Prenatal versus postnatal repair procedures for spina bifida for improving infant and maternal outcomes

The effect of using synthetic vs. biological dural substitutes during prenatal and postnatal repair of spina bifida on spinal cord tethering-a review of literature

Spina bifida is a congenital neural tube closure defect, with myelomeningocele being the most clinically significant open neural tube defect occurring in one in 1000 births worldwide as reported by Phillips LA et al. (Curr Probl Pediatr Adolesc Health Care 47(7):173-177, 2017) and Zerah M and Kulkarni AV (Handb Clin Neurol 112:975-991, 2013). With advances in fetal surgery, this condition can be corrected in utero. Despite such precision surgery, many complications may still arise, with consequent spinal cord tethering being a major one. When the roots of the spinal cord adhere to the spinal canal instead of floating freely within the dural sleeve within the canal, it is termed as "tethering" as discussed by Martínez-Lage JF et al. (Neurocirugia (Astur) 18(4):312-319, 2007). Tethering has a variety of complications, which are best avoided by analyzing the outcomes of the different dural substitutes and improving surgical techniques. This literature review evaluates the use of different dural substitutes in fetal and postnatal surgery, with their effects on spinal cord tethering. Finding a significant difference in spinal cord adherence outcomes between these two groups can help one introspect on the impact of ideal surgical techniques to be implemented, thus reducing subsequent tethering and other future surgical interventions.

The Association of Prenatal Diagnoses with Mortality and Long-Term Morbidity in Children with Specific Isolated Congenital Anomalies: A European Register-Based Cohort Study

OBJECTIVES

To compare 5-year survival rate and morbidity in children with spina bifida, transposition of great arteries (TGA), congenital diaphragmatic hernia (CDH) or gastroschisis diagnosed prenatally with those diagnosed postnatally.

METHODS

Population-based registers' data were linked to hospital and mortality databases.

RESULTS

Children whose anomaly was diagnosed prenatally (n = 1088) had a lower mean gestational age than those diagnosed postnatally (n = 1698) ranging from 8 days for CDH to 4 days for TGA. Children with CDH had the highest infant mortality rate with a significant difference (p < 0.001) between those prenatally (359/1,000 births) and postnatally (116/1,000) diagnosed. For all four anomalies, the median length of hospital stay was significantly greater in children with a prenatal diagnosis than those postnatally diagnosed. Children with prenatally diagnosed spina bifida (79% vs 60%; p = 0.002) were more likely to have surgery in the first week of life, with an indication that this also occurred in children with CDH (79% vs 69%; p = 0.06).

CONCLUSIONS

Our findings do not show improved outcomes for prenatally diagnosed infants. For conditions where prenatal diagnoses were associated with greater mortality and morbidity, the findings might be attributed to increased detection of more severe anomalies. The increased mortality and morbidity in those diagnosed prenatally may be related to the lower mean gestational age (GA) at birth, leading to insufficient surfactant for respiratory effort. This is especially important for these four groups of children as they have to undergo anaesthesia and surgery shortly after birth. Appropriate prenatal counselling about the time and mode of delivery is needed.

Outcomes of autologous bone marrow mononuclear cell administration in the treatment of neurologic sequelae in children with spina bifida

BACKGROUND

To evaluate the safety and efficacy of autologous bone marrow mononuclear cell (BMMNC) infusion in the management of neurological sequelae in children with spina bifida (SB).

METHODS

BMMNCs were harvested from bilateral anterior iliac crests. Two intrathecal BMMNC administrations were performed with an interval of 6 months. The measurements of outcomes included clinical assessments, cystomanometry and rectomanometry.

RESULTS

Eleven children with SB underwent autologous BMMNC infusions from 2016 to 2020. There were no severe adverse events during the study period. The number of patients requiring assistance to expel stools decreased from 11 before cell infusion to 3 after the second cell infusion. The number of patients who had urine leakage decreased from 9 patients at baseline to 3 patients after the second BMMNC infusion. The mean bladder capacity increased from 127.7 ± 59.2 ml at baseline to 136.3 ± 54.8 ml at six months and to 158.3 ± 56.2 ml at 12 months after BMMNC infusions. Detrusor pressure (pdet) decreased from 32.4 ± 22.0 cm H₂O at baseline to 21.9 ± 11.8 cm H₂O after 12 months of follow-up. At baseline, six patients could walk independently. After the 2nd infusion, eight patients could walk independently.

