Introduction
Myelomeningocele (MMC) is considered the most severe type of spina bifida (congenital abnormality brought on by improper formation of the spinal cord and spine). It happens when the nerves from the spinal cord protrude through the opening in the spine and are exposed externally. Typically, myelomeningocele is detected during routine ultrasound scans in pregnancy. If diagnosed during pregnancy, mothers may have the option of fetal surgery to correct the defect before birth, which can potentially reduce the long-term impact of the condition.
What Is Myelomeningocele?
Myelomeningocele is a congenital defect of the central nervous system that is devastating and has no cure. It is characterized by the protrusion of the spinal cord and meninges through open vertebral arches, leading to paralysis that lasts a lifetime. The natural history of this condition includes a range of symptoms that are related to the extent of the defect. These symptoms include hindbrain herniation, hydrocephalus, cognitive and motor impairments, bladder and bowel incontinence, social and emotional challenges, and lifelong quality of life issues.
What Is the Treatment for Myelomeningocele?
In the United States, 1 in 3,000 live infants suffer from myelomeningocele, a severe form of spina bifida. The amount of the myelomeningocele defect usually determines how severe the disability is; more severe deficiencies are usually caused by upper-level lesions. Myelomeningocele repair with open maternal-fetal surgery is a difficult process with consequences for both the mother and the fetus. The fetus may benefit from the procedure, but there is also a risk of serious consequences for the mother before, during, and after the procedure, as well as in future pregnancies.
Open maternal-fetal surgery is one of the management choices accessible to women whose pregnancies are affected by fetal myelomeningocele and who meet precise requirements for in-utero repair. These women should get unbiased counseling on all other options. It is crucial to only provide maternal-fetal surgery for the repair of myelomeningocele to carefully chosen patients in settings with the required staff and resources.
What Is Fetal Surgery for Myelomeningocele?
Prenatal repair of myelomeningocele is a complex surgical technique that involves fetal surgeons opening the uterus and closing the incision in the baby's spine while the infant is still in the womb. This ground-breaking operation has transformed the treatment of birth abnormalities, giving families facing this problem hope.
Although fetal spina bifida surgery is not a cure, it has shown promising results compared to traditional postnatal repair. Studies have demonstrated that prenatal repair can significantly improve outcomes, reducing the need for brain fluid diversion and enhancing mobility. It also increases the likelihood of a child being able to walk independently, giving them a better chance at a fulfilling life.
Who Can Undergo Fetal Surgery for Myelomeningocele?
Fetal surgery for spina bifida can be considered as a viable option for severe myelomeningocele, provided that certain criteria are met:
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The pregnancy is a singleton pregnancy, meaning there is only one child.
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The mother is between 19 and 26 weeks pregnant.
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The baby does not have any additional medical conditions or anatomical concerns unrelated to spina bifida.
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The mother does not have any major medical conditions.
In order to determine eligibility, imaging tests such as ultrasound and MRI, and a review of the mother's medical history, including any prior pregnancies are conducted.
What Are the Advantages of Fetal Surgery for Myelomeningocele?
Prenatal surgery for spina bifida offers remarkable advantages, which encompass:
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A substantial decrease of over 50 percent in the necessity for shunting treatment to address hydrocephalus.
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An impressive nearly tenfold reduction in the occurrence of secondary neurological conditions, like Chiari malformation type 2, by the age of one.
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Enhanced spinal cord function, leading to a better level of overall functionality.
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A remarkable doubling in the ability to walk independently, without requiring any assistance.
What Are the Steps Involved in Fetal Surgery for Myelomeningocele?
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Prenatal repair of myelomeningocele is typically conducted between the gestational ages of 23 weeks and 26 weeks. This procedure involves the administration of general anesthesia to the mother, which not only induces relaxation of the uterus but also provides anesthesia to the fetus.
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During the procedure, fetal surgeons perform a laparotomy, which involves making an incision across the mother's abdomen. A maternal-fetal medicine specialist then utilizes sterile intraoperative ultrasound to accurately determine the position of the placenta and the fetus. Additionally, this ultrasound allows for visualization of the baby's back.
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To gain access to the uterus, a uterine stapling device is used to create an opening. This device effectively seals off all blood vessels and ensures that the membranes remain securely attached to the uterine muscle. Subsequently, a pediatric neurosurgeon carefully removes the myelomeningocele sac, if present, and returns the spinal cord to its proper position within the spinal canal. The surrounding tissue and skin are then closed to protect the spinal cord from exposure to the amniotic fluid.
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Following the procedure, both the uterus and the abdominal incision are closed. Throughout the surgery, a fetal cardiologist utilizes echocardiography to closely monitor the baby's heart, ensuring its well-being. These comprehensive measures are implemented to prioritize the safety of both the mother and the baby.
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Typically, mothers remain hospitalized for a period of three to five days after the surgery. During this time, they are advised to engage in modified bed rest for approximately three to four weeks. This precautionary measure aims to minimize the risk of preterm labor.
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Regular follow-up sessions for ultrasound monitoring and usual prenatal care are scheduled for the remainder of the pregnancy. If labor does not begin sooner, a planned cesarean section is arranged at 37 weeks. The baby will be cared for at the neonatal intensive care unit after birth.
Conclusion
Maternal-fetal surgery for myelomeningocele correction is a complicated treatment that poses hazards to both the mother and the fetus. While there are possible benefits for the fetus, there are also major risks before and after the procedure, as well as during the pregnancy and subsequent pregnancies. Despite the medical team's experience, this treatment necessitates highly competent surgeons. Therefore, it is crucial that this type of surgery is only offered to carefully chosen patients at facilities equipped with the necessary staff and resources.
