Fetoscopic two-layer closure of open neural tube defects

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.

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.

Surgical treatment outcome of children with neural-tube defect: A prospective cohort study in a high volume center in Addis Ababa, Ethiopia

Introduction

Prevalence of neural tube defects (NTD) is high thus many children are born with a neural tube defect in Addis Ababa, and surgical closure is a commonly performed procedure at the pediatric neurosurgical specialty center.

Research question

The primary aim is to study the outcomes in children undergoing surgical closure of NTDs and to identify risk factors for readmission, complications and mortality.

Material and methods

Single-center prospective study of all surgically treated NTDs from April 2019 to May 2020.

Results

A total of 228 children, mean age 11 days (median 4) underwent surgery during the study period. There were no in-hospital deaths. Perioperatively 11 (4.8%) children developed wound complications, none of them needed surgery and there was no perioperative mortality. The one-year follow-up rate was 62.7% (143/228) and neurological status remained stable since discharge in all. The readmission and reoperation rates were 38 % and 8 % and risk factors for readmission were hydrocephalus (80%) and open defects (88%). Hydrocephalus (P = 0.05) and younger age (P = 0.02) were identified as risk factors for mortality. The wound-related complication rate was 55% at and was associated with large defects (P = 0.04) and delayed closure due to late hospital presentation (P = 0.01).

Discussion and conclusion

The study reveals good perioperative surgical outcome and further need for systematic improvement in treatment and follow-up of NTD patients especially with hydrocephalus. We identified risk factors for wound-related complications, readmission and mortality.

Presurgery motor level assessment for prediction of motor level at birth in fetuses undergoing prenatal repair of open spina bifida: time to abandon anatomical level in counseling

OBJECTIVES

First, to investigate the correlation between prenatal presurgery anatomical and motor levels of the lesion with motor level at birth in cases undergoing prenatal repair of open spina bifida and, second, to identify factors leading to a loss of two or more motor levels between the presurgery and postnatal assessments.

METHODS

This was an observational study of singleton pregnancies undergoing prenatal repair of open spina bifida, conducted between March 2011 and May 2022. All fetuses underwent an ultrasound assessment at 20-24 weeks of gestation to determine the motor and anatomical levels of the lesion before surgery. The anatomical level of the lesion was defined as the highest open posterior vertebral arch. The motor level was determined by systematic observation of the lower limb movements and was defined as the most distal active muscle present. Prenatal repair was performed at 23-26 weeks. At birth, motor level was assessed by a rehabilitation specialist by physical examination. Cases of intrauterine death or termination of pregnancy and those delivered at other sites were excluded from the neonatal assessment. The agreement between presurgery motor level and motor level at birth, and between presurgery anatomical level and motor level at birth, was assessed using the weighted kappa index (wκ). Logistic regression analysis was used to assess factors leading to a loss of two or more motor levels between the presurgery and postnatal assessments.

RESULTS

Presurgery motor and anatomical levels were assessed in 61 fetuses at a median gestational age of 22.7 (interquartile range (IQR), 21.6-24.4) weeks. Prenatal repair was performed at a median gestational age of 24.6 (IQR, 23.7-25.7) weeks. Motor level at birth was assessed in 52 neonates after exclusion of nine fetuses due to loss to follow-up or fetal loss. There was moderate agreement between presurgery motor level and motor level at birth (wκ = 0.42; 95% CI, 0.21-0.63), with a median difference of 0 (IQR, -2 to 9) levels. Factors leading to a loss of two or more motor levels between the presurgery ultrasound assessment and postnatal examination were higher presurgery anatomical level (odds ratio (OR), 0.59 (95% CI, 0.35-0.98); P = 0.04) and larger difference between the anatomical and motor levels before surgery (OR, 1.85 (95% CI, 1.12-3.06); P = 0.017). None of the other ultrasound, surgery-related or neonatal variables assessed was associated significantly with a loss of two or more motor levels. There was slight agreement between the presurgery anatomical level of the lesion and motor level at birth (wκ = 0.07; 95% CI, -0.02 to 0.15).

