First 60 fetal in-utero myelomeningocele repairs at Saint Louis Fetal Care Institute in the post-MOMS trial era: hydrocephalus treatment outcomes (endoscopic third ventriculostomy versus ventriculo-peritoneal shunt)

Amniotic fluid-derived stem cells: potential factories of natural and mimetic strategies for congenital malformations

Background

Mesenchymal stem cells (MSCs) from gestational tissues represent promising strategies for in utero treatment of congenital malformations, but plasticity and required high-risk surgical procedures limit their use. Here we propose natural exosomes (EXOs) isolated from amniotic fluid-MSCs (AF-MSCs), and their mimetic counterparts (MIMs), as valid, stable, and minimally invasive therapeutic alternatives.

Methods

MIMs were generated from AF-MSCs by combining sequential filtration steps through filter membranes with different porosity and size exclusion chromatography columns. Physiochemical and molecular characterization was performed to compare them to EXOs released from the same number of cells. The possibility to exploit both formulations as mRNA-therapeutics was explored by evaluating cell uptake (using two different cell types, fibroblasts, and macrophages) and mRNA functionality overtime in an in vitro experimental setting as well as in an ex vivo, whole embryo culture using pregnant C57BL6 dams.

Results

Molecular and physiochemical characterization showed no differences between EXOs and MIMs, with MIMs determining a 3-fold greater yield. MIMs delivered a more intense and prolonged expression of mRNA encoding for green fluorescent protein (GFP) in macrophages and fibroblasts. An ex-vivo whole embryo culture demonstrated that MIMs mainly accumulate at the level of the yolk sac, while EXOs reach the embryo.

Conclusions

The present data confirms the potential application of EXOs for the prenatal repair of neural tube defects and proposes MIMs as prospective vehicles to prevent congenital malformations caused by in utero exposure to drugs.

Surgically Correctable Congenital Anomalies: Reducing Morbidity and Mortality in the First 8000 Days of Life

BACKGROUND

Congenital anomalies are a leading cause of morbidity and mortality worldwide. We aimed to review the common surgically correctable congenital anomalies with recent updates on the global disease burden and identify the factors affecting morbidity and mortality.

METHOD

A literature review was done to assess the burden of surgical congenital anomalies with emphasis on those that present within the first 8000 days of life. The various patterns of diseases were analyzed in both low- and middle-income countries (LMIC) and high-income countries (HIC).

RESULTS

Surgical problems such as digestive congenital anomalies, congenital heart disease and neural tube defects are now seen more frequently. The burden of disease weighs more heavily on LMIC. Cleft lip and palate has gained attention and appropriate treatment within many countries, and its care has been strengthened by global surgical partnerships. Antenatal scans and timely diagnosis are important factors affecting morbidity and mortality. The frequency of pregnancy termination following prenatal diagnosis of a congenital anomaly is lower in many LMIC than in HIC.

CONCLUSION

Congenital heart disease and neural tube defects are the most common congenital surgical diseases; however, easily treatable gastrointestinal anomalies are underdiagnosed due to the invisible nature of the condition. Current healthcare systems in most LMICs are still unprepared to tackle the burden of disease caused by congenital anomalies. Increased investment in surgical services is needed.

Global neurosurgery: Reflections on myelomeningocele in the Zanzibar archipelago (Tanzania)

Objective

Our main goal was to describe the general characteristics and demographic data of myelomeningocele (MMC) patients at Mnazi Mmoja Surgical NED Institute (MMSNI) in Zanzibar and to assess the clinical characteristics and medium-term result-impact of the implemented health care measures.

Methods

This is a retrospective study on 41 MMC patients treated at the MMSNI in Zanzibar (Tanzania) from September 2016 to September 2018. Patient demographics, prenatal care, clinical and radiographic characteristics, surgical management and nursing care, and clinical outcomes were abstracted.

Results

The mean age of the patients was 6.1 ± 4.6 days, and 53.7% were males. A total of 51.2% came from Zanzibar, 39% to Pemba, and 9.8% from mainland Tanzania. Maternal ultrasound checkups revealed hydrocephalus in 18.7% of the cases. 85.4% of the newborns were operated on. Surgical wound infection was the most frequent complication (28.6%). A significantly higher risk of complications was observed in children from Pemba Island (p = 0.046) and those born by vaginal delivery (p = 0.694), particularly infections. During follow-up, 48.57% of the patients presented with infantile hydrocephalus and in the majority of them, a ventriculoperitoneal shunt was inserted.

Conclusions

Proper prenatal care with early diagnosis, together with the neurosurgical and nursing standard of care in a specialized institution, are all essential to increase the chances of successful treatment of newborns harboring MMC and is one of the main goals pursued in the MMSNI, as the only referral public health center with locally trained health personnel in Zanzibar archipelago.

Risk factors for shunting at 12 months following open fetal repair of spina bifida by mini-hysterotomy

OBJECTIVES

Open spina bifida (OSB) is the most common neural tube defect. Prenatal repair reduces the need for ventriculoperitoneal shunting (VPS) due to hydrocephalus from 80-90% to 40-50%. We aimed to determine which variables work as risk factors for VPS at 12 months of age in our population.

METHODS

Thirty-nine patients underwent prenatal repair of OSB by mini-hysterotomy. The main outcome was occurrence of VPS in the first 12 months of life. Logistic regression was used to estimate the odds ratios (OR) between prenatal variables and the need for shunting.

RESULTS

VPS at 12 months occurred in 34.2% of the children. Larger ventricle size before surgery (62.5% ≥15 mm; 46.2% between 12 and 15 mm; 11.8% <12 mm; p=0.008), higher lesion level (80% >L2, vs. 17.9% ≤L3; p=0.002; OR, 18.4 [2.96-114.30]), and later gestational age at surgery (25.25 ± 1.18 vs. 24.37 ± 1.06 weeks; p=0.036; OR, 2.23 [1.05-4.74]) were related to increased need for shunting. In the multivariate analysis, larger ventricle size before surgery (≥15 mm vs. <12 mm; p=0.046; OR, 1.35 [1.01-1.82]) and higher lesion level (>L2 vs. ≤L3; p=0.004; OR, 39.52 [3.25-480.69]) were risk factors for shunting.

CONCLUSIONS

Larger ventricle size before surgery (≥15 mm) and higher lesion level (>L2) are independent risk factors for VPS at 12 months of age in fetuses undergoing prenatal repair of OSB by mini-hysterotomy in the studied population.

Advances in Fetal Surgical Repair of Open Spina Bifida

Spina bifida remains a common congenital anomaly of the central nervous system despite national fortification of foods with folic acid, with a prevalence of 2-4 per 10,000 live births. Prenatal screening for the early detection of this condition provides patients with the opportunity to consider various management options during pregnancy. Prenatal repair of open spina bifida, traditionally performed by the open maternal-fetal surgical approach through hysterotomy, has been shown to improve outcomes for the child, including decreased need for cerebrospinal fluid diversion surgery and improved lower neuromotor function. However, the open maternal-fetal surgical approach is associated with relatively increased risk for the patient and the overall pregnancy, as well as future pregnancies. Recent advances in minimally invasive prenatal repair of open spina bifida through fetoscopy have shown similar benefits for the child but relatively improved outcomes for the pregnant patient and future childbearing.

Intrauterine closure of myelomeningocele defects with primary linear repair versus bipedicle fasciocutaneous flaps: a post-MOMS cohort study with long-term follow-up

OBJECTIVE

The objective of this study was to determine the effects of in utero bipedicle flaps on maternal-fetal morbidity/mortality, the need for CSF diversion, and long-term functional outcomes.

METHODS

Eighty-six patients who underwent fetal myelomeningocele repair from 2011 to 2021 at a single institution were reviewed. Primary outcomes included intrauterine fetal demise, postnatal death, postnatal myelomeningocele repair dehiscence, and CSF diversion by final follow-up.

