Unique model of chronic hypoxia in fetal lambs demonstrates abnormal contrast-enhanced ultrasound brain perfusion.

BACKGROUND: Children with congenital heart disease (CHD) demonstrate long-term neurodevelopmental impairments. We investigated contrast-enhanced ultrasound (CEUS) cerebral perfusion in a fetal animal model exposed to sub-physiologic oxygen at equivalent levels observed in human fetuses with CHD. METHODS: Fifteen fetal lambs [hypoxic animals (n = 9) and normoxic controls (n = 6)] maintained in an extrauterine environment underwent periodic brain CEUS. Perfusion parameters including microvascular flow velocity (MFV), transit time, and microvascular blood flow (MBF) were extrapolated from a standardized plane; regions of interest (ROI) included whole brain, central/thalami, and peripheral parenchymal analyses. Daily echocardiographic parameters and middle cerebral artery (MCA) pulsatility indices (PIs) were obtained. RESULTS: Hypoxic lambs demonstrated decreased MFV, increased transit time, and decreased MBF (p = 0.026, p = 0.016, and p < 0.001, respectively) by whole brain analyses. MFV and transit time were relatively preserved in the central/thalami (p = 0.11, p = 0.08, p = 0.012, respectively) with differences in the peripheral parenchyma (all p < 0.001). In general, cardiac variables did not correlate with cerebral CEUS perfusion parameters. Hypoxic animals demonstrated decreased MCA PI compared to controls (0.65 vs. 0.78, respectively; p = 0.027). CONCLUSION: Aberrations in CEUS perfusion parameters suggest that in environments of prolonged hypoxia, there are regional microvascular differences incompletely characterized by MCA interrogation offering insights into fetal conditions which may contribute to patient outcomes. IMPACT: This work utilizes CEUS to study cerebral microvascular perfusion in a unique fetal animal model subjected to chronic hypoxic conditions equal to fetuses with congenital heart disease. CEUS demonstrates altered parameters with regional differences that are incompletely characterized by MCA Doppler values. These findings show that routine MCA Doppler interrogation may be inadequate in assessing microvascular perfusion differences. To our knowledge, this study is the first to utilize CEUS to assess microvascular perfusion in this model. The results offer insight into underlying conditions and physiological changes which may contribute to known neurodevelopmental impairments in those with congenital heart disease.

Assessment of extremely premature lambs supported by the Extrauterine Environment for Neonatal Development (EXTEND).

BACKGROUND: Our team has previously reported physiologic support by the EXTra-uterine Environment for Neonatal Development (EXTEND) of 105 to 117 days gestational age (GA) lambs for up to 28 days with normal organ maturation. However, the fetal lamb brain matures more rapidly, requiring the study of 90-105 day GA fetal lambs to assess more neurodevelopmentally equivalent lambs to the 23-25 week GA extreme premature infant. METHODS: Extremely preterm lambs (90-95 days of GA) were delivered by C-section and supported by EXTEND. Estimated circuit flows were maintained at around 325 ml/kg/min. After support on EXTEND, MRI and histopathologic analysis were performed and compared to 105-112 days GA control lambs. RESULTS: The extremely preterm group includes 10 animals with a mean GA of 91.6 days, a mean weight at cannulation of 0.98 kg and a mean length of stay on EXTEND of 13.5 days (10-21 days). Hemodynamics and oxygenation showed stable parameters. Animals showed growth and physiologic cardiac function. MRI volumetric and diffusion analysis was comparable to controls. Histologic brain analysis revealed no difference between study groups. CONCLUSION: EXTEND appears to support brain and cardiac development in an earlier gestation, less mature, lamb model. IMPACT: Prolonged (up to 21 days) physiological support of extremely preterm lambs of closer neurodevelopmental equivalence to the 24-28 gestational week human was achieved using the EXTEND system. EXTEND treatment supported brain growth and development in extremely preterm fetal lambs and was not associated with intraventricular hemorrhage or white matter injury. Daily echocardiography demonstrated physiologic heart function, absence of cardiac afterload, and normal developmental increase in cardiac chamber dimensions. This study demonstrates hemodynamic and metabolic support by the EXTEND system in the extremely preterm ovine model.