CONCLUSIONS

There is moderate agreement between fetal motor level of the lesion before prenatal repair of open spina bifida and motor level at birth, as opposed to only slight agreement between presurgery anatomical level and motor level at birth. A loss of two or more motor levels between the presurgery and postnatal assessments is associated with a higher presurgery anatomical level and with a larger difference between the presurgery anatomical and motor levels. Consequently, motor level, rather than the anatomical level, should be used for prenatal counseling. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

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.

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.

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 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.

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.

Fetal heart rate monitoring during fetoscopic repair of open spinal neural tube defects: a single-centre observational cohort study

BACKGROUND

During fetal surgery, the haemodynamic stability of the fetus depends on the haemodynamic stability of the mother. The primary objective of this study was to assess changes in fetal heart rate (FHR) throughout the different stages of surgery. The secondary objective was to assess potential changes in maternal physiological parameters and their association with FHR.

METHODS

This was a single-center observational cohort study conducted between 2015 and 2019 in 26 women undergoing intra-uterine fetoscopic repair of open spina bifida. The primary outcome was FHR. Maternal physiologic parameters were measured at the beginning, during and after surgery. The linear mixed-effects model fitted by maximum likelihood was used to assess changes in each variable at specific times throughout the surgery, and the repeated measures correlation coefficient was used to study the association between FHR and maternal physiological parameters.

RESULTS

One (3.8%) case of fetal bradycardia (FHR <110 beats per minute) required the administration of intramuscular atropine. No other significant FHR changes were observed during surgery. Maternal oesophageal temperature (P <0.001), lactate levels (P=0.002), and mean arterial pressure (P=0.016) changed significantly during surgery, although none of these changes was clinically relevant. The FHR showed a significant association with maternal carbon dioxide tension (r=0.285, 95% CI 0.001 to 0.526) and maternal heart rate (r=0.302, 95% CI 0.025 to 0.535).

CONCLUSION

The FHR remained stable during intra-uterine fetoscopic repair of open spina bifida. Maternal carbon dioxide tension and heart rate may have a mild influence on FHR.

Validation of a high-fidelity training model for fetoscopic spina bifida surgery

Open fetal surgery for spina bifida (SB) is safe and effective yet invasive. The growing interest in fetoscopic SB repair (fSB-repair) prompts the need for appropriate training. We aimed to develop and validate a high-fidelity training model for fSB-repair. fSB-repair was simulated in the abdominal cavity and on the stomach of adult rabbits. Laparoscopic fetal surgeons served either as novices (n = 2) or experts (n = 3) based on their experience. Technical performance was evaluated using competency Cumulative Sum (CUSUM) analysis and the group splitting method. Main outcome measure for CUSUM competency was a composite binary outcome for surgical success, i.e. watertight repair, operation time ≤ 180 min and Objective-Structured-Assessment-of-Technical-Skills (OSATS) score ≥ 18/25. Construct validity was first confirmed since competency levels of novices and experts during their six first cases using both methods were significantly different. Criterion validity was also established as 33 consecutive procedures were needed for novices to reach competency using learning curve CUSUM, which is a number comparable to that of clinical fSB-repair. Finally, we surveyed expert fetal surgeons worldwide to assess face and content validity. Respondents (26/49; 53%) confirmed it with ≥ 71% of scores for overall realism ≥ 4/7 and usefulness ≥ 3/5. We propose to use our high-fidelity model to determine and shorten the learning curve of laparoscopic fetal surgeons and retain operative skills.

Placental gas exchange during amniotic carbon dioxide insufflation in sheep

OBJECTIVE

Insufflation of the amniotic cavity with carbon dioxide (CO₂ ) is used clinically to improve visibility during complex fetoscopic surgery. Insufflation with heated, humidified CO₂ has recently been shown to reduce fetal hypercapnia and acidosis in sheep, compared with use of cold and dry CO₂ , but the underlying mechanisms are unclear. The aim of this study was to investigate whether differences in placental CO₂ and oxygen (O₂ ) exchange during insufflation with heated and humidified vs cold and dry CO₂ could explain these findings.

