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.

Potential sealing and repair of human FM defects after trauma with peptide amphiphiles and Cx43 antisense.

OBJECTIVE: We examined whether peptide amphiphiles functionalised with adhesive, migratory or regenerative sequences could be combined with amniotic fluid (AF) to form plugs that repair fetal membrane (FM) defects after trauma and co-culture with connexin 43 (Cx43) antisense. METHODS: We assessed interactions between peptide amphiphiles and AF and examined the plugs in FM defects after trauma and co-culture with the Cx43antisense. RESULTS: Confocal microscopy confirmed directed self-assembly of peptide amphiphiles with AF to form a plug within minutes, with good mechanical properties. SEM of the plug revealed a multi-layered, nanofibrous network that sealed the FM defect after trauma. Co-culture of the FM defect with Cx43 antisense and plug increased collagen levels but reduced GAG. Culture of the FM defect with peptide amphiphiles incorporating regenerative sequences for 5 days, increased F-actin and nuclear cell contraction, migration and polarization of collagen fibers across the FM defect when compared to control specimens with minimal repair. CONCLUSIONS: Whilst the nanoarchitecture revealed promising conditions to seal iatrogenic FM defects, the peptide amphiphiles need to be designed to maximize repair mechanisms and promote structural compliance with high mechanical tolerance that maintains tissue remodeling with Cx43 antisense for future treatment.

Fetal Diagnosis and Therapy during the COVID-19 Pandemic: Guidance on Behalf of the International Fetal Medicine and Surgery Society.

The COVID-19 pandemic has stressed patients and healthcare givers alike and challenged our practice of antenatal care, including fetal diagnosis and therapy. This document aims to review relevant recent information to allow us to optimize prenatal care delivery. We discuss potential modifications to obstetric management and fetal procedures in SARS-CoV2-negative and SARS-CoV2-positive patients with fetal anomalies or disorders. Most fetal therapies are time sensitive and cannot be delayed. If personnel and resources are available, we should continue to offer procedures of proven benefit, acknowledging any fetal and maternal risks, including those to health care workers. There is, to date, minimal, unconfirmed evidence of spontaneous vertical transmission, though it may theoretically be increased with some procedures. Knowing a mother's preoperative SARS-CoV-2 status would enable us to avoid or defer certain procedures while she is contagious and to protect health care workers appropriately. Some fetal conditions may alternatively be managed neonatally. Counseling regarding fetal interventions which have a possibility of additional intra- or postoperative morbidity must be performed in the context of local resource availability. Procedures of unproven benefit should not be offered. We encourage participation in registries and trials that may help us to understand the impact of COVID-19 on pregnant women, their fetuses, and neonates.

Folic Acid Exposure Rescues Spina Bifida Aperta Phenotypes in Human Induced Pluripotent Stem Cell Model.

Neural tube defects (NTDs) are severe congenital abnormalities, caused by failed closure of neural tube during early embryonic development. Periconceptional folic acid (FA) supplementation greatly reduces the risk of NTDs. However, the molecular mechanisms behind NTDs and the preventive role of FA remain unclear. Here, we use human induced pluripotent stem cells (iPSCs) derived from fetuses with spina bifida aperta (SBA) to study the pathophysiology of NTDs and explore the effects of FA exposure. We report that FA exposure in SBA model is necessary for the proper formation and maturation of neural tube structures and robust differentiation of mesodermal derivatives. Additionally, we show that the folate antagonist methotrexate dramatically affects the formation of neural tube structures and FA partially reverts this aberrant phenotype. In conclusion, we present a novel model for human NTDs and provide evidence that it is a powerful tool to investigate the molecular mechanisms underlying NTDs, test drugs for therapeutic approaches.

Proton-pump inhibitor omeprazole attenuates hyperoxia induced lung injury.

BACKGROUND: The administration of supplemental oxygen to treat ventilatory insufficiency may lead to the formation of reactive oxygen species and subsequent tissue damage. Cytochrome P4501A1 (CYP1A1) can modulate hyperoxic lung injury by a currently unknown mechanism. Our objective was to evaluate the effect of administration of omeprazole on the induction of CYP1A1 and its influence on hyperoxic lung injury in an established preterm rabbit model. METHODS: Omeprazole was administered either (1) directly to the fetus, (2) to the mother or (3) after birth to the pups in different doses (2-10 or 20 mg/kg). Controls were injected with the same amount of saline. Pups were housed in normoxia (21 %) or hyperoxia (>95 %) for 5 days. Outcome parameters were induction of CYP1A1 measured by real-time polymerase chain reaction (RT-PCR) immediately after delivery, at day 3 and day 5 as well as lung function, morphometry and immunohistochemistry assessed at day 5 of life. Transcriptome analysis was used to define the targeted pathways. RESULTS: Daily neonatal injections demonstrated a dose-dependent increase in CYP1A1. Lung function tests showed a significant improvement in tissue damping, tissue elasticity, total lung capacity, static compliance and elastance. Morphometry revealed a more developed lung architecture with thinned septae in animals treated with the highest dose (20 mg/kg) of omeprazole. Surfactant protein B, vascular endothelial growth factor and its receptor were significantly increased on immunohistochemical stainings after omeprazole treatment. CONCLUSIONS: Neonatal administration of omeprazole induces CYP1A1 in a dose-dependent matter and combined pre- and postnatal administration attenuates hyperoxic lung injury in preterm rabbits, even with the lowest dose of omeprazole without clear CYP1A1 induction.

Hysteropexy in the treatment of uterine prolapse stage 2 or higher: a multicenter randomized controlled non-inferiority trial comparing laparoscopic sacrohysteropexy with vaginal sacrospinous hysteropexy (LAVA-trial, study protocol).

