Fetoscopic Open Neural Tube Defect Repair: Development and Refinement of a Two-Port, Carbon Dioxide Insufflation Technique

The clinical experience of fetoscopic repair of myelomeningocele in Taiwan: The dilemma in prenatal decision-making and first successful case

OBJECTIVE

Objective: Myelomeningocele (MMC) is the most severe type of spina bifida, with an incidence of 1.87 per 10,000 live births in Taiwan. Exposure of the lesion to amniotic fluid exacerbates neurological outcomes, while fetal surgery for MMC repair, now a routine practice, improves postnatal outcomes. However, Asian women and their families often find it difficult to accept prenatal defects, leading nearly all pregnancies with fetal MMC to opt for termination without considering fetal surgery.

MATERIALS AND METHODS

In Taiwan's first approved trial of fetoscopic MMC repair, we prospectively recruited 15 cases from 2020 to 2023. Final diagnoses were confirmed using MRI and ultrasound. The medical team provided non-direct consultations to discuss possible outcomes of fetal surgery with family members. For those opting for fetal surgery, we offered total percutaneous fetoscopic MMC repair.

RESULTS

Over 30 months, 14 of 15 cases (93%) chose to terminate their pregnancies between 18 and 26 weeks of gestational age. Decision factors included potential disabilities, morbidities, economic, social, and psychological aspects. Despite supportive groups in the country, the termination rate remained high among the Chinese population. One out of the 15 cases underwent fetal surgery successfully, resulting in a 30-month-old child without motor function delays, able to walk and run naturally.

CONCLUSION

We initiated the first fetoscopic MMC repair in Taiwan with promising outcomes, though we faced a high termination rate here and similar situation in other Asian countries. Continuous social education through media could play a crucial role in changing perceptions and increasing acceptance of fetal surgery.

A new ex vivo model system to analyze factors affecting the integrity of fetal membranes in fetoscopic surgery

We developed an ex vivo model system to analyze the influence of relevant environmental and mechanical factors potentially affecting the integrity of fetal membranes during fetoscopic surgery. The set-up exposes amniochorion membranes to insufflation at predefined levels of gas pressure, flow, humidity, and temperature. Change in fetal membranes stiffness is quantified during the phase mimicking surgery through measurement of membranes' strain in response to cyclic overpressure. The trocar induced perforation creates a mechanical weakness whose stability is assessed by increasing the insufflation pressure until membrane rupture. Damage of the epithelial cells lining the amnion is assessed through live-dead staining. Initial experiments demonstrated the functionality of the new apparatus and the feasibility of the proposed protocols. Fetal membranes exposed to air with low humidity for approximately 1 h demonstrated significant embrittlement, while their mechanical integrity was maintained in case of gas insufflation at high humidity (air as well as CO2). Under dry circumstances, there was a significant rate of epithelial cell death. Separation of amnion and chorion in the region of the trocar site was visible in all experiments. This new model is a versatile platform for analyzing the mechanical, histological, and biological implications of fetoscopic surgery on fetal membranes.

Ambulation after in-utero fetoscopic or open neural tube defect repair: predictors for ambulation at 30 months

OBJECTIVES

To compare the ambulatory status of a cohort of children who had undergone prenatal repair of an open neural tube defect (ONTD) using one of two different methods (fetoscopic or open hysterotomy) with that of a cohort who had undergone postnatal repair, and to identify the best predictors of ambulation at 30 months of age.

METHODS

This was a retrospective review of a cohort of children who underwent ONTD repair either prenatally (n = 110), by fetoscopic surgery (n = 73) or open hysterotomy surgery (n = 37), or postnatally (n = 51), in a single tertiary hospital between November 2011 and May 2023. The cohort comprised a consecutive sample of cases who had undergone ONTD repair in-utero following Management of Myelomeningocele Study (MOMS) trial criteria and cases who had undergone postnatal repair, meeting the same criteria, which were also followed up after birth at the same institution. Motor function assessment by ultrasound was recorded at referral, 6 weeks after prenatal repair, or after referral in postnatally repaired cases, and at the last ultrasound scan before delivery. Clinical examinations to assess motor function at birth and at 12 months were retrieved from records. Intact motor function was defined as first sacral myotome (S1) motor function. Ambulatory status data at each follow-up visit were collected. The proportion of children who were able to walk independently after 30 months of age was compared between those who had undergone fetoscopic vs open prenatal surgery and between prenatal (by either fetoscopic or open surgery) and postnatal ONTD repair. Logistic regression analyses were performed to identify predictors for independent ambulation.

RESULTS

After 30 months, the proportion of infants who were able to walk independently was higher in prenatally vs postnatally repaired cases (51.8% vs 15.7%, P < 0.01), and there was no difference between those with fetoscopic (52.1%) vs open (51.4%) prenatal repair (P = 0.66). In the prenatally repaired group, having intact motor function at 12 months (adjusted odds ratio (aOR), 9.14 (95% CI, 2.64-31.63), P < 0.01) and at birth (aOR, 4.50 (95% CI, 1.21-16.80), P = 0.02) were significant predictors of independent walking at 30 months; an anatomical level of lesion below L2 at referral (aOR, 1.83 (95% CI, 1.30-2.58), P = 0.01) and female gender (aOR, 3.51 (95% CI, 1.43-8.61), P < 0.01) were also predictive for this outcome.

CONCLUSIONS

Prenatally repaired cases of ONTD have a better chance of being able to walk independently at 30 months than do those who undergo postnatal repair. In patients with prenatally repaired ONTD, ambulatory status at 30 months can be predicted by observing a low lesion level at referral (below L2) and intact motor function postnatally. These results have implications for parental counseling and planning for supportive therapy in pregnancies affected by ONTD. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Proposal for standardized prenatal assessment of fetal open dysraphisms by the European reference network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies (ITHACA) and eUROGEN

Open dysraphisms, that is, myelomeningocele and myeloschisis, are rare diseases associated with a risk of severe disability, including lower limb motor and sensory deficiency, sphincter deficiency, and potential intellectual deficiency. Open dysraphism is diagnosed in Europe in 93.5% of cases. In case of suspicion of fetal open dysraphism, a detailed fetal morphologic assessment is required to confirm the diagnosis and exclude associated structural anomalies, as well as genetic assessment. In case of isolated fetal open dysraphism, assessment of prognosis is based on fetal imaging including the level of the lesion, the presence or not of a sac, the presence and nature of intra cranial anomalies, and the anatomical and functional evaluation of the lower extremities. Based on these biomarkers, a personalized prognosis as well as comprehensive information about prenatal management alternatives will allow parents to decide on further management options. Standardization of prenatal assessment is essential to compare outcomes with benchmark data and make assessment of surgical innovation possible. Herein, we propose a protocol for the standardized ultrasound assessment of fetuses with isolated open dysraphism.

Fetal bradycardia in open versus fetoscopic prenatal repair of spina bifida

OBJECTIVE

To compare the occurrence of fetal bradycardia in open versus fetoscopic fetal spina bifida surgery.

METHODS

This is a single-institution retrospective cohort study of patients undergoing open (n = 25) or fetoscopic (n = 26) spina bifida repair between 2017 and 2022. From October 2017 to June 2020, spina bifida repairs were performed via an open classical hysterotomy, and from November 2020 to June 2022 fetoscopic repairs were performed following transition to this technique. Fetal heart rate (FHR) in beats per minute (bpm) was recorded via echocardiography every 15 min during the procedure. Cohort characteristics, fetal bradycardia and maternal physiologic parameters were compared between the groups.

RESULTS

Fetuses undergoing an open repair more frequently developed bradycardia defined as <110 bpm (32% vs. 3.8%, p = 0.008), and a trend was observed for FHR decreases more than 25 bpm from baseline (20% vs. 3.8%, p = 0.073). Profound bradycardia less than 80 bpm was rare, occurring in only three operations (two in open, one in fetoscopic repair) with two fetuses (one in each group) requiring emergency cesarean delivery.

CONCLUSION

When compared to open fetal surgery, fetal bradycardia occurred less frequently in fetoscopic surgery despite a significantly greater anesthetic exposure and the use of the intraamniotic carbon dioxide insufflation.

Fetal surgery for open neural tube defect with severe ventriculomegaly

OBJECTIVE

Prenatal open neural tube defect (ONTD) repair is performed to decrease the risk of needing treatment for hydrocephalus after birth and to preserve motor function. Some centers may not consider patients to be candidates for surgery if severe ventriculomegaly is present and there is no expected benefit in risk for hydrocephalus treatment. This study sought to compare the postnatal outcome of fetuses with ONTD and severe ventriculomegaly (ventricular width ≥ 15 mm) that underwent prenatal repair with the outcome of fetuses with severe ventriculomegaly that underwent postnatal repair and fetuses without severe ventriculomegaly (< 15 mm) that underwent prenatal repair.

METHODS

This was a retrospective study of fetuses with ONTD that underwent prenatal or postnatal repair between 2012 and 2021 at a single institution. The cohort was divided into two groups based on preoperative fetal ventricular size: those with severe ventriculomegaly (ventricular width ≥ 15 mm) and those without severe ventriculomegaly (< 15 mm). Fetal ventricular size was measured by magnetic resonance imaging before surgery using the standardized approach and the mean size of the left and right ventricles was used for analysis. Motor function of the lower extremities was assessed at the time of referral by ultrasound and if flexion-extension movements of the ankle were seen it was considered as preserved S1 motor function. Postnatal outcomes, including motor function of the lower extremities at birth and the need for a diversion procedure for hydrocephalus treatment during the first year after birth, were collected and compared between groups. Multivariate regression analysis was used to adjust for potential confounders.

