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.

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.

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.

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.

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.

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.

Fetal heart rate mirrors maternal temperature during posterior fossa craniotomy: a case report.

While it is well known that maternal temperature affects fetal heart rate, the exact relationship is not well described. The circumstances accompanying most cases of maternal hypothermia and rewarming (e.g. a drowning event) have precluded a precise quantitative description of this relationship. We describe hypothermia and controlled rewarming during resection of a maternal brain stem tumor in the early third trimester. Continuous electronic fetal heart rate and core temperature monitoring demonstrated a near linear relationship during the development of hypothermia and rewarming. Recognition of the close relationship between maternal temperature and fetal heart rate can help safeguard maternal and fetal health, and prevent unnecessary delivery during non-obstetric surgery in pregnancy.

Prenatal predictors of motor function in children with open spina bifida: a retrospective cohort study.

OBJECTIVE: To identify predictors for intact motor function (MF) at birth and at 12 months of life in babies with prenatally versus postnatally repaired open spina bifida (OSB). DESIGN: Retrospective cohort study. SETTING: Texas Children's Hospital, 2011-2018. POPULATION: Patients who underwent either prenatal or postnatal OSB repair. METHODS: Prenatal MF of the lower extremities was evaluated by ultrasound following a metameric distribution at the time of diagnosis (US1), 6 weeks postoperatively (or 6 weeks after initial evaluation in postnatally repaired cases) (US2) and at the last ultrasound before delivery (US3). At birth and at 12 months, MF was assessed clinically. Intact MF (S1) was defined as the observation of plantar flexion of the ankle. Results from logistic regression analysis are expressed as odds ratios (95% confidence intervals, P values). RESULTS: A total of 127 patients were included: 93 with prenatal repair (51 fetoscopic; 42 open hysterotomy repair) and 34 with postnatal repair. In the prenatal repair group, predictors for intact MF at birth and at 12 months included: absence of clubfeet (OR 11.3, 95% CI 3.2-39.1, P < 0.01; OR 10.8 95% CI 2.4-47.6, P < 0.01); intact MF at US1 (OR 19.7, 95% CI 5.0-76.9, P < 0.01; OR 8.7, 95% CI 2.0-38.7, P < 0.01); intact MF at US2 (OR 22, 95% CI 6.5-74.2, P < 0.01; OR 13.5, 95% 3.0-61.4, P < 0.01); intact MF at US3 (OR 13.7, 95% CI 3.4-55.9, P < 0.01; OR 12.6, 95% CI 2.5-64.3, P < 0.01); and having a flat lesion (OR 11.2, 95% CI 2.4-51.1, P < 0.01; OR 4.1, 95% CI 1.1-16.5, P = 0.04). In the postnatal repair group, the only predictor of intact MF at 12 months was having intact MF at birth (OR 15.2, 95% CI 2.0-113.3, P = 0.03). CONCLUSIONS: The detection of intact MF in utero from mid-gestation to delivery predicts intact MF at birth and at 12 months in babies who undergo prenatal OSB repair. TWEETABLE ABSTRACT: Detection of intact motor function in utero predicts intact motor function at birth and at 1 year in fetuses who undergo prenatal OSB repair.

Longitudinal evaluation of motor function in patients who underwent prenatal or postnatal neural tube defect repair.