RESULTS

The cohorts were no different with regard to race, ethnicity, maternal age at fetal surgery, body mass index, gravidity, parity, gestational age at fetal surgery, estimated fetal weight at fetal surgery, or fetal lesion level. Of the 86 patients, 64 underwent primary linear repair and 22 underwent bipedicle flap repair. There were no significant differences in rates of intrauterine fetal demise, postnatal mortality, midline repair site dehiscence, or the need for CSF diversion by final follow-up. Operative times were longer (32.5 vs 18.7 minutes, p < 0.001) and gestational age at delivery was lower (232 vs 241 days, p = 0.01) in the bipedicle flap cohort, but long-term functional outcomes were not different.

CONCLUSIONS

Analysis of the total cohort affirms the long-term benefits of fetal myelomeningocele repair. In utero bipedicle flaps are safe and can be used for high-tension lesions without increasing perioperative risks to the mother or fetus. In utero flaps preserve the long-term benefits seen with primary linear repair and may expand inclusion criteria for fetal repair, providing life-changing care for more patients.

Fetal Surgery for Myelomeningocele: Neurosurgical Perspectives

More than 30 years have elapsed since it was recognised that folic acid supplementation could substantially reduce the risk of open neural tube defects (ONTDs). During that time, many countries have adopted policies of food fortification with demonstrable reduction in the incidence of both cranial and spinal ONTDs. Improved prenatal detection and termination has also resulted in a reduction in the number of affected live births. Nonetheless, in the USA about 1500 children, and in the UK around 500 children are born each year with myelomeningocele (MMC) and so the management of MMC and its complications continues to constitute a significant clinical workload for many paediatric neurosurgical units around the world.Until recently, the options available following antenatal diagnosis of MMC were termination of pregnancy or postnatal repair. As a result of the MOMS trial, prenatal repair has become an additional option in selected cases (Adzick et al., N Engl J Med 364(11):993-1004, 2011). Fetal surgery for myelomeningocele is now offered in more than 30 centres worldwide. The aim of this chapter is to review the experimental basis of prenatal repair of MMC, to critically evaluate the neurosurgical implications of this intervention and to describe the technique of 'open' repair, comparing this with emerging minimally invasive alternatives.

Anesthesia for fetal operative procedures: A systematic review

Objective

The anesthetic management of fetal operative procedures (FOP) is a highly debated topic. Literature on fetal pain perception and response to external stimuli is rapidly expanding. Nonetheless, there is no consensus on the fetal consciousness nor on the instruments to measure pain levels. As a result, no guidelines or clinical recommendations on anesthesia modality during FOP are available. This systematic literature review aimed to collect the available knowledge on the most common fetal interventions, and summarize the reported outcomes for each anesthetic approach. Additional aim was to provide an overall evaluation of the most commonly used anesthetic agents.

Methods

Two systematic literature searches were performed in Embase, Medline, Web of Science Core Collection and Cochrane Central Register of Controlled Trials up to December 2021. To best cover the available evidence, one literature search was mostly focused on fetal surgical procedures; while anesthesia during FOP was the main target for the second search. The following fetal procedures were included: fetal transfusion, laser ablation of placental anastomosis, twin-reversed arterial perfusion treatment, fetoscopic endoluminal tracheal occlusion, thoraco-amniotic shunt, vesico-amniotic shunt, myelomeningocele repair, resection of sacrococcygeal teratoma, ligation of amniotic bands, balloon valvuloplasty/septoplasty, ex-utero intrapartum treatment, and ovarian cyst resection/aspiration. Yielded articles were screened against the same inclusion criteria. Studies reporting anesthesia details and procedures’ outcomes were considered. Descriptive statistical analysis was performed and findings were reported in a narrative manner.

Results

The literature searches yielded 1,679 articles, with 429 being selected for full-text evaluation. A total of 168 articles were included. Overall, no significant differences were found among procedures performed under maternal anesthesia or maternal-fetal anesthesia. Procedures requiring invasive fetal manipulation resulted to be more effective when performed under maternal anesthesia only. Based on the available data, a wide range of anesthetic agents are currently deployed and no consistency has been found neither between centers nor procedures.

Conclusions

This systematic review shows great variance in the anesthetic management during FOP. Further studies, systematically reporting intraoperative fetal monitoring and fetal hormonal responses to external stimuli, are necessary to identify the best anesthetic approach. Additional investigations on pain pathways and fetal pain perception are advisable.

Huge unrepaired myelocystocele, progressive sac enlargement in later stages of life: a case report

BACKGROUND

Spinal dysraphism is characterized by failure of fusion at dorsal midline structures through the embryonic developmental stages. A terminal myelocystocele consists of a skin-covered lumbosacral spina bifida and meningocele that directly continuous with the spinal subarachnoid space.

OBSERVATION

A 43-year-old woman who was diagnosed at birth with myelocystocele in the lower segments of the lumbar spine. She was not operated in the early stages of life. At the 43th years of her old, during 9-months, the sac began to progressively increase in size. In our initial examination before surgery, an extremely large skin-covered myelocystocele sac was observed in the thoracolumbar with a diameter of approximately 60 * 70 * 40 cm. patient operated and sac repaired. More than 20 liter of cerebrospinal fluid drainaged from cyst during surgery.

LESSONS

The mechanism of cyst enlargement is not well understood. Progressive and severe increase in size of unrepaired myelocystocele sac is possible in old ages even without cerebral hydrocephalus.

Endoscopic third ventriculostomy with or without choroid plexus coagulation for myelomeningocele-associated hydrocephalus: systematic review and meta-analysis

OBJECTIVE

While ventriculoperitoneal shunt (VPS) insertion is the standard treatment for myelomeningocele-associated hydrocephalus (MAH), it can be complicated by infection and shunt malfunction. As such, endoscopic third ventriculostomy (ETV), with or without choroid plexus coagulation (CPC), has been proposed as an alternative. The aim of this review was to determine the success, technical failure, and complication rates of ETV with or without CPC in patients with MAH.

METHODS

PubMed, Scopus, and Cochrane Central Register of Controlled Trials databases were searched from inception to June 2020 for case series, cohort studies, or randomized controlled trials reporting success, technical failure, or complication rates. Random-effects analysis was performed to determine the estimates for these outcome measures. Studies were evaluated using the Newcastle-Ottawa Scale for quality and risk of bias.

RESULTS

Thirteen studies with a total of 325 patients who underwent either ETV or ETV+CPC were included in the review. Using random-effects modeling, the pooled estimate of the success rate was 56% (95% CI 44%-68%, I2 = 78%), while the technical failure rate was 2% (95% CI 0%-6%, I2 = 32%). The estimate for the success rate had high heterogeneity, due to the type of surgical intervention (ETV vs ETV+CPC, p < 0.001). Random-effects analysis of 9 studies with 117 patients who underwent ETV alone yielded an estimated success rate of 48% (95% CI 0.39-0.57, I2 = 0%), while analysis of 4 studies with 166 patients who underwent ETV+CPC revealed a success rate of 75% (95% CI 67%-82%, I2 = 21%). The estimates for the mild/moderate, severe, and fatal complication rates were 0 (95% CI 0%-4%, I2 = 0%), 2% (95% CI 0%-10%, I2 = 52%), and 0 (95% CI 0%-1%, I2 = 0%), respectively.

CONCLUSIONS

ETV+CPC was associated with a higher success rate than ETV alone for MAH in a meta-analysis of published studies. ETV, with or without CPC, was technically feasible and safe for this patient population.

Closure of a large lumbosacral myelomeningocele defect with a human pericardial graft: a case report

INTRODUCTION

Myelomeningocele (MMC) is a complex congenital defect resulting from incomplete closure of the neural tube. The aim of this study is to present an unusual technique for the closure of a large defect.

CASE REPORT

Here we report a patient that was prenatally diagnosed with MMC. At birth, a skin defect of approximately 5 x 7 cm was observed. To repair the defect, a Z-plasty was performed; however, necrosis of the flap developed 3 days after the surgery. The devitalized tissue was removed, and a human pericardial graft was used to cover the defect.