RESULTS

In this study, 154 patients were included: 145 underwent fetal surgery (101 fetoscopic and 44 open hysterotomy) and nine with severe ventriculomegaly underwent postnatal repair. Among the 145 patients who underwent fetal surgery, 22 presented with severe ventriculomegaly. Fetuses with severe ventriculomegaly at referral that underwent prenatal repair were significantly more likely to need hydrocephalus treatment by 12 months after birth than those without severe ventriculomegaly (61.9% vs 28.9%, P < 0.01). However, motor function assessment at birth was similar between both prenatal repair groups (odds ratio, 0.92 (95% CI, 0.33-2.59), P = 0.88), adjusted for the anatomical level of the lesion. The prenatal repair group with severe ventriculomegaly had better preserved motor function at birth compared to the postnatal repair group with severe ventriculomegaly (median level, S1 vs L3, P < 0.01; proportion with S1 motor function, 68.2% vs 11.1%, P < 0.01). Fetuses with severe ventriculomegaly that underwent prenatal repair had an 18.9 (95% CI, 1.2-290.1)-times higher chance of having intact motor function at birth, adjusted for ethnicity, presence of club foot at referral and gestational age at delivery, compared with the postnatal repair group. There was no significant difference in the need for hydrocephalus treatment in the first year after birth between prenatal and postnatal repair groups with severe ventriculomegaly (61.9% vs 87.5%, P = 0.18).

CONCLUSIONS

Although fetuses with ONTD and severe ventriculomegaly do not seem to benefit from fetal surgery in terms of postnatal hydrocephalus treatment, there is an increased chance of preserved motor function at birth. Results from this study highlight the benefit of prenatal ONTD repair for cases with severe ventriculomegaly at referral to preserve motor function. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Advances in foetal anaesthesia

Nowadays, widespread antenatal ultrasound screenings detect congenital anomalies earlier and more frequently. This has sparked research into foetal surgery, offering treatment options for various conditions. These surgeries aim to correct anomalies or halt disease progression until after birth. Minimally invasive procedures can be conducted under local anaesthesia (with/without maternal sedation), while open mid-gestational procedures necessitate general anaesthesia. Anaesthesia serves to prevent maternal and foetal pain, to provide immobilization, and to optimize surgical conditions by ensuring uterine relaxation. As early as 12 weeks after conception, the foetus may experience pain. Thus, in procedures involving innervated foetal tissue or requiring foetal immobilization, anaesthetic drugs can be administered directly to the foetus (intramuscular or intravenous) or indirectly (transplacental) to the mother. However, animal studies have indicated that exposure to prenatal anaesthesia might impact foetal brain development, translating these findings to the clinical setting remains difficult.

The impact of a biocellulose-based repair of fetal open spina bifida on the need to untether the cord: is it time to unify techniques for prenatal repair?

OBJECTIVE

To report the need for cord untethering after prenatal repair of open spina bifida using a unique biocellulose-based technique performed at a later gestational age.

METHODS

An observational cohort study was conducted to determine the incidence of tethered cord syndrome. Between May 2013 and May 2022, we performed 172 procedures using the percutaneous fetoscopic approach in fetuses at 26-28 weeks of gestation. After placode dissection, a biocellulose patch was placed to cover the placode, a myofascial flap (when possible) was dissected, and the skin was closed. Owing to death or loss to follow-up, 23 cases were excluded. Cord tethering syndrome was defined as symptoms of medullary stretching, and the infants were evaluated and operated on by local neurosurgeons after an magnetic resonance imaging examination. Infants over 30-month had ambulation and neurodevelopment evaluations (PEDI scale).

RESULTS

Among 172 cases operated at a median gestational age of 26.7 weeks and delivered at 33.2 weeks, 149 cases were available for postnatal follow-up, and cord untethering was needed in 4.4% of cases (6/136; excluding 13 cases younger than 12 months). Cerebrospinal fluid diversion and bladder catheterization were needed in 38% and 36% of cases, respectively. Of the 78 cases evaluated at 30 months, 49% were ambulating independently, and 94% had normal social function.

CONCLUSION

The biocellulose-based technique was associated with a low rate of cord tethering, wich may be attributed to the lack of the duramater suture during prenatal repair, the formation of a neoduramater and/or later gestational age of surgery.

Pain Scores after Open Fetal Spina Bifida Repair and Caesarean Section: A Longitudinal Cohort Study

INTRODUCTION

In fetal surgery, successful pain management is crucial for postoperative mobilization, prophylaxis of contractions, and fast recovery. This study analyzed patient's pain experience after open fetal spina bifida (fSB) repair in comparison to pain scores after the subsequent Caesarean section (C-section).

MATERIALS AND METHODS

Data were collected with a questionnaire given to 91 women, who had fSB repair and then C-section at our center between 2019 and 2022. It comprised 12 questions covering different aspects of pain experience and satisfaction with pain therapy and was answered by 67 women after fSB repair and 53 after C-section. Postoperative pain was rated on a Likert scale from 0 (slight/rarely) to 100 (strongest/always). Outcomes after fSB repair were compared to those after C-section. Additionally, subgroup analysis compared outcomes of women with different pain levels (group 1-5) after fSB repair.

RESULTS

Compared to women after C-section women after fSB repair reported significantly higher maximum pain scores (MPS) (p = 0.03), higher sleep disturbance due to pain (p = 0.03), and sedation rates (p = 0.001) as side effect from pain therapy. No differences were found regarding feelings of insecurity (p = 0.20) or helplessness (p = 0.40), as well as involvement in (p = 0.3) and satisfaction with pain therapy (p = 0.5). Subgroup analysis revealed that women with higher MPS after fSB repair were significantly more often non-Caucasians (p = 0.003) and more often affected by pain while lying in bed (p = 0.007) and during mobilization (p = 0.005). Additionally, they reported higher rates of dizziness (p = 0.02) and lower satisfaction rates with pain therapy (p = 0.03). Postoperative complication rate did not differ among groups.

CONCLUSION

Although women after fSB repair reported higher MPS compared to after C-section, the current pain management was generally perceived as satisfactory.

High-fidelity, low-cost synthetic training model for fetoscopic spina bifida repair

BACKGROUND

Fetoscopic spina bifida repair is increasingly being practiced, but limited skill acquisition poses a barrier to widespread adoption. Extensive training in relevant models, including both ex vivo and in vivo models may help. To address this, a synthetic training model that is affordable, realistic, and that allows skill analysis would be useful.

OBJECTIVE

This study aimed to create a high-fidelity model for training in the essential neurosurgical steps of fetoscopic spina bifida repair using synthetic materials. In addition, we aimed to obtain a cheap and easily reproducible model.

STUDY DESIGN

We developed a 3-layered, silicon-based model that resemble the anatomic layers of a typical myelomeningocele lesion. It allows for filling of the cyst with fluid and conducting a water tightness test after repair. A compliant silicon ball mimics the uterine cavity and is fixed to a solid 3-dimensional printed base. The fetal back with the lesion (single-use) is placed inside the uterine ball, which is reusable and repairable to allow for practicing port insertion and fixation multiple times. Following cannula insertion, the uterus is insufflated and a clinical fetoscopic or robotic or prototype instruments can be used. Three skilled endoscopic surgeons each did 6 simulated fetoscopic repairs using the surgical steps of an open repair. The primary outcome was surgical success, which was determined by water tightness of the repair, operation time <180 minutes and an Objective Structured Assessment of Technical Skills score of ≥18 of 25. Skill retention was measured using a competence cumulative sum analysis of a composite binary outcome of surgical success. Secondary outcomes were cost and fabrication time of the model.

RESULTS

We made a model that can be used to simulate the neurosurgical steps of spina bifida repair, including anatomic details, port insertion, placode release and descent, undermining of skin and muscular layer, and endoscopic suturing. The model was made using reusable 3-dimensional printed molds and easily accessible materials. The 1-time startup cost was €211, and each single-use, simulated myelomeningocele lesion cost €9.5 in materials and 50 minutes of working time. Two skilled endoscopic surgeons performed 6 simulated, 3-port fetoscopic repairs, whereas a third used a Da Vinci surgical robot. Operation times decreased by more than 30% from the first to the last trial. Six experiments per surgeon did not show an obvious Objective Structured Assessment of Technical Skills score improvement. Competence cumulative sum analysis confirmed competency for each surgeon.

CONCLUSION

This high-fidelity, low-cost spina bifida model allows simulated dissection and closure of a myelomeningocele lesion. VIDEO ABSTRACT.

Trends in research related to fetal therapy from 2012 to 2022: a bibliometric analysis

Background

The development of prenatal diagnosis technology allows prompt detection of severe fetal diseases. To address adverse factors that threaten fetal survival, fetal therapy came into existence, which aims to preserve the function after birth to a higher degree and improve the quality of life.

Objective

To conduct a comprehensive bibliometric analysis of studies on fetal therapy in the past decade and explore the research trends and hotspots in this field.

Methods

We conducted a systematic search on the Web of Science Core Collection to retrieve studies related to fetal therapy published from 2012 to 2022. VOSviewer and CiteSpace were used to analyze the key features of studies, including annual output, countries/regions, institutions, authors, references, research hotspots, and frontiers.

Results

A total of 9,715 articles were included after eliminating duplicates. The annual distribution of the number of articles showed that the number of articles published in fetal therapy had increased in the past decade. Countries and institutions showed that fetal therapy is more mature in the United States. Author analysis showed the core investigators in the field. Keyword analysis showed the clustering and emergence frequency, which helped summarize the research results and frontier hotspots in this field. The cocited references were sorted out to determine the literature with a high ranking of fetal therapy in recent years, and the research trend in recent years was analyzed.