OBJECTIVE: To compare the evolution of motor function from mid-gestation to 12 months of age between prenatally and postnatally repaired cases of open neural tube defect (ONTD). METHODS: This was a retrospective cohort study of all fetuses that underwent prenatal (fetoscopic or open hysterotomy) or postnatal ONTD repair at a single institution between November 2011 and December 2018. The anatomical level of the lesion was defined as the upper bony spinal defect at initial magnetic resonance imaging assessment. Prenatal motor function of the lower extremities was evaluated by ultrasound according to the metameric level of the neurological lesion, based on the methodology of Carreras et al. Fetal motor function was assessed at referral, at 6 weeks after surgery in prenatally repaired cases or 6 weeks after referral in postnatally repaired cases (6-week follow-up) and at the last scan before delivery. In addition, motor function was assessed by a detailed neurological examination at birth and 12 months of age. First sacral (S1) neurological level of the lesion was considered as intact motor function. For statistical comparisons, we attributed numerical scores to each neurological level and motor function was expressed as median (range) neurological level. Motor function (as numerical score) and the proportion of cases with intact motor function and with motor function two or more levels better than expected based on the anatomical level of the lesion were compared between the prenatal- and postnatal-repair groups. Fetal motor function was compared to the anatomical level of the lesion at referral and a better motor function was defined when it was two or more levels better than the anatomical level of the lesion. To assess the evolution of motor function, we compared motor function at referral with that at each follow-up assessment using paired t-tests. RESULTS: We included 127 patients with ONTD, of whom 93 underwent prenatal (51 fetoscopic and 42 open hysterotomy) and 34 postnatal repair. At the time of referral, cases in the prenatal- and postnatal-repair groups presented with a similar anatomical level of lesion (L3 (T9-S1) vs L3 (T7-S1); P = 0.52), similar motor function (S1 (L1-S1) vs S1 (L1-S1); P = 0.52) and a similar proportion of cases with intact motor function (81% vs 79%; P = 0.88) and with motor function two or more levels better than expected based on the anatomical level of the lesion (62% vs 74%; P = 0.24). When compared with prenatally repaired cases, postnatally repaired cases showed worse motor function at birth (S1 (L1-S1) vs L4 (L1-S1); P < 0.01) and at 12 months of age (S1 (L1-S1) vs L4 (L1-S1); P < 0.01). In the prenatal-repair group, motor function remained stable from the time of referral to 12 months of age (P = 0.26). Furthermore, the proportion of patients with intact motor function at referral (81% (75/93)) was similar to that at the 6-week follow-up (74% (64/87)), at the last scan before birth (74% (42/57)), at birth (68% (63/93)) and at 12 months of age (67% (39/58)) in the prenatal-repair group. In the postnatal-repair group, worse motor function, starting from the third trimester to 12 months of age, was observed. The proportion of patients with intact motor function at referral (79% (27/34)) was similar to that at 6-week follow-up (80% (12/15); P = 0.92), but was lower at the last assessment before birth (25% (2/8); P < 0.01), at birth (24% (8/34); P < 0.01) and at 12 months of age (28% (7/25); P < 0.01). Similar findings were noted when assessing the evolution of the proportion of cases with motor function two or more levels better than expected based on the anatomical level of the lesion in each group. CONCLUSIONS: Infants with ONTD that underwent postnatal repair had worse motor function at birth and at 12 months of age than at mid-gestation and when compared with infants that underwent prenatal ONTD repair. Prenatal motor function assessment by ultrasound is an adequate tool to identify those infants who should have a good clinical motor function after delivery. Information obtained by fetal motor function assessment can have an important role for patient counseling and case selection for surgery. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Economic analysis of prenatal fetoscopic vs open-hysterotomy repair of open neural tube defect.

