Fetal surgery for myelomeningocele: progress and perspectives

Analysis of long-term family dynamics in mothers who have undergone fetal myelomeningocele surgery using telemedicine: a pilot study

OBJECTIVE

The aim of this study was to understand the dynamics of families with children with myelomeningocele undergoing intrauterine fetal surgery.

METHODS

A retrospective cohort pilot study was carried out with 11 mothers of children who had undergone intrauterine myelomeningocele repair. Participants in this study responded to an electronic questionnaire (via Google Forms), developed by the study authors, that consisted of 22 multiple-choice questions, of which 17 were closed-ended and 5 had a standardized format.

RESULTS

The mean (± standard deviation) of the mothers' age was 37.6 (± 3.5) years. The median of gestational age at delivery and birthweight were 34.9 (range, 33 to 36.1) weeks and 2,300 (range, 1,950 to 2,763) g, respectively. The majority of mothers were white (81.8%), had university degree (81.8%), were Catholic (63.6%), and were married (100%). The majority of mothers rated their relationship with their husband, family, and friends as excellent (54.5, 72.7, and 54.5%, respectively). All 11 mothers reported that the newborn with myelomeningocele was born <37 weeks gestation and the birthweight most often<2,500 g. Approximately 64% of the mothers reported that their child required adaptations or had special needs, of which walking aids (50%) and bladder control (50%) were the most common ones.

CONCLUSION

Telemedicine proved to be a useful tool in the long-term follow-up of children who underwent intrauterine surgery to correct myelomeningocele.

Neurologic Outcome Comparison between Fetal Open-, Endoscopic- and Neonatal-Intervention Techniques in Spina Bifida Aperta

INTRODUCTION

In spina bifida aperta (SBA), fetal closure of the myelomeningocele (MMC) can have a neuroprotective effect and improve outcomes. In Europe, surgical MMC closure is offered by fetal-open (OSBAR), fetal-endoscopic (FSBAR), and neonatal (NSBAR) surgical techniques. Pediatric neurologists facing the challenging task of counseling the parents may therefore seek objective outcome comparisons. Until now, such data are hardly available. In SBA, we aimed to compare neurologic outcomes between OSBAR, FSBAR, and NSBAR intervention techniques.

METHODS

We determined intervention-related complications, neuromuscular integrity, and neurologic outcome parameters after OSBAR (n = 17) and FSBAR (n = 13) interventions by age- and lesion-matched comparisons with NSBAR-controls. Neurological outcome parameters concerned: shunt dependency, segmental alterations in muscle ultrasound density (reflecting neuromuscular integrity), segmental motor-, sensory- and reflex conditions, and the likelihood of intervention-related gain in ambulation.

RESULTS

Compared with NSBAR-controls, fetal intervention is associated with improved neuromuscular tissue integrity, segmental neurological outcomes, reduced shunt dependency, and a higher chance of acquiring ambulation in ≈20% of the operated children. Children with MMC-lesions with a cranial border at L3 revealed the most likely intervention-related motor function gain. The outcome comparison between OSBAR versus FSBAR interventions revealed no significant differences.

CONCLUSION

In SBA, OSBAR- and FSBAR-techniques achieved similar neuroprotective results. A randomized controlled trial is helpful in revealing and compare ongoing effects by surgical learning curves.

Fetal Intraventricular Hemorrhage in Open Neural Tube Defects: Prenatal Imaging Evaluation and Perinatal Outcomes

BACKGROUND AND PURPOSE

Fetal imaging is crucial in the evaluation of open neural tube defects. The identification of intraventricular hemorrhage prenatally has unclear clinical implications. We aimed to explore fetal imaging findings in open neural tube defects and evaluate associations between intraventricular hemorrhage with prenatal and postnatal hindbrain herniation, postnatal intraventricular hemorrhage, and ventricular shunt placement.

MATERIALS AND METHODS

After institutional review board approval, open neural tube defect cases evaluated by prenatal sonography between January 1, 2013 and April 24, 2018 were enrolled (n = 504). The presence of intraventricular hemorrhage and gray matter heterotopia by both prenatal sonography and MR imaging studies was used for classification. Cases of intraventricular hemorrhage had intraventricular hemorrhage without gray matter heterotopia (n = 33) and controls had neither intraventricular hemorrhage nor gray matter heterotopia (n = 229). A total of 135 subjects with findings of gray matter heterotopia were excluded. Outcomes were compared with regression analyses.

RESULTS

Prenatal and postnatal hindbrain herniation and postnatal intraventricular hemorrhage were more frequent in cases of prenatal intraventricular hemorrhage compared with controls (97% versus 79%, 50% versus 25%, and 63% versus 12%, respectively). Increased third ventricular diameter, specifically >1 mm, predicted hindbrain herniation (OR = 3.7 [95% CI, 1.5-11]) independent of lateral ventricular size and prenatal intraventricular hemorrhage. Fetal closure (n = 86) was independently protective against postnatal hindbrain herniation (OR = 0.04 [95% CI, 0.01-0.15]) and postnatal intraventricular hemorrhage (OR = 0.2 [95% CI, 0.02-0.98]). Prenatal intraventricular hemorrhage was not associated with ventricular shunt placement.