Conclusions

This study reveals that countries, institutions, and researchers should promote wider cooperation and establish multicenter research cooperation in fetal therapy research. Moreover, fetal therapy has been gradually explored from traditional surgical treatment to gene therapy and stem cell therapy. In recent years, fetoscopic laser surgery, guideline, and magnetic resonance imaging have become the research hotspots in the field.

Perforation of cavum septi pellucidi in open spina bifida and need for hydrocephalus treatment by 1 year of age

OBJECTIVE

In-utero repair of an open neural tube defect (ONTD) reduces the risk of developing severe hydrocephalus postnatally. Perforation of the cavum septi pellucidi (CSP) may reflect increased intraventricular pressure in the fetal brain. We sought to evaluate the association of perforated CSP visualized on fetal imaging before and/or after in-utero ONTD repair with the eventual need for hydrocephalus treatment by 1 year of age.

METHODS

This was a retrospective cohort study of consecutive patients who underwent laparotomy-assisted fetoscopic ONTD repair between 2014 and 2021 at a single center. Eligibility criteria for surgery were based on those of the Management of Myelomeningocele Study (MOMS), although a maternal prepregnancy body mass index of up to 40 kg/m2 was allowed. Fetal brain imaging was performed with ultrasound and magnetic resonance imaging (MRI) at referral and 6 weeks postoperatively. Stored ultrasound and MRI scans were reviewed retrospectively to assess CSP integrity. Medical records were reviewed to determine whether hydrocephalus treatment was needed within 1 year of age. Parametric and non-parametric tests were used as appropriate to compare outcomes between cases with perforated CSP and those with intact CSP as determined on ultrasound at referral. Logistic regression analysis was performed to assess the predictive performance of various imaging markers for the need for hydrocephalus treatment.

RESULTS

A total of 110 patients were included. Perforated CSP was identified in 20.6% and 22.6% of cases on preoperative ultrasound and MRI, respectively, and in 26.6% and 24.2% on postoperative ultrasound and MRI, respectively. Ventricular size increased between referral and after surgery (median, 11.00 (range, 5.89-21.45) mm vs 16.00 (range, 7.00-43.5) mm; P < 0.01), as did the proportion of cases with severe ventriculomegaly (ventricular width ≥ 15 mm) (12.7% vs 57.8%; P < 0.01). Complete CSP evaluation was achieved on preoperative ultrasound in 107 cases, of which 22 had a perforated CSP and 85 had an intact CSP. The perforated-CSP group presented with larger ventricles (mean, 14.32 ± 3.45 mm vs 10.37 ± 2.37 mm; P < 0.01) and a higher rate of severe ventriculomegaly (40.9% vs 5.9%; P < 0.01) compared to those with an intact CSP. The same trends were observed at 6 weeks postoperatively for mean ventricular size (median, 21.0 (range, 13.0-43.5) mm vs 14.3 (range, 7.0-29.0) mm; P < 0.01) and severe ventriculomegaly (95.0% vs 46.8%; P < 0.01). Cases with a perforated CSP at referral had a lower rate of hindbrain herniation (HBH) reversal postoperatively (65.0% vs 88.6%; P = 0.01) and were more likely to require treatment for hydrocephalus (89.5% vs 22.7%; P < 0.01). The strongest predictor of the need for hydrocephalus treatment within 1 year of age was lack of HBH reversal on MRI (odds ratio (OR), 36.20 (95% CI, 5.96-219.12); P < 0.01) followed by perforated CSP on ultrasound at referral (OR, 23.40 (95% CI, 5.42-100.98); P < 0.01) and by perforated CSP at 6-week postoperative ultrasound (OR, 19.48 (95% CI, 5.68-66.68); P < 0.01).

CONCLUSIONS

The detection of a perforated CSP in fetuses with ONTD can reliably identify those cases at highest risk for needing hydrocephalus treatment by 1 year of age. Evaluation of this brain structure can improve counseling of families considering fetal surgery for ONTD, in order to set appropriate expectations about postnatal outcome. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Exteriorization of the uterus reduces fetoscopic cannula-induced stress and strain: A finite element model analysis

OBJECTIVE

To estimate stresses and strains in the uterine wall and fetal membranes with single/multi-port fetoscopy, simulating either a percutaneous access or via exteriorized uterus.

STUDY DESIGN

Finite element models based on anatomical dimensions, material properties and boundary conditions were created to simulate stresses, strains and displacements on the uterine wall and fetal membranes during simulated fetal surgery either via exteriorized uterus or percutaneous approach, and with one or three cannulas. Clinically, we measured the anatomical layer thickness and cannula entry point displacement in patients undergoing single port percutaneous fetoscopy.

RESULTS

Simulations demonstrate that single port percutaneous fetoscopy increases stress on the fetal membranes (+105%, 128 to 262 kPa) and uterine wall (+115%, 0.89 to 1.9 kPa) compared to exteriorized uterine access. Using three ports increases stress by 110% (148 to 312 kPa) on membranes and 113% (1.08 to 2.3 kPa) on uterine wall. Finite Element Method showed 0.75 cm uterine entry point displacement from the cutaneous entry, while clinical measurements demonstrated displacement of more than double (1.69 ± 0.58 cm), suggesting modeled measurements may be underestimations.

CONCLUSION

The stresses and strains on the fetal membranes and uterus are double as high when entering percutaneously than via an exteriorized uterus. Based on what can be clinically measured, this may be an underestimation.

Training model for the fetal myelomeningocele correction with multiportal endoscopic technique

PURPOSE

The recent history of myelomeningocele has shown that treatment during the fetal life may reduce the risk of developing hydrocephalus in individuals by approximately 50%. Thus, a significant advancement involves fetal surgery performed through an endoscopic technique in which portals are placed to introduce the forceps and laparoscopic instruments. However, the development of this technique requires training; therefore, this study aimed to develop a training model for fetal myelomeningocele repair technique with multi-portal endoscopy.

METHODS

Two stages of endoscopic technique development were performed. The first stage consisted of exercises in order to familiarize the surgeon with 2D-vision endoscopic surgery, associated with the application of exercises focused on surgical skills, such as the development of laparoscopic knots in a synthetic model. The second stage involved the creation and application of the stages of myelomeningocele closure with a non-living animal model consisting of a chicken breast to simulate the myelomeningocele and a basketball to simulate the gravid uterus, in which perforations were made to introduce vascular introducers (portals) that, as in vivo, are used as portals (trocars) for the introduction of laparoscopic instruments. Overall, two different scenarios with three portals and two portals were tested.

RESULTS

In three-portal simulator, the triangular apex trocar was used for the introduction of 4-mm 0° or 30° optics or even Minop type neurodoscope (Aesculap®, Germany) that was operated by the assistant surgeon; the other two portals are used for the introduction of laparoscopic instruments. Thus, the surgeon is able to perform maneuvers bimanually since dissection to laparoscopic sutures. In two-portal simulator, the surgeon and assistant stay side by side and one of the portals is used for the optic and the other for the laparoscopic instruments. There is no possibility of bimanual dissection in this method.

CONCLUSION

Realistic simulation models for endoscopic fetal surgery for myelomeningocele correction are easily performed and help develop the necessary skills for fetal surgery teams.

Duration of fetoscopic spina bifida repair does not affect the central nervous system in fetal lambs

BACKGROUND

Prenatal spina bifida aperta repair improves neurologic outcomes yet comes with a significant risk of prematurity and uterine scar-related complications. To reduce such complications, different fetoscopic techniques, for example, with varying numbers of ports, are being explored. This has an effect on the duration of the procedure, potentially affecting central nervous system development. Both the condition and anesthesia can affect the central nervous system, particularly the hippocampus, a region crucial for prospective and episodic memory. Previous animal studies have shown the potential influence of anesthesia, premature delivery, and maternal surgery during pregnancy on this area.

OBJECTIVE

This study aimed to compare the effects of 2- vs 3-port fetoscopic spina bifida aperta repair in the fetal lamb model using neuron count of the hippocampus as the primary outcome.

STUDY DESIGN

Based on the hippocampal neuron count from previous lamb experiments, we calculated that we required 5 animals per group to achieve a statistical power of ≥ 80%. A spina bifida aperta defect was developed in fetal lambs at 75 days of gestation (term: 145 days). At 100 days, fetuses underwent either a 2-port or 3-port fetoscopic repair. At 143 days, all surviving fetuses were delivered by cesarean delivery, anesthetized, and transcardially perfused with a mixture of formaldehyde and gadolinium. Next, they underwent neonatal brain and spine magnetic resonance imaging after which these organs were harvested for histology. Hippocampus, frontal cortex, caudate nucleus, and cerebellum samples were immunostained to identify neurons, astrocytes, microglia, and markers associated with cell proliferation, myelination, and synapses. The degree of hindbrain herniation and the ventricular diameter were measured on magnetic resonance images and volumes of relevant brain and medulla areas were segmented.