OBJECTIVE: Fetal repair of an open neural tube defect (ONTD) by open hysterotomy has been shown to reduce the need for ventriculoperitoneal shunting and improve motor outcomes for infants, but increases the risk of Cesarean section and prematurity. Fetoscopic repair is an alternative approach that may confer similar neurological benefits but allows for vaginal delivery and reduces the incidence of hysterotomy-related complications. We sought to compare the costs of care from fetal surgery until neonatal discharge, as well as the clinical outcomes, associated with each surgical approach. METHODS: This was a retrospective cohort study of patients who underwent prenatal ONTD repair, using either the open-hysterotomy or the fetoscopic approach, at a single institution between 2012 and 2018. Clinical outcomes were collected by chart review. A cost-consequence analysis was conducted from the hospital perspective, and included all inpatient and ambulatory hospital and physician costs incurred for the care of mothers and their infants, from the time of maternal admission for fetal ONTD repair up to postnatal maternal and infant discharge. Costs were estimated using cost-to-charge ratios for hospital billing and the Medicare physician fee schedule for physician billing. RESULTS: Seventy-eight patients were included in the analysis, of whom 47 underwent fetoscopic repair and 31 underwent open-hysterotomy repair. In the fetoscopic-repair group, compared with the open-repair group, fewer women underwent Cesarean section (53% vs 100%; P < 0.001) and the median gestational age at birth was significantly higher (38.1 weeks (interquartile range (IQR), 35.2-39.1 weeks) vs 35.7 weeks (IQR, 33.9-37.0 weeks); P < 0.001). No case of uterine dehiscence was observed in the fetoscopic-repair group, compared with an incidence of 16% in the open-repair group. After adjusting for baseline characteristics, there was no significant difference in the total cost of care between the fetoscopic-repair and the open-repair groups (median, $76 978 (IQR, $60 312-$115 386) vs $65 103 (IQR, $57 758-$108 103); P = 0.458). CONCLUSIONS: Fetoscopic repair of ONTD, when compared with the open-hysterotomy approach, reduces the incidence of Cesarean section and preterm delivery with no significant difference in total costs of care from surgery to infant discharge. This novel approach may represent a cost-effective alternative to improve maternal and neonatal outcomes for this high-risk population. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Impact of the size of the lesion in prenatal neural tube defect repair on imaging, neurosurgical and motor outcomes: a retrospective cohort study.

OBJECTIVES: (1) To compare brain findings between large and non-large neural tube defect (NTD); (2) to evaluate the impact of large lesion on the surgical parameters; (3) to study any associations between the size of the lesions and brain findings 6 weeks postoperatively and neurological short-term outcomes. DESIGN: Retrospective cohort study. SETTING: Texas Children's Hospital, between 2011 and 2018. POPULATION: Patients who underwent prenatal NTD repair. METHODS: Large lesion was defined when the lesion's surface was >75th centile of our cohorts' lesions. MAIN OUTCOME MEASURES: Time of referral: ventriculomegaly and anatomical level of the lesion; surgery: duration and need for relaxing incisions. 6 weeks postoperative: hindbrain herniation (HBH) and ventriculomegaly. After delivery: dehiscence, need for hydrocephalus treatment and motor function. RESULTS: A total of 99 patients were included, 25 of whom presented with large lesions. Type of lesion and ventriculomegaly were comparable between individuals with large and non-large lesions. Individuals with large lesions were associated with increased need for relaxing incisions by 5.4 times (95% CI 1.3-23.2, P = 0.02). Six weeks postoperatively, having a large lesion decreased by ten times the likelihood of having a postoperative reversal of HBH (odds ratio = 0.1, 95% CI 0.1-0.4, P < 0.01). At birth, larger lesions increased the risk for repair dehiscence by 6.1 times (95% CI 1.6-22.5, P < 0.01) and the risk of dehiscence or leakage of cerebrospinal fluid at birth by 5.5 times (95% CI 1.6-18.9, P < 0.01). CONCLUSION: Prenatal repair of patients with large NTD presents a lower proportion of HBH reversal 6 weeks after the surgery, a higher risk of dehiscence and a higher need for postnatal repair. TWEETABLE ABSTRACT: Evaluation of the size of fetal NTD can predict adverse neurological outcomes after prenatal NTD repair.

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.

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 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.

Learning curves of open and endoscopic fetal spina bifida closure: systematic review and meta-analysis.

