Fetal cephaloceles: prenatal diagnosis and course of pregnancy in 65 consecutive cases

Neurosurgical intervention for the Meckel-Gruber Syndrome: A systematic review

INTRODUCTION

Meckel-Gruber Syndrome (MKS) is an autosomal recessive genetic disorder, notable for its triad of occipital encephalocele, polycystic renal dysplasia, and postaxial polydactyly. Identified by Johann Friederich Meckel in 1822, MKS is categorized as a ciliopathy due to gene mutations. Diagnosis is confirmed by the presence of at least two key features. The condition is incompatible with life, leading to death in the womb or shortly after birth. Recent studies have largely focused on the genetic aspects of MKS, with limited information regarding the impact of neurosurgical approaches, particularly in treating encephaloceles.

METHODS

A systematic review was performed according to the PRISMA statement. The PubMed, Embase, and Web of Science databases were consulted for data screening and extraction, which was conducted by two independent reviewers. The search strategy aimed to encompass studies documenting cases of MKS with published reports of encephalocele excisions, and the search strings for all databases were: Meckel-Gruber syndrome OR Meckel Gruber syndrome OR Meckel-gruber OR Meckel Gruber.

RESULTS

The study included 10 newborns with MKS associated with occipital encephalocele or meningocele, all of whom underwent surgical repair of the occipital sac. The mean gestational age at birth was 36 (± 2) weeks. The mean of birth weight was 3.14 (± 0.85) kilograms. The average head circumference at birth was 33.82 cm (± 2.17). The mean diameter of the encephalocele/meningocele was 5.91 (± 1.02) cm. Other common central nervous system abnormalities included hydrocephalus, Dandy-Walker malformation, and agenesis of the corpus callosum. 40% required shunting for hydrocephalus. Surgery to remove the occipital sac occurred at a median age of 2.5 days (1.5-6.5). The most common post-surgical complication was the need for mechanical ventilation. The most common cause of death was pneumonia and the median age at death was 6.66 (0.03-18) months.

CONCLUSION

Our findings suggest that neurosurgical intervention, especially for managing encephaloceles, may offer some improvement in survival, albeit within a context of generally poor prognosis. However, these results should be interpreted with caution.

Evaluating the potential role of determinants of health on encephalocele patient outcomes - a combined retrospective study and systematic review

INTRODUCTION

To evaluate the outcomes and demographics of encephalocele patients who were born and received treatment in our neonatal ICU and conduct a PRISMA literature review.

METHODS

An Institutional Review Board (IRB)-approved retrospective cohort study was undertaken to investigate the results of treating encephalocele patients at Jackson Memorial Hospital (JMH) from 1998 to 2022. The study focused on assessing outcomes and the impact of maternal socioeconomic factors, such as religion, age, and education, along with the timing of diagnosis, in connection with a systematic review.

RESULTS

A total of 20 encephalocele patients were identified (13 females and 7 males), with 15 having available medical records for review. Most of these cases involved occipital encephaloceles (73.3%). Maternal ages at the time of delivery ranged from 15 to 42 years, with a mean age of 27.3 years. The average gestational age at birth was 37 weeks. Ten cases had a prenatal diagnosis documented, occurring between 12 and 24.5 weeks of gestation. Three of the surviving patients had records of prenatal counseling that included discussions about termination. No infections were reported. Among the 15 cases, 11 patients (73.3%) were alive at the last follow-up, with a mean age at follow-up of 4.12 years, ranging from 6 weeks to 15 years post-birth. Hydrocephalus was noted in 26.7%. Only 1 mother had completed high school. Most mothers were either on Medicaid (9 patients) or uninsured (3 patients), with only 3 having commercial insurance. Religious affiliations varied among the mothers, with 14 out of 15 identifying with a particular religion. The systematic review identified 22 articles from various countries, with 11 articles meeting the inclusion criteria for qualitative analysis. These articles revealed potential maternal risk factors for encephaloceles, including low-nutrient diets, inadequate folic acid intake, young maternal age, advanced maternal age, low socioeconomic status, and limited educational attainment.

CONCLUSIONS

In the twenty-first century, there is a positive trend in the survival rates of children born with encephalocele. However, maternal factors such as low socioeconomic status and limited educational attainment remain prominent, affecting their ability to access timely prenatal care and impacting follow-up medical care for these children.

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.

Contribution of computed tomography and magnetic resonance imaging in the analysis of fetal craniofacial malformations

A wide range of craniofacial malformations can be diagnosed in utero using ultrasonography. However, even with highly experienced sonographers and diagnostic physicians and optimal conditions of examination, some anatomical structures cannot be properly analyzed by this technique. The aim of this pictorial essay is to show the additional value of fetal magnetic resonance imaging and computed tomography in this setting and to illustrate the role of these modalities in facial clefts; craniosynostosis; ear, eye and nose abnormalities; otomandibular dysplasias; and facial cephaloceles.