A fetal wound healing program after intrauterine bile duct injury may contribute to biliary atresia.

BACKGROUND & AIMS: Biliary atresia (BA) is an obstructive cholangiopathy that initially affects the extrahepatic bile ducts (EHBDs) of neonates. The etiology is uncertain, but evidence points to a prenatal cause. Fetal tissues have increased levels of hyaluronic acid (HA), which plays an integral role in fetal wound healing. The objective of this study was to determine whether a program of fetal wound healing is part of the response to fetal EHBD injury. METHODS: Mouse, rat, sheep, and human EHBD samples were studied at different developmental time points. Models included a fetal sheep model of prenatal hypoxia, human BA EHBD remnants and liver samples taken at the time of the Kasai procedure, EHBDs isolated from neonatal rats and mice, and spheroids and other models generated from primary neonatal mouse cholangiocytes. RESULTS: A wide layer of high molecular weight HA encircling the lumen was characteristic of the normal perinatal but not adult EHBD. This layer, which was surrounded by collagen, expanded in injured ducts in parallel with extensive peribiliary gland hyperplasia, increased mucus production and elevated serum bilirubin levels. BA EHBD remnants similarly showed increased HA centered around ductular structures compared with age-appropriate controls. High molecular weight HA typical of the fetal/neonatal ducts caused increased cholangiocyte spheroid growth, whereas low molecular weight HA induced abnormal epithelial morphology; low molecular weight HA caused matrix swelling in a bile duct-on-a-chip device. CONCLUSION: The fetal/neonatal EHBD, including in human EHBD remnants from Kasai surgeries, demonstrated an injury response with prolonged high levels of HA typical of fetal wound healing. The expanded peri-luminal HA layer may swell and lead to elevated bilirubin levels and obstruction of the EHBD. IMPACT AND IMPLICATIONS: Biliary atresia is a pediatric cholangiopathy associated with high morbidity and mortality rates; although multiple etiologies have been proposed, the fetal response to bile duct damage is largely unknown. This study explores the fetal pathogenesis after extrahepatic bile duct damage, thereby opening a completely new avenue to study therapeutic targets in the context of biliary atresia.

Ethics Considerations Regarding Artificial Womb Technology for the Fetonate.

Since the early 1980's, with the clinical advent of in vitro fertilization resulting in so-called "test tube babies," a wide array of ethical considerations and concerns regarding artificial womb technology (AWT) have been described. Recent breakthroughs in the development of extracorporeal neonatal life support by means of AWT have reinitiated ethical interest about this topic with a sense of urgency. Most of the recent ethical literature on the topic, however, pertains not to the more imminent scenario of a physiologically improved method of neonatal care through AWT, but instead to the remote scenario of "complete ectogenesis" that imagines human gestation occurring entirely outside of the womb. This scoping review of the ethical literature on AWT spans from more abstract concerns about complete ectogenesis to more immediate concerns about the soon-to-be-expected clinical life support of what we term the fetal neonate or fetonate. Within an organizing framework of different stages of human gestational development, from conception to the viable premature infant, we discuss both already identified and newly emerging ethical considerations and concerns regarding AWT and the care of the fetonate.

Benefit of epidural analgesia for postoperative pain control after a Kasai Portoenterostomy: A ten-year retrospective cohort study.