CONCLUSION

Intrathecal infusions of autologous bone marrow mononuclear cells are safe and may improve bowel, bladder, and motor function in children with SB.

TRIAL REGISTRATION

NCT, NCT05472428. Registered July 25, 2022- Retrospectively registered, https://www.

CLINICALTRIALS

gov/ct2/show/NCT05472428 .

Postnatal Repair of Open Neural Tube Defects: A Single Center with 90-Month Interdisciplinary Follow-Up

After publication of the Management of Myelomeningocele Study (MOMS) there is confusion regarding which treatment of open neural tube defects (NTD) is best. We report our results of postnatally repaired open NTDs born between 2007–2018 (n = 36) in critical reflection of the MOMS study. Neurosurgical, orthopedic, and urologic data were assessed. We also introduce a new entity: “status post prenatal repair”. FU ranged from 29 to 161 months (mean: 89.1 m) in 7 cases of myeloschisis and 24 myelomeningoceles in the final collective n = 31. The shunt rate was 41.9%, and the endoscopic third ventriculostomy rate was 16.1%. Hydrocephalus requiring treatment was not associated with the anatomical level, but with premature birth (p = 0.048). Myeloschisis was associated with shunt placement (p = 0.008). ROC analysis revealed birth <38.5th week predicts the necessity for hydrocephalus treatment (sensitivity: 89%; specificity: 77%; AUC= 0.71; p = 0.055). Eight (25.8%), patients are wheelchair-bound, 2 (6.5%) ambulate with a posterior walker, 10 (32.3%) with orthosis and 11 (35.5%) independently. One (3.2%) patient underwent detethering at 5.5 years. A total of three patients underwent five Chiari decompressions (9.6%). Further, nineteen orthopedic procedures were performed in nine patients (29.0%). A total of 17 (54.8%) patients self-catheterize, which was associated with an anatomical lesion at L3 or below (p = 0.032) and 23 (74.2%) take anticholinergic medication. In conclusion, shunt dependency is associated with myeloschisis, not with the anatomical defect level. Hydrocephalus treatment is associated with premature birth. In this postnatal cohort with significantly longer follow-up data than the MOMs study, the ambulation rate is better, the shunt rate lower and the secondary tethered cord rate better compared to the MOMS study.

Neonatal and infant mortality associated with spina bifida: A systematic review and meta-analysis

Objectives

A systematic review was conducted in high-income country settings to analyse: (i) spina bifida neonatal and IMRs over time, and (ii) clinical and socio-demographic factors associated with mortality in the first year after birth in infants affected by spina bifida.

Data sources

PubMed, Embase, Ovid, Web of Science, CINAHL, Scopus and the Cochrane Library were searched from 1^st January, 1990 to 31^st August, 2020 to review evidence.

Study selection

Population-based studies that provided data for spina bifida infant mortality and case fatality according to clinical and socio-demographical characteristics were included. Studies were excluded if they were conducted solely in tertiary centres. Spina bifida occulta or syndromal spina bifida were excluded where possible.

Data extraction and synthesis

Independent reviewers extracted data and assessed their quality using MOOSE guideline. Pooled mortality estimates were calculated using random-effects (+/- fixed effects) models meta-analyses. Heterogeneity between studies was assessed using the Cochrane Q test and I² statistics. Meta-regression was performed to examine the impact of year of birth cohort on spina bifida infant mortality.

Results

Twenty studies met the full inclusion criteria with a total study population of over 30 million liveborn infants and approximately 12,000 spina bifida-affected infants. Significant declines in spina bifida associated infant and neonatal mortality rates (e.g. 4.76% decrease in IMR per 100, 000 live births per year) and case fatality (e.g. 2.70% decrease in infant case fatality per year) were consistently observed over time. Preterm birth (RR 4.45; 2.30–8.60) and low birthweight (RR 4.77; 2.67–8.55) are the strongest risk factors associated with increased spina bifida infant case fatality.

