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

OBJECTIVE: To report the need for cord untethering after prenatal repair of open spina bifida using a unique biocellulose-based technique performed at a later gestational age. METHODS: An observational cohort study was conducted to determine the incidence of tethered cord syndrome. Between May 2013 and May 2022, we performed 172 procedures using the percutaneous fetoscopic approach in fetuses at 26-28 weeks of gestation. After placode dissection, a biocellulose patch was placed to cover the placode, a myofascial flap (when possible) was dissected, and the skin was closed. Owing to death or loss to follow-up, 23 cases were excluded. Cord tethering syndrome was defined as symptoms of medullary stretching, and the infants were evaluated and operated on by local neurosurgeons after an magnetic resonance imaging examination. Infants over 30-month had ambulation and neurodevelopment evaluations (PEDI scale). RESULTS: Among 172 cases operated at a median gestational age of 26.7 weeks and delivered at 33.2 weeks, 149 cases were available for postnatal follow-up, and cord untethering was needed in 4.4% of cases (6/136; excluding 13 cases younger than 12 months). Cerebrospinal fluid diversion and bladder catheterization were needed in 38% and 36% of cases, respectively. Of the 78 cases evaluated at 30 months, 49% were ambulating independently, and 94% had normal social function. CONCLUSION: The biocellulose-based technique was associated with a low rate of cord tethering, wich may be attributed to the lack of the duramater suture during prenatal repair, the formation of a neoduramater and/or later gestational age of surgery.

Longitudinal evolution of central nervous system anomalies in fetuses with open spina bifida fetoscopic repair and correlation with neurologic outcome.

BACKGROUND: Open spina bifida is associated with central nervous system anomalies such as abnormal corpus callosum and heterotopias. However, the impact of prenatal surgery over these structures remains unclear. OBJECTIVE: This study aimed to describe longitudinal changes of central nervous system anomalies before and after prenatal open spina bifida repair and to evaluate their relationship with postnatal neurologic outcomes. STUDY DESIGN: Retrospective cohort study of fetuses with open spina bifida who underwent percutaneous fetoscopic repair from January 2009 to August 2020. All women had presurgical and postsurgical fetal magnetic resonance imaging, at an average of 1 week before and 4 weeks after surgery, respectively. We evaluated defect characteristics in the presurgical magnetic resonance images; and fetal head biometry, clivus supraocciput angle, and the presence of structural central nervous system anomalies, such as abnormalities in corpus callosum, heterotopias, ventriculomegaly, and hindbrain herniation, in both presurgical and postsurgical magnetic resonance images. Neurologic assessment was performed using the Pediatric Evaluation of Disability Inventory scale in children who were 12 months or older, covering 3 different sections, namely self-care, mobility, and social and cognitive function. RESULTS: A total of 46 fetuses were evaluated. Presurgery and postsurgery magnetic resonance imaging were performed at a median gestational age of 25.3 and 30.6 weeks, with a median interval of 0.8 weeks before surgery, and 4.0 weeks after surgery. There was a 70% reduction in hindbrain herniation (100% vs 32.6%; P<.001), and a normalization of the clivus supraocciput angle after surgery (55.3 [48.8-61.0] vs 79.9 [75.2-85.4]; P<.001). No significant increase in abnormal corpus callosum (50.0% vs 58.7%; P=.157) or heterotopia (10.8% vs 13.0%; P=.706) was observed. Ventricular dilation was higher after surgery (15.6 [12.7-18.1] vs 18.8 [13.7-22.9] mm; P<.001), with a higher proportion of severe ventricular dilation after surgery (≥15mm) (52.2% vs 67.4%; P=.020). Thirty-four children underwent neurologic assessment, with 50% presenting a global optimal Pediatric Evaluation of Disability Inventory result and 100% presenting a normal social and cognitive function. Children with optimal global Pediatric Evaluation of Disability Inventory presented a lower rate of presurgical anomalies in corpus callosum and severe ventriculomegaly. When analyzed as independent variables to global Pediatric Evaluation of Disability Inventory scale, the presence of abnormal corpus callosum and severe ventriculomegaly showed an odds ratio of 27.7 (P=.025; 95% confidence interval, 1.53-500.71) for a suboptimal result. CONCLUSION: Prenatal open spina bifida repair did not change the proportion of abnormal corpus callosum nor heterotopias after surgery. The combination of presurgical abnormal corpus callosum and severe ventricular dilation (≥15 mm) is associated with an increased risk of suboptimal neurodevelopment.

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.