Fetal neurosurgery

Isolated Fetal Ventriculomegaly: Diagnosis and Treatment in the Prenatal Period

Fetal ventriculomegaly (VM) is a defect of the central nervous system, typically diagnosed during the second-trimester ultrasound in fetuses with an atrial diameter (AD) of >10 mm. Non-isolated ventriculomegaly (NIVM) is heterogeneous in nature, coexisting with additional intracranial and/or extracranial malformations and genetic syndromes, resulting in an unfavorable prognosis for the further development of the child. Both the pregnancy management and counseling are dependent on the findings of combined ultrasound/MRI, genetic testing, and gestational age at diagnosis. The purpose of this review is to propose a hypothesis that diagnostic advancements allow to define the process of identification of the isolated forms of VM (IVM). Based on the evidence presented in the literature, we consider whether prenatal decompression for severe isolated VM (ISVM) is supported by the experimental trials and whether it might be implemented in clinical practice. Also, we describe the evolution of the diagnostic methods and expert opinions about the previously used prenatal decompression techniques for ISVM. In conclusion, we introduce the idea that fetal surgery centers have either reached or nearly reached the necessary level of expertise to perform such procedures. Endoscopic cystoventriculostomy (ETV) appears to be the most promising, as it is associated with minimal perinatal complications and favorable neurological outcomes in the neonatal period. Randomized trials with long-term neurodevelopmental follow-up of children who underwent prenatal decompression due to ISVM are necessary.

Fetal surgery for occipital encephalocele: A case report

Background

Occipital encephalocele is a congenital defect of the neural tube at the level of the cranial midline, which results in herniation of meninges and brain tissue. The results of the management of myelomeningocele study determine the maternal and fetal risks for an open fetal surgery and have motivated the constant review of the concepts and strategies which the pediatric neurosurgeon can employ for the treatment of neural tube defects in the prenatal period.

Case Description

We present a case of a female patient in utero of 26 gestational weeks with the diagnosis of an occipital encephalocele treated by open fetal surgery. During week 20 of gestation, the diagnosis of occipital encephalocele was made by ultrasound, which was corroborated by fetal magnetic resonance that showed cranial protrusion of neural and meningeal content in the occipital region, measuring 1.6 × 2.8 × 3.3 cm with an approximate volume of 7.7 cc through a bone defect of 6 mm. The closure of the defect was performed by the postnatal surgical technique adapted to the open fetal surgery. Later, the patient was born transabdominal with a 2.8 cm occipital wound, with suture points and approximated borders, normocephalic, without clinical signs of sepsis, hydrocephalus, or overt neurologic compromise.

Conclusion

Open fetal surgery is a therapeutic option in the face of an isolated occipital encephalocele. This case report demonstrates the viability of the surgical procedure by the adaptation of a postnatal surgical technique to a prenatal surgery. Further studies are needed to evaluate the long-term functional results, comparing them with those seen in patients who undergo a postnatal procedure.