Significance

Significant declines in spina bifida associated infant/neonatal mortality and case fatality were consistently observed, advances in treatment and mandatory folic acid food fortification both likely play an important role. Particular attention is warranted from clinicians caring for preterm and low birthweight babies affected by spina bifida.

Anesthesia-Related Factors Associated with Preterm Labor and Delivery after Open Fetal Surgery

BACKGROUND

Fetal surgery, such as for meningomyelocele repair, has a clear clinical fetal benefit. In patients who undergo in utero repair of meningomyelocele, for example, there is reduced long-term disease morbidity. However, despite the beneficial effects of early intervention, women who undergo fetal interventions have an increased risk of preterm labor and delivery. Several surgery-related factors have been described but no specific anesthesia-related factors.

OBJECTIVE

The aim of this study was to determine if any aspects of the perioperative anesthetic management influenced maternal complications following in utero surgery.

METHODS

This was a retrospective chart review of the anesthetic management of mothers and fetuses who presented for open and fetoscopic myelomeningocele repair, between 2011 and 2015, at Texas Children's Fetal Center®.

RESULTS

Forty-six women underwent open or fetoscopic repair of neural tube defects at our institution. We found the maternal heart rate in the postoperative period to be associated with a higher likelihood of preterm labor, but not delivery. The odds of having preterm delivery was higher for nulliparous patients and those with lower intraoperative diastolic pressure.

CONCLUSIONS

Our findings confirm what has been previously reported regarding the association of nulliparity with preterm delivery. Additionally, this study highlights the importance of maintaining stable perioperative hemodynamics during the intraoperative and postoperative phases of care for patients undergoing in utero surgery.

Interventions during pregnancy to prevent preterm birth: an overview of Cochrane systematic reviews

BACKGROUND

Preterm birth (PTB) is a major factor contributing to global rates of neonatal death and to longer-term health problems for surviving infants. Both the World Health Organization and the United Nations consider prevention of PTB as central to improving health care for pregnant women and newborn babies. Current preventative clinical strategies show varied efficacy in different populations of pregnant women, frustrating women and health providers alike, while researchers call for better understanding of the underlying mechanisms that lead to PTB.

OBJECTIVES

We aimed to summarise all evidence for interventions relevant to the prevention of PTB as reported in Cochrane systematic reviews (SRs). We intended to highlight promising interventions and to identify SRs in need of an update.

METHODS

We searched the Cochrane Database of Systematic Reviews (2 November 2017) with key words to capture any Cochrane SR that prespecified or reported a PTB outcome. Inclusion criteria focused on pregnant women without signs of preterm labour or ruptured amniotic membranes. We included reviews of interventions for pregnant women irrespective of their risk status. We followed standard Cochrane methods.We applied GRADE criteria to evaluate the quality of SR evidence. We assigned graphic icons to classify the effectiveness of interventions as: clear evidence of benefit; clear evidence of harm; clear evidence of no effect or equivalence; possible benefit; possible harm; or unknown benefit or harm. We defined clear evidence of benefit and clear evidence of harm to be GRADE moderate- or high-quality evidence with a confidence interval (CI) that does not cross the line of no effect. Clear evidence of no effect or equivalence is GRADE moderate- or high-quality evidence with a narrow CI crossing the line of no effect. Possible benefit and possible harm refer to GRADE low-quality evidence with a clear effect (CI does not cross the line of no effect) or GRADE moderate- or high-quality evidence with a wide CI. Unknown harm or benefit refers to GRADE low- or very low-quality evidence with a wide CI.

MAIN RESULTS

We included 83 SRs; 70 had outcome data. Below we highlight key results from a subset of 36 SRs of interventions intended to prevent PTB.

