Fetal surgery for occipital encephalocele

Perinatal Management of Pregnancies with Fetal Congenital Anomalies: A Guide to Obstetricians and Pediatricians

BACKGROUND

Congenital anomalies are responsible for approximately 20% of all neonatal deaths worldwide. Improvements in antenatal screening and diagnosis have significantly improved the prenatal detection of birth defects; however, these improvements have not translated into the improved neonatal prognosis of babies born with congenital anomalies.

OBJECTIVES

An attempt has been made to summarise the prenatal interventions, if available, the optimal route, mode and time of delivery and discuss the minimum delivery room preparations that should be made if expecting to deliver a fetus with a congenital anomaly.

METHODS

The recent literature related to the perinatal management of the fetus with prenatally detected common congenital anomalies was searched in English peer-reviewed journals from the PubMed database to work out an evidence-based approach for their management.

RESULTS

Fetuses with prenatally detected congenital anomalies should be delivered at a tertiary care centre with facilities for neonatal surgery and paediatric intensive care if needed. There is no indication for preterm delivery in the majority of cases. Only a few congenital malformations, like highrisk sacrococcygeal teratoma, congenital lung masses with significant fetal compromise, fetal cerebral lesions or neural tube defects with Head circumference >40 cm or the biparietal diameter is ≥12 cm, gastroschisis with extracorporeal liver, or giant omphaloceles in the fetus warrant caesarean section as the primary mode of delivery.

CONCLUSION

The prognosis of a fetus with congenital anomalies can be significantly improved if planning for delivery, including the place and time of delivery, is done optimally. A multidisciplinary team should be available for the fetus to optimize conditions right from when it is born.

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.

Fetal neurosurgery

Among fetal surgical procedures, neurosurgery stands out due to the number of cases and the possibility of developing new procedures that can be performed in the fetal period. To perform fetal neurosurgical procedures, there is a need for specialized centers that have experts in the diagnosis of fetal pathologies and a highly complex obstetrics service with specialized maternal-fetal teams associated with a pediatric neurosurgery center with expertise in the diverse pathologies of the fetus and the central nervous system that offers multidisciplinary follow-up during postnatal life. Services that do not have these characteristics should refer their patients to these centers to obtain better treatment results. It is essential that the fetal neurosurgical procedure be performed by a pediatric neurosurgeon with extensive experience, as he will be responsible for monitoring these patients in the postnatal period and for several years. The objective of this manuscript is to demonstrate the diagnostic and treatment possibilities, in the fetal period, of some neurosurgical diseases such as hydrocephalus, tumors, occipital encephalocele, and myelomeningocele.

Characterization of Torquetenovirus in amniotic fluid at the time of in utero fetal surgery: correlation with early premature delivery and respiratory distress

Torquetenovirus (TTV) is a commensal virus present in many healthy individuals. Although considered to be non-pathogenic, its presence and titer have been shown to be indicative of altered immune status in individuals with chronic infections or following allogeneic transplantations. We evaluated if TTV was present in amniotic fluid (AF) at the time of in utero surgery to correct a fetal neurological defect, and whether its detection was predictive of adverse post-surgical parameters. AF was collected from 27 women by needle aspiration prior to a uterine incision. TTV titer in the AF was measured by isolation of viral DNA followed by gene amplification and analysis. The TTV genomes were further characterized and sequenced by metagenomics. Pregnancy outcome parameters were subsequently obtained by chart review. Three of the AFs (11.1%) were positive for TTV at 3.36, 4.16, and 4.19 log10 copies/mL. Analysis of their genomes revealed DNA sequences similar to previously identified TTV isolates. Mean gestational age at delivery was >2  weeks earlier (32.5 vs. 34.6  weeks) and the prevalence of respiratory distress was greater (100% vs. 20.8%) in the TTV-positive pregnancies. TTV detection in AF prior to intrauterine surgery may indicate elevated post-surgical risk for earlier delivery and newborn respiratory distress.