CONCLUSIONS

Intraventricular hemorrhage is relatively common in the prenatal evaluation of open neural tube defects. Hindbrain herniation is more common in cases of intraventricular hemorrhage, but in association with increased third ventricular size. Fetal closure reverses hindbrain herniation and decreases the rate of intraventricular hemorrhage postnatally, regardless of the presence of prenatal intraventricular hemorrhage.

Development of a Core outcome set for fetal Myelomeningocele (COSMiC): study protocol

BACKGROUND

Open spina bifida (OSB) is one of the most common congenital central nervous system defects and leads to long-term physical and cognitive disabilities. Open fetal surgery for OSB improves neurological outcomes and reduces the need for ventriculoperitoneal shunting, compared to postnatal surgery, but is associated with a significant risk of prematurity and maternal morbidity. Fetoscopic surgery comes with less maternal morbidity, yet the question remains whether the procedure is neuroprotective and reduces prematurity. Comparison of outcomes between different treatment options is challenging due to inconsistent outcome reporting. We aim to develop and disseminate a core outcome set (COS) for fetal OSB, to ensure that outcomes relevant to all stakeholders are collected and reported in a standardised fashion in future studies.

METHODS

The COS will be developed using a validated Delphi methodology. A systematic literature review will be performed to identify outcomes previously reported for prenatally diagnosed OSB. We will assess maternal (primary and subsequent pregnancies), fetal, neonatal and childhood outcomes until adolescence. In a second phase, we will conduct semi-structured interviews with stakeholders, to ensure representation of additional relevant outcomes that may not have been reported in the literature. We will include patients and parents, as well as health professionals involved in the care of these pregnancies and children (fetal medicine specialists, fetal surgeons, neonatologists/paediatricians and allied health). Subsequently, an international group of key stakeholders will rate the importance of the identified outcomes using three sequential online rounds of a modified Delphi Survey. Final agreement on outcomes to be included in the COS, their definition and measurement will be achieved through a face-to-face consensus meeting with all stakeholder groups. Dissemination of the final COS will be ensured through different media and relevant societies.

DISCUSSION

Development and implementation of a COS for fetal OSB will ensure consistent outcome reporting in future clinical trials, systematic reviews and clinical practice guidelines. This will lead to higher quality research, better evidence-based clinical practice and ultimately improved maternal, fetal and long-term childhood outcomes.

TRIAL REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO) CRD42018104880 . Registered on December 5, 2018. Core Outcome Measures in Effectiveness Trials (COMET): 1187.

Fetal surgical intervention for myelomeningocele: lessons learned, outcomes, and future implications

Fetal myelomeningocele (fMMC) closure (spina bifida aperta) has become a care option for patients that meet inclusion criteria, but it is clear that fetal intervention, while improving outcomes, is not a cure. This review will: (1) focus on the rationale for fMMC surgery based on preclinical studies and observations that laid the foundation for human pilot studies and a randomized controlled trial; (2) summarize important clinical outcomes; (3) discuss the feasibility, efficacy, and safety of recent developments in fetal surgical techniques and approaches; and (4) highlight future research directions. Given the increased risk of maternal and fetal morbidity associated with prenatal intervention, accompanied by the increasing number of centres performing interventions worldwide, teams involved in the care of these patients need to proceed with caution to maintain technical expertise, competency, and patient safety. Ongoing assessment of durability of the benefits of fMMC surgery, as well as additional refinement of patient selection criteria and counselling, is needed to further improve outcomes and reduce the risks to the mother and fetus. WHAT THIS PAPER ADDS: High-quality prospective studies are needed to broaden the indication for fetal surgery in the general myelomeningocele population. Innovative minimally invasive approaches have had promising results, yet lack comprehensive and robust experimental or clinical evaluation. Important information to help families make informed decisions regarding fetal surgery for myelomeningocele is provided.

Prenatal Repair of Myelomeningocele and School-age Functional Outcomes

BACKGROUND AND OBJECTIVES

The Management of Myelomeningocele Study (MOMS), a randomized trial of prenatal versus postnatal repair for myelomeningocele, found that prenatal surgery resulted in reduced hindbrain herniation and need for shunt diversion at 12 months of age and better motor function at 30 months. In this study, we compared adaptive behavior and other outcomes at school age (5.9-10.3 years) between prenatal versus postnatal surgery groups.

METHODS

Follow-up cohort study of 161 children enrolled in MOMS. Assessments included neuropsychological and physical evaluations. Children were evaluated at a MOMS center or at a home visit by trained blinded examiners.

RESULTS

The Vineland composite score was not different between surgery groups (89.0 ± 9.6 in the prenatal group versus 87.5 ± 12.0 in the postnatal group; P = .35). Children in the prenatal group walked without orthotics or assistive devices more often (29% vs 11%; P = .06), had higher mean percentage scores on the Functional Rehabilitation Evaluation of Sensori-Neurologic Outcomes (92 ± 9 vs 85 ± 18; P < .001), lower rates of hindbrain herniation (60% vs 87%; P < .001), had fewer shunts placed for hydrocephalus (49% vs 85%; P < .001) and, among those with shunts, fewer shunt revisions (47% vs 70%; P = .02) than those in the postnatal group. Parents of children repaired prenatally reported higher mean quality of life z scores (0.15 ± 0.67 vs 0.11 ± 0.73; P = .008) and lower mean family impact scores (32.5 ± 7.8 vs 37.0 ± 8.9; P = .002).