METHODS

Thirteen fetal lambs at 105 days of gestation (term, 146 days) were exteriorized partially, via a midline laparotomy and hysterotomy, and instrumented with an umbilical artery catheter, an umbilical vein catheter and a common umbilical vein flow probe. Arterial and venous catheters and flow probes were also inserted into the maternal uterine circulation. Six ewes were insufflated with cold, dry CO₂ (22°C; 0-5% humidity) and seven with heated, humidified CO₂ (40°C; 95-100% humidity) at 15 mmHg for 180 min. Blood-flow recordings and paired arterial and venous blood gases were sampled from uterine and umbilical vessels. Rates of placental CO₂ and O₂ exchange were calculated.

RESULTS

After 180 min of insufflation, fetal survival was 33% (2/6) using cold, dry CO₂ and 71% (5/7) using heated, humidified CO₂ . By 120 min, fetuses insufflated with heated, humidified CO₂ had lower arterial CO₂ levels and higher arterial pH compared to those insufflated with cold, dry gas. Insufflation decreased significantly placental gas exchange in both groups, as measured by rates of both (i) fetal CO₂ clearance and O₂ uptake and (ii) maternal O₂ delivery and CO₂ uptake from the fetal compartment.

CONCLUSIONS

Lower arterial CO₂ and higher pH levels in fetuses insufflated with heated and humidified, compared to cold and dry, CO₂ could not be explained by differences in placental gas exchange. Instead, heated and humidified insufflation appeared to reduce fetal CO₂ absorption from the uterus, supporting its use in preference to cold, dry CO₂ . © 2019 International Society of Ultrasound in Obstetrics and Gynecology.

Chorioamniotic membrane separation following fetal myelomeningocele repair: incidence, risk factors and impact on perinatal outcome

OBJECTIVES

Prenatal myelomeningocele (MMC) repair has been shown to provide significant benefits to the infant, decreasing the postnatal need for ventriculoperitoneal shunt and improving motor outcome. Chorioamniotic membrane separation (CAS) is a potential complication following prenatal MMC repair and may increase the risk of preterm prelabor rupture of membranes (PPROM) and preterm birth. The objectives of this study were: (1) to evaluate the incidence of CAS after prenatal MMC repair; (2) to determine risk factors associated with its occurrence; and (3) to assess its association with adverse perinatal outcomes.

METHODS

This was a retrospective cohort study of patients who underwent fetal MMC repair between November 2011 and December 2018. Surgery was performed using either a fetoscopic (laparotomy or exteriorized uterus) approach or an open-hysterotomy approach. Eligibility criteria were those reported in the Management of Myelomeningocele Study. If CAS was detected on ultrasound (US), its severity was graded as 'mild' if amnion detachment involved < 25% of the uterine cavity, 'moderate' if it involved 25-50% and 'severe' if it involved > 50%. Evolution of CAS was classified as stable, increasing or decreasing based on the difference in severity grading between the time at first diagnosis and the last US scan before delivery. Logistic regression analysis was performed to identify pre- or perisurgical factors associated with the development of CAS and to determine the risk of adverse perinatal outcome associated with CAS.

RESULTS

In total, 91 cases were included. Fetoscopic or open-hysterotomy repair of MMC was performed in 52/91 (57.1%) and 39/91 (42.9%) cases, at a median gestational age (GA) of 25.0 weeks (range, 22.9-26.0 weeks) and 25.0 weeks (range, 21.3-25.9 weeks), respectively. CAS was diagnosed in 31/91 (34.1%) patients, at a median GA of 28.1 weeks (range, 24.4-37.6 weeks). Anterior placenta was identified as a risk factor for the postoperative development of CAS (odds ratio (OR), 3.72 (95% CI, 1.46-9.5); P < 0.01). This risk was dependent on the repair technique. An anterior placenta significantly increased the risk of CAS after fetoscopic repair (OR, 3.94 (95% CI, 1.14-13.6); P = 0.03) but not after open repair (OR, 2.8 (95% CI, 0.6-12.5); P = 0.16). There was no significant difference in the rate of CAS after fetoscopic repair (21/52 (40.4%)) vs open-hysterotomy repair (10/39 (25.6%)) (P = 0.14), nor were there any differences in GA at diagnosis of CAS, interval between surgery and diagnosis, distribution of CAS severity or progression of CAS between the two groups. CAS increased the risk of PPROM (50% in those with vs 12% in those without CAS) (OR, 7.6 (95% CI, 2.5-21.9); P < 0.01) and preterm delivery (70% vs 38%) (OR, 3.2 (95% CI, 1.3-8.1); P < 0.01). Fetoscopically repaired cases with CAS had a higher rate of PPROM (12/20 (60.0%) vs 2/31 (6.5%); P < 0.01) and preterm delivery (13/20 (65.0%) vs 5/31 (16.1%); P < 0.01) than those that did not develop CAS, while the differences were not significant in cases with open-hysterotomy repair. Early detection of CAS (before 30 weeks' gestation) was a risk factor for preterm delivery (90% before 30 weeks vs 36% at or after 30 weeks) (OR, 15.7 (95% CI, 2.3-106.3); P < 0.01). There was no association between PPROM or preterm delivery and the severity or progression of CAS.