OUTCOME

preterm birthClear evidence of benefitFour SRs reported clear evidence of benefit to prevent specific populations of pregnant women from giving birth early, including midwife-led continuity models of care versus other models of care for all women; screening for lower genital tract infections for pregnant women less than 37 weeks' gestation and without signs of labour, bleeding or infection; and zinc supplementation for pregnant women without systemic illness. Cervical cerclage showed clear benefit for women with singleton pregnancy and high risk of PTB only.Clear evidence of harmNo included SR reported clear evidence of harm.No effect or equivalenceFor pregnant women at high risk of PTB, bedrest for women with singleton pregnancy and antibiotic prophylaxis during the second and third trimester were of no effect or equivalent to a comparator.Possible benefitFour SRs found possible benefit in: group antenatal care for all pregnant women; antibiotics for pregnant women with asymptomatic bacteriuria; pharmacological interventions for smoking cessation for pregnant women who smoke; and vitamin D supplements alone for women without pre-existing conditions such as diabetes.Possible harmOne SR reported possible harm (increased risk of PTB) with intramuscular progesterone, but this finding is only relevant to women with multiple pregnancy and high risk of PTB. Another review found possible harm with vitamin D, calcium and other minerals for pregnant women without pre-existing conditions.

OUTCOME

perinatal deathClear evidence of benefitTwo SRs reported clear evidence of benefit to reduce pregnant women's risk of perinatal death: midwife-led continuity models of care for all pregnant women; and fetal and umbilical Doppler for high-risk pregnant women.Clear evidence of harmNo included SR reported clear evidence of harm.No effect or equivalenceFor pregnant women at high risk of PTB, antibiotic prophylaxis during the second and third trimester was of no effect or equivalent to a comparator.Possible benefitOne SR reported possible benefit with cervical cerclage for women with singleton pregnancy and high risk of PTB.Possible harmOne SR reported possible harm associated with a reduced schedule of antenatal visits for pregnant women at low risk of pregnancy complications; importantly, these women already received antenatal care in settings with limited resources.

OUTCOMES

preterm birth and perinatal deathUnknown benefit or harmFor pregnant women at high risk of PTB for any reason including multiple pregnancy, home uterine monitoring was of unknown benefit or harm. For pregnant women at high risk due to multiple pregnancy: bedrest, prophylactic oral betamimetics, vaginal progesterone and cervical cerclage were all of unknown benefit or harm.

AUTHORS' CONCLUSIONS

Implications for practiceThe overview serves as a map and guide to all current evidence relevant to PTB prevention published in the Cochrane Library. Of 70 SRs with outcome data, we identified 36 reviews of interventions with the aim of preventing PTB. Just four of these SRs had evidence of clear benefit to women, with an additional four SRs reporting possible benefit. No SR reported clear harm, which is an important finding for women and health providers alike.The overview summarises no evidence for the clinically important interventions of cervical pessary, cervical length assessment and vaginal progesterone because these Cochrane Reviews were not current. These are active areas for PTB research.The graphic icons we assigned to SR effect estimates do not constitute clinical guidance or an endorsement of specific interventions for pregnant women. It remains critical for pregnant women and their healthcare providers to carefully consider whether specific strategies to prevent PTB will be of benefit for individual women, or for specific populations of women.Implications for researchFormal consensus work is needed to establish standard language for overviews of reviews and to define the limits of their interpretation.Clinicians, researchers and funders must address the lack of evidence for interventions relevant to women at high risk of PTB due to multiple pregnancy.

Homologous cryopreserved amniotic membrane in the repair of myelomeningocele: preliminary experience

OBJECTIVE

Surgical management of spinal dysraphism often requires the use of dural substitutes. Amniotic membrane (AM) has drawn the interest of clinicians for its valuable concentration of cytokines and factors capable of promoting wound healing, re-epithelialization, inhibiting fibrosis and regulating angiogenesis. These beneficial qualities could make AM an interesting dural substitute for spina bifida repair. In this study, we describe the use of banked homologous AM as a dural substitute for the repair of spinal dysraphism in newborns. Our purpose is to test the mechanical characteristics, as well as the safety and effectiveness of AM in preventing postoperative complications and re-tethering.

METHODS

The AM patch was carefully detached from the chorion of donors undergoing caesarean section, rinsed in saline solution, and cryopreserved in liquid nitrogen. Five newborns were treated using AM: three affected by open spinal dysraphism and two by spina bifida occulta. The AM patch was used as a dural substitute with two different positions and purposes: the amnion-side down covering the placode to prevent adhesions or placed extradurally facing the dura to avoid scarring and facilitating the sliding of the dural sac itself under the extradural tissue layers.

