Myelomeningocele: Long-Term Neurosurgical Management.

Open spina bifida, also known as myelomeningocele (MMC), is the most challenging and severe birth defect of the central nervous system compatible with life and it is due to a failure in the dorsal fusion of the nascent neural tube during embryonic development. MMC is often accompanied by a constellation of collateral conditions, including hydrocephalus, Arnold - Chiari II malformation, brainstem disfunction, hydrosyringomyelia, tethered cord syndrome and scoliosis. Beyond early surgical repair of the dorsal defect, MMC requires lifelong cares. Several additional surgical procedures are generally necessary to improve the long-term outcomes of patients affected by MMC and multidisciplinary evaluations are crucial for early identification and management of the various medical condition that can accompany this pathology. In this chapter, the most common pathological entities associated with MMC are illustrated, focusing on clinical manifestations, treatment strategies and follow up recommendations.

Risk of meningomyelocele mediated by the common 22q11.2 deletion.

Meningomyelocele is one of the most severe forms of neural tube defects (NTDs) and the most frequent structural birth defect of the central nervous system. We assembled the Spina Bifida Sequencing Consortium to identify causes. Exome and genome sequencing of 715 parent-offspring trios identified six patients with chromosomal 22q11.2 deletions, suggesting a 23-fold increased risk compared with the general population. Furthermore, analysis of a separate 22q11.2 deletion cohort suggested a 12- to 15-fold increased NTD risk of meningomyelocele. The loss of Crkl, one of several neural tube-expressed genes within the minimal deletion interval, was sufficient to replicate NTDs in mice, where both penetrance and expressivity were exacerbated by maternal folate deficiency. Thus, the common 22q11.2 deletion confers substantial meningomyelocele risk, which is partially alleviated by folate supplementation.

Aberrant Dorsal Nerve Root as a Concomitant Cause of Spinal Cord Tethering Associated with a Dorsal Type Lipomyelomeningocele in a Child With Caudal Agenesis.

ABSTRACT: Tethered cord syndrome is a neurological disorder closely associated with congenital spinal dysraphism. Aberrant dorsal nerve roots may be one of the possible and relatively rare tethering pathologies, especially in the complex form of occult spinal dysraphism such as caudal regression syndrome or split cord malformation. We report an illustrative case of caudal regression syndrome with spinal cord tethering due to a combination of a contiguous bundle of an aberrant dorsal nerve root, and a dorsal-type lipomyelomeningocele, with a thickened filum terminale treated with microneurosurgical untethering.

Quality of life of families and siblings of children and adolescents with meningomyelocele.

BACKGROUND: Children with meningomyelocele may require continuous care. Consequently, there is a risk for caregiver burden and impact on family quality of life (QoL), including siblings' QoL. Some studies analysed caregivers' burden and family QoL separately. However, none of these studies evaluated siblings' QoL and the associations between these three dimensions. This study investigated the associations between caregivers' burden, family QoL and siblings' QoL in Brazilian families of children with meningomyelocele and its correlations with sociodemographic, functional and clinical variables. Siblings' QoL was specifically assessed using as a parameter the QoL of typically developed Brazilian children. METHODS: One hundred and fifty families, 150 caregivers and 68 siblings completed the Family Quality of Life Scale, Burden Interview, KIDSCREEN-27 Child and Adolescent Version and Parents Version questionnaires. RESULTS: Most families and caregivers reported a high family QoL and a low caregiver burden. Family QoL was significantly lower as caregivers' burden increased. Caregiver's burden was significantly lower with increasing family QoL levels. Self-reported siblings' QoL was significantly worse than that of typically developed peers. There were no significant differences between self and parent-reported siblings' QoL. Self-reported siblings' QoL was significantly worse as their age increased and better with increasing family QoL levels. Parent-reported siblings' QoL was significantly worse with increasing levels of caregiver's burden and significantly better as family QoL increased. There were no significant associations with functional and clinical variables. CONCLUSIONS: Despite the cross-sectional nature of the available data precludes any statements of causality, our results reinforce the relevance of knowing the factors that influence the QoL of families and siblings of children and adolescents with meningomyelocele and the relevance of actions aimed at reducing caregivers' burden, improving family QoL and meeting siblings' individual needs. Future multicenter studies may validate the generalizability of our findings.

2- to 20-year myelomeningocele follow-up outcomes from a referral center in Southern Iran: the Shiraz experience.