INTRODUCTION: Biliary atresia is a rare obstructive cholangiopathy that presents in infants. The Kasai portoenterostomy procedure, which reestablishes biliary drainage into the intestine, is a surgical procedure that has been found to improve survival with the native liver. The options for postoperative analgesia include systemic opioids and epidural analgesia. The primary objective of this study was to compare the postoperative systemic opioids used in morphine equivalents (mg/kg) on postoperative days 0 through 3 between patients who underwent a Kasai portoenterostomy and received a thoracic epidural infusion to those without thoracic epidural analgesia. METHODS: We conducted a retrospective cohort study of 91 infants with biliary atresia undergoing a Kasai portoenterostomy between January 1, 2009, and September 1, 2019, at the Children's Hospital of Philadelphia. RESULTS: Sixty-three of the 91 patients (69%) had a continuous epidural catheter placed intraoperatively for postoperative analgesia. The total opioid requirement (morphine equivalents) for the first 72 h in the epidural group of (Mean (95% confidence interval): 0.52 mg/kg (0.38, 0.67 mg/kg) was lower than the non-epidural group (Mean (95% confidence interval): 1.15 mg/kg (0.8, 1.48 mg//kg) for a difference in mean opioid requirement (95% confidence interval) of 0.63 mg/kg (0.32, 0.94 mg/kg). Patients in the non-epidural group had higher rates of unplanned ICU admissions (36% non-epidural group vs. 3.3% epidural group, difference in proportion (95% confidence interval) 32.7% (13, 52%), p < .01). A higher percentage of patients in the non-epidural group had a postoperative oxygen requirement (32.1% vs. 11.3%, difference in proportion (95% confidence interval) 21% (2, 40%), p = .02). CONCLUSION: In our cohort study, continuous thoracic epidural analgesia in patients undergoing a Kasai portoenterostomy was associated with lower postoperative opioid use. We also observed that the epidural group had a lower ICU admission rate and a lower rate of postoperative supplemental oxygen requirement over the first three postoperative days.

Radiographic and histologic characterisation of white matter injury in a sheep model of CHD.

Nearly one in five children with CHD is born with white matter injury that can be recognised on postnatal MRI by the presence of T1 hyperintense lesions. This pattern of white matter injury is known to portend poor neurodevelopmental outcomes, but the exact aetiology and histologic characterisation of these lesions have never been described. A fetal sheep was cannulated at gestational age 110 days onto a pumpless extracorporeal oxygenator via the umbilical vessels and supported in a fluid environment for 14.5 days. The fetus was supported under hypoxic conditions (mean oxygen delivery 16 ml/kg/day) to simulate the in utero conditions of CHD. At necropsy, the brain was fixed, imaged with MRI, and then stained to histologically identify areas of injury. Under hypoxemic in utero conditions, the fetus developed a T1 hyperintense lesion in its right frontal lobe. Histologically, this lesion was characterised by microvascular proliferation and astrocytosis without gliosis. These findings may provide valuable insight into the aetiology of white matter injury in neonates with CHD.

The EXTrauterine Environment for Neonatal Development: Present and Future.

Despite advances in clinical care and modest improvement in mortality rates for extreme prematurity, morbidity remains a significant challenge. The ideal environment to support prematurity would be fluidic and rely on natural fetal circulation to mimic the natural fetal amniotic environment, yet such an environment has been unsuccessful in long-term support until recently. Our group has succeeded in developing such a support system to foster fetal growth in the premature lamb model that shows promise for clinical translation. Here, we describe the EXTrauterine Environment for Neonatal Development (EXTEND) from its conception onwards, review published literature on fetal development and support of the premature lamb model in EXTEND, and discuss future applications.

Chronic foetal hypoxaemia does not cause elevation of serum markers of brain injury.

