Flap Closure in Neonatal Neural Tube Defects: Challenges in Flap Design and Lessons Learnt.

Background: Management of neural tube defects (NTDs) is challenging and the outcome is demanding. Aims: To analyze the outcomes in operated cases of NTDs closed using various types of flaps. Materials and Methods: The data between June 2017 and May 2023 were analyzed. The mode of presentation, timing of intervention, type of flap, neurological status after closure, status of the wound, presence of hydrocephalous, flap blackening, flap necrosis, features of sepsis, and the outcome were recorded and analyzed. Covered NTD; closure done using primary closure or 'Z' Plasty (everywhere); incomplete data; lost to follow-up; and not giving consent were excluded from the study. Results: Out of 92 cases, 35 were operated using the rhomboid flap, 33 using dufourmentel modification of limberg flap, and 24 using keystone island flap. The mean age at presentation was 4 days (range: 0-28 days). The mean duration of surgery after presentation was 2 days (range: 1-3 days). Mean operating time was 1.15 h (range: 0.45-3.15 h). A ventriculoperitoneal shunt was required in 62 cases at various stages. The preoperative and the postoperative power were nearly the same in all. Wound infection was seen in 2, 3, and 1 cases in each group. Blackening of the flap was seen in 3, 2, and 1 cases in three groups. Cerebrospinal fluid (CSF) leak was seen in 2, 2, and 0 cases. Wound dehiscence was present in one case in each group and sepsis was present in 2, 3, and 2, respectively. Conclusion: The management of open NTD requires adequate planning. CSF shunting and flap closure are often required.

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

BACKGROUND: In utero repair of open neural tube defects using an open hysterotomy approach (hereafter referred to as "open") has been shown to reduce the need for ventriculoperitoneal shunting and to improve motor outcomes for affected infants. Laparotomy-assisted fetoscopic repair (hereafter referred to as "hybrid") is an alternative approach that may confer similar neurologic benefits while reducing the incidence of hysterotomy-related complications. OBJECTIVE: This study aimed to analyze procedure-related maternal and fetal complications of in utero repair using the Clavien-Dindo classification, and to compare the outcomes of the hybrid and open approaches. STUDY DESIGN: This was a retrospective cohort study conducted in a single center between September 2011 and July 2021. All patients who met the Management of Myelomeningocele Study criteria and who underwent either hybrid or open fetal surgery were included. Maternal complications were classified using a unique adaptation of the Clavien-Dindo scoring system, allowing the development of a comprehensive complication index score specific to fetal surgery. Primary fetal outcome was defined as gestational age at delivery and summarized according to the World Health Organization definitions of preterm delivery. RESULTS: There were 146 fetuses with open neural tube defects who were eligible for, and underwent, in utero repair during the study period. Of these, 102 underwent hybrid fetoscopic repair and 44 underwent open hysterotomy repair. Gestational age at the time of surgery was higher in the hybrid group than in the open group (25.1 vs 24.8 weeks; P=.004). Maternal body mass index was lower in the hybrid than in the open group (25.4 vs 27.1 kg/m2; P=.02). The duration of hybrid fetoscopic surgery was significantly longer in the hybrid than in the open group (250 vs 164 minutes; P<.001). There was a significantly lower Clavien-Dindo Grade III complication rate (4.9% vs 43.2%; P<.001) and a significantly lower overall comprehensive maternal complication index (8.7 vs 22.6; P=.021) in the hybrid group than in the open group. Gestational age at delivery was significantly higher in the hybrid group than in the open group (38.1 vs 35.8 weeks; P<.001), and this finding persisted when gestational age at delivery was analyzed using the World Health Organization definitions of preterm delivery. CONCLUSION: Use of our adaptation of the standardized Clavien-Dindo classification to assess the maternal complications associated with in utero open neural tube defect repair provides a new method for objectively assessing different fetal surgical approaches. It also provides a much-needed standardized tool to allow objective comparisons between methods, which can be used when counseling patients. The hybrid open neural tube defect repair was associated with lower rates of maternal adverse events , and later gestational age at delivery compared with the open approach.

Fetal MRI prior to intrauterine surgery of open neural tube defects: What does the radiologist need to know.

