Clinical outcomes that fetal surgery for myelomeningocele needs to achieve

The development of techniques to close open neural tube malformations prior to birth has generated great interest and hope for fetal interventions and their outcomes. To plan a randomized trial, as is being discussed at three centres in the United States, the determination of what constitutes a clinically significant improvement in outcome is critical. To date, preliminary observations from two centres suggest that improvements may occur, not in spinal cord function as originally postulated, but in the extent of the hindbrain hernia and the frequency that shunting is required to control hydrocephalus.

The determination of what outcome would constitute an important and clinically significant difference in outcome to be achieved by fetal intervention for myelomeningocele.

Parents of patients and patients treated in our myelomeningocele clinic were surveyed using a structured and validated tool. From the perspective of a recommendation to a close friend or family member, the interviewees were asked to quantify on a scale from 0 to 100 the chance of specific outcomes (need for a shunt, need for a wheelchair, change of urinary incontinence) that a fetal operation would need to predictably achieve.

Responses were obtained from 77 patients/families. The fifty percentile response in each study dimension was as follows: the chance of needing a shunt was 12 % (range 0 - 50 %), the chance of needing a wheelchair was 8 % and the chance of being incontinent was 5 % (range 0 - 25 %).

Fetal interventions will have to achieve significant improvements in the control of hydrocephalus, mobilization and continence over postnatal treatment to be justified.