RESULTS

No adverse events occurred, and the surgical wounds healed without complications. MRI scans taken at 3 and 6 months after surgery showed a satisfying de-tethering of the spinal cord with no obvious evidence of new adherence formation.

CONCLUSIONS

We present a multimodal interposition technique using AM as a reconstructive and anti-adhesive tissue for the treatment of open myelomeningocele (MMC) and lipomeningocele (LMC) treatment. In our experience, AM proved its efficacy in restoring the dural sac integrity without complications. We support the use of AM as a promising dural substitute, speculating on how the use of AM could potentially change reconstructive strategies for spinal dysraphism.

Imaging spectrum of spinal dysraphism on magnetic resonance: A pictorial review

Congenital malformations of spine and spinal cord are collectively termed as spinal dysraphism. It includes a heterogeneous group of anomalies which result from faulty closure of midline structures during development. Magnetic resonance imaging (MRI) is now considered the imaging modality of choice for diagnosing these conditions. The purpose of this article is to review the normal development of spinal cord and spine and reviewing the MRI features of spinal dysraphism. Although imaging of spinal dysraphism is complicated, a systematic approach and correlation between neuro-radiological, clinical and developmental data helps in making the correct diagnosis.

A systematic review of the quality of conduct and reporting of systematic reviews and meta-analyses in paediatric surgery

OBJECTIVE

Our objective was to evaluate quality of conduct and reporting of published systematic reviews and meta-analyses in paediatric surgery. We also aimed to identify characteristics predictive of review quality.

BACKGROUND

Systematic reviews summarise evidence by combining sources, but are potentially prone to bias. To counter this, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was published to aid in reporting. Similarly, the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) measurement tool was designed to appraise methodology. The paediatric surgical literature has seen an increasing number of reviews over the past decade, but quality has not been evaluated.

METHODS

Adhering to PRISMA guidelines, we performed a systematic review with a priori design to identify systematic reviews and meta-analyses of interventions in paediatric surgery. From 01/2010 to 06/2016, we searched: MEDLINE, EMBASE, Cochrane, Centre for Reviews and Dissemination, Web of Science, Google Scholar, reference lists and journals. Two reviewers independently selected studies and extracted data. We assessed conduct and reporting using AMSTAR and PRISMA. Scores were calculated as the sum of reported items. We also extracted author, journal and article characteristics, and used them in exploratory analysis to determine which variables predict quality.

RESULTS

112 articles fulfilled eligibility criteria (53 systematic reviews; 59 meta-analyses). Overall, 68% AMSTAR and 56.8% PRISMA items were reported adequately. Poorest scores were identified with regards a priori design, inclusion of structured summaries, including the grey literature, citing excluded articles and evaluating bias. 13 reviews were pre-registered and 6 in PRISMA-endorsing journals. The following predicted quality in univariate analysis:, word count, Cochrane review, journal h-index, impact factor, journal endorses PRISMA, PRISMA adherence suggested in author guidance, article mentions PRISMA, review includes comparison of interventions and review registration. The latter three variables were significant in multivariate regression.

CONCLUSIONS

There are gaps in the conduct and reporting of systematic reviews in paediatric surgery. More endorsement by journals of the PRISMA guideline may improve review quality, and the dissemination of reliable evidence to paediatric clinicians.

A comparison of the MOMS trial results to a contemporaneous, single-institution, postnatal closure cohort

PURPOSE

We evaluate a single-institution cohort of mothers contemporaneous with the Management of Myelomeningocele Study (MOMS) trial to determine the generalizability of MOMS results and compare shunt rates.

METHODS

A retrospective chart review identified patients with myelomeningocele born between 2003 and 2009. We applied MOMS eligibility criteria and compared sociodemographic variables between patients at our institution who would have been eligible or ineligible and MOMS participants. Finally, we applied the original MOMS primary outcome and the revised primary outcome to our cohort.