OBJECTIVES: The objective of this study was to investigate changes in serum biomarkers of acute brain injury, including white matter and astrocyte injury during chronic foetal hypoxaemia. We have previously shown histopathological changes in myelination and neuronal density in fetuses with chronic foetal hypoxaemia at a level consistent with CHD. METHODS: Mid-gestation foetal sheep (110 ± 3 days gestation) were cannulated and attached to a pumpless, low-resistance oxygenator circuit, and incubated in a sterile fluid environment mimicking the intrauterine environment. Fetuses were maintained with an oxygen delivery of 20-25 ml/kg/min (normoxemia) or 14-16 ml/kg/min (hypoxaemia). Myelin Basic Protein and Glial Fibrillary Acidic Protein serum levels in the two groups were assessed by ELISA at baseline and at 7, 14, and 21 days of support. RESULTS: Based on overlapping 95% confidence intervals, there were no statistically significant differences in either Myelin Basic Protein or Glial Fibrillary Acidic Protein serum levels between the normoxemic and hypoxemic groups, at any time point. No statistically significant correlations were observed between oxygen delivery and levels of Myelin Basic Protein and Glial Fibrillary Acidic Protein. CONCLUSION: Chronic foetal hypoxaemia during mid-gestation is not associated with elevated serum levels of acute white matter (Myelin Basic Protein) or astrocyte injury (Glial Fibrillary Acidic Protein), in this model. In conjunction with our previously reported findings, our data support the hypothesis that the brain dysmaturity with impaired myelination found in fetuses with chronic hypoxaemia is caused by disruption of normal developmental pathways rather than by direct cellular injury.

Donor cell engineering with GSK3 inhibitor-loaded nanoparticles enhances engraftment after in utero transplantation.

Host cell competition is a major barrier to engraftment after in utero hematopoietic cell transplantation (IUHCT). Here we describe a cell-engineering strategy using glycogen synthase kinase-3 (GSK3) inhibitor-loaded nanoparticles conjugated to the surface of donor hematopoietic cells to enhance their proliferation kinetics and ability to compete against their fetal host equivalents. With this approach, we achieved remarkable levels of stable, long-term hematopoietic engraftment for up to 24 weeks post-IUHCT. We also show that the salutary effects of the nanoparticle-released GSK3 inhibitor are specific to donor progenitor/stem cells and achieved by a pseudoautocrine mechanism. These results establish that IUHCT of hematopoietic cells decorated with GSK3 inhibitor-loaded nanoparticles can produce therapeutic levels of long-term engraftment and could therefore allow single-step prenatal treatment of congenital hematological disorders.

Artificial placenta and womb technology: Past, current, and future challenges towards clinical translation.

Extreme prematurity remains a major cause of neonatal mortality and severe long-term morbidity. Current neonatal care is associated with significant morbidity due to iatrogenic injury and developmental immaturity of extreme premature infants. A more physiologic approach, replacing placental function and providing a womb-like environment, is the foundational principle of artificial placenta (AP) and womb (AW) technology. The concept has been studied during the past 60 years with limited success. However, recent technological advancements and a greater emphasis on mimicking utero-placental physiology have improved the success of experimental models, bringing the technology closer to clinical translation. Here, we review the rationale for and history of AP and AW technology, discuss the challenges that needed to be overcome, and compare recent successful models. We conclude by outlining some remaining challenges to be addressed on the path towards clinical translation and opportunities for future research.

Evaluation of umbilical venous flow volume measured using ultrasound compared to circuit flow volume in the EXTra-uterine Environment for Neonatal Development (EXTEND) system in fetal sheep.

OBJECTIVE: To compare and validate umbilical venous flow volume (UVFV) measured at the intra-abdominal portion using ultrasound with actual flow volume of umbilical vein (UV) in fetal sheep sustained on the EXTrauterine Environment for Neonatal Development (EXTEND) system. METHODS: Circuit flow volume through the oxygenator was obtained using sensors. Ultrasound derived UVFV (ml/min) was calculated as (UV diameter [cm]/2)2 × 3.14 × maximum velocity (cm/s) × 0.5 × 60, measured at approximately the mid portion between its abdominal insertion and the origin of the ductus venosus. UVFV was measured by ultrasound once daily and was compared to the average of daily circuit flow volume directly measured. RESULTS: UVFV was measured 168 times in 15 fetal sheep. The ratio of circuit flow volume to combined cardiac output remained stable within the anticipated physiological range throughout. UVFV measured by ultrasound showed good correlation to directly measured circuit flow (r = 0.72). Interclass correlation coefficients for intra-observer variability was 0.991 (95% confidence interval [CI], 0.979-0.996). CONCLUSION: UVFV measured at the intra-abdominal portion using ultrasound shows a good correlation with directly measured circuit flow volume in UV of fetal sheep on the EXTEND system. Regular incorporation of such validated UVFV measures into clinical use may offer opportunities to better understand conditions of placental dysfunction.