DISCUSSION

Different techniques have been described for the repair of MMC with a large skin defect, such as rotation skin flaps as well as synthetic and biological grafts. In our patient, a new technique without prior experience consisting of the application of human cadaveric pericardial graft was used with good results and no complications.

CONCLUSION

Closure of MMC is often a surgical challenge. Here we describe a surgical technique for the closure of large skin defects.

Sociodemographic disparities in fetal surgery for myelomeningocele: a single-center retrospective review

OBJECTIVE

Fetal surgery for myelomeningocele has become an established treatment that offers less risk of requiring a ventricular shunt and improved functional outcomes for patients. An increasing body of literature has suggested that social determinants of health have a profound influence on health outcomes. The authors sought to determine the socioeconomic and racial and ethnic backgrounds of patients who were treated with fetal surgery versus those who underwent postnatal repair.

METHODS

Demographic data, the method of myelomeningocele repair, insurance status, and zip code data for patients entered into the National Spina Bifida Patient Registry (NSBPR) from Children's Wisconsin were collected. The zip code was used to determine the Distressed Communities Index (DCI) score, a composite socioeconomic ranking with scores ranging from 0 (no distress) to 100 (severe distress). The zip code was also used to determine the median household income for each patient based on the US Census Bureau 2013-2017 American Community Survey 5-year estimates.

RESULTS

A total of 205 patients were identified with zip code and insurance data. There were 23 patients in the fetal surgery group and 182 patients in the postnatal surgery group. All patients were born between 2000 and 2019. Patients in the fetal surgery group were more likely to have commercial insurance (100% vs 52.2%, p < 0.001). Fetal surgery patients were also more likely to be non-Hispanic White (95.7% vs 68.7%, p = 0.058), just missing the level of statistical significance. Patients who underwent fetal surgery tended to reside in zip codes with a higher median household income (mean $66,507 vs $59,133, p = 0.122) and less-distressed communities (mean DCI score 31.3 vs 38.5, p = 0.289); however, these differences did not reach statistical significance.

CONCLUSIONS

Patients treated with fetal surgery were more likely to have commercial insurance and have a non-Hispanic White racial and ethnic background. The preliminary data suggest that socioeconomic and racial and ethnic disparities may exist regarding access to fetal surgery, and investigation of a larger population of spina bifida patients is warranted.

Controversies in Fetal Surgery: Prenatal Repair of Myelomeningocele in the Modern Era

Fetal surgery is a constantly evolving field that showed noticeable progress with the treatment of myelomeningocele (MMC) using prenatal repair. Despite this success, there are ongoing questions regarding the optimal approach for fetal myelomeningocele repair, as well as which patients are eligible. Expansion of the inclusion and exclusion criteria is an important ongoing area of study for myelomeningocele including the recent Management of Myelomeningocele Plus trial. The significant personal and financial burden required of families seeking treatment has likely limited its accessibility to the general population.

A comparison of Adult and Pediatric Hydrocephalus

Hydrocephalus is a common clinical problem encountered in neurosurgical practice. With greater subspecialisation, pediatric neurosurgery has emerged as a special discipline in several countries. However, in the developing world, which inhabits a large pediatric population, a limited number of neurosurgeons manage all types of hydrocephalus across all ages. There are some essential differences in pediatric and adult hydrocephalus. The spectrum of hydrocephalus of dysgenetic origin in a neonate and that of normal pressure hydrocephalus of the old age has a completely different strategy of management. Endoscopic third ventriculostomy outcomes are known to be closely associated with age at presentation and surgery. Efficacy of alternative pathways of CSF absorption also differs according to age. Managing this disease in various age groups is challenging because of these differences in etiopathology, tempo of the disease, modalities of investigations and various treatment protocols as well as prognosis.

Spontaneous third ventriculostomy in patients undergoing fetal surgery for myelomeningocele correction

INTRODUCTION

Spontaneous third ventriculostomy (STV) is characterized by the spontaneous rupture of one of the ventricle walls due to increased pressure in the third ventricle caused by obstructive hydrocephalus. Clinically, STV results in resolution of signs and symptoms of intracranial hypertension and head circumference stabilization. No spontaneous STV cases in patients with myelomeningocele have been reported in the literature. The objective of this study was to report three cases of STV in patients with type 2 Chiari malformation who underwent intrauterine treatment.

CASE PRESENTATION

All patients presented clinically with increased head circumference during outpatient follow-up. Only one patient required a ventriculoperitoneal shunt implantation. The other patients did not require further intervention.

CONCLUSION

STV is a rare entity that is difficult to diagnose and should always be suspected in spontaneous hydrocephalus resolution, especially in early childhood. STV is not synonymous with hydrocephalus resolution.

Hydrocephalus in myelomeningocele

PURPOSE

To investigate certain aspects of hydrocephalus in patients with myelomeningocele.

METHODS

We retrospectively analyzed data of 1050 patients with myelomeningocele who underwent surgical treatment between June 1991 and June 2021. These patients were divided into three groups: group 1 consisted of patients who underwent surgery after the first 6 h of life, group 2 consisted of patients who underwent surgery within the first 6 h, and group 3 consisted of patients who underwent surgery during the fetal period and before 26 6/7 weeks of gestation.

RESULTS

There were 125, 590, and 335 patients in groups 1, 2, and 3, respectively. In groups 1 and 2, 593 (83%) patients developed hydrocephalus after birth and required ventriculoperitoneal shunt placement in the maternity ward, mainly within the first 4 days of life. In contrast, in group 3, 24 (7.2%) patients required surgery to treat hydrocephalus after birth. Hydrocephalus was the primary cause of mortality in groups 1 and 2, with mortality rates of 35% and 10%, respectively. In group 3, the mortality rate was 0.8% and was not related to hydrocephalus.

CONCLUSION

The onset of hydrocephalus is directly related to myelomeningocele closure in neurosurgery.

Hydrocephalus in Spina Bifida

Hydrocephalus is the most important co-morbidity in myelomeningocele from a neurosurgical perspective. Historically, 75-80% of patients with myelomeningocele have required treatment with a shunt but recent advances including intra-uterine myelomeningocele closure and ETV-CPC are reducing this burden. The expression of hydrocephalus differs between patients and across the life span. Hydrocephalus impacts the clinical expression of other important co-morbidities including the Chiari II malformation and tethered spinal cord. Shunt failure is often the key stress to prompt symptomatic worsening of these other conditions. Shunt failure may occur with minimal ventricular change on CT or MRI in Spina Bifida patients. Waiting for radiographic changes in symptomatic SB patients with shunts may result in hydrocephalus related fatalities. It is hypothesized but not proven that shunt failure may contribute to respiratory insufficiency and be a risk factor for sudden death in adult patients with spina bifida. Excellence in hydrocephalus management in MMC is essential for proper care, good outcomes, and quality of life for patients and families.

Endoscopic Third Ventriculostomy - A Review

BACKGROUND

Endoscopic third ventriculostomy (ETV) has become a proven modality for treating obstructive and selected cases of communicating hydrocephalus.

OBJECTIVE

This review aims to summarize the indications, preoperative workup, surgical technique, results, postoperative care, complications, advantages, and limitations of an ETV.

MATERIALS AND METHODS

A thorough review of PubMed and Google Scholar was performed. This review is based on the relevant articles and authors' experience.

RESULTS

ETV is indicated in obstructive hydrocephalus and selected cases of communicating hydrocephalus. Studying preoperative imaging is critical, and a detailed assessment of interthalamic adhesions, the thickness of floor, arteries or membranes below the third ventricle floor, and prepontine cistern width is essential. Blunt perforation in a thin floor, while bipolar cautery at low settings and water jet dissection are preferred in a thick floor. The appearance of stoma pulsations and intraoperative ventriculostomography reassure stoma and basal cistern patency. The intraoperative decision for shunt, external ventricular drainage, or Ommaya reservoir can be taken. Magnetic resonance ventriculography and cine phase-contrast magnetic resonance imaging can determine stoma patency. Good postoperative care with repeated cerebrospinal fluid drainage enhances outcomes in selected cases. Though the complications mostly occur in an early postoperative phase, delayed lethal ones may happen. Watching live surgeries, assisting expert surgeons, and practicing on cadavers and models can shorten the learning curve.