OBJECTIVE: The Management of Myelomeningocele Study (MOMS) trial demonstrated the safety and efficacy of open fetal surgery for spina bifida aperta (SBA). Recently developed alternative techniques may reduce maternal risks without compromising the fetal neuroprotective effects. The aim of this systematic review was to assess the learning curve (LC) of different fetal SBA closure techniques. METHODS: MEDLINE, Web of Science, EMBASE, Scopus and Cochrane databases and the gray literature were searched to identify relevant articles on fetal surgery for SBA, without language restriction, published between January 1980 and October 2018. Identified studies were reviewed systematically and those reporting all consecutive procedures and with postnatal follow-up ≥ 12 months were selected. Studies were included only if they reported outcome variables necessary to measure the LC, as defined by fetal safety and efficacy. Two authors independently retrieved data, assessed the quality of the studies and categorized observations into blocks of 30 patients. For meta-analysis, data were pooled using a random-effects model when heterogeneous. To measure the LC, we used two complementary methods. In the group-splitting method, competency was defined when the procedure provided results comparable to those in the MOMS trial for 12 outcome variables representing the immediate surgical outcome, short-term neonatal neuroprotection and long-term neuroprotection at ≥ 12 months of age. Then, when raw patient data were available, we performed cumulative sum analysis based on a composite binary outcome defining successful surgery. The composite outcome combined four clinically relevant variables for safety (absence of extreme preterm delivery < 30 weeks, absence of fetal death ≤ 7 days after surgery) and efficacy (reversal of hindbrain herniation and absence of any neonatal treatment of dehiscence or cerebrospinal fluid leakage at the closure site). RESULTS: Of 6024 search results, 17 (0.3%) studies were included, all of which had low, moderate or unclear risk of bias. Fetal SBA closure was performed using standard hysterotomy (11 studies), mini-hysterotomy (one study) or fetoscopy by either exteriorized-uterus single-layer closure (one study), percutaneous single-layer closure (three studies) or percutaneous two-layer closure (one study). Only outcomes for standard hysterotomy could be meta-analyzed. Overall, outcomes improved significantly with experience. Competency was reached after 35 consecutive cases for standard hysterotomy and was predicted to be achieved after ≥ 57 cases for mini-hysterotomy and ≥ 56 for percutaneous two-layer fetoscopy. For percutaneous and exteriorized-uterus single-layer fetoscopy, competency was not reached in the 81 and 28 cases available for analysis, respectively, and LC prediction analysis could not be performed. CONCLUSIONS: The number of cases operated is correlated with the outcome of fetal SBA closure, and the number of operated cases required to reach competency ranges from 35 for standard hysterotomy to ≥ 56-57 for minimally invasive modifications. Our observations provide important information for institutions looking to establish a new fetal center, develop a new fetal surgery technique or train their team, and inform referring clinicians, potential patients and third parties. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Curvas de aprendizaje del cierre de la espina bífida fetal mediante cirugía abierta y endoscópica: revisión sistemática y metaanálisis OBJETIVO: El ensayo del Estudio sobre la Gestión del Mielomeningocele (MOMS, por sus siglas en inglés) demostró la seguridad y eficacia de la cirugía fetal abierta para la espina bífida aperta (EBA). Las técnicas alternativas recientemente desarrolladas pueden reducir los riesgos de la madre sin comprometer los efectos neuroprotectores del feto. El objetivo de esta revisión sistemática fue evaluar la curva de aprendizaje (CA) de diferentes técnicas de cierre de la EBA fetal. MÉTODOS: Se realizaron búsquedas en las bases de datos de MEDLINE, Web of Science, EMBASE, Scopus y Cochrane, así como en la literatura gris, para identificar artículos relevantes sobre cirugía fetal para la EBA, sin restricción de idioma, publicados entre enero de 1980 y octubre de 2018. Se examinaron sistemáticamente los estudios identificados y se seleccionaron los que informaban de todos los procedimientos consecutivos y con seguimiento postnatal ≥12 meses. Los estudios se incluyeron sólo si informaban sobre las variables de resultado necesarias para medir la CA, definidas por la seguridad y la eficacia para el feto. Dos autores recuperaron los datos de forma independiente, evaluaron la calidad de los estudios y clasificaron las observaciones en bloques de 30 pacientes. Para el metaanálisis, los datos se agruparon mediante un modelo de efectos aleatorios cuando fueron heterogéneos. Para medir la CA, se usaron dos métodos complementarios. En el método de división de grupos, la competencia se definió cuando el procedimiento proporcionó resultados comparables a los del ensayo MOMS para 12 variables de resultados que representaban el resultado quirúrgico inmediato, la neuroprotección neonatal a corto plazo y la neuroprotección a largo plazo a ≥12 meses de edad. Luego, cuando se dispuso de los datos brutos de los pacientes, se realizó un análisis de suma acumulada basado en un resultado binario compuesto que definió el éxito de la cirugía. El resultado compuesto combinó cuatro variables clínicamente relevantes en cuanto a la seguridad (ausencia de parto pretérmino extremo <30 semanas; ausencia de muerte fetal a ≤7 días después de la cirugía) y eficacia (reducción de la hernia del rombencéfalo y ausencia de cualquier tratamiento neonatal de dehiscencia o derrame de líquido cefalorraquídeo en el lugar del cierre). RESULTADOS: De los 6024 resultados de la búsqueda, se incluyeron 17 (0,3%) estudios, todos ellos con un riesgo de sesgo bajo, moderado o incierto. El cierre de la EBA fetal se realizó mediante histerotomía estándar (11 estudios), mini histerotomía (un estudio) o fetoscopia, ya fuera mediante el cierre exteriorizado del útero de una sola capa (un estudio), el cierre percutáneo de una sola capa (tres estudios) o el cierre percutáneo de dos capas (un estudio). Sólo se pudieron metaanalizar los resultados de la histerotomía estándar. En general, los resultados mejoraron significativamente con la experiencia. Se alcanzó la competencia después de 35 casos consecutivos para la histerotomía estándar y se predijo que se alcanzaría después de ≥57 casos para la mini histerotomía y ≥56 para la fetoscopia percutánea de dos capas. En el caso de las fetoscopias percutánea y exteriorizada del útero de una sola capa, no se alcanzó la competencia en los 81 y 28 casos disponibles para el análisis, respectivamente, y no se pudo realizar el análisis de predicción de la CA. CONCLUSIONES: El número de casos operados está correlacionado con el resultado del cierre de la EBA fetal, y el número de casos operados necesarios para alcanzar la competencia estuvo entre 35 para la histerotomía estándar y ≥56-57 para las operaciones con mínima agresividad. Las observaciones realizadas proporcionan información importante para las instituciones que buscan establecer un nuevo centro fetal, desarrollar una nueva técnica de cirugía fetal o entrenar a su equipo, e informar a los médicos que remiten a especialistas a los posibles pacientes y a terceros. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Does fetoscopic or open repair for spina bifida affect fetal and postnatal growth?