Contrast-Enhanced Brain Ultrasound Perfusion Metrics in the EXTra-Uterine Environment for Neonatal Development (EXTEND): Correlation With Hemodynamic Parameters.

OBJECTIVES: Contrast-enhanced ultrasound (CEUS) can provide quantitative perfusion metrics and may be useful to detect cerebral pathology in neonates and premature infants, particularly in extrauterine environments. The effect of hemodynamics on cerebral perfusion metrics is unknown, which limits the clinical application of this technology. We aimed to determine associations between systemic hemodynamics and concurrently measured brain perfusion parameters in an animal model of extrauterine support. METHODS: Nine fetal lambs were transferred to an extrauterine support device. Lumason® ultrasound contrast (0.1-0.3 ml) was administered via the umbilical vein and 90-second cine clips were obtained. Time-intensity-curves (TICs) were generated and time-dependent and area-under-curve (AUC) parameters were derived. Associations between brain perfusion metrics and hemodynamics including heart rate (HR) and mean arterial pressure (MAP) were evaluated by multilevel linear mixed-effects models. RESULTS: Eighty-six ultrasound examinations were performed and 72 examinations were quantifiable. Time-dependent measurements were independent of all hemodynamic parameters (all p ≥.05). Oxygen delivery and mean blood flow were correlated with AUC measurements (all p ≤.01). Physiologic HR and MAP were not correlated with any measurements (all p ≥.05). CONCLUSION: Detected aberrations in time-dependent CEUS measurements are not correlated with hemodynamic parameters and are thought to reflect the changes in cerebral blood flow, thus providing a promising tool for evaluation of brain perfusion. CEUS brain perfusion parameters are not correlated with physiologic HR and MAP, but AUC-dependent measurements are correlated with oxygen delivery and blood flow, suggesting that CEUS offers additional value over standard monitoring. Overall, these findings enhance the applicability of this technology.

Quantitative contrast-enhanced ultrasound of the brain on twin fetal lambs maintained by the extrauterine environment for neonatal development (EXTEND): initial experience.

BACKGROUND: With the development of an artificial environment to support the extremely premature infant, advanced imaging techniques tested in this extrauterine system might be beneficial to evaluate the fetal brain. OBJECTIVE: We evaluated the feasibility of (a) performing contrast-enhanced ultrasound (CEUS) and (b) quantifying normal and decreased brain perfusion in fetal lambs maintained on the extrauterine environment for neonatal development (EXTEND) system. MATERIALS AND METHODS: Twin premature fetal lambs (102 days of gestational age) were transferred to the EXTEND system. Twin B was subjected to sub-physiological flows (152 mL/kg/min) and oxygen delivery (15.9 mL/kg/min), while Twin A was maintained at physiological levels. We administered Lumason contrast agent into the oxygenator circuit and performed serial CEUS examinations. We quantified perfusion parameters and generated parametric maps. We also recorded hemodynamic parameters, serum blood analysis, and measurements across the oxygenator. Postmortem MRIs were performed. RESULTS: No significant changes in hemodynamic variables were attributable to CEUS examinations. On gray-scale images, Twin B demonstrated ventriculomegaly and progressive parenchymal volume loss culminating in hydranencephaly. By CEUS, Twin B demonstrated decreased peak enhancement and decreased overall parenchymal perfusion when compared to Twin A by perfusion parameters and parametric maps. Changes in perfusion parameters were detected immediately following blood transfusion. Postmortem MRI confirmed ultrasonographic findings in Twin B. CONCLUSION: In this preliminary experience, we show that CEUS of the brain is feasible in fetal lambs maintained on the EXTEND system and that changes in perfusion can be quantified, which is promising for the application of CEUS in this extrauterine system supporting the premature infant.