CONCLUSIONS

There was no significant difference between surgery groups in overall adaptive behavior. Long-term benefits of prenatal surgery included improved mobility and independent functioning and fewer surgeries for shunt placement and revision, with no strong evidence of improved cognitive functioning.

Neurosurgery guidelines for the care of people with spina bifida

Myelomeningocele (MMC) arises from an early neural developmental anomaly and results in a variety of structural abnormalities and associated functional neurologic deficits. As such, neurologic issues are central to virtually all clinical problems. Neurosurgical intervention strives to correct or improve these defects and prevent secondary complications. These interventions include closure of the open myelomeningocele and management (across the life span) of hydrocephalus, the Chiari II malformation (C2M) and tethered spinal cord (TSC). The development of pre-natal closure techniques and reports of improved outcome with in-utero closure (IUMC) have revolutionized the neurosurgical approach to myelomeningocele. Controversies remain surrounding patient selection, maternal risks, technique of IUMC (endoscopic vs. open) and long-term outcomes. However, real gains include reduced rates of hydrocephalus, modestly improved motor capabilities and reduction in C2M morbidity. For many decades, the cornerstone of treatment of hydrocephalus for many decades has been the placement and support of ventricular shunts. Endoscopic third ventriculostomy (ETV) with or without choroid plexus coagulation (ETV/CPC) is an appealing alternate strategy that avoids the morbidity and complications associated with shunts. The exact criteria for ETV-CPC candidacy and best metrics for outcome analysis remain active areas of debate and controversy. Similarly, neurosurgical management C2M, has centered upon the indications and clinical thresholds for performing posterior fossa surgical decompression. Tethered spinal cord management incorporates the diagnosis and surgical management of adhesions formed at the initial closure site, the consequent longitudinal traction related stress on the cord and the resulting neurologic signs and symptoms.

Just choice: a Danielsian analysis of the aims and scope of prenatal screening for fetal abnormalities

Developments in Non-Invasive Prenatal Testing (NIPT) and cell-free fetal DNA analysis raise the possibility that antenatal services may soon be able to support couples in non-invasively testing for, and diagnosing, an unprecedented range of genetic disorders and traits coded within their unborn child's genome. Inevitably, this has prompted debate within the bioethics literature about what screening options should be offered to couples for the purpose of reproductive choice. In relation to this problem, the European Society of Human Genetics (ESHG) and American Society of Human Genetics (ASHG) tentatively recommend that any expansion of this type of screening, as facilitated by NIPT, should be limited to serious congenital and childhood disorders. In support of this recommendation, the ESHG and ASHG cite considerations of distribution justice. Notably, however, an account of justice in the organization and provision of this type of screening which might substantiate this recommendation has yet to be developed. This paper attempts to redress this oversight through an investigation of Norman Daniels' theory of Just health: meeting health needs fairly. In line with this aim, the paper examines what special moral importance (for Just health) screening for the purpose of reproductive choice might have where concerning serious congenital and childhood disorders in particular. The paper concludes that screening for reproductive choice where concerning serious congenital and childhood disorders may be important for providing women with fair opportunity to protect their health (by either having or not having an affected child).

Evaluation and Disposition of Fetal Myelomeningocele Repair Candidates: A Large Referral Center Experience

BACKGROUND

Fetal myelomeningocele (fMMC) repair yields superior outcomes to postnatal repair and is increasingly offered at select fetal centers.

OBJECTIVES

To report the fMMC referral process from initial referral to evaluation and surgical intervention in a large fetal referral center.

METHODS

We conducted a retrospective cohort study of patients referred to Texas Children's Fetal Center for fMMC between September 2013 and January 2018, reviewing the process from referral to final disposition. The stepwise evaluation included a phone interview followed by multidisciplinary consultation at our fetal center. We modified the Management of Myelomeningocele Study inclusion and exclusion criteria to allow a maternal body mass index of 35-40 on an individual basis.

RESULTS

A total of 204 referrals were contacted for a phone interview; 175 (86%) pursued outpatient evaluation, and 80 (46%) of them qualified for repair. Among the eligible patients, 37 (46%) underwent fetoscopic repair, 20 (25%) underwent open repair, and 17 (21%) declined prenatal surgery. Of the 89 noneligible patients (53%) excluded upon outpatient evaluation, 64 (72%) were excluded for fetal and 17 (19%) for maternal reasons. No hindbrain herniation (16%) and maternal BMI and/or hypertension (5%) were the most common reasons for fetal and maternal exclusion, respectively. A total of 31% of our referral population underwent fetal surgery.

CONCLUSIONS

A small percentage of fMMC referrals ultimately undergo prenatal surgery. Stepwise evaluation and multidisciplinary teams are key to the success of large referral programs.

Fetal Surgery

Fetal surgery is an established but still rapidly evolving specialty, born from the rationale that destructive embryologic processes, recognized early in gestation, can be curtailed by prenatal correction. As more and more centers begin offering fetal interventions, quality of care must be verified through transparency about clinical capabilities and resources. Level designations should be assigned based on capability, as in trauma and neonatal ICU centers for excellence, and volume requirements must be set for fetal surgery certification. Regionalization of this specialty care may be required to optimize outcomes.