OBJECTIVE: The effect of fetoscopic myelomeningocele (MMC) repair on fetal growth is unknown. Fetal surgery itself and/or exposure to a carbon dioxide (CO2 ) environment during spina bifida repair may affect placental function and impair fetal growth. Our aim was to assess and compare growth in fetuses, neonates and infants who underwent prenatal fetoscopic or open MMC repair. METHODS: Fetal biometrics were obtained serially using ultrasound after fetoscopic (n = 32) or open hysterotomy (n = 34) MMC repair in utero at a single institution between November 2011 and July 2017. Measurements obtained during growth scans on initial evaluation prior to surgery, and those taken at 6 weeks post-surgery, were transformed into percentiles and compared between groups. Additional neonatal and infant anthropometric measurements, including weight, length/height and head circumference, were also transformed into percentiles and compared between the groups. The proportions of cases in each group with estimated fetal weight (EFW) or postnatal weight < 10th and < 3rd percentiles were calculated and compared. A linear mixed model was used to analyze the serial fetal growth measurements of each parameter, and random intercepts and slopes were used to compare study variables between the study groups. The duration of surgery (skin-to-skin time at fetoscopic and open MMC repair) and duration of CO2 exposure (fetoscopic repair) were evaluated for any effect on the fetal, neonatal or infant biometric percentiles. RESULTS: Fetuses which underwent fetoscopic repair had a larger abdominal circumference percentile at referral (57 ± 21 vs 46 ± 23; P = 0.04). There were no other differences between the two groups in fetal biometric percentiles at the time of referral, 6 weeks post-surgery or at birth. There were no differences between groups in EFW percentile or in proportions of cases with birth weight < 10th and < 3rd percentiles. Linear mixed-model analysis did not show any significant differences in any fetal growth parameter between the groups over time. There were no significant correlations between duration of surgery or duration of CO2 exposure and any of the biometric percentiles evaluated. Postnatal growth showed no significant differences between the groups in weight, height or head circumference percentiles, at 6-18, 18-30 or > 30 months of age. CONCLUSIONS: Babies exposed to fetoscopic or open MMC repair in-utero did not show significant differences in fetal or postnatal growth parameters. These results support the safety of the use of CO2 gas for fetoscopic surgery. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Prenatal brain imaging for predicting need for postnatal hydrocephalus treatment in fetuses that had neural tube defect repair in utero.