Treatment of Chiari III Malformation in Infant with 4K 3D ORBEYE Exoscope

Chiari malformation (CM)-III is the rarest anomaly among CMs.1 Treatment of choice is surgical repair,2 although poor outcome and postoperative mortality has been reported.3 Surgical timing is still debated.4,5 We present the case of a male infant with a prenatal diagnosis of encephalocele. Presentation was characterized by hemodynamic instability, horizontal nystagmus, and left shoulder dystocia due to caesarean section, with a 64 mm × 49 mm × 76 mm soft, fluctuant, and translucent suboccipital-cervical sac. Magnetic resonance imaging revealed a median occipital bone defect with the meningoencephalic sac communicating with the vermian cistern and the fourth ventricle, moderate hydrocephalus, reduction of the posterior cranial fossa volume, hypoplasia of cerebellar hemispheric, vermian structures, and corpus callosum hypoplasia. The patient underwent surgery on day 4 with the use of a 4K 3D ORBEYE exoscope (Video 1). Surgery consisted of disengagement of nervous structures and repair of the neurocutaneous defect, followed on day 12 by a ventriculoperitoneal shunt with a programmable valve. The procedures were well tolerated. At the 14-month follow-up visit he was in range with growth charts (weight, height, and cranic circumference) and gained the physiologic stages of growth. He had no motor impairment but still present were convergent strabismus and mild left C5-C6 radiculopathy, secondary to shoulder dystocia. This is the first case reported in the literature of CM-III treated with the 4K 3D ORBEYE exoscope. Advantages of the exoscope were ergonomic positions for operative staff, possibility for the team to assist in the 4K 3D view, especially in cases with a narrow operative field, with a clear and detailed vision, although a learning curve is required6 to become a valid alternative in pediatric neurosurgery.

Prenatal intracranial hypotension syndrome in congenital cephalocele: Insights into pathophysiologic mechanisms and importance of defect coverage

OBJECTIVE

To compare specific fetal cranial and cerebral findings indicative of prenatal intracranial hypotension (PICH) syndrome between open and closed cephaloceles.

METHODS

Two groups of fetuses with cephalocele who underwent magnetic resonance imaging scan were selected based on the defect coverage: covered ("closed cephalocele" group, n = 4) and uncovered by skin ("open cephalocele" group, n = 8). The presence of signs associated with PICH syndrome was evaluated and findings compared between groups.

RESULTS

Cases from the open cephalocele group showed statistically significant differences in comparison with the closed cephalocele group regarding reduction of the interpeduncular angle (p = 0.006), reduced amount of cerebrospinal fluid in the subarachnoid space (p = 0.01), collapsed/severely reduced fourth ventricle (p = 0.03), cephalocele content (p = 0.03), and identification of a vector traction (p = 0.03). There were no differences in the presence of cerebellar tonsillar descent, obstructive ventriculomegaly, and presence of the lemon sign. In comparison with gestational age-matched controls, only the biparietal diameter but not the head circumference was significantly smaller in both the open and closed cephalocele groups (p < 0.05).

CONCLUSION

Congenital cephaloceles present distinct imaging behavior depending on the defect coverage. Therefore, the classification of cephalocele should include, in addition to location and content, the presence or absence of skin fully covering the defect.

Fetal Open Surgery for Occipital Encephalocele: First Experience in a Tertiary Public Hospital in Brazil

Occipital encephalocele is a rare neural tube defect characterized by an opening in the occipital bone, resulting in herniation of meninges and brain tissue. Current treatment consists of surgical repair in the postnatal period. The main objective of intrauterine surgery for encephalocele is to decrease/stop the progression of the brain herniation and reversal of microcephaly, contributing to better perinatal outcomes. We reported the first experience of a fetal open surgery for occipital encephalocele in a Brazilian Public Health Service. The surgery took place with gestational age of 27 + 2 weeks of pregnancy. Careful dissection was performed between the skin and the dura that herniated through the bone defect, and the redundant tissue was removed and the dura was opened for access to neural tissue. Cesarean section was indicated prematurely at 34 + 4 weeks due to significant thinning of the myometrial wall with risk of uterine rupture. The newborn was discharged from the neonatal intensive care unit at 21 days after delivery and from the hospital at 30 days in good conditions. Fetal open surgery for encephalocele is still an experimental therapy with maternal–fetal risks; however, the postnatal follow-up is critical for the assessment of the real benefits of this surgery.

Ultrasound and magnetic resonance imaging features of fetal intracranial cystic lesions: A pictorial essay

This pictorial essay focuses on ultrasound (US) and magnetic resonance imaging (MRI) features of fetal intracranial cysts. Intracranial cysts are common findings in prenatal imaging, and if great attention is paid to their size, location, and imaging features, they can be diagnosed accurately. They are usually detected by fetal ultrasound exams. However, when ultrasound data on cystic lesion characteristics is insufficient, MRI and fetal neurosonogram are the best options for detecting other associated anomalies. The prognosis is highly dependent on their location and whether they are associated with other fetal anomalies.