CONCLUSIONS

The presence of an anterior placenta was the only factor that increased the risk for CAS after fetoscopic MMC repair. Detection of CAS after fetoscopic MMC repair significantly increases the risk for PPROM and preterm delivery. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Comparison of two fetoscopic open neural tube defect repair techniques: single- vs three-layer closure

OBJECTIVES

We reported previously on an exteriorized-uterus fetoscopic repair for open neural tube defect (ONTD) using a single-layer closure (SLC) technique. However, because SLC was associated with a high rate of cerebrospinal fluid (CSF) leakage at birth, we developed a three-layer closure (3LC) technique comprising a bovine collagen patch, a myofascial layer and a skin layer. The aims of this study were to compare SLC and 3LC in terms of intraoperative, postoperative and obstetric outcomes, as well as short-term neonatal neurologic and non-neurologic outcomes.

METHODS

This was a retrospective analysis of prospectively collected data, from 32 consecutive SLC controls and 18 consecutive 3LC cases, that underwent exteriorized-uterus two-port fetoscopic repair of ONTD at our center, between April 2014 and December 2018. All patients satisfied the Management of Myelomeningocele Study (MOMS) criteria. Obstetric, maternal, fetal and early neonatal outcomes were compared between the SLC and 3LC groups.

RESULTS

Maternal demographics and mean gestational age (GA) at fetal surgery (25.0 ± 0.7 vs 25.0 ± 0.5 weeks' gestation; P = 0.96), and at delivery (36.5 ± 3.5 vs 37.6 ± 3.0 weeks; P = 0.14), were similar between the SLC and 3LC groups, respectively. The rate of preterm prelabor rupture of membranes (PPROM) < 37 weeks (28% vs 29%; P = 0.9), mean GA at PPROM (32.3 ± 3.4 vs 32.7 ± 1.9 weeks; P = 0.83) and rate of vaginal delivery (50% vs 47%; P = 0.84) were similar for the SLC vs 3LC groups, respectively. In pregnancies that had SLC compared with those that had 3LC, there was a significantly higher incidence of CSF leakage at birth (8/32 (25%) vs 0/17 (0%); P = 0.02) and a significantly lower rate of reversal of hindbrain herniation at 6 weeks postoperatively (18/30 (60%) vs 14/15 (93%); P = 0.02). The rate of infants that met the MOMS criteria for shunt placement or died before 12 months of age (23/31 (74%) vs 7/12 (58%); P = 0.31) and those that required treatment for hydrocephalus by 12 months (15/32 (47%) vs 4/12 (33%); P = 0.42) were similar between the SLC and 3LC groups, respectively.

CONCLUSIONS

Compared to SLC, 3LC preserves the fetal and obstetric benefits of fetoscopic repair and shows improved rates of CSF leakage and reversal of hindbrain herniation at 6 weeks postoperatively. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Maternal and obstetric complications in fetal surgery for prenatal myelomeningocele repair: a systematic review

OBJECTIVE

Comparing prenatal and postnatal surgical repair techniques for myelomeningocele (MMC), in utero fetal surgery has increasingly gained acceptance and is considered by many specialized centers the first choice of treatment. Despite its benefits, as demonstrated in the Management of Myelomeningocele Study (MOMS), including reduced need for CSF shunting in neonates and improved motor outcomes at 30 months, there is still an ongoing debate on fetal and maternal risks associated with the procedure. Prenatal open hysterotomy, fetoscopic MMC repair techniques, and subsequent delivery by cesarean section are associated with maternal complications. The aim of this systematic review is to assess the available literature on maternal and obstetric complication rates and perinatal maternal outcomes related to fetal MMC repair.