RESULTS

Of the 78 patients, 55 (70.5%) were eligible for the MOMS trial. Mean maternal age, race, and marital status were different from both MOMS groups. Comparing our series to MOMS postnatal shows fewer female infants (44.9 vs. 63.8%, p = 0.017) and more thoracic lesions (12.8 vs. 3.8%, p = 0.038). Shunt rates in our cohort (84.6%) were higher than MOMS prenatal and similar to MOMS postnatal (44.0 and 83.7%, respectively). Fewer children met the original primary outcome than the postnatal group (84.6 vs. 97.8%, p = 0.002). There was no significant difference between our cohort and the prenatal group (84.6 vs. 72.5%, p = 0.058). When applying the revised criteria, we find the opposite: a significant difference between local and MOMS prenatal (84.6 vs. 49.5%, p < 0.001) but no difference between the local group and MOMS postnatal (84.6 vs. 87.0%, p = 0.662).

CONCLUSIONS

Mothers in our cohort differ from mothers enrolled in MOMS via several sociodemographic factors. Baseline fetal characteristics show a significantly higher functional lesion level in between our cohort and MOMS. Treatment of hydrocephalus in our series tracks almost identically with original MOMS shunt criteria. Revision of the criteria led to greater concordance between meeting criteria and receiving a shunt in MOMS patients, but changes the results in our series.

Neuropathic bladders: Investigation and treatment through their lifetime

The child with a neuropathic bladder requires lifelong dedicated care. Just as each patient presents with unique physiology, each phase of their life presents varying challenges. The primary concern for our patients is their renal health, but continence and independence also play significant roles. Most patients can be managed conservatively, but a myriad of surgical options are also available, reinforcing our emphasis on individualized care. Appropriate pre-surgical planning is required to ensure the right patient receives the best operation for his/her wants and needs. Furthermore, the numerous potential complications must be understood and long-term followup and surveillance is required. This review outlines the basic pathophysiology, investigations, and treatments, with a focus on the changing needs throughout their lives.

Fetoscopic versus Open Repair for Spina Bifida Aperta: A Systematic Review of Outcomes

Objective: To compare outcomes of fetoscopic spina bifida aperta repair (FSBAR) with the results of the open approach (OSBAR) as in the Management Of Myelomeningocele Study (MOMS). Methods: This was a systematic comparison of reports on FSBAR with data from the MOMS (n = 78). Inclusion criteria were studies of spina bifida aperta patients who underwent FSBAR and were followed for ≥12 months. Primary outcome was perinatal mortality. Secondary outcomes included operative, maternal, fetal, neonatal and infant outcomes. Results: Out of 16 reports, we included 5 from 2 centers. Due to bias and heterogeneity, analysis was restricted to two overlapping case series (n = 51 and 71). In those, FSBAR was technically different from OSBAR, had comparable perinatal mortality (7.8 vs. 2.6%, p = 0.212) and shunt rate at 12 months (45 vs. 40%, p = 0.619), longer operation time (223 vs. 105 min, p < 0.001), higher preterm prelabor membrane rupture rate (84 vs. 46%, p < 0.001), earlier gestational age at birth (32.9 vs. 34.1 weeks, p = 0.03), higher postnatal reoperation rate (28 vs. 2.56%, p < 0.001) and absence of uterine thinning or dehiscence (0 vs. 36%, p < 0.001). Functional outcomes were not available. Conclusion: FSBAR utilizes a different neurosurgical technique, takes longer to complete, induces more prematurity, requires additional postnatal procedures, yet has a comparable shunt rate and is not associated with uterine thinning or dehiscence. Long-term functional data are awaited.

Fetoscopy for meningomyelocele repair: past, present and future

Meningomyelocele is a malformation with high prevalence, and one of its main comorbidities is Arnold-Chiari malformation type II. The intrauterine repair of this defect has been studied to reduce the progressive spinal cord damage during gestation. The purpose of the present review was to describe the evolution of fetal surgery for meningomyelocele repair. Searches on PubMed database were conducted including articles published in the last 10 years. Twenty-seven articles were selected, 16 experimental studies and 11 studies in humans. A recent study demonstrated that the fetal correction results in better prognosis of neurological and psychomotor development, but open surgery, which has being used widely, has considerable maternal risks. Studies in animal and human models show that the endoscopic approach is feasible and leads to lower maternal morbidity rates. Two endoscopic techniques are currently under assessment - one in Germany and another in Brazil, and we believe that the endoscopic approach will be the future technique for prenatal repair of this defect.