Simple Approach to Increase Donor Hematopoietic Stem Cell Dose and Improve Engraftment in the Murine Model of Allogeneic In Utero Hematopoietic Cell Transplantation.

The rationale for in utero hematopoietic cell transplantation (IUHCT) rests on exploitation of normal events during hematopoietic and immunologic ontogeny to allow allogeneic hematopoietic engraftment without myeloablative conditioning.  Host hematopoietic competition is among the primary barriers to engraftment in IUHCT. In the murine model this can be partially overcome by delivery of larger donor cell doses, but volume is limiting. Enrichment of donor hematopoietic stem cells (HSCs) would seem to offer a more efficient approach, but such enriched populations have engrafted poorly in existing models of IUHCT. To increase HSC dose while maintaining the presence of accessory cells, we used a less stringent enrichment protocol of single-step lineage depleted cells alone (lin-) or in combination with whole donor bone marrow mononuclear cells. Our results confirm that increasing doses of HSCs in combination with bone marrow accessory cells can dramatically improve engraftment after IUHCT. This represents a practical and clinically applicable strategy to maximize the engraftment potential of the donor graft without risk of treatment-associated toxicity.

In Utero Transplantation of Expanded Autologous Amniotic Fluid Stem Cells Results in Long-Term Hematopoietic Engraftment.

In utero transplantation (IUT) of hematopoietic stem cells (HSCs) has been proposed as a strategy for the prenatal treatment of congenital hematological diseases. However, levels of long-term hematopoietic engraftment achieved in experimental IUT to date are subtherapeutic, likely due to host fetal HSCs outcompeting their bone marrow (BM)-derived donor equivalents for space in the hematopoietic compartment. In the present study, we demonstrate that amniotic fluid stem cells (AFSCs; c-Kit+/Lin-) have hematopoietic characteristics and, thanks to their fetal origin, favorable proliferation kinetics in vitro and in vivo, which are maintained when the cells are expanded. IUT of autologous/congenic freshly isolated or cultured AFSCs resulted in stable multilineage hematopoietic engraftment, far higher to that achieved with BM-HSCs. Intravascular IUT of allogenic AFSCs was not successful as recently reported after intraperitoneal IUT. Herein, we demonstrated that this likely due to a failure of timely homing of donor cells to the host fetal thymus resulted in lack of tolerance induction and rejection. This study reveals that intravascular IUT leads to a remarkable hematopoietic engraftment of AFSCs in the setting of autologous/congenic IUT, and confirms the requirement for induction of central tolerance for allogenic IUT to be successful. Autologous, gene-engineered, and in vitro expanded AFSCs could be used as a stem cell/gene therapy platform for the in utero treatment of inherited disorders of hematopoiesis. Stem Cells 2019;37:1176-1188.

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.

INTERVENCIÓN QUIRÚRGICA FETAL PARA MIELOMENINGOCELE: LECCIONES APRENDIDAS, RESULTADOS E IMPLICACIONES FUTURAS: El cierre del mielomeningocele fetal (fMMC) (espina bífida) se ha convertido en una opción de atención para pacientes que cumplen con los criterios de inclusión, pero está claro que la intervención fetal mientras se mejoran los resultados no es una cura. Esta revisión: (1) se centrará en la justificación de la cirugía fMMC basada en estudios preclínicos y observaciones que sentaron las bases para estudios piloto humanos y un ensayo controlado aleatorio; (2) resumir resultados clínicos importantes; (3) discutir la viabilidad, eficacia y seguridad de los desarrollos recientes en técnicas y enfoques de cirugía fetal; y (4) resaltar futuras direcciones de investigación. Dado el mayor riesgo de morbilidad materna y fetal asociada con la intervención prenatal, acompañado por el creciente número de centros que realizan intervenciones en todo el mundo, los equipos involucrados en la atención de estos pacientes deben proceder con precaución para mantener la experiencia técnica, la competencia y la seguridad del paciente. Se necesita una evaluación continua de la durabilidad de los beneficios de la cirugía fMMC, así como un refinamiento adicional de los criterios de selección de pacientes y asesoramiento, para mejorar aún más los resultados y reducir los riesgos para la madre y el feto.