Neurodevelopmental outcome of children with spina bifida aperta repaired prenatally vs postnatally: systematic review and meta-analysis

OBJECTIVE

To assess the neurodevelopmental outcome of children with spina bifida aperta (SBA) treated prenatally as compared to those treated postnatally.

METHODS

We performed a systematic review of the literature in PubMed/MEDLINE, EMBASE, Web of Science and The Cochrane Library, comparing the neurological outcome of infants with SBA treated prenatally vs postnatally. Only randomized controlled trials (RCTs) and non-randomized prospective controlled studies were included. The primary outcome assessed was neurodevelopmental impairment at the age of 1 year or later. Secondary outcomes were preterm birth, need for ventriculoperitoneal (VP) shunt by 12 months of age, absence of signs of hindbrain herniation at the first postnatal magnetic resonance imaging (MRI) evaluation and independent ambulation evaluated at 30 months.

RESULTS

Of 11 359 studies identified through the electronic search, six met the inclusion criteria and were assessed in full text and two, one RCT and one prospective cohort study, were ultimately included in the meta-analysis. Sensitivity analysis did not show any difference between the outcomes of the RCT alone and those of the pooled RCT and prospective cohort study. This allowed neurodevelopmental assessment of 213 children between 14 and 53 months of age. Neurodevelopment was assessed by the Bayley Scales of Infant Development II (BSID-II) mental development index corrected for chronological age, with a cut-off of ≥ 70 (representing no more than 2 SD below the mean). The presence of neurodevelopmental impairment was similar between children who underwent prenatal (25/105 (23.8%)) and those who had postnatal (30/108 (27.8%)) repair of SBA (odds ratio (OR), 0.82 (95% CI, 0.43-1.56); P = 0.54), although the risk of prematurity was higher in the prenatal-repair group (OR, 17.62 (95% CI, 7.60-40.87); P < 0.0001). For every two fetuses operated on before birth, there was, compared with those operated on after birth, one additional premature birth (number needed to harm = 2 (95% CI, 1-3)). The need for VP shunt placement by 12 months of age was lower in the prenatal-repair group (45/109 (41.3%)) than in children that had postnatal repair (93/112 (83.0%); OR, 0.14 (95% CI, 0.08-0.26); P < 0.0001). Data on neurodevelopmental impairment in children with a shunt were available only for patients from the prenatal-surgery group of the RCT; in this subgroup, the likelihood for impairment was similar between children who did (7/39 (17.9%)) and those who did not (4/48 (8.3%)) have shunt placement (P = 0.21). At first postnatal MRI evaluation, no signs of hindbrain herniation were detected in 28/88 (31.8%) children who were operated on prenatally compared with 4/89 (4.5%) who had postnatal repair (OR, 9.45 (95% CI, 3.12-28.64); P < 0.0001). Independent ambulation at 30 months was achieved by 41/109 (37.6%) children who underwent prenatal repair compared with 21/111 (18.9%) who had postnatal repair (OR, 2.59 (95% CI, 1.39-4.86); P = 0.003).

CONCLUSION

The risk of neurodevelopmental impairment in infants with SBA was similar between those who underwent prenatal and those who had postnatal surgical repair, despite an increased risk of prematurity in the prenatally repaired group. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Ethical Issues in Intrauterine Myelomeningocele Surgery

Intrauterine surgery shows that the prognosis of neonates with myelomeningocele (MMC) has improved, both in survival and in quality of life. In order to study the current efficacy of intrauterine surgery for MMC and to make an ethical analysis of its proportionality, we conducted a PubMed search using the keywords "myelomeningocele", "intrauterine surgery", "MOMS", and "trial". Thirty-eight articles were found. The literature investigated the risks and benefits of intrauterine surgery based on the physiological parameters of MMC. Intrauterine surgery produces clear benefits. However, it also has disadvantages, such as premature birth, fetal or neonatal death, and uterine complications. The option of surgery is positive. However, since the intervention is risky, the final decision must be prudential, and thus should involve an ethical analysis of therapeutic proportionality. This requires a specific clinical evaluation of the fetus ensuring fetal survival in all cases and minimizing the risks arising from extremely premature birth.

Experience in shunt management on revision free survival in infants with myelomeningocele

OBJECTIVE

Depending on the etiology of hydrocephalus in childhood, the shunt therapy still remains challenging due to frequent shunt complications leading to possible revisions such as shunt infection or shunt malfunction. In myelomeningocele (MMC) patients who often require shunt therapy, higher revisions rates were reported. In a single-center retrospective study, experiences on shunt regimen on hydrocephalus associated with MMC are presented.

METHODS

Data of 160 infant hydrocephalus cases younger than 1 year of age at the time of implantation were retrospectively reviewed from the hospital database. These patients received an adjustable differential pressure valve with gravitational unit and antibiotic impregnated catheters as a primary or secondary implant during the time period of April 2007 to July 2015. The subgroup of infants cases with MMC (n = 44; age 50.6 ± 80.6 days) were compared to the remaining cohort of other hydrocephalus etiology (control group). The shunt and valve revision free survival rates were recorded until July 2017.