RESULTS

Both treatment groups included 5 fetuses and 9 unoperated littermates served as normal controls. The durations for both skin-to-skin (341±31 vs 287±40 minutes; P=.04) and fetal surgery (183±30 vs 128±22; P=.01) were longer for the 2-port approach than for the 3-port approach. There was no significant difference in neuron density in the hippocampus, frontal cortex, and cerebellum. In the caudate nucleus, the neuron count was higher in the 2-port group (965±156 vs 767±92 neurons/mm2; P=.04). There were neither differences in proliferation, astrogliosis, synaptophysin, or myelin. The tip of the cerebellar vermis was closer to the foramen magnum in animals undergoing the 2-port approach than in animals undergoing the 3-port approach (-0.72±0.67 vs -2.47±0.91 mm; P=.009). There was no significant difference in the ratio of the hippocampus, caudate nucleus, or cerebellar volume to body weight. For the spine, no difference was noted in spine volume-to-body weight ratio for the lower (L1-L2), middle (L3-L4), and higher (L5-L6) levels. Compared with controls, in repaired animals, the cerebellar vermis tip laid closer to the foramen magnum, parietal ventricles were enlarged, and medulla volumes were reduced.

CONCLUSION

In the experimental spina bifida fetal lamb model, a 2-port repair took 40% longer than a 3-port repair. However, there was no indication of any relevant morphologic differences in the fetal brain.

Fetal neurosurgery

Among fetal surgical procedures, neurosurgery stands out due to the number of cases and the possibility of developing new procedures that can be performed in the fetal period. To perform fetal neurosurgical procedures, there is a need for specialized centers that have experts in the diagnosis of fetal pathologies and a highly complex obstetrics service with specialized maternal-fetal teams associated with a pediatric neurosurgery center with expertise in the diverse pathologies of the fetus and the central nervous system that offers multidisciplinary follow-up during postnatal life. Services that do not have these characteristics should refer their patients to these centers to obtain better treatment results. It is essential that the fetal neurosurgical procedure be performed by a pediatric neurosurgeon with extensive experience, as he will be responsible for monitoring these patients in the postnatal period and for several years. The objective of this manuscript is to demonstrate the diagnostic and treatment possibilities, in the fetal period, of some neurosurgical diseases such as hydrocephalus, tumors, occipital encephalocele, and myelomeningocele.

Implementation and Assessment of a Laparotomy-Assisted Three-Port Fetoscopic Spina Bifida Repair Program

Open spina bifida (OSB) is a congenital, non-lethal malformation with multifactorial etiology. Fetal therapy can be offered under certain conditions to parents after accurate prenatal diagnostic and interdisciplinary counseling. Since the advent of prenatal OSB surgery, various modifications of the original surgical techniques have evolved, including laparotomy-assisted fetoscopic repair. After a two-year preparation time, the team at the University of Giessen and Marburg (UKGM) became the first center to provide a three-port, three-layer fetoscopic repair of OSB via a laparotomy-assisted approach in the German-speaking area. We point out that under the guidance of experienced centers and by intensive multidisciplinary preparation and training, a previously described and applied technique could be transferred to a different setting.

Systematic classification and comparison of maternal and obstetrical complications following 2 different methods of fetal surgery for the repair of open neural tube defects

BACKGROUND

In utero repair of open neural tube defects using an open hysterotomy approach (hereafter referred to as "open") has been shown to reduce the need for ventriculoperitoneal shunting and to improve motor outcomes for affected infants. Laparotomy-assisted fetoscopic repair (hereafter referred to as "hybrid") is an alternative approach that may confer similar neurologic benefits while reducing the incidence of hysterotomy-related complications.

OBJECTIVE

This study aimed to analyze procedure-related maternal and fetal complications of in utero repair using the Clavien-Dindo classification, and to compare the outcomes of the hybrid and open approaches.

STUDY DESIGN

This was a retrospective cohort study conducted in a single center between September 2011 and July 2021. All patients who met the Management of Myelomeningocele Study criteria and who underwent either hybrid or open fetal surgery were included. Maternal complications were classified using a unique adaptation of the Clavien-Dindo scoring system, allowing the development of a comprehensive complication index score specific to fetal surgery. Primary fetal outcome was defined as gestational age at delivery and summarized according to the World Health Organization definitions of preterm delivery.

RESULTS

There were 146 fetuses with open neural tube defects who were eligible for, and underwent, in utero repair during the study period. Of these, 102 underwent hybrid fetoscopic repair and 44 underwent open hysterotomy repair. Gestational age at the time of surgery was higher in the hybrid group than in the open group (25.1 vs 24.8 weeks; P=.004). Maternal body mass index was lower in the hybrid than in the open group (25.4 vs 27.1 kg/m2; P=.02). The duration of hybrid fetoscopic surgery was significantly longer in the hybrid than in the open group (250 vs 164 minutes; P<.001). There was a significantly lower Clavien-Dindo Grade III complication rate (4.9% vs 43.2%; P<.001) and a significantly lower overall comprehensive maternal complication index (8.7 vs 22.6; P=.021) in the hybrid group than in the open group. Gestational age at delivery was significantly higher in the hybrid group than in the open group (38.1 vs 35.8 weeks; P<.001), and this finding persisted when gestational age at delivery was analyzed using the World Health Organization definitions of preterm delivery.

CONCLUSION

Use of our adaptation of the standardized Clavien-Dindo classification to assess the maternal complications associated with in utero open neural tube defect repair provides a new method for objectively assessing different fetal surgical approaches. It also provides a much-needed standardized tool to allow objective comparisons between methods, which can be used when counseling patients. The hybrid open neural tube defect repair was associated with lower rates of maternal adverse events , and later gestational age at delivery compared with the open approach.

Implication of chromosomal microarray analysis prior to in-utero repair of fetal open neural tube defect

OBJECTIVE

In-utero repair of open neural tube defects (ONTD) is an accepted treatment option with demonstrated superior outcome for eligible patients. While current guidelines recommend genetic testing by chromosomal microarray analysis (CMA) when a major congenital anomaly is detected prenatally, the requirement for an in-utero repair, based on the Management of Myelomeningocele Study (MOMS) criteria, is a normal karyotype. In this study, we aimed to evaluate if CMA should be recommended as a prerequisite for in-utero ONTD repair.

METHODS

This was a retrospective cohort study of pregnancies complicated by ONTD that underwent laparotomy-assisted fetoscopic repair or open-hysterotomy fetal surgery at a single tertiary center between September 2011 and July 2021. All patients met the MOMS eligibility criteria and had a normal karyotype. In a subset of the pregnancies (n = 77), CMA testing was also conducted. We reviewed the CMA results and divided the cohort into two groups according to whether clinically reportable copy-number variants (CNV) were detected (reportable-CNV group) or not (normal-CMA group). Surgical characteristics, complications, and maternal and early neonatal outcomes were compared between the two groups. The primary outcomes were fetal or neonatal death, hydrocephalus, motor function at 12 months of age and walking status at 30 months of age. Standard parametric and non-parametric statistical tests were employed as appropriate.

RESULTS

During the study period, 146 fetuses with ONTD were eligible for and underwent in-utero repair. CMA results were available for 77 (52.7%) patients. Of those, 65 (84%) had a normal CMA and 12 (16%) had a reportable CNV, two of which were classified as pathogenic. The first case with a pathogenic CNV was diagnosed with a 749-kb central 22q11.21 deletion spanning low-copy-repeat regions B-D of chromosome 22; the second case was diagnosed with a 1.3-Mb interstitial deletion at 1q21.1q21.2. Maternal demographics, clinical characteristics, operative data and postoperative complications were similar between those with normal CMA results and those with reportable CNVs. There were no significant differences in gestational age at delivery or any obstetric and early neonatal outcome between the study groups. Motor function at birth and at 12 months of age, and walking status at 30 months of age, were similar between the two groups.

CONCLUSIONS

Standard diagnostic testing with CMA should be offered when an ONTD is detected prenatally, as this approach has implications for counseling regarding prognosis and recurrence risk. Our results indicate that the presence of a clinically reportable CNV should not a priori affect eligibility for in-utero repair, as overall pregnancy outcome is similar in these cases to that of cases with normal CMA. Nevertheless, significant CMA results will require a case-by-case multidisciplinary discussion to evaluate eligibility. To generalize the conclusion of this single-center series, a larger, multicenter long-term study should be considered. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Open and endoscopic fetal myelomeningocele surgeries display similar in-hospital safety profiles in a large, multi-institutional database

BACKGROUND

Open intrauterine fetal myelomeningocele repair has demonstrated decreased ventriculoperitoneal shunting and improved motor outcomes despite maternal and fetal risks. Few data directly compare the safety of open vs endoscopic approaches.

OBJECTIVE

This study aimed to analyze in-hospital maternal and fetal outcomes of pregnant patients undergoing open vs endoscopic fetal myelomeningocele repair using a large, multi-center database.

STUDY DESIGN

This was a review of the Pediatric Health Information System database from October 1, 2015, to December 31, 2021. All patients who underwent open or endoscopic fetal myelomeningocele repair according to the International Classification of Diseases, Tenth Revision, were identified. Demographics, gestational age, and outcomes were analyzed. Descriptive and univariate statistics were used.

RESULTS

A total of 378 pregnant patients underwent fetal myelomeningocele repair. The approach was endoscopic in 143 cases (37.8%) and open in 235 cases (62.2%). Overall postprocedural outcomes included no maternal in-hospital mortalities or intensive care unit admissions, a median length of stay of 4 days (interquartile range, 4-5), 14 cases (3.7%) of surgical and postoperative complications, 6 cases (1.6%) of intrauterine infections, 12 cases (3.2%) of obstetrical complications (including preterm premature rupture of membranes), 3 cases (0.8%) of intrauterine fetal demise, and 16 cases (4.2%) of preterm delivery. Compared with an open approach, the endoscopic approach occurred at a later gestational age (25 weeks [interquartile range, 24-25] vs 24 weeks [interquartile range, 24-25]; P<.001) and had an increased rate of intrauterine infection (6 [4.2%] cases vs 0 [0%] case; P=.002). There was no difference between approaches in the rates of surgical complications, obstetrical complications, intrauterine fetal demise, or preterm deliveries.