CONCLUSION

ETV is an excellent technique for managing obstructive and selected cases of communicating hydrocephalus. Good case selection, methodical technique, and proper training under experts are vital.

Hydrocephalus in Low and Middle-Income Countries - Progress and Challenges

Hydrocephalus remains one of the most commonly treated neurosurgical conditions worldwide. Caring for patients with hydrocephalus requires infrastructure and political support and initiative; these are often difficult to obtain in low- and middle-income countries (LMICs). Some innovations that have arisen in LMICs have traveled up the financial gradient to high-income countries, such as the combination of endoscopic third ventriculostomy with choroid plexus coagulation to manage hydrocephalus. The development of neuro-endoscopy has played a major role in managing hydrocephalus worldwide; however, LMICs still face specific challenges, such as limited access to shunt hardware, a disproportionately high incidence of post-infectious hydrocephalus, unique microbiological spectra, and often poor access to follow-up care and neuroimaging. This has received increased attention since the Lancet Commission on Global Surgery. The goal of improving access to quality neurosurgical care through various initiatives in LMICs will be discussed in this manuscript. The need for neurosurgeons continues to grow in LMICs, where better access to neurosurgical care, adequate neurosurgical training and political support, and patient education are needed to improve the quality of life for patients with common neurosurgical conditions. Despite these challenges, treating hydrocephalus remains a worthwhile endeavor for many patients.

Myelomeningocele Surgery over the 10 Years Following the MOMS Trial: A Systematic Review of Outcomes in Prenatal versus Postnatal Surgical Repair

Background and Objectives: Myelomeningocele is the most severe form of spina bifida, a congenital neural tube defect arising from an incomplete neural tube closure during early development with damage worsening with advancing gestational age. The Management of Myelomeningocele Study (MOMS) Trial proved that surgery performed before 26 weeks of gestation significantly improved the prognosis, significantly changing treatment paradigms. This article aims to provide a review of the changes and updates in spina bifida repair over the 10-year period following the MOMS Trial. Material and methods: We performed a systematic review in the PubMed and Cochrane databases as well as a hand-search of high-impact journals using the reference list of all identified articles, searching for randomized controlled trials and observational studies. Results: We identified 27 articles published between 2011 and 2021 that fulfilled the inclusion criteria and review them in the present study. Conclusions: With growing experience and with the improvement of prenatal open and fetoscopic techniques, the outcome of SB-associated conditions could be improved and the risks to both the mother and the fetus reduced. A continuous follow-up of the treated infants and further randomized trials are essential to study the complications and advantages or disadvantages of any given treatment strategy.

Emerging magnetic resonance imaging techniques in open spina bifida in utero

Magnetic resonance imaging (MRI) has become an essential diagnostic modality for congenital disorders of the central nervous system. Recent advancements have transformed foetal MRI into a clinically feasible tool, and in an effort to find predictors of clinical outcomes in spinal dysraphism, foetal MRI began to unveil its potential. The purpose of our review is to introduce MRI techniques to experts with diverse backgrounds, who are involved in the management of spina bifida. We introduce advanced foetal MRI postprocessing potentially improving the diagnostic work-up. Importantly, we discuss how postprocessing can lead to a more efficient utilisation of foetal or neonatal MRI data to depict relevant anatomical characteristics. We provide a critical perspective on how structural, diffusion and metabolic MRI are utilised in an endeavour to shed light on the correlates of impaired development. We found that the literature is consistent about the value of MRI in providing morphological cues about hydrocephalus development, hindbrain herniation or outcomes related to shunting and motor functioning. MRI techniques, such as foetal diffusion MRI or diffusion tractography, are still far from clinical use; however, postnatal studies using these methods revealed findings that may reflect early neural correlates of upstream neuronal damage in spinal dysraphism.

Fetal surgery and stem cell therapy for meningomyelocele

PURPOSE OF REVIEW

To review the advance of maternal--fetal surgery, the research of stem cell transplantation and tissue engineering in prenatal management of fetal meningomyelocele (fMMC).

RECENT FINDINGS

Advance in the imaging study provides more accurate assessment of fMMC in utero. Prenatal maternal--fetal surgery in fMMC demonstrates favourable postnatal outcome. Minimally invasive fetal surgery minimizes uterine wall disruption. Endoscopic fetal surgery is performed via laparotomy-assisted or entirely percutaneous approach. The postnatal outcome for open and endoscopic fetal surgery shares no difference. Single layer closure during repair of fMMC is preferred to reduce postnatal surgical intervention. All maternal--fetal surgeries impose anesthetic and obstetric risk to pregnant woman. Ruptured of membrane and preterm delivery are common complications. Trans-amniotic stem cell therapy (TRASCET) showed potential tissue regeneration in animal models. Fetal tissue engineering with growth factors and dura substitutes with biosynthetic materials promote spinal cord regeneration. This will overcome the challenge of closure in large fMMC. Planning of the maternal--fetal surgery should adhere to ethical framework to minimize morbidity to both fetus and mother.

SUMMARY

Combination of endoscopic fetal surgery with TRASCET or tissue engineering will be a new vision to achieve to improve the outcome of prenatal intervention in fMMC.

Ventricular size measurement methods in fetuses considered for prenatal closure of myelomeningocele

OBJECTIVE

Prenatal closure of myelomeningocele is associated with a reduced rate of hydrocephalus treatment. This need for hydrocephalus treatment is positively correlated with fetal ventricular width. When ventricular width is 15 mm or greater, the benefits of prenatal closure, as a method to decrease hydrocephalus treatment, are reduced. Thus, fetal ventricular size is an important factor when counseling families who are considering intrauterine surgery with mitigation of hydrocephalus as the primary goal. This study sought to determine whether imaging modality (ultrasound [US] vs MRI) and interobserver variability were factors in any ventricular size disparity seen on imaging studies.

METHODS

The imaging studies of 15 consecutive fetuses who underwent prenatal myelomeningocele repair at Children's Mercy Fetal Health Center, Kansas City, Missouri, were reviewed. All fetuses were imaged with US and fetal MRI; on average (range), procedures were performed 3.8 (0-20) days apart. Three comparisons were performed to analyze interobserver and intermodality variability in ventricular width measurements: 1) retrospective comparison of dictated ventricular widths measured with MRI and US by pediatric radiologists (PRs) and maternal-fetal medicine specialists (MFMs), respectively; 2) blinded measurements obtained with US by PRs versus initial US-based measurements by MFMs, and blinded measurements obtained with MRI by PRs versus initial MRI-based measurements by PRs; and 3) blinded measurements obtained with MRI by PRs versus those obtained with US.

RESULTS

Retrospective comparison showed that measurements with MRI by PRs were on average 2.06 mm (95% CI 1.43-2.69, p < 0.001) larger than measurements with US by MFMs. Blinded measurements with US by PRs were on average larger than dictated measurements obtained with US by MFMs, but by only 0.6 mm (95% CI 0.31-0.84, p < 0.001). When PRs measured ventricular size in a blinded fashion with both US and MRI, the mean width determined with MRI was significantly larger by 2.0 mm (95% CI 1.26-2.67, p < 0.0001).

CONCLUSIONS

The ventricular width of these fetuses was larger when measured with MRI than US by an amount that could impact recommendations for fetal surgery. Every center involved in counseling families about the risks and benefits of fetal intervention for spina bifida needs to be aware of these possible imaging-based disparities.