RESULTS

During the mean follow-up of 48.7 ± 19.2 (7-114) months, the shunt revision free survival was 87% at 1 year and 49% at 60 months in the MMC cohort. The control group showed a shunt survival rate of 68% at 1 year and 39% at 60 months. Similarly, the valve revision free survival rate showed a significant higher rate of 92% at 1 year and 69% at 60 months in the MMC group compared to the control group (75% at 1 year and 51% at 60 months; p < 0.05). During the entire follow-up period, 37% of the MMC infants underwent a revision operation in contrast to the control group of 40%.

CONCLUSION

The presented shunt strategy showed improved revision free survival rates in infants with a MMC-related hydrocephalus in comparison to other etiologies of hydrocephalus in infants, which might relate to infection prophylaxis and high drainage resistance integrated in the shunt system.

In utero repair of fetal rat myelomeningocele affects neuromuscular development in the bladder

Fetal repair of myelomeningocele (MMC) has been proven to be beneficial for the central nervous system development; however, the effect of fetal MMC repair on bladder function remains controversial. The objective of the present study was to establish an early timepoint for in utero MMC repair using a rat model, and to investigate the changes in bladder development subsequent to that intervention. Sprague Dawley rats were divided into the MMC, MMC repair and control groups. MMC rat fetus models were created by treating pregnant rats with all-trans retinoic acid. The MMC defect was then repaired in utero at embryonic day 17 (E17) using a chitosan-gelatin membrane patch. Fetal rat bladders were removed at E19 and E21 in each group, as well as at stage E17 in the MMC and control groups. Differential expression of β-III-tubulin, α-smooth muscle actin (α-SMA), nerve growth factor (NGF) and acetylcholinesterase (AChE) mRNA, and β-III-tubulin and α-SMA protein in the bladder following fetal repair was measured and compared among the three groups. In addition, the expression of NGF mRNA was significantly elevated at E21 in the MMC group compared with that of the control group, however, the level decreased in the repair group at stage E21. The expression of α-SMA mRNA significantly increased at E19 and then decreased at E21 in the repair group compared with that of the MMC group; however, there were no significant changes in α-SMA protein following the repair. Furthermore, the repair enhanced β-III-tubulin mRNA expression at E19, but ameliorated the decrease of β-III-tubulin protein at E21. The expression of AChE mRNA increased in the MMC group at E19 and E21 compared with that of the control group, although it was not significantly altered following repair as compared with that of the MMC group. In conclusion, in the current study, abnormal neuromuscular development was observed in the MMC bladder, which enabled a certain degree of improvement in the in utero MMC repair.

Long-term neurofunctional outcome, executive functioning, and behavioral adaptive skills following fetal myelomeningocele surgery

BACKGROUND

Myelomeningocele (MMC) represents the first nonlethal anomaly to be treated by prenatal intervention. Case series and a prospective, randomized study show that fetal surgery for MMC before 26 weeks' gestation may preserve neurological function. Long-term follow-up is a fundamental component to evaluate the overall efficacy of any new medical or surgical procedure. To further delineate the long-term impact of fMMC surgery, we continued to follow children treated in our institution before the Management of Myelomeningocele Study trial by the means of parental questionnaires to assess changes in functional, developmental, and cognitive status as these unique patients grow older.

OBJECTIVE

The objective of the study was to evaluate the long-term neurological outcome, executive functioning (EF), and behavioral adaptive skills (BAS) following fetal myelomeningocele (fMMC) surgery.

STUDY DESIGN

Prior to the Management of Myelomeningocele Study trial, 54 patients underwent fMMC surgery at our institution. Parents of 42 children (78%) participated in structured questionnaires focusing on neurofunctional outcome. EF and BAS were measured by the Behavior Rating Inventory of Executive Function (BRIEF) and the Adaptive Behavioral Assessment System II. The BRIEF is organized into 3 primary indices including the following: Global Executive Composite, Metacognition Index, and Behavioral Regulation Index. The Adaptive Behavioral Assessment System II results in a general adaptive composite score. Based on SD intervals, EF and BAS were categorized as being average, borderline, or impaired.

RESULTS

At a median follow-up age of 10 years (range, 8-14 years), 33 (79%) are community ambulators, 3 (9%) are household ambulators, and 6 (14%) are wheelchair dependent. Preschool ambulation was predictive of long-term ambulation (P < .01), whereas the need for tethered cord surgery was associated with persistent deterioration of ambulatory status (P = .007). Normal bladder function was found in 26%. Although the majority scored within the average range for the Behavioral Regulation Index, Metacognition Index, and Global Executive Composite indices, significantly more children who had fMMC surgery had deficits in EF in all 3 BRIEF indices compared with the population norms. The general adaptive composite scores were also more likely to fall below average following fMMC surgery. Normal early neurodevelopmental outcomes were predictive of normal EF and BAS (P < .01). Need for shunting was associated with a significant impairment of BAS (P = .02).

CONCLUSION

The present study suggests that fMMC surgery improves long-term functional outcome. The majority of fMMC children can successfully complete everyday tasks at home and at school. Abnormalities of BAS appear to be more common than impairments in EF and therefore offer an area for early screening and interventional therapy for these at-risk children. Non-shunted fMMC children with normal early neurodevelopmental outcome are less likely to experience problems with EF and BAS. fMMC surgery improves long-term ambulatory status. Symptomatic spinal cord tethering with or without intradural inclusion cyst is associated with functional loss. More than expected fMMC children are continent, but bowel and bladder control continue to be an ongoing challenge for the fMMC children.