INTERVENÇÃO CIRÚRGICA FETAL PARA MIELOMENINGOCELE: LIÇÕES APRENDIDAS, RESULTADOS E IMPLICAÇÕES FUTURAS: O fechamento fetal da mielomeningocele (fFMM), ou espinha bífida aberta, se tornou uma opção de cuidado para pacientes que atendem aos critérios de inclusão, mas está claro que, embora melhore os resultados, a intervenção fetal não representa cura. Esta revisão irá: 1) focar nos princípios da cirurgia de fFMM com base em estudos pré-clínicos e observações que basearam estudos pilotos com humanos e um estudo randomizado controlado; 2) sintetizar resultados clínicos importantes; 3) discutir a viabilidade, eficácia e segurança dos desenvolvimentos recentes em técnicas e abordagens de cirurgia fetal; e 4) destacar direções para futuras pesquisas. Dado o risco aumentado de morbidade maternal e fetal associado com a intervenção pré-natal, acompanhado pelo aumento no número de centros que realizam a intervenção no mundo, equipes envolvidas no cuidado destes pacientes precisam proceder com cautela para manter a especialidade técnica, competência e segurança dos pacientes. Contínua avaliação da durabilidade dos benefícios da fFMMM, assim como refinamento adicional dos critérios de seleção de pacientes e aconselhamento, são necessários para melhorar os resultados e reduzir os riscos para mãe e feto.

Imaging of fetal tumors and other dysplastic lesions: A review with emphasis on MR imaging.

Fetal tumors and other dysplastic masses are relatively rare. They are usually the result of failure of differentiation and maturation during embryonic or fetal life; dysplastic lesions may be the consequence of an obstruction sequence. In this review, we present the most commonly encountered tumors and masses seen during fetal life. Imaging characteristics, tumoral organ of origin, and its effect on the surrounding organs and overall fetal hemodynamics are descriptors that must be relayed to the fetal surgeon and maternal fetal medicine expert, in order to institute most accurate parental counseling and appropriate perinatal treatment plan.

A Rabbit Model for Optimization of Amniotic Fluid Components in the EXTrauterine Environment for Newborn Development (EXTEND) System.

In this model article, we present a protocol for continuous amniotic fluid exchange in rabbits using a novel system to test the effects of growth factor-deficient, artificial amniotic fluid on bowel development. BACKGROUND: Ideally, the EXTrauterine Environment for Neonatal Development (EXTEND) will provide physiologic support to the extreme premature infant. An important component of that environment is the amniotic fluid. Thus, we developed an animal model to study the growth factors found within amniotic fluid and inform design of a synthetic fluid to optimize fetal development. METHODS: We designed a model of amniotic fluid exchange within the pregnant rabbit, continuously removing the natural fluid from around 2 fetuses per doe and replacing it with a physiologic electrolyte solution during the final 100 h of gestation. Two fetuses from the contralateral uterine horn were used as sham-operated controls. Thirty-eight fetuses were analyzed, 19 in each group. We analyzed the fetal growth and bowel development. RESULTS: Ultrasound after 100 h of exchange showed equivalent fluid volumes, p = 0.63. Cultures were negative for bacterial colonization. Final fluid protein concentrations were 11.6% that of control fluid (mean 1,451 ± 224.2 vs. 12,491 ± 849.2 µg/mL). There was no significant difference in fetal growth, with experimental weights 91.4% of control weights, p = 0.07. Fetal bowel weights (90.1%, p = 0.16) and lengths (94.2%, p = 0.49) were also not significantly less compared to controls. There was no significant difference in villous height or crypt depth measurements between the groups, and absorptive capacity of the bowel was not different between groups, p = 0.44. CONCLUSION: This animal model allows for manipulation of the components of amniotic fluid. Marked reduction of natural amniotic fluid proteins during gestation does not appear to significantly impair fetal growth or bowel development. Further work with this model will assess the importance of amniotic fluid components for normal development to inform design of a synthetic fluid for use during EXTEND.