Surgical repair of a meningoencephalocoele in a kākāpō (Strigops habroptilus)

CASE HISTORY

A kākāpō (Strigops habroptilus) chick hatched on an off-shore island of New Zealand with a small white mass protruding through the cranial skin of the head. The chick's growth followed a normal pattern for kākāpō but at 3 weeks of age the cranium mass was non-reducible and fixed in place and the chick was removed from the island for diagnostic imaging and hand-rearing.

CLINICAL FINDINGS AND TREATMENT

A computed tomography (CT) examination revealed a full-thickness circular defect in the central cranium with suspected herniation of brain and dura. Surgery was performed at 37 days of age, and the herniated dura was dissected from the open fontanelle. Attempts to reduce the herniated tissue were unsuccessful, so the herniated dura and cortex were clamped and resected. The dura was closed and the periosteum of the skull was scarified and monofilament polypropylene mesh was secured tautly over the fontanelle. The mesh graft was infused with autologous bone marrow harvested from the ulna in an attempt to stimulate osteogenesis in the mesh repair. The skin flap was then closed. Post-operative recovery and healing were without complication. A CT examination 4 weeks after surgery showed no recurrence of the hernia, and a composite of mesh and scar over the open fontanelle which had reduced in diameter. The chick was released back onto an off-shore island with a radio transmitter and it continues to be monitored regularly.

PATHOLOGICAL FINDINGS

The tissue resected at surgery consisted of a cylindrical core of cerebral parenchyma overlain by a mildly hyperplastic epidermis, and large amounts of oedematous fibrovascular tissue arising from the leptomeninges.

DIAGNOSIS

Rostral parietal meningoencephalocoele.

CLINICAL RELEVANCE

This is the first report of successful surgical resolution of a meningoencephalocoele in any bird. Techniques from human neurosurgery were adapted for the unique anatomical features of the avian skull. The risks of the procedure included increased intra-cranial pressure resulting in anaesthetic complications or death, cerebrospinal fluid leakage, meningitis or recurrence of the meningoencephalocoele. In the longer term, there was a risk of developmental deficits in cognition or behaviour. None of these complications eventuated in the short to medium term, probably due to the small size of the meningoencephalocoele.

Prenatal diagnosis of frontal encephalocele

Encephalocele is a rare congenital form of neural tube defect characterized by a protrusion of the meninges and cerebral tissue through a skull defect. These defects are classified according to their location: frontal, parietal and occipital, the last one being the most common form of presentation. The prognosis is related to the anatomical site, the volume of the neural contents and the presence of coexisting abnormalities. Most pregnancies are terminated, since the prognosis is poor. We report a case of an isolated fetal frontal encephalocele diagnosed at 21 weeks of gestation.

A prenatally diagnosed case of Meckel-Gruber syndrome with novel compound heterozygous pathogenic variants in the TXNDC15 gene

Background

Meckel–Gruber syndrome (MKS) is a well‐known rare disease that can be detected on prenatal ultrasound. Meckel–Gruber syndrome has very heterogeneous etiology; at least, 17 genes have been described in association with MKS. The characteristic findings in fetuses affected by MKS are encephalocele (usually occipital), postaxial polydactyly, and polycystic dysplastic kidneys. However, the association of the TXNDC15 gene with MKS has been reported only once before in three consanguineous families.

Methods

We report a new case of MKS diagnosed at 12 + 1 weeks of gestation with typical ultrasound findings, but with novel compound heterozygous pathogenic variants in the TXNDC15 gene identified by whole‐exome sequencing (WES).

Results

This is the second clinical report supporting TXNDC15 as a novel causative gene of MKS, and the first describing a case in a non‐consanguineous family with causative compound heterozygous mutations.

Conclusions

Meckel–Gruber syndrome is a very heterogeneous syndrome in terms of the associated causal genes. In the first‐line diagnosis, we used an next‐generation sequencing (NGS)‐based large gene panel, but only 10 MKS genes were available on the platform used. In the case of prenatal ultrasound findings that are highly suggestive of MKS and a negative NGS MKS gene panel, WES should also be performed to not miss rare gene associations.

A large posterior encephalocele associated with severe ventriculomegaly, cerebellar atrophy and transposition of the great arteries

Posterior encephalocele is a neural tube defect, which is a sac-like protrusion of the neural tissue and cerebrospinal fluid through a defect in the occipital bone. This embryonic anomaly may coexist with cortical dysplasia, agenesis of the corpus callosum, hydrocephalus, microcephaly, craniofacial abnormalities, ventricular and atrial septal defect. We report a case of a large posterior encephalocele in a fetus accompanied by unexpected major abnormalities including transposition of the great arteries, severe ventriculomegaly and cerebellar atrophy. Postnatal surgical corrections of the posterior encephalocele and then of the transposition of the great arteries were performed but the neonate died 2 months after delivery.