Prenatal ultrasound evaluation of segmental level of neurological lesion in fetuses with myelomeningocele: development of a new technique

OBJECTIVES

To report our preliminary experience in the use of prenatal ultrasound examination to assess lower-limb movements in fetuses with myelomeningocele. We aimed to determine the accuracy of this method to establish the segmental level of neurological lesion, as this is the best known predictor of the future ability to walk.

METHODS

This was a preliminary, observational study including fetuses with myelomeningocele operated on prenatally. The patterns of movements present and absent in the affected fetuses' lower limbs were evaluated systematically by ultrasound examination. According to the known nerve function associated with each muscle group, the segmental level of neurological lesion was established before birth. The agreement for the segmental levels assigned, between the prenatal ultrasound technique and the classical neurological clinical examination after birth (gold standard), was tested using the weighed kappa (wκ) index.

RESULTS

Seventy-one fetuses with myelomeningocele were evaluated at the Hospital Universitari Vall d'Hebron. After counseling, the parents opted for prenatal surgery (26 cases), termination of pregnancy (43 cases) or postnatal repair (two cases). Five patients did not fulfil the inclusion criteria for prenatal surgery and three were excluded after birth. In the 18 fetuses that underwent surgery and were analyzed, the agreement between prenatal and postnatal segmental levels assigned was 91.7% for the right limb (wκ = 0.80) and 88.9% for the left limb (wκ = 0.73).

CONCLUSIONS

The agreement found between prenatal and postnatal assignment of level of lesion in this preliminary study suggests that neurological sonographic evaluation is feasible before birth. This may provide accurate individualized information about the motor function and future ambulation prognosis of fetuses with myelomeningocele.

Percutaneous minimally invasive fetoscopic surgery for spina bifida aperta. Part III: neurosurgical intervention in the first postnatal year

OBJECTIVE

To evaluate the need for postnatal neurosurgical intervention after fetoscopic patch coverage of spina bifida aperta (SBA).

METHODS

This was a retrospective analysis of a cohort of 71 fetuses which underwent minimally invasive fetoscopic patch coverage of SBA between 21 + 0 and 29 + 1 weeks of gestation. Postnatal neurosurgical procedures were classified into two types: re-coverage of the SBA within the first 3 months following birth, and shunt placement as treatment of associated hydrocephalus within the first year.

RESULTS

Location of the SBA was lumbosacral in 59 cases, lumbar in seven, thoracic in three and sacral in two. In total, 20/71 (28%) patients underwent early postnatal neurosurgical intervention by means of re-coverage of the SBA. This was performed because of cerebrospinal fluid leakage in seven (35%), adhesions with functional deterioration in three (15%), incomplete coverage in five (25%) and skin defect in five (25%) cases. Ventriculoperitoneal shunt placement within 1 year was required in 32 (45%) cases and was preceded by ventriculostomy in two. Three (4%) infants needed Chiari decompression surgery in the first 12 months following birth, because of syringomyelia or gait disturbance.

CONCLUSIONS

Fetoscopic patch coverage of SBA may require postnatal re-coverage in some cases. In most cases, conservative wound treatment shows good results, without requiring neurosurgical intervention. The low 1-year-shunt rate is comparable to data of the Management of Myelomeningocele Study and lower compared with published data of patients with postnatal only coverage of SBA.

In utero therapy for congenital disorders using amniotic fluid stem cells

Congenital diseases are responsible for over a third of all pediatric hospital admissions. Advances in prenatal screening and molecular diagnosis have allowed the detection of many life-threatening genetic diseases early in gestation. In utero transplantation (IUT) with stem cells could cure affected fetuses but so far in humans, successful IUT using allogeneic hematopoietic stem cells (HSCs), has been limited to fetuses with severe immunologic defects and more recently IUT with allogeneic mesenchymal stem cell transplantation, has improved phenotype in osteogenesis imperfecta. The options of preemptive treatment of congenital diseases in utero by stem cell or gene therapy changes the perspective of congenital diseases since it may avoid the need for postnatal treatment and reduce future costs. Amniotic fluid stem (AFS) cells have been isolated and characterized in human, mice, rodents, rabbit, and sheep and are a potential source of cells for therapeutic applications in disorders for treatment prenatally or postnatally. Gene transfer to the cells with long-term transgenic protein expression is feasible. Recently, pre-clinical autologous transplantation of transduced cells has been achieved in fetal sheep using minimally invasive ultrasound guided injection techniques. Clinically relevant levels of transgenic protein were expressed in the blood of transplanted lambs for at least 6 months. The cells have also demonstrated the potential of repair in a range of pre-clinical disease models such as neurological disorders, tracheal repair, bladder injury, and diaphragmatic hernia repair in neonates or adults. These results have been encouraging, and bring personalized tissue engineering for prenatal treatment of genetic disorders closer to the clinic.