CONCLUSION

Compared with an open approach, endoscopic fetal myelomeningocele repair displays a comparable rate of fetal complications, including intrauterine fetal demise and preterm delivery, and a similar in-hospital maternal safety profile despite an association with increased intrauterine infection.

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.

Fetal surgery is not associated with increased inflammatory placental pathology

OBJECTIVE

Fetal surgery has improved neonatal outcomes; however, it is unknown if the intervention contributes to the developmental of inflammatory pathologies in the placenta. Here, an association between fetal surgery and placental pathology was examined.

METHOD

This case-control study compared pregnancies with fetal surgery (n = 22), pregnancies with an indication for fetal surgery but without an intervention being done (n = 13), and gestational-age and fetus-number matched controls (n = 36). Data on maternal, infant, and placental outcomes were abstracted. Additionally, immunohistochemistry identified expression of lymphoid and myeloid cells in the placenta on a subset of cases. Comparisons were performed using Kruskal-Wallis or Pearson's chi-squared tests.

RESULTS

Maternal characteristics were comparable between groups. Most fetal interventions were for diaphragmatic hernia, spina bifida, or twin-to-twin transfusion syndrome. Fetuses who were operated on before birth were more likely to be born preterm (p = 0.02). There was no increase in the rate of observed placental pathologies or immune cell infiltration in fetal surgery cases compared to controls.

CONCLUSION

The data suggest that fetal surgery is not associated with increased inflammatory or morphologic pathology in the placenta. This observation supports the growing field of fetal surgery.

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.

Minimally Invasive Fetal Surgery and the Next Frontier

Most patients with congenital anomalies do not require prenatal intervention. Furthermore, many congenital anomalies requiring surgical intervention are treated adequately after birth. However, there is a subset of patients with congenital anomalies who will die before birth, shortly after birth, or experience severe postnatal complications without fetal surgery. Fetal surgery is unique in that an operation is performed on the fetus as well as the pregnant woman who does not receive any direct benefit from the surgery but rather lends herself to risks, such as hemorrhage, abruption, and preterm labor. The maternal risks involved with fetal surgery have limited the extent to which fetal interventions may be performed but have, in turn, led to technical innovations that have significantly advanced the field. This review will examine congenital abnormalities that can be treated with minimally invasive fetal surgery and introduce the next frontier of prenatal management of fetal surgical pathology.

Effect of preoperative low-normal cervical length on perinatal outcome after laparotomy-assisted fetoscopic spina bifida repair

OBJECTIVE

To determine if preoperative cervical length in the low-normal range increases the risk of adverse perinatal outcome in patients undergoing fetoscopic spina bifida repair.

METHODS

This was a retrospective cohort study of patients who underwent fetal spina bifida repair between September 2014 and May 2022 at a single center. Cervical length was measured on transvaginal ultrasound during the week before surgery. Eligibility for laparotomy-assisted fetoscopic spina bifida repair was as per the criteria of the Management of Myelomeningocele Study, although maternal body mass index (BMI) up to 40 kg/m² was allowed. Laparotomy-assisted fetoscopic spina bifida repair was performed, with carbon dioxide insufflation via two 12-French ports in the exteriorized uterus. All patients received the same peri- and postoperative tocolysis regimen, including magnesium sulfate, nifedipine and indomethacin. Postoperative follow-up ultrasound scans were performed either weekly (< 32 weeks' gestation) or twice a week (≥ 32 weeks). Perinatal outcome was compared between patients with a preoperative cervical length of 25-30 mm vs those with a cervical length > 30 mm. Logistic regression analyses and generalized linear mixed regression analyses were used to predict delivery at less than 30, 34 and 37 weeks' gestation.

RESULTS

The study included 99 patients with a preoperative cervical length > 30 mm and 12 patients with a cervix 25-30 mm in length. One further case which underwent spina bifida repair was excluded because cervical length was measured > 1 week before surgery. No differences in maternal demographics, gestational age (GA) at surgery, duration of surgery or duration of carbon dioxide uterine insufflation were observed between groups. Cases with low-normal cervical length had an earlier GA at delivery (median (range), 35.2 (25.1-39.7) weeks vs 38.2 (26.0-40.9) weeks; P = 0.01), higher rates of delivery at < 34 weeks (41.7% vs 10.2%; P = 0.01) and < 30 weeks (25.0% vs 1.0%; P < 0.01) and a higher rate of preterm prelabor rupture of membranes (PPROM) (58.3% vs 26.3%; P = 0.04) at an earlier GA (mean ± SD, 29.3 ± 4.0 weeks vs 33.0 ± 2.4 weeks; P = 0.05) compared to those with a normal cervical length. Neonates of cases with low-normal cervical length had a longer stay in the neonatal intensive care unit (20 (7-162) days vs 9 (3-253) days; P = 0.02) and higher rates of respiratory distress syndrome (50.0% vs 14.4%; P < 0.01), sepsis (16.7% vs 1.0%; P = 0.03), necrotizing enterocolitis (16.7% vs 0%; P = 0.01) and retinopathy (33.3% vs 1.0%; P < 0.01). There was an association between preoperative cervical length and risk of delivery at < 30 weeks which was significant only for patients with a maternal BMI < 25 kg/m² (odds ratio, 0.37 (95% CI, 0.07-0.81); P = 0.02).

CONCLUSIONS

Low-normal cervical length (25-30 mm) as measured before in-utero laparotomy-assisted fetoscopic spina bifida repair may increase the risk of adverse perinatal outcomes, including PPROM and preterm birth, leading to higher rates of neonatal complications. These data warrant further research and are of critical relevance for clinical teams considering the eligibility of patients for in-utero spina bifida repair. Based on this evidence, patients with a low-normal cervical length should be aware of their increased risk for adverse perinatal outcome. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Neuroprotection is improved by watertightness of fetal spina bifida repair in the sheep model

OBJECTIVES

A contributing factor to unsuccessful prenatal spina bifida aperta (SBA) repair via an open approach may be incomplete neurosurgical repair causing persistent in-utero leakage of cerebrospinal fluid (CSF) and exposure of the fetal spinal cord to amniotic fluid. We aimed to investigate the neurostructural and neurofunctional efficacy of watertight prenatal SBA repair in a validated SBA fetal lamb model.

METHODS

A well-powered superiority study was conducted in the validated SBA fetal lamb model (n = 7 per group). The outcomes of lambs which underwent watertight or non-watertight multilayer repair through an open approach were compared to those of unrepaired SBA lambs (historical controls) at delivery (term = 145 days). At ∼75 days, fetal lambs underwent standardized induction of lumbar SBA. At ∼100 days, they were assigned to an either watertight or non-watertight layered repair group based on an intraoperative watertightness test using subcutaneous fluorescein injection. At 1-2 days postnatally, as primary outcome, we assessed reversal of hindbrain herniation using magnetic resonance imaging (MRI). Secondary proxies of neuroprotection were: absence of CSF leakage at the repair site; hindlimb motor function based on joint-movement score, locomotor grade and Motor Evoked Potential (MEP); four-score neuroprotection scale, encompassing live birth, complete hindbrain herniation reversal, absence of CSF leakage and joint-movement score ≥ 9/15; and brain and spinal cord histology and immunohistochemistry. As the watertightness test cannot be used clinically due to its invasiveness, we developed a potential surrogate intraoperative three-score skin-repair-quality scale based on visual assessment of the quality of the skin repair (suture inter-run distance ≤ 3 mm, absence of tear and absence of ischemia), with high quality defined by a score ≥ 2/3 and low quality by a score < 2/3, and assessed its relationship with improved outcome.

RESULTS

Compared with unrepaired lambs, lambs with watertight repair achieved a high level of neuroprotection (neuroprotection score of 4/4 in 5/7 vs 0/7 lambs) as evidenced by: a significant 100% (vs 14%) reversal of hindbrain herniation on MRI; low CSF leakage (14% vs 100%); better hindlimb motor function, with higher joint-movement score, locomotor grade and MEP area under the curve and peak-to-peak amplitude; higher neuronal density in the hippocampus and corpus callosum; and higher reactive astrogliosis at the SBA lesion epicenter. Conversely, lambs with non-watertight SBA repair did not achieve the same level of neuroprotection (score of 4/4 in 1/7 lambs) compared with unrepaired lambs, with: a non-significant 86% (vs 14%) reversal of hindbrain herniation; high CSF leakage (43% vs 100%); no improvement in motor function; low brain neuron count in both the hippocampus and corpus callosum; and small spinal astroglial cell area at the epicenter. Both watertight layered repair and high (≥ 2/3) intraoperative skin-repair-quality score were associated with improved outcome, but the watertightness test and skin-repair-quality scale could not be used interchangeably due to result discrepancies.

CONCLUSIONS

Watertight layered fetal SBA repair is neuroprotective since it improves brain and spinal-cord structure and function in the fetal lamb model. This translational research has important clinical implications. A neurosurgical technique that achieves watertightness should be adopted in all fetal centers to improve neuroprotection. Future clinical studies could assess whether a high skin-repair-quality score (≥ 2/3) correlates with neuroprotection. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

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.