The management of myelomeningocele study trial showed significant prognostic improvement in fetal repair before 26 weeks of gestation. Hence, surgery in utero represents the best treatment option for open-neural tube defects (NTDs). Fetal surgery of open-NTDs has specific inclusion and exclusion criteria, which can be adequately studied with fetal MRI. The main concern: the spine (spinal defects other than Myelomeningocele and Myeloschisis, the level of the lesion higher than T1 or lower than S1 and the degree of kyphosis ≥ 30°), the skull/brain (no cerebellum herniation and Chiari II malformation and the presence of any intracranial abnormality unrelated to open NTDs), the uterus (cervix length less than 2 cm, multiple gestations and placental and uterine abnormalities) and any other fetal abnormality not attributed to spinal defect. In this review, we describe the fundamental role of fetal MRI in supporting therapeutic decisions in pre-surgery intrauterine planning through the accurate and comprehensive description of findings, providing a proposal of a structured report. In addition, we describe how post-surgical MRI is important in investigating the effectiveness of surgery and detecting repairing complications.

Comparison of dorsal intercostal perforator artery flap and primary closure in myelomeningocele repair.

PURPOSE: Of the many suggested techniques, we used dorsal intercostal perforator artery flap (DIPAF) for the closure of myelomeningocele defects. This study compared the outcomes of primary closure and DIPAF in the closure of myelomeningoceles. METHODS: Data of 24 patients that underwent myelomeningocele surgery at a single institution between November 2015 and September 2019 were retrospectively reviewed. RESULTS: The primary closure group had 13 patients (54.17%) and the DIPAF group had 11 (45.83%). The mean age was 7.91 ± 13.27 days (1-60 days). Twelve patients were female and 12 were male. In 22 patients, the myelomeningocele sacs were in the lumbosacral region, while in 2, they were in the thoracolumbar region. The mean defect sizes were 14.20 ± 4.62 cm2 and 18.44 ± 3.49 cm2 in the primary closure and DIPAF groups, respectively. In each group, four patients had a kyphotic deformity. In the primary closure group, three patients had wound necrosis, two had wound dehiscence, and four had cerebrospinal fluid (CSF) leakage. In the DIPAF group, one patient had wound necrosis and one had CSF leakage. Significantly fewer complications related to the operation area were observed in the DIPAF group (p < 0.05). Increased defect size, kyphotic deformity, and presence of hydrocephalus were found to be risk factors for complications related to the operation area. CONCLUSION: This surgical treatment protects neural tissue, prevent CSF leakage, and reduce central nervous system infection rates in myelomeningocele patients. Closure technique with the fasciocutaneous skin flap has more satisfying results than primary closure.

Laboratory screening and diagnosis of open neural tube defects, 2019 revision: a technical standard of the American College of Medical Genetics and Genomics (ACMG).

Open neural tube defects (ONTDs) include open spina bifida (OSB) and anencephaly. These defects are caused by incomplete closure of the neural tube at about 4 weeks of pregnancy. Levels of early second-trimester maternal serum (ms) alpha-fetoprotein (AFP) are sufficiently elevated in affected pregnancies to be used as a population-based screening test. The basic screening methodology was described in the late 1970s and screening programs were active a few years later. By identifying pregnancies with the highest msAFP levels, about 80% of OSB and 95% of anencephaly can be identified as early as 16 weeks gestation. The interpretation of msAFP levels is complicated by the need to consider multiple factors such as gestational age, maternal weight, maternal race, multiple gestations, and more. Testing for AFP and acetylcholinesterase in amniotic fluid and/or identification of the lesion by targeted ultrasound is considered diagnostic of ONTD. When a diagnosis is made, options include termination, surgery after delivery, or in utero surgery, depending on factors such as location and size of the defect, and the presence of any additional anomalies. Screening for ONTD should be performed as part of a comprehensive program linking primary obstetrical care providers, laboratorians, and high-risk clinicians.

Prenatal Repair of Spina Bifida: A 2-Center Experience with Open Intrauterine Neurosurgery in Chile.