Diagnostic imaging of posterior fossa anomalies in the fetus and neonate: part 2, Posterior fossa disorders

This second portion of a two-part review illustrates examples of posterior fossa disorders detectable on prenatal ultrasound and MRI, with postnatal or pathology correlation where available. These disorders are discussed in the context of an anatomic classification scheme described in Part 1 of this posterior fossa anomaly review. Assessment of the size and formation of the cerebellar hemispheres and vermis is critical. Diagnoses discussed here include arachnoid cyst, Blake's pouch cyst, Dandy-Walker malformation, vermian agenesis, Joubert syndrome, rhombencephalosynapsis, Chiari II malformation, ischemia, and tumors.

Fetal surgery for neural tube defects

A recently completed randomized, controlled, prospective multicenter trial, the Management of Myelomeningocele Study (MOMS), demonstrated that maternal-fetal surgery for myelomeningocele (MMC) before 26 weeks of gestation decreases the need for ventriculoperitoneal shunting, decreases hindbrain herniation, and preserves neurological function. However, the study also found that fetal MMC surgery is not without significant risks, such as premature delivery or maternal complications. The primary objective of this review is to provide a critical overview of the rationale for in-utero intervention for MMC in the context of pathological observations, animal models, initial clinical experience with human fetal MMC surgery, and the results of the randomized trial. The secondary objective is to briefly discuss our approach to fetal MMC. Finally, the ongoing clinical research and the recent developments of potential alternative fetal surgical techniques will be highlighted.

Human amniotic fluid-derived mesenchymal cells from fetuses with a neural tube defect do not deposit collagen type i protein after TGF-β1 stimulation in vitro

In spina bifida, the neural tube fails to close during the embryonic period. Exposure of the neural tube to the amniotic fluid during pregnancy causes additional neural damage. Intrauterine tissue engineering using a biomaterial seeded with stem cells might prevent this additional damage. For this purpose, autologous cells from the amniotic fluid are an attractive source. To close the defect, it is important that these cells deposit an extracellular matrix. However, it is not known if amniotic fluid mesenchymal cells (AFMCs) from a fetus with a neural tube defect (NTD) share the same characteristics as AFMCs from a healthy fetus. We found that cells derived from fetuses with a NTD, in contrast to healthy human amniotic fluid cells, did not deposit collagen type I. Furthermore, the NTD cells showed, compared with both healthy amniotic fluid cells and fetal fibroblasts, much lower mRNA expression levels of genes that are involved in collagen biosynthesis [procollagen C-endopeptidase enhancer proteins (PCOLCE), PCOLCE2, ADAM metallopeptidase with thrombospondin type 1 motif, 2 (ADAMTS2), ADAMTS14]. This indicates that NTD-AFMCs have different characteristics compared with healthy AFMCs and might not be suitable for fetal therapy to close the defect in spina bifida patients.

Comparison of prenatal and postnatal treatments of spina bifida in Poland--a non-randomized, single-center study

OBJECTIVE

The aim of this study was a comparison of the outcomes of intrauterine myelomeningocele (MMC) repairs (IUMR) in type II Chiari malformation (II CM) fetuses with clinical data of newborns and infants operated on postnatally.

METHODS

The study group (SG) comprised 46 pregnant women whose type II CM children underwent IUMR, while 47 pregnant women whose type II CM children were operated on postnatally constituted the control group (CG). A total of 24 SG and 20 CG patients reached the endpoint of the study.

RESULTS

High incidence of prelabor rupture of membranes (24 (52.2%), CI: 3.74 (1.69-8.26) (p < 0.001) was noted in the group of prenatal surgeries as compared to controls. The need for ventriculoperitoneal shunt implantation was statistically significantly lower (p < 0.008) in the group of children after IUMR as compared to controls (5 (27.8%) and 16 (80%), respectively, CI: 0.35 (0.16-0.75). None of the postnatally treated CG children can walk without adaptive equipment. In contrast, two children from the SG (2 (11.1%) CI: 1.86 (1.00-3.48) p < 0.05) are able to walk independently.

CONCLUSIONS

Prenatal MMC closure significantly lowers further adverse evolution of the II CM. Further studies are needed, especially on preventive measures for preterm labor and iatrogenic preterm prelabor rupture of membranes (iPPRM) in the postoperative course of IUMR.

Anesthesia for in utero repair of myelomeningocele

Recently published results suggest that prenatal repair of fetal myelomeningocele is a potentially preferable alternative when compared to postnatal repair. In this article, the pathology of myelomeningocele, unique physiologic considerations, perioperative anesthetic management, and ethical considerations of open fetal surgery for prenatal myelomeningocele repair are discussed. Open fetal surgeries have many unique anesthetic issues such as inducing profound uterine relaxation, vigilance for maternal or fetal blood loss, fetal monitoring, and possible fetal resuscitation. Postoperative management, including the requirement for postoperative tocolysis and maternal analgesia, are also reviewed. The success of intrauterine myelomeningocele repair relies on a well-coordinated multidisciplinary approach. Fetal surgery is an important topic for anesthesiologists to understand, as the number of fetal procedures is likely to increase as new fetal treatment centers are opened across the United States.