Lifesaving Treatments for the Tiniest Patients-A Narrative Description of Old and New Minimally Invasive Approaches in the Arena of Fetal Surgery

Fetal surgery has become a lifesaving reality for hundreds of fetuses each year. The development of a formidable spectrum of safe and effective minimally invasive techniques for fetal interventions since the early 1990s until today has led to an increasing acceptance of novel procedures by both patients and health care providers. From his vast personal experience of more than 20 years as one of the pioneers at the forefront of clinical minimally invasive fetal surgery, the author describes and comments on old and new minimally invasive approaches, highlighting their lifesaving or quality-of-life-improving potential. He provides easy-to-use practical information on how to perform partial amniotic carbon dioxide insufflation (PACI), how to assess lung function in fetuses with pulmonary hypoplasia, how to deal with giant CPAMS, how to insert shunts into fetuses with LUTO and hydrothorax when conventional devices are not available, and how to resuscitate a fetus during fetal cardiac intervention. Furthermore, the author proposes a curriculum for future fetal surgeons, solicits for the centralization of patients, for adequate maternal counseling, for adequate pain management and adequate hygienic conditions during interventions, and last but not least for starting the process of academic recognition of the matured field as an independent specialty. These steps will allow more affected expectant women and their unborn children to gain access to modern minimally invasive fetal surgery and therapy. The opportunity to treat more patients at dedicated centers will also result in more opportunities for the research of rare diseases and conditions, promising even better pre- and postnatal care in the future.

International Society for Prenatal Diagnosis 2022 DEBATE: There should be formal accreditation and ongoing quality assurance/review for units offering fetal therapy that includes public reporting of outcomes

The field of fetal therapy has so far escaped from formal accreditation and quality control. Despite that, current published evidence shows that outcomes of interventions in younger fetal therapy centers are similar to what is achieved in more experienced centers and outcomes of interventions have improved over time. The question however remains what is not being published and what should be the standard of care, given the lack of level 1 evidence from randomized controlled trials for many interventions. Formal collaborative networks such as NAFTnet and others allow for anonymized benchmarking of center outcomes, without publicly shaming (and financially punishing) underperforming centers. Large registries also allow for tracking of rare complications and may result in improved patient outcomes over time. Core outcome sets, which could serve as a basis for outcome reporting, are available for some conditions, but certainly not for all, resulting in communication difficulties between centers. Formal accreditation, quality control, and outcome reporting are hard to implement, expensive, and may result in decreasing access to care by pushing smaller centers out of the market. Despite the existing difficulties, international societies have committed to quality improvement, and fetal therapy programs are strongly recommended to participate in voluntary outcome tracking.

Fetoscopic Myelomeningocele Repair with Complete Release of the Tethered Spinal Cord Using a Three-Port Technique: Twelve-Month Follow-Up-A Case Report

Open spina bifida is one of the most common congenital defects of the central nervous system. Open fetal surgery, which is one of the available therapeutic options, remains the gold standard for prenatal repairs. Fetoscopic closure may lower the number of maternal complications associated with open fetal surgery. Regardless of the approach, the outcome may be compromised by the development of tethered spinal cord (TSC) syndrome. At 24.2 weeks of gestation, a primipara was admitted due to fetal myelomeningocele and was deemed eligible for fetoscopic repair. Fetal surgery was performed at 25.0 weeks of gestation. It was the first complete untethering of the spinal cord and anatomic reconstruction (dura mater, spinal erectors, skin) achieved during a fetoscopic repair of spina bifida. Cesarean section due to placental abruption was performed at 31.1 weeks of gestation. VP shunting, with no need for revision, was performed at 5 weeks postdelivery due to progressing ventriculomegaly. No clinical or radiological signs of secondary tethering were observed. Neurological examination at 11 months postdelivery revealed cranial nerves without any signs of damage, axial hypotonia, decreased muscle tone in the lower extremities, and absent pathological reflexes. Motor development was slightly retarded. Complete untethering of the neural structures should always be performed, regardless of the surgical approach, as it is the only course of action that lowers the risk for developing secondary TSC.

Association between ambulatory skills and diffusion tensor imaging of corpus callosal white matter in infants with spina bifida

OBJECTIVES

To assess brain white matter using diffusion tensor imaging (DTI) at 1 year of age in infants diagnosed with open neural tube defect (ONTD) and explore the association of DTI parameters with ambulatory skills at 30 months of age.

METHODS

Magnetic resonance imaging (MRI) was performed at an average of 12 months of age and included an echo planar axial DTI sequence with diffusion gradients along 20 non-collinear directions. TORTOISE software was used to correct DTI raw data for motion artifacts, and DtiStudio, DiffeoMap and RoiEditor were used for further postprocessing. DTI data were analyzed in terms of fractional anisotropy (FA), trace, radial diffusivity and axial diffusivity. These parameters reflect the integrity and maturation of white-matter motor pathways. At 30 months of age, ambulation status was evaluated by a developmental pediatrician, and infants were classified as ambulatory if they were able to walk independently with or without orthoses or as non-ambulatory if they could not. Linear mixed-effects method was used to examine the association between study outcomes and study group. Possible confounders were sought, and analyses were adjusted for age at MRI scan and ventricular size by including them in the regression model as covariates.

RESULTS

Twenty patients with ONTD were included in this study, including three cases that underwent postnatal repair and 17 cases that underwent prenatal repair. There were five ambulatory and 15 non-ambulatory infants evaluated at a mean age of 31.5 ± 5.7 months. MRI was performed at 50.3 (2-132.4) weeks postpartum. When DTI analysis results were compared between ambulatory and non-ambulatory infants, significant differences were observed in the corpus callosum (CC). Compared with non-ambulatory infants, ambulatory infants had increased FA in the splenium (0.62 (0.48-0.75) vs 0.41 (0.34-0.49); P = 0.01, adjusted P = 0.02), genu (0.64 (0.47-0.80) vs 0.47 (0.35-0.61); P = 0.03, adjusted P = 0.004) and body (0.55 (0.45-0.65) vs 0.40 (0.35-0.46), P = 0.01, adjusted P = 0.01). Reduced trace was observed in the CC of ambulatory children at the level of the splenium (0.0027 (0.0018-0.0037) vs 0.0039 (0.0034-0.0044) mm² /s; P = 0.04, adjusted P = 0.03) and genu (0.0029 (0.0020-0.0038) vs 0.0039 (0.0033-0.0045) mm² /s; P = 0.04, adjusted P = 0.01). In addition, radial diffusivity was reduced in the CC of the ambulatory children at the level of the splenium (0.00057 (0.00025-0.00089) vs 0.0010 (0.00084-0.00120) mm² /s; P = 0.02, adjusted P = 0.02) and the genu (0.00058 (0.00028-0.00088) vs 0.0010 (0.00085-0.00118) mm² /s; P = 0.02, adjusted P = 0.02). There were no differences in axial diffusivity between ambulatory and non-ambulatory children.

CONCLUSION

This study demonstrates a significant association between white matter integrity of connecting fibers of the corpus callosum, as assessed by DTI, and ambulatory skills at 30 months of age in infants with ONTD. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Minimally Invasive Bimanual Fetal Surgery—A Review

Background: The aim of this review is to discuss experimental and clinical techniques and interventions of fetal surgery which have been performed minimally invasively by the means of a three-port approach for the fetoscope and instruments for the left and right hand of the surgeon (bimanual minimally invasive fetal surgery). Methods: a print and electronic literature search was performed; the titles and abstracts were screened and included reports were reviewed in a two-step approach. First, reports other than minimally invasive fetal surgery were excluded, then a full text review and analysis of the reported data was performed. Results: 17 reports were included. The heterogeneity of the included reports was high. Although reports on human fetoscopic surgical procedures can be found, most of them do not pick out bimanual fetal surgery as a central theme but rather address interventions applying a fetoscope with a working channel for a laser fiber, needle or flexible instrument. Most reports were on experimentation in animal models, the human application of minimally invasive fetoscopic bimanual surgery is rare and has at best been explored for the prenatal treatment of spina bifida. Some reported bimanual fetoscopic procedures were performed on the exteriorized uterus via a maternal laparotomy and can therefore not be classified as being truly minimally invasive. Discussion: our results demonstrate that minimally invasive fetoscopic bimanual surgery is rare, even in animal models, excluding many other techniques and procedures that are loosely termed ‘minimally invasive fetal surgery’ which we suggest to better label as ‘interventions’. Thus, more research on percutaneous minimally invasive bimanual fetoscopic surgery is warranted, with the aim to reduce the maternal, uterine and fetal trauma for correction of congenital malformations.

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.

Resuscitation decisions in fetal myelomeningocele repair should center on parents' values: a counter analysis

In our response to, "Parental request for non-resuscitation in fetal myelomeningocele repair: an analysis of the novel ethical tensions in fetal intervention" by Wolfe and co-authors, we argue that parental authority should guide resuscitation decision-making for a fetus at risk for preterm delivery as a complication of fetal myelomeningocele (fMMC) repair. Due to the elevated morbidity and mortality risks of combined myelomeningocele, extreme prematurity, and fetal hypoxia, parents' values regarding the acceptability of possible outcomes should be elicited and their preferences honored. Ethical decision-making in these situations must also consider the broader context of the fetal-maternal dyad. Innovations in fetoscopic approaches to fMMC repair may pose additional complexity to these resuscitation decisions.

Percutaneous/mini-laparotomy fetoscopic repair of open spina bifida: a novel surgical technique

Open spina bifida (OSB) is the most common congenital anomaly of the central nervous system compatible with life. Prenatal repair of open spina bifida via open maternal-fetal surgery has been shown to improve postnatal neurological outcomes, including reducing the need for ventriculoperitoneal shunting and improving lower neuromotor function. Fetoscopic repair of OSB minimizes the maternal risks while providing similar neurosurgical outcomes to the fetus. Two fetoscopic techniques are currently in use: (1) the laparotomy-assisted approach, and (2) the percutaneous approach. The laparotomy-assisted fetoscopic technique appears to be associated with less risk of preterm birth compared to the percutaneous approach. However, the percutaneous approach avoids laparotomy and uterine exteriorization, and is associated with less anesthesia risk and improved maternal post-surgical recovery. The purpose of this paper is to describe our experience with a novel surgical approach, which we call percutaneous/mini-laparotomy fetoscopy (PML), in which access to the uterus for one of the ports is done via a mini-laparotomy, while the other ports are inserted percutaneously. This technique draws on the benefits of both the laparotomy-assisted and the percutaneous techniques, while minimizing their drawbacks. This surgical approach may prove invaluable in the prenatal repair of open spina bifida as well as other complex fetal surgical procedures.