OBJECTIVE: To report the experience with prenatal repair of open spina bifida (OSB) from 2 centers in Chile. METHODS: Women with a second-trimester fetus with OSB were offered intrauterine neurosurgical repair following the protocol from the Management of Myelomeningocele Study (MOMS) trial. Pediatric follow-up with infants reaching 12 and 30 months of life was also reviewed. RESULTS: Fifty-eight fetuses with OSB underwent intrauterine repair at an average (±SD) gestational age of 24.8 ± 0.9 weeks. There were 3 (5.1%) intrauterine deaths. The average gestational age at delivery of the remaining 55 cases was 33.3 ± 3.6 weeks, and the average birth weight was 2,172 ± 751 g. Delivery before 30 weeks occurred in 11 cases (20.0%). Two (3.6%) neonatal deaths (<28 days) occurred. At 12 months, a ventriculoperitoneal shunt or an endoscopic third ventriculostomy was required in 25% of the cases. At 30 months, 72.4% of the infants were able to walk. DISCUSSION: Prenatal neurosurgical repair of OSB is a complex and challenging intervention. Major complications include perinatal death and severe prematurity. No major maternal complications occurred in our series. A reduction in the need for cerebrospinal fluid diversion and an improved ability to walk seem to be the greatest long-term advantages of this procedure.

Prenatal diagnosis of spina bifida: from intracranial translucency to intrauterine surgery.

Accurate and timely prenatal diagnosis of spina bifida (SB) is a major goal of modern antenatal care. Prenatal screening for open SB should be first performed at the time of routine first-trimester ultrasound by examining the posterior fossa for obliteration or non-visualization of the fourth ventricle ("intracranial translucency") and cisterna magna. The second step of screening is the second-trimester anatomy scan, at which time the features of the Chiari type II malformation should be looked for, including ventriculomegaly, scalloping of the frontal bones ("lemon" sign), and backward and caudal displacement of the cerebellar vermis with obliteration of the cisterna magna ("banana" sign). In cases with positive findings, evaluation must include a focused examination of the spine for defects. In cases of closed SB and SB occulta, the cranial and posterior fossa features will not be present as they are not associated with leaking of spinal fluid and resultant hindbrain herniation, highlighting the fact that the spine should be examined thoroughly whenever possible during the second-trimester scan. In tertiary fetal medicine centers, two-dimensional and three-dimensional ultrasound allows an accurate determination of the location, type, extent, and upper level of the spinal defect as well as the presence of associated anomalies. Fetal magnetic resonance imaging should be restricted to candidates for intrauterine surgery as part of the preoperative protocol.

Sonographic spectrum of first-trimester fetal cephalocele: review of 35 cases.

OBJECTIVE: To describe the sonographic features of fetal cephalocele diagnosed at the time of first-trimester ultrasound screening for aneuploidy. METHODS: This was a retrospective review of cases of cephalocele diagnosed in the first trimester at four fetal medicine referral centers. Once diagnosis was suspected, a transvaginal ultrasound examination was offered to improve depiction of the cranial defect and enhance examination of fetal anatomy, with special attention given to the location, size and content of defects. To assure consistency in diagnosis, representative pictures and videoclip sequences of the cranial defect were obtained and reviewed by at least two authors. Cases were classified and compared with the assessment made at diagnosis. RESULTS: Of the 35 affected fetuses identified, 33 were of a singleton pregnancy and two were of twin pregnancies in which the other fetus was unaffected. The lesion was classified as a cranial meningocele in 13 (37%) cases and as an encephalocele in 22 (63%). The bone defect was occipital in 27 (77%), frontal in three (9%), parietal in three (9%) and non-classifiable in two (6%). Twelve (34%) were considered as small in size, 11 (31%) as medium and 12 (34%) as large. There were no reported cases of aneuploidy; however, four (11%) cases were associated with Meckel-Gruber syndrome, two (6%) with a disruptive syndrome and one (3%) with skeletal dysplasia. Eight (23%) pregnancies were lost to follow-up. Parents opted for termination of pregnancy in 21 of the 27 remaining cases and, of the six ongoing pregnancies, four patients miscarried or the fetus died in utero during the second trimester, one liveborn infant died shortly after delivery and one underwent neonatal surgery for an isolated cranial meningocele and is currently doing well. CONCLUSIONS: First-trimester sonographic diagnosis of cephalocele is accomplished easily with a detailed examination of the skull contour at the time of routine assessment of the axial and sagittal views of the head for measurement of the biparietal diameter and nuchal translucency, respectively. However, the sonographic features are highly variable. A significant proportion of cases are associated with genetic or disruptive syndromes. Prenatal diagnosis of cephalocele in the first trimester was associated with a high rate of termination of pregnancy and early intrauterine fetal demise. Only one fetus in this series survived and is neurologically intact; therefore, the prognosis of this condition remains poor.