Fetal myelomeningocele repair: a narrative review of the history, current controversies and future directions

Fetal surgery is a relatively new field of medicine. The purpose of this narrative review is to present the history of how fetal surgery became the standard of care for myelomeningocele (MMC), the current controversies of this treatment, and active areas of research that may change how MMC is treated. Fetal surgery for MMC emerged out of the University of California, San Francisco in the 1980s in the laboratory of Dr. Michael Harrison. Initial research focused on testing the hypothesis that the in utero repair of MMC could improve outcomes in the ovine model. Evidence from this model suggested that in utero repair decreases the secondary damage to the exposed neural tissue and improves post-natal neurologic outcomes, opening the door for human intervention. This was followed by the Management of Myelomeningocele Study (MOMS), which was a multicenter randomized controlled trial comparing the prenatal versus postnatal MMC repair. The MOMS trial was stopped early due to the improved outcomes of the prenatal repair, establishing the open fetal MMC repair as the standard of care. Since the MOMS trial, two primary areas of controversy have arisen: the operative approach and criteria for the repair. The three operative approaches include open, endoscopic and a hybrid approach combining open and endoscopic. Several of the inclusion and exclusion criteria from the MOMS trial have been challenged, to include body mass index, gestational diabetes, other fetal abnormalities, maternal infections and Rh alloimmunization. New areas of research have also emerged, exploring cell based therapies to improve fetal outcomes, alternatives to fetal surgery and alternatives to primary skin closure of the fetus.

Fetal surgery for spina bifida in Zurich: results from 150 cases

PURPOSE

Over the past 10 years, over 150 fetal spina bifida surgeries were performed at the Zurich Center for Fetal Diagnosis and Therapy. This study looks at surrogates for success and failure of this approach.

METHODS

We focused on key outcome parameters including hydrocephalus shunt rate at one year, bladder control at 4, independent ambulation at 3 years, and maternal, fetal, and neonatal complications.

RESULTS

From the first 150 patients undergoing fetal surgery for spina bifida, 148 (98.7%) were included in the study. Maternal-fetal surgery was uneventful in 143/148 (97%) cases. Intraoperative problems included resuscitation in 4/148 fetuses (2.7%). 1/148 fetuses (0.7%) died on postoperative day 4. Maternal complications included chorioamniotic membrane separation in 22/148 (15%), lung embolism in 3/148 (2.1%), chorioamnionitis in 2/148 (1.4%), AV-block III and uterine rupture in 1/148 each (0.7%). 1/148 (0.7%) newborn death was recorded. Hindbrain herniation was identified preoperatively in 132/148 (90%) fetuses and resolved completely in 119/132 (90%). At one year, 39/106 (37%) children had required a CSF diversion. At 4 years, 4/34 patients (12%) had normal bladder control. At 3 years, 48/57 (84%) walked independently.

CONCLUSION

A majority of patients benefitted from prenatal intervention, in that the shunt rate was lower and the rates of continent and walking patients were higher than reported with postnatal care.

Open Fetal Microneurosurgery for Intrauterine Spina Bifida Repair

OBJECTIVES

The aim of the study was to describe the feasibility of open fetal microneurosurgery for intrauterine spina bifida (SB) repair and to compare perinatal outcomes with cases managed using the classic open fetal surgery technique.

METHODS

In this study, we selected a cohort of consecutive fetuses with isolated open SB referred to our fetal surgery center in Queretaro, Mexico, during a 3.5-year period (2016-2020). SB repair was performed by either classic open surgery (6- to 8-cm hysterotomy with leakage of amniotic fluid, which was replaced before uterine closure) or open microneurosurgery, which is a novel technique characterized by a 15- to 20-mm hysterotomy diameter, reduced fetal manipulation by fixing the fetal back, and maintenance of normal amniotic fluid and uterine volume during the whole surgery. Perinatal outcomes of cases operated with the classic open fetal surgery technique and open microneurosurgery were compared.

RESULTS

Intrauterine SB repair with a complete 3-layer correction was successfully performed in 60 cases either by classic open fetal surgery (n = 13) or open microneurosurgery (n = 47). No significant differences were observed in gestational age (GA) at fetal intervention (25.4 vs. 25.1 weeks, p = 0.38) or surgical times (107 vs. 120 min, p = 0.15) between both groups. The group with open microneurosurgery showed a significantly lower rate of oligohydramnios (0 vs. 15.4%, p = 0.01), preterm rupture of the membranes (19.0 vs. 53.8%, p = 0.01), higher GA at birth (35.1 vs. 32.7 weeks, p = 0.03), lower rate of preterm delivery <34 weeks (21.4 vs. 61.5%, p = 0.01), and lower rate of perinatal death (4.8 vs. 23.1%, p = 0.04) than the group with classic open surgery. During infant follow-up, the rate of hydrocephalus requiring ventriculoperitoneal shunting was similar between both groups (7.5 vs. 20%, p = 0.24). All patients showed an intact hysterotomy site at delivery.

CONCLUSION

Intrauterine spina repair by open fetal microneurosurgery is feasible and was associated with better perinatal outcomes than classic open fetal surgery.

Diffusion tensor imaging in children following prenatal myelomeningocele repair and its predictive value for the need and timing of subsequent CSF diversion surgery for hydrocephalus

OBJECTIVE

The aim of this study was to investigate diffusion tensor imaging (DTI), an objective and noninvasive neuroimaging technique, for its potential as an imaging biomarker to predict the need and timing of CSF diversion surgery in patients after prenatal myelomeningocele (MMC) repair.

METHODS

This was a retrospective analysis of data based on 35 pediatric patients after prenatal MMC repair (gestational age at birth 32.68 ± 3.42 weeks, range 24-38 weeks; 15 females and 20 males). A logistic regression analysis was used to classify patients to determine the need for CSF diversion surgery. The model performance was compared between using the frontooccipital horn ratio (FOHR) alone and using the FOHR combined with DTI values (the genu of the corpus callosum [gCC] and the posterior limb of the internal capsule [PLIC]). For patients who needed to be treated surgically, timing of the procedure was used as the clinical outcome to test the predictive value of DTI acquired prior to surgery based on a linear regression analysis.

RESULTS

Significantly lower fractional anisotropy (FA) values in the gCC (p = 0.014) and PLIC (p = 0.037) and higher mean diffusivity (MD) values in the gCC (p = 0.013) were found in patients who required CSF diversion surgery compared with those who did not require surgery (all p values adjusted for age). Based on the logistic regression analysis, the FOHR alone showed an accuracy of performance of 0.69 and area under the receiver operating characteristic curve (AUC) of 0.60. The performance of the model was higher when DTI measures were used in the logistic regression model (accuracy = 0.77, AUC = 0.84 for using DTI values in gCC; accuracy = 0.75, AUC = 0.84 for using DTI values in PLIC). Combining the DTI values of the gCC or PLIC and FOHR did not improve the model performance when compared with using the DTI values alone. In patients who needed CSF diversion surgery, significant correlation was found between DTI values in the gCC and the time interval between imaging and surgery (FA: ρ = 0.625, p = 0.022; MD: ρ = -0.6830, p = 0.010; both adjusted for age and FOHR).

CONCLUSIONS

The authors' data demonstrated that DTI could potentially serve as an objective biomarker differentiating patients after prenatal MMC repair regarding those who may require surgery for MMC-associated hydrocephalus. The predictive value for the need and timing of CSF diversion surgery is highly clinically relevant for improving and optimizing decision-making for the treatment of hydrocephalus in this patient population.

Fetal Surgery for Open Spina Bifida in Canada: Initial Results

OBJECTIVE

Fetal myelomeningocele closure results in better infant outcomes than postnatal closure at the cost of potential prematurity and maternal morbidity. Our aim is to describe the setup of a fetal myelomeningocele closure program in Canada and document its outcomes.

METHODS

We conducted a retrospective review of all open fetal myelomeningocele closure surgeries performed at the Ontario Fetal Centre in its first 3 years of operation (2017-2020). Maternal and fetal baseline characteristics, surgical details, pregnancy outcomes, and infant follow-up until 1 year of age were recorded.