Care Levels for Fetal Therapy Centers

Fetal therapies undertaken to improve fetal outcome or to optimize transition to neonate life often entail some level of maternal, fetal, or neonatal risk. A fetal therapy center needs access to resources to carry out such therapies and to manage maternal, fetal, and neonatal complications that might arise, either related to the therapy per se or as part of the underlying fetal or maternal condition. Accordingly, a fetal therapy center requires a dedicated operational infrastructure and necessary resources to allow for appropriate oversight and monitoring of clinical performance and to facilitate multidisciplinary collaboration between the relevant specialties. Three care levels for fetal therapy centers are proposed to match the anticipated care complexity, with appropriate resources to achieve an optimal outcome at an institutional and regional level. A level I fetal therapy center should be capable of offering fetal interventions that may be associated with obstetric risks of preterm birth or membrane rupture but that would be very unlikely to require maternal medical subspecialty or intensive care, with neonatal risks not exceeding those of moderate prematurity. A level II center should have the incremental capacity to provide maternal intensive care and to manage extreme neonatal prematurity. A level III therapy center should offer the full range of fetal interventions (including open fetal surgery) and be able manage any of the associated maternal complications and comorbidities, as well as have access to neonatal and pediatric surgical intervention including indicated surgery for neonates with congenital anomalies.

Fetal Surgery for Gastroschisis—A Review with Emphasis on Minimally Invasive Procedures

(1) Background: The morbidity of gastroschisis is defined by exposure of unprotected intestines to the amniotic fluid leading to inflammatory damage and consecutive intestinal dysmotility, the viscero-abdominal disproportion which results in an abdomen too small to incorporate the herniated and often swollen intestine, and by associated pathologies, such as in complex gastroschisis. To prevent intestinal damage and to provide for growth of the abdominal cavity, fetal interventions such as amnio exchange, gastroschisis repair or covering have been evaluated in several animal models and human trials. This review aims to evaluate the reported techniques for the fetal treatment of gastroschisis by focusing on minimally invasive procedures. (2) Methods: We conducted a systematic database search, quality assessment and analyzed relevant articles which evaluate or describe surgical techniques for the prenatal surgical management of gastroschisis in animal models or human application. (3) Results: Of 96 identified reports, 42 eligible studies were included. Fetal interventions for gastroschisis in humans are only reported for EXIT procedures and amnio exchange. In animal models, particularly in the fetal sheep model, several techniques of open or minimally invasive repair of gastroschisis or covering the intestine have been described, with fetoscopic covering being the most encouraging. (4) Discussion: Although some promising minimally invasive techniques have been demonstrated in human application and animal models, most of them are still associated with relevant fetal morbidity and mortality and barely appear to be currently applicable in humans. Further research on specific procedures, instruments and materials is needed before any human application.

Manejo anestésico en histerotomía más corrección intrauterina de espina bífida abierta o mielomeningocele

La correcta puesta en marcha de la anestesia pediátrica y obstétrica es determinante para óptimos desenlaces en el manejo quirúrgico de las mujeres que durante su embarazo han presentado diagnóstico de mielomeningocele fetal (MMC). El objeto de realizar la resolución de ésta entidad antes del nacimiento se basa en menor requerimiento de derivaciones ventrículo peritoneal y mejoría en la función motora de los miembros inferiores. Dentro de las variables que representa este reto quirúrgico se encuentra la morbilidad materna, dehiscencia de histerorrafia, ruptura uterina secundaria a histerotomía y los consiguientes partos al actual por cesárea. La presente es una revisión no sistemática de la literatura acerca del manejo anestésico para el binomio madre-producto con MMC y con ello socializar al servicio de anestesiología la mejor estrategia en el manejo perioperatorio de estos pacientes.

Fetoscopic insufflation of heated-humidified carbon dioxide during simulated spina bifida repair is safe under controlled anesthesia in the fetal lamb

OBJECTIVE

To assess the safety of Partial-Amniotic-Insufflation-of-heated-humidified-CO₂ (hPACI) during fetoscopic spina bifida repair (fSB-repair).

METHOD

A simulated fSB-repair through an exteriorized uterus under hPACI was performed in 100-day fetal lambs (term = 145 days) under a laboratory anesthesia protocol (n = 5; group 1) which is known to induce maternal-fetal acidosis and hypercapnia. Since these may not occur clinically, we applied a clinical anesthesia protocol (n = 5; group 2), keeping maternal parameters within physiological conditions, that is, controlled maternal arterial carbon dioxide (CO2) pressure (pCO₂  = 30 mmHg), blood pressure (≥67 mmHg), and temperature (37.1-39.8°C). Our superiority study used fetal pH as the primary outcome.

RESULTS

Compared to group 1, controlled anesthesia normalized fetal pH (7.23 ± 0.02 vs. 7.36 ± 0.02, p < 0.001), pCO₂ (70.0 ± 9.1 vs. 43.0 ± 1.0 mmHg, p = 0.011) and bicarbonate (27.8 ± 1.1 vs. 24.0 ± 0.9 mmol/L, p = 0.071) at baseline. It kept them within clinically acceptable limits (pH ≥ 7.23, pCO₂  ≤ 70 mmHg, bicarbonate ≤ 30 mm/L) for ≥120 min of hPACI as opposed to ≤30 min in group one. Fetal pO₂ and lactate were comparable between groups and generally within normal range. Fetal brain histology demonstrated fewer apoptotic cells and higher neuronal density in the prefrontal cortex in group two. There was no difference in fetal membrane inflammation, which was mild.

CONCLUSION

Fetoscopic insufflation of heated-humidified CO₂ during simulated fSB-repair through an exteriorized uterus can be done safely under controlled anesthesia.

Complex gastroschisis: a new indication for fetal surgery?

Gastroschisis (GS) is a congenital abdominal wall defect, in which the bowel eviscerates from the abdominal cavity. It is a non-lethal isolated anomaly and its pathogenesis is hypothesized to occur as a result of two hits: primary rupture of the 'physiological' umbilical hernia (congenital anomaly) followed by progressive damage of the eviscerated bowel (secondary injury). The second hit is thought to be caused by a combination of mesenteric ischemia from constriction in the abdominal wall defect and prolonged amniotic fluid exposure with resultant inflammatory damage, which eventually leads to bowel dysfunction and complications. GS can be classified as either simple or complex, with the latter being complicated by a combination of intestinal atresia, stenosis, perforation, volvulus and/or necrosis. Complex GS requires multiple neonatal surgeries and is associated with significantly greater postnatal morbidity and mortality than is simple GS. The intrauterine reduction of the eviscerated bowel before irreversible damage occurs and subsequent defect closure may diminish or potentially prevent the bowel damage and other fetal and neonatal complications associated with this condition. Serial prenatal amnioexchange has been studied in cases with GS as a potential intervention but never adopted because of its unproven benefit in terms of survival and bowel and lung function. We believe that recent advances in prenatal diagnosis and fetoscopic surgery justify reconsideration of the antenatal management of complex GS under the rubric of the criteria for fetal surgery established by the International Fetal Medicine and Surgery Society (IFMSS). Herein, we discuss how conditions for fetoscopic repair of complex GS might be favorable according to the IFMSS criteria, including an established natural history, an accurate prenatal diagnosis, absence of fully effective perinatal treatment due to prolonged need for neonatal intensive care, experimental evidence for fetoscopic repair and maternal and fetal safety of fetoscopy in expert fetal centers. Finally, we propose a research agenda that will help overcome barriers to progress and provide a pathway toward clinical implementation. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Experience of 300 cases of prenatal fetoscopic open spina bifida repair: report of the International Fetoscopic Neural Tube Defect Repair Consortium

BACKGROUND

The multicenter randomized controlled trial Management of Myelomeningocele Study demonstrated that prenatal repair of open spina bifida by hysterotomy, compared with postnatal repair, decreases the need for ventriculoperitoneal shunting and increases the chances of independent ambulation. However, the hysterotomy approach is associated with risks that are inherent to the uterine incision. Fetal surgeons from around the world embarked on fetoscopic open spina bifida repair aiming to reduce maternal and fetal/neonatal risks while preserving the neurologic benefits of in utero surgery to the child.

OBJECTIVE

This study aimed to report the main obstetrical, perinatal, and neurosurgical outcomes in the first 12 months of life of children undergoing prenatal fetoscopic repair of open spina bifida included in an international registry and to compare these with the results reported in the Management of Myelomeningocele Study and in a subsequent large cohort of patients who received an open fetal surgery repair.

STUDY DESIGN

All known centers performing fetoscopic spina bifida repair were contacted and invited to participate in a Fetoscopic Myelomeningocele Repair Consortium and enroll their patients in a registry. Patient data entered into this fetoscopic registry were analyzed for this report. Fisher exact test was performed for comparison of categorical variables in the registry with both the Management of Myelomeningocele Study and a post-Management of Myelomeningocele Study cohort. Binary logistic regression analyses were used to assess the registry data for predictors of preterm birth at <30 weeks' gestation, preterm premature rupture of membranes, and need for postnatal cerebrospinal fluid diversion in the fetoscopic registry.