METHODS

The authors identified references for inclusion in this review by searching PubMed and MEDLINE, with restrictions to English language, case series, case reports, clinical trials, controlled clinical trials, meta-analyses, randomized controlled trials, reviews, and systematic reviews. The rate of maternal and obstetric complications was analyzed based on studies focusing on this issue and presenting clear results on the matter.

RESULTS

Of 1264 articles screened, 36 were included in this systemic review, whereof 11 were eligible for data analysis and comparison. The average overall rate of maternal and obstetric complications corresponds to 78.6%. The majority of the described events are obstetric complications, varying from chorioamniotic membrane separation in 65.6% of cases, oligohydramnios in 13.0% of cases, placental abruption in 5.0% of cases, spontaneous or preterm premature membrane rupture in 42.0% of cases, and early preterm delivery in 11.3% of cases due to uterine dehiscence, occurring in 0.9% of cases. The most common medical complications are development of pulmonary edema occurring in 2.8%, gestational diabetes in 3.7%, gestational hypertension/preeclampsia in 3.7%, and need for blood transfusions in 3.2% of cases. Limitations of the review arise from the lack of data in the current literature, with maternal and obstetric complications being underreported.

CONCLUSIONS

Although the efforts of further advancement of intrauterine prenatal MMC repair aim to increase neonatal outcomes, maternal health hazard will continue to be an issue of crucial importance and further studies are required.

Fetal open spinal dysraphism repair through a mini-hysterotomy: Influence of gestational age at surgery on the perinatal outcomes and postnatal shunt rates

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 perinatal outcomes and the infants' ventriculoperitoneal shunt rates.

METHODS

Retrospective study of cases of fetal OSD correction performed from 2014 and 2019.

RESULTS

One hundred and ninety women underwent fetal surgery for OSD through a mini-hysterotomy, and 176 (176/190:92.6%) have since delivered. Fetal OSD correction performed earlier in the gestational period, ranging from 19.7 to 26.9 weeks, was associated with lower rates of postnatal ventriculoperitoneal shunting (P: .049). Earlier fetal surgeries were associated with shorter surgical times (P: .01), smaller hysterotomy lengths (P < .001), higher frequencies of hindbrain herniation reversal (P: .003), and longer latencies from surgery to delivery (P < .001). Median GA at delivery was 35.3 weeks. Multivariate binary logistic regression showed that both fetal lateral ventricle-to-hemisphere ratio (%; P < .001; OR: 1.14 [95% CI: 1.09-1.21]) and GA at the time of fetal surgery (P: .016; OR: 1.37 [95% CI: 1.07-1.77]) were independent predictors of postnatal ventriculoperitoneal shunting.

CONCLUSION

Fetuses with OSD who were operated on earlier in the gestational interval, which ranged from 19.7 to 26.9 weeks, were less prone to receiving postnatal ventriculoperitoneal shunts.

Comparison of brain microstructure after prenatal spina bifida repair by either laparotomy-assisted fetoscopic or open approach

OBJECTIVE

To compare prenatal and postnatal brain microstructure between infants that underwent fetoscopic myelomeningocele (MMC) repair and those that had open-hysterotomy repair.

METHODS

This was a longitudinal retrospective cohort study of 57 fetuses that met the Management of Myelomeningocele Study (MOMS) trial criteria and underwent prenatal MMC repair, by a fetoscopic (n = 27) or open-hysterotomy (n = 30) approach, at 21.4-25.9 weeks' gestation. Fetoscopic repair was performed under CO₂ insufflation, according to our protocol. Diffusion-weighted magnetic resonance imaging (MRI) was performed before surgery in 30 cases (14 fetoscopic and 16 open), at 6 weeks postsurgery in 48 cases (24 fetoscopic and 24 open) and within the first year after birth in 23 infants (five fetoscopic and 18 open). Apparent diffusion coefficient (ADC) values from the basal ganglia, frontal, occipital and parietal lobes, mesencephalon and genu as well as splenium of the corpus callosum were calculated. ADC values at each of the three timepoints (presurgery, 6 weeks postsurgery and postnatally) and the percentage change in the ADC values between the timepoints were compared between the fetoscopic-repair and open-repair groups. ADC values at 6 weeks after surgery in the two prenatally repaired groups were compared with those in a control group of eight healthy fetuses that underwent MRI at a similar gestational age (GA). Comparison of ADC values was performed using the Student's t-test for independent samples (or Mann-Whitney U-test if non-normally distributed) and multivariate general linear model analysis, adjusting for GA or age at MRI and mean ventricular width.