RESULTS

Twenty-seven women underwent fetal myelomeningocele closure surgery, 10 of whom (37%) resided outside of Ontario. Mean gestational age at surgery was 25.0 ± 0.7 weeks. All surgeries were technically uncomplicated and no fetal deaths occurred. There was a significant negative correlation between increasing experience and skin-to-skin surgical time (R² = 0.36; P = 0.001). Of the 26 patients who have delivered, 4 (15.4%) experienced preterm prelabour rupture of membranes. Mean gestational age at delivery was 34.9±3.0 weeks. All but 1 patient delivered by cesarean. Maternal complications occurred in 9 women (34.6%). There were no maternal deaths, but 3 (11.5%) infant deaths. Of the 14 surviving infants who have reached at least 1 year of age, 5 (35.7%) underwent ventriculo-peritoneal shunting. Of the 9 infants who have not yet reached 1 year of age, 3 (33.3%) underwent endoscopic third ventriculostomy and none underwent shunting.

CONCLUSION

Fetal open spina bifida closure can be performed in Canada, with results similar to those reported by other international expert centres. Long-term follow-up is ongoing.

Detailed Analysis of Hydrocephalus and Hindbrain Herniation After Prenatal and Postnatal Myelomeningocele Closure: Report From a Single Institution

BACKGROUND

The Management of Myelomeningocele Study (MOMS) demonstrated that fetal myelomeningocele (fMMC) closure results in improved hydrocephalus and hindbrain herniation when compared to postnatal closure.

OBJECTIVE

To report on the outcomes of a single institution's experience in the post-MOMS era, with regard to hydrocephalus absence and hindbrain herniation resolution.

METHODS

A single-center retrospective study of a subset of post-MOMS patients who underwent fetal/postnatal myelomeningocele closure was performed. Primary outcomes included cerebrospinal fluid (CSF) diversion status and hindbrain herniation resolution. Families were contacted via telephone for outcome information if care was transitioned to outside institutions. Univariate/multivariable analyses were performed using several prenatal and postnatal variables.

RESULTS

From January 2011 to May 2016, data were reviewed from families of 62 postnatal and 119 fMMC closure patients. In the postnatal group, 80.6% required CSF diversion compared to 38.7% fetal cases (P < .01). Hindbrain herniation resolution occurred in 81.5% fetal repairs compared to 32.6% postnatal (P < .01). In the fetal group, fetal/premature neonatal demise occurred in 6/119 (5.0%) patients. There was a 42.0% decrease (95% CI -55.2 to -28.8) and 48.9% increase (95% CI 33.7 to 64.1) in risk difference for CSF diversion and hindbrain herniation resolution, respectively, in the fetal group. On univariate analysis for both groups, prenatal atrial diameter, frontal-occipital horn ratio, and hindbrain herniation resolution were significantly associated with the absence of clinical hydrocephalus. The treatment of hydrocephalus was significantly delayed in the fetal group compared to the postnatal group (10 mo vs 13.8 d).

CONCLUSION

This study demonstrates the benefits of fMMC closure with regard to CSF dynamics.

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.

Contemporary management and outcome of myelomeningocele: the Rotterdam experience

OBJECTIVE

Myelomeningocele (MMC) is the most common form of spina bifida, with a lifelong impact on the quality of life for infants born with this condition. In recent decades, fetal surgery has evolved from an experimental therapy to standard of care for many centers in the world. In this study, the authors aimed to provide an overview of the current management and outcomes for infants with MMC managed at their institution. This then provides a center-specific historical cohort for comparison with future antenatal-treated MMC cases.

METHODS

This is a retrospective, single-institution cohort study including all consecutive MMC cases between January 1, 2000, and June 1, 2018, at Erasmus MC. Outcome data included closure of the defect (location, timing, and surgical parameters), hydrocephalus management, Chiari malformation type II (CMTII) management, incidence of spinal cord tethering and outcome, motor outcomes, and continence.

RESULTS

A total of 93 patients were included with predominantly lumbosacral lesions. Two patients died during follow-up. Hydrocephalus was present in 84%, with a 71% ventriculoperitoneal shunt reoperation rate. Surgery was performed in 12% for a tethered spinal cord at a mean age of 8 years. Decompression surgery was performed in 3 patients for CMTII. Special education in 63% was significantly associated with hydrocephalus (p < 0.015). Nineteen percent of patients were able to walk independently, and 47% were nonambulators. Social continence for urine was obtained in 75% of patients, 4% had fecal incontinence.

CONCLUSIONS

This study provides an overview of current MMC outcomes at the authors' center and will serve as a historical cohort for comparison with future fetal surgery cases operated on at the center in the coming years. Apart from a relatively low surgical untethering rate, the authors' outcome data are comparable to those in the literature. Hydrocephalus is highly prevalent in postnatally treated MMC patients; in this study as in much of the literature, hydrocephalus is correlated with a low cognitive function. Fetal surgery for MMC halves the need for shunt treatment in a select group of MMC pregnancies, constituting a major indication for us to undergo the transition to a fetal surgery center. The fetal benefits of open antenatal surgery for MMC are well established, yet long-term data on especially tethered spinal cord are eagerly awaited.

Progressive hydrocephalus despite early complete reversal of hindbrain herniation after prenatal open myelomeningocele repair

OBJECTIVE

Open prenatal myelomeningocele (MMC) repair is typically associated with reversal of in utero hindbrain herniation (HBH) and has been posited to be associated with a reduction in both postoperative prenatal and immediate postnatal hydrocephalus (HCP) risks. However, the long-term postnatal risk of HCP following HBH reversal in these cases has not been well defined. The authors describe the results of a long-term HCP surveillance in a cohort of patients who underwent prenatal MMC repair at their institution.

METHODS

A retrospective review of all prenatal MMC repair operations performed at the Mayo Clinic between 2012 and 2017 was conducted. Pertinent data regarding the clinical courses of these patients before and after MMC repair were summarized. Outcomes of interest were occurrences of HBH and HCP and the need for intervention.

RESULTS

A total of 9 prenatal MMC repair cases were identified. There were 7 cases in which MRI clearly demonstrated prenatal HBH, and of these 86% (6/7) had evidence of HBH reversal after repair and prior to delivery. After a mean postnatal follow-up of 20 months, there were 3 cases of postnatal HCP requiring intervention. One case that failed to show complete HBH reversal after MMC repair required early ventriculoperitoneal shunting. The other 2 cases were of progressive, gradual-onset HCP despite complete prenatal HBH reversal, requiring endoscopic third ventriculostomy with choroid plexus cauterization at ages 5 and 7 months.

CONCLUSIONS

Although prenatal MMC repair can achieve HBH reversal in a majority of well-selected cases, the prevention of postnatal HCP requiring intervention appears not to be predicated on this outcome alone. In fact, it appears that in a subset of cases in which HBH reversal is achieved, patients can experience a progressive, gradual-onset HCP within the 1st year of life. These findings support continued rigorous postnatal surveillance of all prenatal MMC repair patients, irrespective of postoperative HBH outcome.

Myelomeningocele-associated hydrocephalus: nationwide analysis and systematic review

OBJECTIVE

Myelomeningocele (MMC), the most severe form of spina bifida, is characterized by protrusion of the meninges and spinal cord through a defect in the vertebral arches. The management and prevention of MMC-associated hydrocephalus has evolved since its initial introduction with regard to treatment of MMC defect, MMC-associated hydrocephalus treatment modality, and timing of hydrocephalus treatment.

METHODS

The Nationwide Inpatient Sample (NIS) database from the years 1998-2014 was reviewed and neonates with spina bifida and hydrocephalus status were identified. Timing of hydrocephalus treatment, delayed treatment (DT) versus simultaneous MMC repair with hydrocephalus treatment (ST), and treatment modality (ETV vs ventriculoperitoneal shunt [VPS]) were analyzed. Yearly trends were assessed with univariable logarithmic regression. Multivariable logistic regression identified correlates of inpatient shunt failure. A PRISMA systematic literature review was conducted that analyzed data from studies that investigated 1) MMC closure technique and hydrocephalus rate, 2) hydrocephalus treatment modality, and 3) timing of hydrocephalus treatment.