RESULTS

There were 300 patients in the fetoscopic registry, 78 in the Management of Myelomeningocele Study, and 100 in the post-Management of Myelomeningocele Study cohort. The 3 data sets showed similar anatomic levels of the spinal lesion, mean gestational age at delivery, distribution of motor function compared with upper anatomic level of the lesion in the neonates, and perinatal death. In the Management of Myelomeningocele Study (26.16±1.6 weeks) and post-Management of Myelomeningocele Study cohort (23.3 [20.2-25.6] weeks), compared with the fetoscopic registry group (23.6±1.4 weeks), the gestational age at surgery was lower (comparing fetoscopic repair group with the Management of Myelomeningocele Study; P<.01). After open fetal surgery, all patients were delivered by cesarean delivery, whereas in the fetoscopic registry approximately one-third were delivered vaginally (P<.01). At cesarean delivery, areas of dehiscence or thinning in the scar were observed in 34% of cases in the Management of Myelomeningocele Study, in 49% in the post-Management of Myelomeningocele Study cohort, and in 0% in the fetoscopic registry (P<.01 for both comparisons). At 12 months of age, there was no significant difference in the number of patients requiring treatment for hydrocephalus between those in the fetoscopic registry and the Management of Myelomeningocele Study.

CONCLUSION

Prenatal and postnatal outcomes up to 12 months of age after prenatal fetoscopic and open fetal surgery repair of open spina bifida are similar. Fetoscopic repair allows for having a vaginal delivery and eliminates the risk of uterine scar dehiscence, therefore protecting subsequent pregnancies of unnecessary maternal and fetal risks.

The Future of Fetal Surgery

The field of fetal medicine has evolved significantly over the past several decades. Our ability to identify and treat the unborn patient has been shaped by advancements in imaging technology, genetic diagnosis, an improved understanding of fetal physiology, and the development and optimization of in utero surgical techniques. The future of the field will be shaped by medical innovators pushing for the continued refinement of minimally invasive surgical technique, the application of pioneering technologies such as robotic surgery and in utero stem cell and gene therapies, and the development of innovative ex utero fetal support systems.

Open surgery for in utero repair of spina bifida: Microneurosurgery versus standard technique - A systematic review

BACKGROUND/OBJECTIVES

Prenatal myelomeningocele (MMC) repair has been shown to improve neurological outcomes. It has been suggested that decreases in the hysterotomy diameter during surgery can improve perinatal outcomes without altering neurologic outcomes. The objective of this study is to describe and compare the main maternal and fetal outcomes of fetuses undergoing open surgery for MMC repair, through the different modifications (standard-classical, mini-hysterotomy, and microneurosurgery).

DATA SOURCE

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Ovid, SciELO, LILACS, PROSPERO.

RESULTS

From a total of 112 studies, seven case series were selected including 399 fetuses with open fetal surgery, five studies using the classical technique (n = 181), one with mini-hysterotomy (n = 176), and one with the microneurosurgery technique (n = 42). The mini-hysterotomy and microneurosurgery techniques presented a lower risk of preterm delivery (21.4% and 30%, respectively) compared to the classic technique (47.3%), premature rupture of membranes (78%, 62%, and 72.5 %, respectively), oligohydramnios (0% and 72.5%, respectively), dehiscence of hysterotomy, maintaining the same frequency of Chiari reversion (78%, 62%, and 72.5%, respectively), postnatal correction requirement (0%, 4.8%, and 5.8%, respectively), and lower frequency of requirement for a ventriculoperitoneal shunt placement (13.0%, 7.5%, and 29.1%, respectively).

CONCLUSION

The least invasive techniques (minihysterotomy-microneurosurgery) are possible and reproduceable, as they are associated with better maternal and perinatal outcomes.

[The ethics of fetal myelomeningocele surgery]

Fetal myelomeningocele surgery was introduced in France in 2014. Developments in prenatal diagnosis of neural tube defects have accompanied the development of prenatal diagnosis. This fetal surgery represents one of the three possible care paths for pregnant women faced with this prenatal diagnosis. The ethical issues of this fetal surgery are discussed and in particular regarding prenatal counselling and patient autonomy of choice.

Fetal open spinal dysraphism repair through a mini-hysterotomy: Influence of gestational age at surgery on children's ability to walk

OBJECTIVE

To analyze the impact of gestational age (GA) at the time of fetal open spinal dysraphism (OSD) repair through a mini-hysterotomy on the ability of children to walk.

METHODS

Children who underwent in utero repair of OSD and had formal neurological assessment after 2.5 years of age were compared regarding their ability to walk in relation to pre-surgical predictors.

RESULTS

Sixty-nine children fulfilled the inclusion criteria. Among them, 63.7% (44/69) were able to walk with or without orthesis. Fetal OSD correction performed earlier in gestation (from 19.7 to 26.9 weeks) was associated with a higher probability of walking with or without orthesis (p = 0.033). The median GA at delivery was 35.3 weeks. Multivariate binary logistic regression showed that the upper anatomical level of the OSD (<L4 or > L5) (p < 0.004; OR: 10.31 [95% CI: 2.07-51.28]) and GA at the time of fetal surgery (p = 0.026; OR = 0.68 [95% CI: 0.48-0.95]) were independent predictors of the postnatal ability to walk with or without orthesis.

CONCLUSION

Fetuses with OSD who were operated on earlier in pregnancy (range: 19.7-26.9 weeks), were more likely to walk with or without orthesis.

Implementation Process and Evolution of a Laparotomy-Assisted 2-Port Fetoscopic Spina Bifida Closure Program

INTRODUCTION

Prenatal closure of open spina bifida via open fetal surgery improves neurologic outcomes for infants in selected pregnancies. Fetoscopic techniques that are minimally invasive to the uterus aim to provide equivalent fetal benefits while minimizing maternal morbidities, but the optimal technique is undetermined. We describe the development, evolution, and feasibility of the laparotomy-assisted 2-port fetoscopic technique for prenatal closure of fetal spina bifida in a newly established program.

METHODS

We conducted a retrospective cohort study of women consented for laparotomy-assisted fetoscopic closure of isolated fetal spina bifida. Inclusion and exclusion criteria followed the Management of Myelomeningocele Study (MOMS). Team preparation involved observation at the originating center, protocol development, ancillary staff training, and surgical rehearsal using patient-matched models through simulation prior to program implementation. The primary outcome was the ability to complete the repair fetoscopically. Secondary maternal and fetal outcomes to assess performance of the technique were collected prospectively.

RESULTS

Of 57 women screened, 19 (33%) consented for laparotomy-assisted 2-port fetoscopy between February 2017 and December 2019. Fetoscopic closure was completed in 84% (16/19) cases. Over time, the technique was modified from a single- to a multilayer closure. In utero hindbrain herniation improved in 86% (12/14) of undelivered patients at 6 weeks postoperatively. Spontaneous rupture of membranes occurred in 31% (5/16) of fetoscopic cases. For completed cases, median gestational age at birth was 37 (range 27-39.6) weeks and 50% (8/16) of women delivered at term. Vaginal birth was achieved in 56% (9/16) of patients. One newborn had a cerebrospinal fluid leak that required postnatal surgical repair.

CONCLUSION

Implementation of a laparotomy-assisted 2-port fetoscopic spina bifida closure program through rigorous preparation and multispecialty team training may accelerate the learning curve and demonstrates favorable obstetric and perinatal outcomes.

Two-port, exteriorized uterus, fetoscopic meningomyelocele closure has fewer adverse neonatal outcomes than open hysterotomy closure

BACKGROUND

In utero closure of meningomyelocele using an open hysterotomy approach is associated with preterm delivery and adverse neonatal outcomes.

OBJECTIVE

This study compared the neonatal outcomes in in utero meningomyelocele closure using a 2-port, exteriorized uterus, fetoscopic approach vs the conventional open hysterotomy approach.

STUDY DESIGN

This retrospective cohort study included all consecutive patients who underwent in utero meningomyelocele closure using open hysterotomy (n=44) or a 2-port, exteriorized uterus, fetoscopic approach (n=46) at a single institution between 2012 and 2020. The 2-port, exteriorized uterus, fetoscopic closure was composed of the following 3 layers: a bovine collagen patch, a myofascial layer, and a skin. The frequency of respiratory distress syndrome and a composite of other adverse neonatal outcomes, including retinopathy of prematurity, periventricular leukomalacia, and perinatal death, were compared between the study groups. Regression analyses were performed to determine any association between the fetoscopic closure and adverse neonatal outcomes, adjusted for several confounders, including gestational age of <37 weeks at delivery.

RESULTS

The fetoscopic closure was associated with a lower rate of respiratory distress syndrome than the open hysterotomy closure (11.5% [5 of 45] vs 29.5% [13 of 44]; P=.037). The proportion of neonates with a composite of other adverse neonatal outcomes in the fetoscopic group was half of that observed patients in the open hysterotomy group; however, this difference did not reach statistical significance (4.3% [2 of 46] vs 9.1% [4 of 44]; P=.429). Here, regression analysis has demonstrated that fetoscopic meningomyelocele closure was associated with a lower risk of respiratory distress syndrome (adjusted odds ratio, 0.23; 95% confidence interval, 0.06-0.84; P=.026) than open hysterotomy closure.

CONCLUSION

In utero meningomyelocele closure using a 2-port, exteriorized uterus, fetoscopic approach was associated with a lower risk of respiratory distress syndrome than the conventional open hysterotomy meningomyelocele closure.