BACKGROUND: Pelvic organ prolapse is a common health problem: the lifetime risk of undergoing surgery for pelvic organ prolapse by the age of 85 years is 19%. Pelvic organ prolapse has significant negative effects on a woman's quality of life. Worldwide, vaginal hysterectomy is the leading treatment method for patients with symptomatic uterovaginal prolapse. Several studies have shown that vaginal sacrospinous hysteropexy and laparoscopic sacrohysteropexy are safe and effective alternatives in treating uterine descent. To date, it is unclear which of these techniques leads to the best operative result and the highest patient satisfaction. Therefore, we conducted the LAVA trial. METHODS: The LAVA trial is a randomized controlled multicenter non-inferiority trial. The study compares laparoscopic sacrohysteropexy with vaginal sacrospinous hysteropexy in women with uterine prolapse stage 2 or higher. The primary outcome of this study is surgical success of the apical compartment at 1 and 5 years follow-up. Secondary outcomes are subjective improvement on urogenital symptoms and quality of life (assessed by disease-specific and general quality of life questionnaires), complications following surgery, hospital stay, post-operative recovery, sexual functioning and costs-effectiveness. Evaluation will take place pre-operatively, and 6 weeks, 6 months, 12 months and annually till 60 months after surgery. Validated questionnaires will be used.Analysis will be performed according to the intention to treat principle. Based on comparable recurrence rates of 3% and a non-inferiority margin of 10%, 62 patients are needed in each arm to prove the hypothesis with a 95% confidence interval. DISCUSSION: The LAVA trial is a randomized controlled multicenter non-inferiority trial that will provide evidence whether the efficacy of laparoscopic sacrohysteropexy is non-inferior to vaginal sacrospinous hysteropexy in women with symptomatic uterine prolapse stage 2 or higher. TRIAL REGISTRATION: Netherlands Trial Register (NTR): NTR4029.

The effect of maternal betamethasone and fetal tracheal occlusion on pulmonary vascular morphometry in fetal rabbits with surgically induced diaphragmatic hernia: a placebo controlled morphologic study.

OBJECTIVES: We studied the vascular effects of betamethasone (BM) and/or tracheal occlusion (TO) in fetal rabbits with surgically induced congenital diaphragmatic hernia (CDH). METHODS: At day 23 (pseudoglandular phase; term = 31 d), 54 ovarian-end fetuses from 27 does underwent induction of CDH. Thirteen did receive either 0.05 mg/kg BM, on days 28 and 29 with a 24-h interval, or 14 saline [controls (CTR)]. At day 28, one ovarian-end fetus underwent TO and harvesting was at term. In total, we compared (ANOVA) lung-to-body weight ratio (LBWR) and vascular morphometric indices in survivors from the following groups (n - number alive at delivery): CDH (9); CDH + TO (10); unoperated controls (14); CDH + BM (10); CDH + TO (9); controls CTR + BM (13). RESULTS: Maternal BM had no effect on LBWR. LBWR was comparable to normal in CDH fetuses undergoing TO. Both TO and BM have an effect on medial thickening due to CDH which is larger when both interventions are combined. CONCLUSIONS: Both TO and BM lessen peripheric muscularization present in CDH lungs and their effect is cumulative.

Effects of maternal retinoic acid administration in a congenital diaphragmatic hernia rabbit model.

Maternal retinoid administration has beneficial effects on lung development in the nitrofen rodent toxic model of congenital diaphragmatic hernia (DH). We wanted to investigate the effects in a surgical model, where the retinoid signaling pathway is not primarily disrupted by the toxic agent. We created DH in fetal rabbits at day 23 of gestation, administrated to the does all trans-retinoic acid (ATRA) or vehicle (VHC) intramuscularly for 8 consecutive days and harvested normal and operated (DH) fetuses at 31 d (n = 7 in each group). Normal lungs exposed to ATRA had increased surfactant protein mRNA levels without change in type II pneumocyte density. There was no measurable effect on lung-to-body weight ratio and airway morphometry by ATRA. In DH lungs (DH/VHC) surfactant protein mRNA levels were increased, as well as the density of type II pneumocytes. When supplemented with ATRA (DH/ATRA) these parameters returned to normal (VHC). Cell proliferation or apoptosis were not influenced by ATRA supplementation. In conclusion, maternal ATRA supplementation does not affect gross anatomic, morphologic or proliferation indices in hypoplastic lungs related to surgically induced DH in rabbit. However, ATRA lowers surfactant protein expression and normalizes type I/II pneumocyte ratio to what is observed in normal lungs.

Modeling severely discordant hematocrits and normal amniotic fluids after incomplete laser therapy in twin-to-twin transfusion syndrome.

Our objective was to explain the clinical presentations of sustained arteriovenous anastomotic transfusion of blood after incomplete laser therapy in twin-to-twin transfusion syndrome (TTTS). We extended our mathematical model of TTTS by adding the dynamics of hematocrit, and simulated incomplete laser therapy, first, by leaving one patent opposite arteriovenous anastomosis from the recipient to the donor and, second, by leaving one patent arteriovenous anastomosis from the donor to the recipient. In both simulations we reproduced the clinical observation of severe hematocrit discordance preceding delayed amniotic fluid imbalance. In conclusion, incomplete laser therapy may cause a severe circulatory imbalance between the twins which presents predominantly as discordant hematocrits rather than discordant amniotic fluid volumes as in primary TTTS. These results imply that the anemia-polycythemia sequence is a sensitive mechanism to identify transfusion reversal after complicated laser therapy, confirming the suggested role of middle cerebral artery peak systolic velocity Doppler measurements as a useful method of follow-up.