RESULTS

A weighted total of 10,627 inpatient MMC repairs were documented in the NIS, 8233 (77.5%) of which had documented hydrocephalus: 5876 (71.4%) were treated with VPS, 331 (4.0%) were treated with ETV, and 2026 (24.6%) remained untreated on initial inpatient stay. Treatment modality rates were stable over time; however, hydrocephalic patients in later years were less likely to receive hydrocephalus treatment during initial inpatient stay (odds ratio [OR] 0.974, p = 0.0331). The inpatient hydrocephalus treatment failure rate was higher for patients who received ETV treatment (17.5% ETV failure rate vs 7.9% VPS failure rate; p = 0.0028). Delayed hydrocephalus treatment was more prevalent in the later time period (77.9% vs 69.5%, p = 0.0287). Predictors of inpatient shunt failure included length of stay, shunt infection, jaundice, and delayed treatment. A longer time between operations increased the likelihood of inpatient shunt failure (OR 1.10, p < 0.0001). However, a meta-analysis of hydrocephalus timing studies revealed no difference between ST and DT with respect to shunt failure or infection rates.

CONCLUSIONS

From 1998 to 2014, hydrocephalus treatment has become more delayed and the number of hydrocephalic MMC patients not treated on initial inpatient stay has increased. Meta-analysis demonstrated that shunt malfunction and infection rates do not differ between delayed and simultaneous hydrocephalus treatment.

Pediatric neurosurgeons' views regarding prenatal surgery for myelomeningocele and the management of hydrocephalus: a national survey

OBJECTIVE

The Management of Myelomeningocele Study (MOMS) compared prenatal with postnatal surgery for myelomeningocele (MMC). The present study sought to determine how MOMS influenced the clinical recommendations of pediatric neurosurgeons, how surgeons' risk tolerance affected their views, how their views compare to those of their colleagues in other specialties, and how their management of hydrocephalus compares to the guidelines used in the MOMS trial.

METHODS

A cross-sectional survey was sent to all 154 pediatric neurosurgeons in the American Society of Pediatric Neurosurgeons. The effect of surgeons' risk tolerance on opinions and counseling of prenatal closure was determined by using ordered logistic regression.

RESULTS

Compared to postnatal closure, 71% of responding pediatric neurosurgeons viewed prenatal closure as either "very favorable" or "somewhat favorable," and 51% reported being more likely to recommend prenatal surgery in light of MOMS. Compared to pediatric surgeons, neonatologists, and maternal-fetal medicine specialists, pediatric neurosurgeons viewed prenatal MMC repair less favorably (p < 0.001). Responders who believed the surgical risks were high were less likely to view prenatal surgery favorably and were also less likely to recommend prenatal surgery (p < 0.001). The management of hydrocephalus was variable, with 60% of responders using endoscopic third ventriculostomy in addition to ventriculoperitoneal shunts.

CONCLUSIONS

The majority of pediatric neurosurgeons have a favorable view of prenatal surgery for MMC following MOMS, although less so than in other specialties. The reported acceptability of surgical risks was strongly predictive of prenatal counseling. Variation in the management of hydrocephalus may impact outcomes following prenatal closure.

The Management of Myelomeningocele Study: Short-Term Neonatal Outcomes

INTRODUCTION

The Management of Myelomeningocele Study was a multicenter randomized trial to compare prenatal and standard postnatal repair of myelomeningocele (MMC). Neonatal outcome data for 158 of the 183 randomized women were published in The New England Journal of Medicine in 2011.

OBJECTIVE

Neonatal outcomes for the complete trial cohort (N = 183) are presented outlining the similarities with the original report and describing the impact of gestational age as a mediator.

METHODS

Gestational age, neonatal characteristics at delivery, and outcomes including common complications of prematurity were assessed.

RESULTS

Analysis of the complete cohort confirmed the initial findings that prenatal surgery was associated with an increased risk for earlier gestational age at birth. Delivery occurred before 30 weeks of gestation in 11% of neonates that had fetal MMC repair. Adverse pulmonary sequelae were rare in the prenatal surgery group despite an increased rate of oligohydramnios. There was no significant difference in other complications of prematurity including patent ductus arteriosus, sepsis, necrotizing enterocolitis, periventricular leukomalacia, and intraventricular hemorrhage.

CONCLUSION

The benefits of prenatal surgery outweigh the complications of prematurity.

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.

Complex Cervicomedullary Junction Malformation and Hypoplastic Cerebellar Tonsils following Fetal Repair of Myelomeningocele: Case Report and Literature Review

BACKGROUND

Following the publication of the Management of Myelomeningocele study (MOMS), fetal repair of myelomeningocele (MMC) has become increasingly prevalent worldwide. However, limited case presentations exist illustrating the potential mechanical and embryological effects of fetal repair. We present a unique case report of a complex embryological cervicomedullary junction (CMJ) malformation and cerebellar hypoplasia following fetal repair of MMC.

CASE DESCRIPTION

A 1-day-old female was referred to the paediatric neurosurgical team after having successful surgical intrauterine closure of MMC abroad at 25 weeks gestation. The patient was born by emergency caesarean section at 33 weeks gestation and had a ventricular-peritoneal shunt inserted at 25 days old due to resulting hydrocephalus. Neonatal MRI scans revealed a complex number of malformations that included a split cord located at the CMJ, hypoplasia of the cerebellum and vermis, and a Chiari type II malformation.

CONCLUSION

It is possible that the clefting of the upper cervical spinal cord was undetected at preoperative MRI; however, this is unlikely given the antenatal images. It is our hypothesis that the malformation may have exhibited mechanical change after the repair, as the preoperative MRI showed only a Chiari II malformation without any of the complex abnormalities being present and the split cord was already there but not obvious. There are no existing reports of such a complex malformation following antenatal surgery in the literature. This should be further explored as more cases and trials become available.

Open fetal surgery for neural tube defects

The most common congenital defect of the central nervous system is myelomeningocele (MMC), which results in significant physical limitations for those affected. Neurologic injury associated with MMC begins with abnormal neurulation and is perpetuated by subsequent traumatic and toxic injury sustained in utero. Treatment historically has involved surgical closure of the MMC after birth along with neonatal management of the associated sequelae including cerebrospinal fluid diversion by ventricular shunting. With improvements in prenatal diagnosis, a defined antenatal natural history, and the concept of fetal intervention to arrest or reverse ongoing in utero damage, maternal-fetal surgery for MMC closure developed as a feasible therapy. Animal studies and early human studies investigating in utero MMC closure were promising, leading to Management of Myelomeningocele Study (MOMS trial). This prospective randomized multicenter trial comparing in utero fetal MMC (fMMC) closure to routine postnatal closure demonstrated a decreased need for shunting, reversal of hindbrain herniation, and improved neurologic function in the prenatal repair group, although maternal complications and prematurity were more frequently encountered. Because of the conclusion of the MOMS trial, fMMC closure has become a standard of care option for pregnancies complicated by a prenatal diagnosis of spina bifida. This article will provide background to the scope of MMC, review the MOMS trial data, and highlight the current clinical status of open fMMC closure.

Review on myelomeningocele management and its current status in Saudi Arabia

Major approaches have emerged in the field of myelomeningocele (MMC) management. The prevalence of MMC in Kingdom of Saudi Arabia is 0.44-1.46/1000 births. Nine point seven percent of pregnant Saudi women take folic acid before conception; MMC is estimated to result in 1,417,500 Saudi Riyals (SAR) in lifetime costs per patient. Abortion should be performed cautiously in Muslim countries; another option may be the intrauterine foetal surgical repair of MMC, which has better neuromotor outcomes and reduces the need for ventriculoperitoneal shunt, albeit with a higher risk of obstetric complications. Seven years after intrauterine foetal surgery emerged, there is a need to establish this service in Kingdom of Saudi Arabia. A multidisciplinary approach is required for MMC patients; surgical closure should be carried out within 72 hours after birth to reduce the risk of infection. Advancing MMC care allows patients to survive to adulthood, and action must be taken to improve the quality of MMC care in Kingdom of Saudi Arabia.

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.

Heated humidified carbon dioxide for partial uterine insufflation in fetoscopic myelomeningocele repair: insights from animal model

Linked Comment: Ultrasound Obstet Gynecol 2018; 53: 340-347.