OBJECTIVE: To determine if brain imaging in fetuses that underwent prenatal repair of neural tube defect (NTD) can predict the need for postnatal hydrocephalus treatment (HT) in the first year postpartum. METHODS: This was a retrospective study of fetuses diagnosed with open NTD that had in-utero myelomeningocele repair between April 2014 and April 2016. Independent variables were collected from four chronological sets of fetal images: presurgery ultrasound, presurgery magnetic resonance imaging (MRI), 6-week postsurgery MRI and predelivery ultrasound. The following independent variables were collected from all image sets unless otherwise noted: gestational age, head circumference, mean ventricular width, ventricular volume (MRI only), hindbrain herniation (HBH) score (MRI only), and level of lesion (LOL), defined as the upper bony spinal defect (presurgery ultrasound only). Based on these measurements, additional variables were defined and calculated including change in degree of HBH, ventricular width growth (mm/week) and ventricular volume growth (mL/week). The need for HT (by either ventriculoperitoneal shunt or endoscopic third ventriculostomy with choroid plexus cauterization) was determined by a pediatric neurosurgeon using clinical and radiographic criteria; a secondary analysis was performed using the MOMS trial criteria for hydrocephalus. The predictive value of each parameter was assessed by receiver-operating characteristics curve and logistic regression analyses. RESULTS: Fifty affected fetuses were included in the study, of which 32 underwent open hysterotomy and 18 fetoscopic repair. Two neonates from the open hysterotomy group died and were excluded from the analysis. The mean gestational ages for the presurgery ultrasound, presurgery MRI, postsurgery MRI and predelivery ultrasound were 21.8 ± 2.1, 22.0 ± 1.8, 30.4 ± 1.6 and 31.0 ± 4.9 weeks, respectively. A total of 16 subjects required HT. The area under the curve (AUC) of predictive accuracy for HT showed that HBH grading on postsurgery MRI had the strongest predictive value (0.86; P < 0.01), outperforming other predictors such as postsurgery MRI ventricular volume (0.73; P = 0.03), MRI ventricular volume growth (0.79; P = 0.01), change in HBH (0.82; P = 0.01), and mean ventricular width on predelivery ultrasound (0.73; P = 0.01). Other variables, such as LOL, mean ventricular width on presurgery ultrasound, mean ventricular width on presurgery and postsurgery MRI, and ventricular growth assessment by MRI or ultrasound, had AUCs < 0.7. Optimal cut-offs of the variables with the highest AUC were evaluated to improve prediction. A combination of ventricular volume growth ≥ 2.02 mL/week and/or HBH of 3 on postsurgery MRI were the optimal cut-offs for the best prediction (odds ratio (OR), 42 (95% CI, 4-431); accuracy, 84%). Logistic regression analyses showed that persistence of severe HBH 6 weeks after surgery by MRI is one of the best predictors for HT (OR, 39 (95% CI, 4-369); accuracy, 84%). There was no significant change in the results when the MOMS trial criteria for hydrocephalus were used as the dependent variable. CONCLUSIONS: Persistence of HBH on MRI 6 weeks after prenatal NTD repair independently predicted the need for postnatal HT better than any ultrasound- or other MRI-derived measurements of ventricular characteristics. These results should aid in prenatal counseling and add support to the hypothesis that HBH is a significant driver of hydrocephalus in myelomeningocele patients. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Imágenes cerebrales prenatales para predecir el tratamiento postnatal de la hidrocefalia en fetos con reparación de defectos del tubo neural OBJETIVOS: Determinar si las imágenes cerebrales en fetos que se sometieron a reparación prenatal de defectos del tubo neural (DTN) pueden predecir la necesidad de tratamiento postnatal de la hidrocefalia (TH) en el primer año después del parto. MÉTODOS: Este fue un estudio retrospectivo de fetos diagnosticados con DTN aun abierto cuyo mielomeningocele fue reparado en el útero, entre abril de 2014 y abril de 2016. Se recolectaron variables independientes de cuatro conjuntos cronológicos de imágenes fetales: ecografía prequirúrgica, imágenes por resonancia magnética (IRM) prequirúrgica, imágenes por resonancia magnética (IRM) posquirúrgica a las seis semanas y ecografía previa al parto. Las siguientes variables independientes se recolectaron de todos los conjuntos de imágenes, a menos que se indique lo contrario: edad gestacional, perímetro cefálico, ancho ventricular medio, volumen ventricular (IRM solamente), puntaje de hernia del rombencéfalo (HR) (IRM solamente) y nivel de lesión (NDL), definido como el defecto espinal óseo superior (ecografía prequirúrgica solamente). A partir de estas mediciones se definieron y calcularon variables adicionales, como el cambio en el grado de HR, el aumento del ancho ventricular (mm/semana) y el aumento del volumen ventricular (mL/semana). La necesidad de TH (ya sea por derivación ventriculoperitoneal o por ventriculostomía endoscópica del tercer ventrículo y cauterización del plexo coroideo) fue determinada por un neurocirujano pediátrico utilizando criterios clínicos y radiográficos; se realizó un análisis secundario utilizando los criterios del estudio MOMS para la hidrocefalia. El valor predictivo de cada parámetro se evaluó mediante un análisis de la curva de la característica operativa del receptor y de la regresión logística. RESULTADOS: Se incluyeron en el estudio 50 fetos afectados, de los cuales 32 se sometieron a histerotomía abierta y 18 a reparación fetoscópica. Dos de los recién nacidos del grupo de histerotomía abierta murieron y fueron excluidos del análisis. Las edades gestacionales medias para la ecografía prequirúrgica, la IRM prequirúrgica, la IRM postoperatoria y la ecografía previa al parto fueron 21,8 ±2,1; 22,0 ±1,8; 30,4 ±1,6 y 31,0 ±4,9 semanas, respectivamente. Un total de 16 sujetos requirieron TH. El área bajo la curva (ABC) de precisión predictiva para la TH mostró que la clasificación de la HR en la IRM postoperatoria tuvo el valor predictivo más fuerte (0,86; P<0.01), por encima de otros valores predictivos como el volumen ventricular en la IRM posquirúrgica (0,73; P=0,03), el crecimiento del volumen ventricular en la IRM (0,79; P=0,01), cambios en la HR (0,82; P=0,01), y el ancho ventricular medio en la ecografía previa al parto (0,73; P=0,01). Otras variables, como el NDL, la anchura ventricular media en la ecografía prequirúrgica, la anchura ventricular media en la IRM prequirúrgica y posquirúrgica, y la evaluación del crecimiento ventricular mediante ecografía o IRM, tuvieron AUC <0,7. Para mejorar la predicción se evaluaron los límites óptimos de las variables con las AUC más altas. Los límites óptimos para la mejor predicción (razones de momios [RM], 42 [IC 95%: 4-431]; precisión, 84%) fueron una combinación de crecimiento del volumen ventricular ≥2,02 mL/semana y/o HR de 3 en la IRM postoperatoria. Los análisis de regresión logística mostraron que la persistencia de la HR grave a las 6 semanas después de la cirugía en IRM es uno de los mejores predictores de la TH (RM, 39 (IC 95%: 4-369); precisión, 84%). Los resultados no cambiaron de forma significativa cuando se utilizaron los criterios del estudio MOMS para la hidrocefalia como variable dependiente. CONCLUSIONES: La persistencia de la HR en la IRM 6 semanas después de la reparación prenatal de DTN predijo independientemente la necesidad de la TH postnatal mejor que cualquier ecografía o que otras mediciones de las características ventriculares a partir de IRM. Estos resultados deberían ayudar en el asesoramiento previo al parto y a apoyar la hipótesis de que la HR es un impulsor significativo de la hidrocefalia en pacientes con mielomeningocele.