Construction and predictive value of risk models of maternal serum alpha-fetoprotein variants and fetal open neural tube defects.

The correlation of maternal serum alpha-fetoprotein (AFP) variants (AFP-L2, AFP-L3), free beta-human chorionic gonadotropin (free ß-hCG), and open neural tube defects (ONTDs) during the second trimester, and the screening efficiency of different risk models remain indistinct. We conducted a retrospective case-control study, and studied 57 pregnant women with ONTD fetuses and 569 pregnant women with normal fetuses. The receiver operating characteristic curve method indicated the best cutoff value and area under the curve (AUC). The predictive value of ONTD risk models by free ß-hCG, AFP, AFP-L2, and AFP-L3 was investigated via integrated discrimination improvement (IDI), net reclassification improvement (NRI), and decision curve analysis (DCA). Compared to the control group, AFP, AFP-L2, and AFP-L3 levels were significantly higher, while free ß-hCG level was significantly lower in the study group. The triple-index model of free ß-hCG + AFP-L2 + AFP-L3 and the dual-index model of AFP-L2 + AFP-L3 showed the best predictive values, respectively (AUC = 0.905; AUC = 0.885). The order of the single-index model AUCs was AFP-L3 > AFP-L2 > AFP > free ß-hCG. The negative predictive value, false positive rate, and negative likelihood ratio of AFP-L2, AFP-L3 alone, or combined with free ß- hCG were better than those of AFP alone; however, the positive likelihood ratio was the opposite. The replacement of AFP by AFP-L2 or AFP-L3 combined with free ß-hCG increased the IDI and NRI for predicting ONTD. The top five DCAs were AFP-L2 + free ß-hCG, free ß-hCG, AFP-L3, AFP + free ß-hCG, and AFP. Indicators of maternal serum free ß-hCG, AFP-L2, and AFP-L3 in the second trimester exhibited high sensitivity and specificity screening for ONTD fetuses. Risk models constructed using AFP-L2 + AFP-L3 and AFP-L2 + AFP-L3 + free ß-hCG demonstrated better screening efficiency.

A comparison of the maternal levels of serum proprotein convertase subtilisin/kexin type 9 in pregnant women with the complication of fetal open neural tube defects.

It was aimed to evaluate the levels of maternal serum proprotein convertase subtilisin/kexin type 9 (PCSK9) in pregnant women with a fetus diagnosed with open neural tube defects (NTDs). This case-control study included 38 pregnant women carrying fetuses with open NTDs and 44 age-matched, pregnant women with no specified risk factors. Comparisons were made of the groups in respect of demographic and clinical data and PCSK9 levels. To examine the performance of PCSK9 levels in the prediction of fetal open NTDs, receiver operating characteristic (ROC) curve analysis was used. In the first and second trimesters, PCSK9 levels were determined to be lower in the NTD group than in the control group (p = 0.010 and p = 0.015, respectively). In the first trimester, the lower PCSK9 levels in the NTD group were not statistically significant (p = 0.575). In the second trimester, the ROC curve value with the best balance of sensitivity/specificity for PCSK9 was 71.9 ng/ml (84.6% sensitivity, 51.7% specificity) and in the first and second trimester combined, 74.4 ng/ml (81.6% sensitivity, 45.5% specificity) (p = 0.015, p = 0.036, respectively). PCSK9 may be involved in the etiopathogenesis of open NTDs at the critical steps of fetal neuronal differentiation. Although it has limitations, PCSK9 may be used as an additional biomarker for the screening of NTDs.

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.

Prenatal serum screening for Down syndrome and neural tube defects in the United States: Changes in utilization patterns from 2012 to 2020.

