Fetal surgery for spina bifida: past, present, future
1The Center for Fetal Diagnosis and Treatment, Children's Hospital of Philadelphia, and Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA. adzick@email.chop.edu
Insights
Fetal surgery for myelomeningocele (MMC) before 26 weeks
Area of Science:
- Neuroscience
- Developmental Biology
- Surgical Innovation
Background:
- Open spina bifida (myelomeningocele, MMC) is a prevalent birth defect causing lifelong disability.
- Current postnatal surgical management offers limited improvement in neurological outcomes.
- The underlying cause of neurological deficits is increasingly understood as chronic in-utero damage to exposed neural tissue.
Purpose of the Study:
- To evaluate the safety and efficacy of fetal surgical repair for myelomeningocele.
- To compare outcomes of fetal surgery versus standard postnatal repair.
- To assess the impact of in utero repair on neurological function and hydrocephalus.
Main Methods:
- A prospective, randomized clinical trial (MOMS trial) was conducted.
- Fetal myelomeningocele repair was performed before 26 weeks' gestation.
- Outcomes were compared between the fetal surgery group and a historical control group receiving postnatal repair.
Main Results:
- Fetal surgery preserved neurologic function compared to postnatal repair.
- In utero repair reversed hindbrain herniation (Chiari II malformation).
- Ventriculoperitoneal shunt placement for hydrocephalus was obviated in a significant portion of the fetal surgery group.
- Fetal surgery carries risks, including uterine scarring and premature birth.
Conclusions:
- Fetal surgical repair of myelomeningocele before 26 weeks' gestation is a viable option for selected patients.
- This intervention can improve neurological outcomes and reduce the need for shunting.
- Further research is needed to understand long-term impacts and refine surgical techniques.
Abstract:
Open spina bifida or myelomeningocele (MMC) is a common birth defect that is associated with significant lifelong morbidity. Little progress has been made in the postnatal surgical management of the child with spina bifida. Postnatal surgery is aimed at covering the exposed spinal cord, preventing infection, and treating hydrocephalus with a ventricular shunt. Experimental and clinical evidence suggest that the primary cause of the neurologic defects associated with MMC is not simply incomplete neurulation, but rather chronic, mechanical and amniotic-fluid induced chemical trauma that progressively damages the exposed neural tissue during gestation. The cerebrospinal fluid leak through the MMC leads to hindbrain herniation and hydrocephalus. In utero repair of open spina bifida is now performed in selected patients and presents an additional therapeutic alternative for expectant mothers carrying a fetus with MMC. In the past, studies in animal models and clinical case series laid the groundwork for a clinical trial to test the safety and efficacy of fetal MMC repair. In the present, a prospective, randomized study (the MOMS trial) has shown that fetal surgery for MMC before 26 weeks' gestation may preserve neurologic function, reverse the hindbrain herniation of the Chiari II malformation, and obviate the need for postnatal placement of a ventriculoperitoneal shunt. However, this study also demonstrates that fetal surgery is associated with significant risks related to the uterine scar and premature birth. In the future, research will expand our understanding of the pathophysiology of MMC, evaluate the long-term impact of in-utero intervention, and to refine timing and technique of fetal MMC surgery using tissue engineering technology.