RESULTS

There were no differences in GA at surgery or GA/postnatal age at MRI between the groups. No significant differences were observed in ADC values in any of the brain areas assessed between the open-repair and fetoscopic-repair groups at 6 weeks after surgery and in the first year after birth. No differences were detected in the ADC values of the studied areas between the control and prenatally repaired groups, except for significantly increased ADC values in the genu of the corpus callosum in the open-hysterotomy and fetoscopic-repair groups. Additionally, there were no differences between the two prenatally repaired groups in the percentage change in ADC values at any of the time intervals analyzed.

CONCLUSIONS

Fetoscopic MMC repair has no detectable effect on brain microstructure when compared to babies repaired using an open-hysterotomy technique. CO₂ insufflation of the uterine cavity during fetoscopy does not seem to have any isolated deleterious effects on fetal brain microstructure. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Spinal Dysraphia, Chiari 2 Malformation, Unified Theory, and Advances in Fetoscopic Repair

Fetal spina bifida, the most common nonlethal birth defect of the central nervous system, results in substantial neurologic morbidity. The unified theory describes the complex relationship between local spinal lesions and development of Chiari 2 malformation, contributing to hydrocephalus. Prenatal ultrasonography reliably allows diagnosis, but fetal MR imaging is an important complement to identify additional brain abnormalities. Fetal surgery improves neurologic and motor outcomes, but various approaches, either open hysterotomy or minimally invasive to the uterus, carry substantial obstetric risks. Optimization of the fetoscopic approach aims to minimize maternal and obstetric risks, but data regarding longer-term outcomes are awaited.

Fetoscopic spina bifida repair

INTRODUCTION

Spina bifida is the most common non-lethal congenital birth defect of the central nervous system that causes chronic disability due to the combined effects of local nerve damage and the sequelae of non-communicating hydrocephalus. This abnormality can be identified early in gestation and the damage can be progressive over the course of pregnancy. Advances in fetal treatment have made minimally invasive prenatal surgery a realistic consideration for spina bifida in order to improve the outcome for children affected this condition.

EVIDENCE ACQUISITION

Prenatal surgery for spina bifida via open fetal surgery with hysterotomy decreases the rate of ventriculoperitoneal shunt placement and improves motor function compared to standard postnatal surgery. Maternal risks of open fetal surgery are primarily related to complications of the hysterotomy including thinning or rupture that begins in the index pregnancy but persists for every future pregnancy. Minimizing maternal risks is the largest impetus to explore and optimize a minimally invasive fetoscopic alternative. Techniques vary from using a complete percutaneous approach to open fetoscopy, which requires laparotomy but is minimally invasive to the uterus. This allows vaginal delivery at term and no scar complications are reported thus far. Fetal short-term neurosurgical outcomes compare favorably with improvement in hindbrain herniation >70% and decreased need for treatment for hydrocephalus between 40-45% after prenatal surgery performed either fetoscopically or through open fetal surgery.

EVIDENCE SYNTHESIS

Maternal obstetric outcomes are superior for fetoscopic spina bifida repair compared to open fetal surgery and avoids the ongoing risk in future pregnancy. Neonatal and infant benefits appear equivalent. The open fetoscopic approach minimizes the risk of ruptured membranes and subsequent preterm delivery as opposed to a completely percutaneous procedure. International collaboration is ongoing to share experience and assess long term treatment effects.

CONCLUSIONS

Continued refinement of a minimally invasive strategy for prenatal treatment of spina bifida is necessary to maximize benefits to the child and further minimize maternal risks and preterm birth.