OBJECTIVE: To compile current usage of serum-based prenatal screening for Down syndrome in the United States and compare it with results from a similar 2011/2012 survey. SETTING: The College of American Pathologists maternal screening proficiency testing survey includes a supplemental question on the first of three yearly distributions. METHODS: Information regarding tests offered and the monthly number of pregnancies tested for US-based laboratories were reviewed. Results were stratified by size of laboratory, tests offered, and pregnancies tested. Findings were compared to an earlier survey. RESULTS: Fifty-six laboratories reported they will have screened 1,131,336 pregnancies in 2020. Of these, 36% are screened by stand-alone first trimester testing, 48% by stand-alone second trimester testing, and 16% using tests that integrate results from both trimesters. Eighty percent of all serum screens were provided by the five laboratories that performed the most screens (at least 50,000). These five performed similar proportions of first or second trimester screens (42.2% and 41.8%, respectively). Compared to eight years earlier, there are now 54% fewer laboratories. Pregnancies screened using the first trimester, second trimester, and integrated protocols were lower by 27%, 69%, and 72%, respectively. The serum screening activity in the US showed a 62% decrease from 2012 levels. During 2012-2020, the number of cell-free DNA tests increased from negligible to 1,492,332. CONCLUSIONS: Maternal serum screening for common aneuploidies has changed significantly in eight years with fewer laboratories, a shift toward larger laboratories and a 2.5-fold reduction in pregnancies tested, likely due to the introduction of cell-free DNA screening.

V-Y Plasty or Primary Repair Closure of Myelomeningocele: Our Experience.

BACKGROUND: Open neural tube defects in the spine most commonly are in the lumbo-sacral region. Surgical closure is the treatment, but in primary closure the chances of CSF leak are more. Hence a novel technique of using an advancement flap called the V-Y plasty for closure of these defects(6). Our study compares the outcomes of primary closure and V-Y plasty in the closure of Myelomeningocoeles. METHODS: A prospective study of the infants who underwent surgical repair for MMC at our hospital from August 2014- January 2018 were included in the study. Total of 22 infants were treated, 9 underwent primary repair and 13 underwent V-Y plasty. RESULTS: The time taken for primary closure was a mean of 120 min, while the advancement flap took longer of 190.7 min. All the 9 who underwent primary closure had CSF leak, 3 developed hydrocephalus, 6 had wound dehiscence, 3 had neurological deficits and 1 died. Of the 13 infants who underwent V-Y plasty 3 had CSF leaks, 1 had hydrocephalus, 5 had neurological deficits and no wound dehiscence or deaths. CONCLUSION: The aim of surgical repair is to cover the exposed neural tissue, prevent CSF leak and reduce CNS infections. V-Y plasty a plastic surgical technique of advancement flaps with intact pedicles improves the outcome of skin closure once the neural placode is placed in the dura and closed. This reduces the morbidity in a one-time procedure.

Congenital malformations of the brain and spine.

In this chapter we briefly address the most common congenital brain and spinal anomalies as well as their most salient imaging, especially magnetic resonance, findings. Some of them, such as Chiari II, and open spinal defects, have become relatively rare due to their detection in utero and repair of the spinal malformation. Regardless of the type of brain anomaly, the most common clinical symptoms are mental retardation, hydrocephalus, and seizure; the latter two may need to be surgically and medically addressed. The most commonly found spinal congenital anomalies include the filum terminale lipoma which is generally asymptomatic and incidental and the caudal regression syndrome for which no primary treatment exists. Any spinal congenital anomaly may present in adulthood as a consequence of spinal cord tethering and/or development of syringomyelia.

Maternal Serum Screening Markers and Adverse Outcome: A New Perspective.

There have been a number of studies evaluating the association of aneuploidy serum markers with adverse pregnancy outcome. More recently, the development of potential treatments for these adverse outcomes as well as the introduction of cell-free fetal DNA (cffDNA) screening for aneuploidy necessitates a re-evaluation of the benefit of serum markers in the identification of adverse outcomes. Analysis of the literature indicates that the serum markers tend to perform better in identifying pregnancies at risk for the more severe but less frequent form of individual pregnancy complications rather than the more frequent but milder forms of the condition. As a result, studies which evaluate the association of biomarkers with a broad definition of a given condition may underestimate the ability of such markers to identify pregnancies that are destined to develop the more severe form of the condition. Consideration of general population screening using cffDNA solely must be weighed against the fact that traditional screening using serum markers enables detection of severe pregnancy complications, not detectable with cffDNA, of which many may be amenable to treatment options.