Natural history of posterior fetal cephaloceles and incidence of progressive cephalocele herniation

OBJECTIVE

In utero repair of fetal posterior cephaloceles (meningocele and encephalocele) is being performed based on the premise that fetal surgery prevents progressive herniation of neural tissue and brain damage during pregnancy. However, the extent to which progressive herniation occurs during pregnancy, specifically from prenatal diagnosis to after delivery, is not well known. The objective of this study was to describe the natural history of patients with fetal cephaloceles focusing on the incidence of progressive herniation.

METHODS

The authors conducted a retrospective cohort study of all patients referred to their center for posterior fetal cephalocele between 2006 and 2021. All patients underwent prenatal and postnatal MRI. Progressive herniation (primary outcome) was defined as an increase in the absolute volume of neural tissue within the cephalocele of > 5% or new herniation of a critical structure into the cephalocele. Total brain and cephalocele volumes were calculated to determine herniation progression from prenatal to postnatal MRI. Information on the presence of hydrocephalus, epilepsy, and developmental delay (secondary outcomes) was collected at 1 year of age.

RESULTS

Twenty patients met all study criteria. Ten patients (50%; 95% CI 0.27-0.73) demonstrated progressive herniation from prenatal to postnatal MRI. Three patients with progressive herniation were diagnosed with a meningocele prenatally and had an encephalocele postnatally. Two patients without progression had meningocele identified prenatally that regressed and became atretic by birth. Both prenatal hindbrain herniation (p = 0.03) and prenatal microcephaly (p = 0.05) were predictive of progressive herniation. The rates of hydrocephalus (44%), epilepsy (44%), and developmental delay (63%) were not associated with the occurrence of progressive herniation in this study.

CONCLUSIONS

In this study, progressive herniation was not a rare event (50%). Fetal hindbrain herniation and fetal microcephaly were associated with the occurrence of progressive herniation. These results support further investigations into why progressive herniation occurs in utero and if progressive cerebral herniation in utero plays a significant role in determining clinical outcome.

Fetal Neurosurgical Interventions for Spinal Malformations, Cerebral Malformations, and Hydrocephalus: Past, Present, and Future

In this article we review the last 40 years of progress in fetal neurosurgery with special attention to current controversies and upcoming challenges in the field. We surveyed the published literature describing prenatal interventions for spinal malformations, cerebral malformations, and hydrocephalus. Even the most mature treatment paradigm, intrauterine repair of myelomeningocele, stands to benefit from advances in imaging and therapeutic modalities to improve patient selection, refine surgical techniques, validate novel biologic therapies, and streamline postoperative patient care. Other conditions under evaluation include congenital cerebral malformations, such as encephalocele, cerebrovascular malformations, and hydrocephalus. We describe cross-cutting needs for advances in fetal neuroimaging, basic disease models and new therapeutic devices to support further progress across various neurosurgical conditions affecting patients during the fetal period.

Wound Dehiscence After Occipital Encephalocele Surgical Repair in a Neonate: Management Alternative

Encephaloceles are congenital malformations of the neural tube, mostly located in the occipital region in the Western world. Its presence is related to many complications, among which cognitive impairment and death are the most important. The diagnosis is usually made in the prenatal period, but sometimes due to poor control, this is not feasible. Surgery is required as early as possible to prevent further damage. Sometimes we can face complications related to the procedure, such as wound dehiscence, which has been the aim of this work. Many different types of treatments have been proposed for this complication: nevertheless, they result in invasive management. We present the case of a neonate's wound dehiscence, managed with potable water washes and a correct sterile technique, shown to be safe, reduce the in-patient costs, as well as improve the patient’s and their family's quality of life (QoL).

Fetal Occipital Encephalocele: A Case Report

Encephaloceles are considered neural tube defects, but their exact cause is unknown. The outcome is dismal, and essential management and counseling are needed for patients. Two-dimensional and three-dimensional sonography can be used to detect encephaloceles as early as 11 weeks, assist in treatment planning, and improve patient care. This case report presents an occipital encephalocele diagnosed by sonography and followed until delivery.