

      To the Editors:

      Harrison was mistaken when he stated that endoscopic coverage of myelomeningocele has not yet been attempted in human fetuses (Harrison MR. Fetal surgery. Am J Obstet Gynecol 1996;174:1255-64). In fact, we have successfully performed an experimental procedure designed to prevent ongoing exposure of the spinal cord to amniotic fluid in two patients at Vanderbilt University Medical Center. This minimally invasive fetal surgery was developed by us in pregnant mixed-breed ewes.
      • Copeland ML
      • Bruner JP
      • Richards WO
      • Sundell HW
      • Tulipan NE
      A model for in utero endoscopic treatment of myelomeningocele.
      The technique we designed consists of placement of a maternal split-thickness skin graft over the exposed neural placode. The skin graft and a covering of oxidized regenerated cellulose (Surgicel, Johnson & Johnson Medical, Arlington, Tex.) are attached in a carbon dioxide atmosphere with fibrin glue prepared from autologous cryoprecipitate.
      Two fetuses with open lumbar myelomeningocele underwent endoscopic coverage of the spinal lesion at 22 and 23 weeks' gestation. One infant, delivered by planned cesarean section at 35 weeks' gestation after demonstration of fetal lung maturity, is 1 year old. The other fetus was delivered 1 week after operation because of the development of amnionitis and died in the delivery room of extreme prematurity.
      • Bruner J
      • Tulipan N
      • Richards W
      Endoscopic repair of fetal spina bifida in utero [abstract].
      A growing body of evidence suggests that, in addition to the congenital neurologic defects associated with the development of myelomeningocele, spinal cord injury may result from prolonged exposure of the neural elements to amniotic fluid.
      • Heffez DF
      • Aryanpur J
      • Hutchins GM
      • Freeman JM
      The paralysis associated with myelomeningocele: clinical and experimental data implicating a preventable spinal cord injury.
      In several animal models the clinical and pathologic manifestations of surgically induced “myelomeningocele” were prevented by in utero repair.
      • Copeland ML
      • Bruner JP
      • Richards WO
      • Sundell HW
      • Tulipan NE
      A model for in utero endoscopic treatment of myelomeningocele.
      We are currently conducting in vitro research in an attempt to identify the timing and etiologic agents of the environmental insult more precisely. In the meantime we agree that surgical treatment of this nonlethal defect is not justified with a standard hysterotomy approach, because of the unacceptably high morbidity and mortality associated with open fetal surgery. Minimally invasive fetal surgery, however, appears to constitute a feasible approach to myelomeningocele and other nonlethal malformations that result in progressive organ damage.

      References

        • Copeland ML
        • Bruner JP
        • Richards WO
        • Sundell HW
        • Tulipan NE
        A model for in utero endoscopic treatment of myelomeningocele.
        Neurosurgery. 1993; 33: 542-545
        • Bruner J
        • Tulipan N
        • Richards W
        Endoscopic repair of fetal spina bifida in utero [abstract].
        Am J Obstet Gynecol. 1996; : 174-487
        • Heffez DF
        • Aryanpur J
        • Hutchins GM
        • Freeman JM
        The paralysis associated with myelomeningocele: clinical and experimental data implicating a preventable spinal cord injury.
        Neurosurgery. 1990; 26: 987-992