In spina bifida aperta, muscle ultrasound can quantify the "second hit of damage"

PURPOSE

In spina bifida aperta (SBA), the "second-hit hypothesis" addresses consequences by delayed neurological damage superimposed upon the congenital myelomeningocele (MMC). This secondary damage is postulated to underlie the disappearance of leg movements shortly after birth. Innovative fetal surgery might prevent this, but results are methodologically hard to prove in small and heterogeneous treatment groups. We reasoned that delayed postnatal alterations in muscle ultrasound density (MUD = muscle echogenicity) could quantitatively reflect consequences by "the second hit" of damage. In the present study, we investigated whether delayed postnatal leg-MUD alterations are associated with postnatal muscle function loss.

METHODS

We cross-sectionally assessed leg-MUD in 16 postnatally operated SBA children (MMC-L5; at 0, 6, and 12 months; in n = 11/16; 11/16, and 15/16 children, respectively) and compared outcomes with 13 healthy control children. Additionally, we assessed SBA MUD caudal and cranial to the MMC and calculated MMC-L5 impact by: dMUD((MMC-L5)) = [MUD(calf muscle/S1-2)] - [MUD(quadriceps muscle/L2-4)] and associated outcomes with leg muscle function caudal to the MMC.

RESULTS

At 0 month, clinically discernible dMUD was more often increased in SBA than in control newborns (p < .05), but a relationship between absolute quantitative differences and leg muscle dysfunction was still lacking. At 6-12 months, additionally increased dMUD outcomes coincided with SBA leg muscle dysfunction (p < .05).

CONCLUSIONS

In post-neonatal SBA, secondarily increased dMUD (i.e., MMC impact) coincides with leg muscle dysfunction. This may implicate that muscle ultrasound could provide a quantitative tool to assess the neuromuscular impact by the second hit of damage.

THE PRENATAL MANAGEMENT OF NEURAL TUBE DEFECTS: TIME FOR A RE-APPRAISAL

The prevalence of neural tube defects (NTD) in Europe is around 9 per 10,000 births making it one of the most frequent congential anomalies affecting the central nervous system. NTD encompass all anomalies that are secondary to failure of closure of the neural tube. In this review, we will first summarize the embryology and some epidemiologic aspects related to NTDs. The review focuses on myelomeningocele (MMC), which is the most common distal closure defect. We will describe the secondary pathologic changes in the central and peripheral nervous system that appear later on in pregnancy and contribute to the condition's morbidity. The postnatal impact of MMC mainly depends on the upper level of the lesion. In Europe, the vast majority of parents with a fetus with prenatally diagnosed NTDs, including MMC, opt for termination of pregnancy, as they are apparently perceived as very debilitating conditions. Animal experiments have shown that prenatal surgery can reverse this sequence. This paved the way for clinical fetal surgery resulting in an apparent improvement in outcome. The results of a recent randomized trial confirmed better outcomes after fetal repair compared to postnatal repair; with follow up for 30 months. This should prompt fetal medicine specialists to reconsider their position towards this condition as well as its prenatal repair. The fetal surgery centre in Leuven did not have a clinical programme for fetal NTD repair until the publication of the MOMS trial. In order to offer this procedure safely and effectively, we allied to a high volume centre willing to share its expertise and assist us in the first procedures. Given the maternal side effects of current open fetal surgical techniques, we have intensified our research programmes to explore minimally invasive alternatives. Below we will describe how we are implementing this.

Fetal endoscopic myelomeningocele closure preserves segmental neurological function

AIM

  Our aim was to compare the effect of prenatal endoscopic with postnatal myelomeningocele closure (fetally operated spina bifida aperta [fSBA]) versus neonatally operated spina bifida aperta [nSBA]) on segmental neurological leg condition.

METHOD

  Between 2003 and 2009, the fetal surgical team (Department of Obstetrics, University of Bonn, Germany) performed 19 fetal endoscopic procedures. Three procedures resulted in fetal death, three procedures were interrupted by iatrogenic hemorrhages and 13 procedures were successful. We matched each successfully treated fSBA infant with another nSBA infant of the same age and level of lesion, resulting in 13 matched pairs (mean age 14 mo; SD 16 mo; f/m=1.6; female-16, male-10). Matched fSBA and nSBA pairs were compared in terms of segmental neurological function and leg muscle ultrasound density (MUD). We also determined intraindividual difference in MUD (dMUD) between myotomes caudal and cranial to the myelomeningocele (reflecting neuromuscular damage by the myelomeningocele) and compared dMUD between fSBA and nSBA infants. Finally, we correlated dMUD with segmental neurological function.

RESULTS

  We found that, on average, the fSBA group were born at a lower gestational age than the nSBA group (median 32 wks [range 25-34 wks] vs 39 wks [34-41 wks]; p=0.001) and experienced more complications (chorioamnionitis, premature rupture of the amniotic membranes, oligohydramnios, and infant respiratory distress syndrome necessitating intermittent positive-pressure ventilation). Neurological function was better preserved after fSBA than after nSBA (median motor and sensory gain of two segments; better preserved knee-jerk [p=0.006] and anal [p=0.032] reflexes). The dMUD was smaller in fSBA than in nSBA infants (mean difference 24, 95% confidence interval [CI] 15-33; p<0.05), which was associated with better preserved segmental muscle function.

INTERPRETATION

  Fetal endoscopic surgery is associated with spinal segmental neuroprotection, but it results in more complications. Before considering clinical implementation of fetal endoscopic myelomeningocele closure as standard care, the frequency of complications should be appropriately reduced and results assessed in larger groups over a longer period of time.