Use of plastic wound retractor at hysterotomy site in prenatal repair of myelomeningocele: a new technique

Objective: To describe the use of a self-retaining thermoplastic polyurethane wound retractor for the management of hysterotomy during prenatal repair of myelomeningocele.Methods: The preliminary experience with 16 consecutive cases of open surgery for prenatal repair of myelomeningocele using a new technique is presented. Under general anesthesia, the gravid uterus was partially exteriorized through a low transverse abdominal incision and a high 3-4-cm midline vertical mini-hysterotomy was performed. After chorioamniotic membranes were opened with scissors, the internal ring of the retractor was placed into the amniotic cavity to compress the chorioamniotic membranes against the internal uterine wall and permit full retraction of the hysterotomy. Once the neurosurgical intervention was completed, the retractor was removed manually and uterine and abdominal incisions were closed using conventional techniques. Intra- and post-operative complications, as well as short-term pregnancy outcomes, were evaluated.Results: Intrauterine surgery was performed at a mean gestational age of 25.3 weeks and all except two of the interventions were completed within 3.0 h. When compared with the technique described in the Management of Myelomeningocele study (MOMS) trial, the use of the retractor was associated with a lower, although statistically nonsignificant, rate of chorioamniotic membrane separation (20/78 (26%) versus 2/16 (13%), respectively), preterm rupture of membranes (36/78 (46%) versus 4/16 (25%), respectively), and persistent oligohydramnios (16/78 (21%) versus 1/16 (6%), respectively) as well as higher gestational age at delivery (34.1 weeks ± 3.1 versus 36.0 weeks ± 1.93, respectively) and birthweight (2383 g ± 688 versus 2790 g ± 529, respectively). There were no intra- or post-operative complications associated with the use of the device. Only one (6%) of the hysterotomy scars was noted to be thin at the time of the cesarean delivery and no cases of dehiscence occurred.Conclusions: The use of a plastic wound retractor at the hysterotomy site provides a less traumatic approach than the conventional technique for the management of the uterine incision during open intrauterine surgery. Our experience with this technique was associated with short-term pregnancy outcomes that are similar and perhaps even superior to the technique reported in the MOMS trial. Because the device is inexpensive, easy to use, and widely available, its use during open intrauterine surgery should be considered. However, further clinical experience is required to reach a definitive conclusion regarding whether this technique should be incorporated into the protocol of prenatal repair of myelomeningocele.

A study to assess global availability of fetal surgery for myelomeningocele

AIM

To establish the provision of fetal surgery for myelomeningocele (MMC) worldwide.

METHODS

Through the International Society for Prenatal Diagnosis (ISPD) Fetal Therapy Special Interest Group and the North American Fetal Therapy Network (NAFTNet), fetal therapy centres were surveyed (September 2017-June 2018) regarding availability of fetal MMC surgical repair, patient inclusion criteria, repair techniques, number of cases, and outcome reporting. Responses were summarised on an interactive map on the ISPD website.

RESULTS

Forty-four of 59 centres responded (74.6%) of which 34 centres (77.1%) currently offered fetal surgery for MMC and seven centres (15.9%) were awaiting a first case after service set up. Patient inclusion criteria were similar and based on the Management of Myelomeningocele (MOMS) trial. Five centres (14.7%) operated beyond 26 weeks' gestational age, outside the MOMS criteria. Open fetal surgery was provided in 23 centres (67.6%), fetoscopic surgery only in five (14.7%), and six centres offered both types (17.6%). Neurosurgical closure was similar for open surgery but highly variable in fetoscopy surgery. The median number of cases per centre was 21 (range 1-253).

CONCLUSIONS

Fetal surgery for MMC is now offered globally. Two thirds of centres offer open repair via hysterotomy using criteria based on the MOMS trial.

Maternal Complications following Open Fetal Myelomeningocele Repair at the Zurich Center for Fetal Diagnosis and Therapy

INTRODUCTION

Despite undoubtable benefits of open fetal myelomeningocele (fMMC) repair, there are considerable maternal risks. The aim of this study was to evaluate and systematically categorize maternal complications after open fMMC repair.

METHODS

We analyzed data of 40 fMMC repairs performed at the Zurich Center for Fetal Diagnosis and Therapy. Maternal complications were classified according to a 5-level grading system based on a classification of surgical complications proposed by Clavien and Dindo.

RESULTS

We observed no grade 5 complication (death of a patient). Five (12.5%) women demonstrated severe grade 4 complications: 1 case of uterine rupture in a nullipara at 36 gestational weeks (GW), a third-degree atrioventricular block which needed short mechanical resuscitation, a bilateral lung embolism requiring intensive care unit (ICU) management due to low-output syndrome, and chorioamnionitis and urosepsis both requiring ICU management at 31 GW. Twenty-six (65%) women had minor (grade 1-3) complications.

CONCLUSIONS

Only one grade 4 complication (uterine rupture, 2.5%) was a clear-cut direct consequence of fetal surgery. The other four grade 4 complications (10%) occurred in the context of, but cannot unequivocally be attributed to, fetal surgery, since they may occur also in other circumstances. The classification system used is a tenable step towards stringent documentation of maternal complications.

Fetal surgery for spina bifida aperta

Spina bifida aperta (SBA) is one of the most common congenital malformations. It can cause severe lifelong physical and neurodevelopmental disabilities. Experimental and clinical studies have shown that the neurological deficits associated with SBA are not simply caused by incomplete neurulation at the level of the lesion. Additional damage is caused by prolonged exposure of the spinal cord and nerves to the intrauterine environment and a suction gradient due to cerebrospinal fluid leakage, leading to progressive downward displacement of the hindbrain. This natural history can be reversed by prenatal repair. A randomised controlled trial demonstrated that mid-gestational maternal-fetal surgery for SBA decreases the need for ventriculoperitoneal shunting and hindbrain herniation at 12 months and improves neurological motor function at 30 months of age. This came at the price of maternal and fetal risks, the most relevant ones being increased prematurity and a persistent uterine corporeal scar. Recently minimally invasive fetal approaches have been introduced clinically yet they lack extensive experimental or clinical trials. We aim to provide clinicians with the essential information necessary to counsel SBA parents as the basis for considering referral of selected patients to expert fetal surgery centres. We review the reported clinical outcomes and discuss recent developments of potentially less invasive fetal SBA approaches.

Myelomeningocele Versus Myelocele on Fetal MR Images: Are There Differences in Brain Findings?

OBJECTIVE

The purpose of this study was to examine differences between patients with myelomeningocele and those with myelocele with respect to brain imaging findings at fetal MRI.

MATERIALS AND METHODS

A single-center retrospective analysis was performed of fetal MRI examinations revealing open spinal dysraphism from 2004 through 2016 with available diagnostic postnatal spinal MR images in conjunction with neurosurgical follow-up findings. Images were reviewed by two board-certified fellowship-trained pediatric neuroradiologists. Relevant clinical data were recorded.

RESULTS

The study included 119 fetal MRI examinations of patients with open spinal dysraphism. Myeloceles were found in 29.4% (35/119) of these examinations and myelomeningoceles in the others. All (35/35) myeloceles showed grade 3 (severe) Chiari II malformations. Only 73.8% (62/84) of myelomeningoceles showed grade 3 Chiari II malformation. Clinically significant spinal kyphosis was found in 5.0% (6/119) of fetuses, and all of these fetuses had grade 3 Chiari II malformations. The size of the spinal dysraphic defect had significant positive correlation with lateral (p < 0.0001) and third (p = 0.006) ventricular size. Mean volume of the myelomeningocele sac was significantly different among Chiari II grades and inversely proportional to Chiari II grade (p = 0.0009).

CONCLUSION

Larger spinal dysraphic defects correlated with increased ventricular size at fetal MRI. All of the fetuses with myelocele or kyphosis had severe Chiari II malformations. Larger myelomeningocele sac size was associated with lower grade of Chiari II malformation, suggesting that myelomeningocele sac formation may be protective against hindbrain herniation.

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.