Open Fetal Surgical Outcomes for Myelomeningocele Closure Stratified by Maternal Body Mass Index in a Large Single-Center Cohort.

BACKGROUND: Open maternal-fetal surgery for in utero closure of myelomeningocele (MMC) has become an accepted treatment option for prenatally diagnosed open neural tube defects. Historically, this option has been limited to women with BMI < 35 due to concern for increasing complications in patients with obesity. OBJECTIVE: The aim of this study was to evaluate maternal, obstetric, and fetal/neonatal outcomes stratified by maternal BMI classification in women who undergo open maternal-fetal surgery for fetal myelomeningocele (fMMC) closure. METHODS: A single-center fMMC closure registry was queried for maternal demographics, preoperative factors, fetal surgery outcomes, delivery outcomes, and neonatal outcomes. Data were stratified based on maternal BMI: <30, 30-34.99, and ≥35-40, corresponding to normal weight/overweight, obesity class I, and obesity class II. Statistical analysis was performed using statistical software SAS v.9.4 (SAS Institute Inc., Cary, NC, USA). RESULTS: A total of 264 patients were analyzed, including 196 (74.2%) with BMI <30, 54 (20.5%) with BMI 30-34.99, and 14 (5.3%) with BMI ≥ 35-40. Maternal demographics and preoperative characteristics were similar among the groups. Operative time increased with increasing BMI; otherwise, perioperative outcomes were similar among the groups. Obstetric and neonatal outcomes were similar among the groups. CONCLUSION: Increasing maternal BMI did not result in a negative impact on maternal, obstetric, and fetal/neonatal outcomes in a large cohort of patients undergoing open maternal-fetal surgery for fMMC closure. Further study is warranted to determine the generalizability of these results.

Benchmarking against the MOMS Trial: Zurich Results of Open Fetal Surgery for Spina Bifida.

INTRODUCTION: The Management of Myelomeningocele Study, a.k.a. the MOMS trial, was published in 2011 in the New England Journal of Medicine. This prospective randomized controlled trial proved to be a milestone publication that provided definitive evidence that fetal surgery is a novel standard of care for select fetuses with spina bifida aperta (SB). The goal of our study is to assess whether our center can match these benchmark results. MATERIALS AND METHODS: Our study was conducted according to the MOMS protocol using the same inclusion and exclusion criteria and looked at the same outcome parameters that were used in the MOMS trial. Zurich and MOMS results were compared. RESULTS: We enrolled 20 patients between December 2010 and May 2015 all of whom underwent fetal surgery for SB. Among 51 different outcome variables, there were only 3 favorable (multiplicity-adjusted) significant differences (gestational age at birth, hindbrain herniation, and psychomotor development). There were no statistically significant differences regarding any other parameters. CONCLUSION: Our findings confirm that rigorous apprenticeship, training, and comprehensive prospective data collection enable centers like the Zurich Center for Fetal Diagnosis and Therapy to achieve benchmark results for open fetal surgery for myelomeningocele and myeloschisis. These results justify the existence and continuation of our program. Outcome documentation is an essential element of quality management. It is medically and ethically fundamental for fetal medicine and surgery centers offering high-end innovative medical care.