BACKGROUND: The current convention for treatment of children with myelomeningocele (MMC) is timely surgical intervention combined with long-term follow-up by a multidisciplinary specialized team. This study aims to investigate the outcomes of MMC patients treated at Namazi Hospital. METHODS: All children presenting to Namazi Hospital with myelomeningocele between May 2001 and August 2020 were eligible for this study. For those with a documented telephone number, follow-up phone surveys with the patient's caregivers, on top of the review of the medical documents were carried out to assess mortality, morbidities, and the functional outcome of the care provided to them. RESULTS: A total of 125 patients were studied (62 females). All of the patients were followed up for a mean duration of 6.28 years (range 1-23 years). The majority were located in the lumbosacral area. All of the patients underwent postnatal surgical intervention for MMC in Namazi Hospital. Mean age at surgery was 9.51 days. There were statistically significant differences between urinary and bowel incontinence and presence of scoliosis, MMT grading of the lower limbs, school attendance, number of readmissions, and requirement of laminectomy at the initial surgical intervention. CONCLUSIONS: This study is the first to characterize the long-term outcomes of MMC patients in Iran. This study illustrates that there is a great need for improved access to and coordination of care in antenatal, perioperative, and long-term stages to improve morbidity and mortality.

Surgical limits, pitfalls, and potential solutions in kyphectomy in myelomeningocele: three cases and systematic review of the literature.

OBJECTIVES: To describe surgical treatment of 3 cases of severe and progressive thoracolumbar kyphosis in myelomeningocele and provide a systematic review of the available literature on the topic. METHODS: Medical records and pre- and post-operative imaging of 3 patients with thoracolumbar kyphosis and myelomeningocele were reviewed. A database search was performed for all manuscripts published on kyphectomy and/or surgical treatment of kyphosis in myelomeningocele. Patients' information, preoperative kyphosis angle, type of surgery, levels of surgery degrees of correction after surgery and at follow-up, and complications were reviewed for the included studies. RESULTS: Three cases underwent posterior vertebral column resection (pVCR) of 2-4 segments at the apex of the kyphosis (kyphectomy). Long instrumentation was performed with all pedicle screws constructed from the thoracic spine to the pelvis using iliac screws. According to literature review, a total of 586 children were treated for vertebral kyphosis related to myelomeningocele. At least one vertebra was excised to gain some degree of correction of the deformity. Different types of instrumentation were used over time and none of them demonstrated to be superior over the other. CONCLUSION: Surgical treatment of progressive kyphosis in myelomeningocele has evolved over the years incorporating all major advances in spinal instrumentation techniques. Certainly, the best results in terms of preservation of correction after surgery and less revision rates were obtained with long construct and screws. However, complication rate remains high with skin problems being the most common complication. The use of low-profile instrumentation remains critical for treatment of these patients.

Reflections upon the intrauterine repair of myelomeningocele.

The intrauterine repair of myelomeningocele presents certain advantages and has gained widespread acceptance. It significantly reduces the incidence of Chiari-2 anomalies and hydrocephalus, and it is thought to enhance the neurologic outcome. Nevertheless, several issues remain unsettled and there are no negligible disadvantages. After working with patients with myelomeningocele for 30 years, I thought about how we currently treat them. There are ethical, organizational, neurological, obstetrical, and postnatal aspects worth discussing.

Surgical outcomes of myelomeningocele repair: A 20-year experience from a single center in a middle-income country.

BACKGROUND AND PURPOSE: Spina bifida is the second major cause of congenital disorders and the most common central nervous system congenital malformation compatible with life primarily. Herein, we describe the short-term outcome of post-natal Myelomeningocele (MMC) surgical management and predictors of its postoperative complications and mortality. METHODS: This retrospective chart review studies the children who underwent post-natal surgical management for MMC in Namazi hospital, a tertiary referral center, in southern Iran from May 2001 to September 2020. RESULTS: 248 patients were included in this study. The mean age at the operation was 8.47 ± 8.69 days. The most common site of involvement of MMC was Lumbosacral (86%, n = 204). At the evaluation conducted prior to the operation, cerebrospinal fluid leak was observed in 7% (n=16) of the patients. Postoperatively, 5.7% of the patients expired in the 30-day follow-up after the operation (n = 14), while 24% needed readmission (n = 47). The most common complications leading to readmission were wound dehiscence (n = 10, 42%) and wound purulence (n = 6, 25%). Only the site of the lesion (p-value = 0.035) was associated with postoperative complication. After controlling for potential confounders, the site of the lesion (adjusted odds ratio = 0.146, 95% confidence interval = 0.035-0.610, p-value = 0.008) and age at surgery (adjusted odds ratio = 1.048, 95% confidence interval = 1.002-1.096, p-value = 0.041) were significantly associated with mortality CONCLUSIONS: The age of the patients at the surgery and the site of the lesion are the two factors that were associated with mortality. However, further investigations into preoperative interventions and risk factors to mitigate the risk of complications and mortality are highly encouraged.

Use of a machine learning algorithm with a focus on spinopelvic parameters to predict development of symptomatic tethered cord after initial untethering surgery.

OBJECTIVE: Among patients with a history of prior lipomyelomeningocele repair, an association between increased lumbosacral angle (LSA) and cord retethering has been described. The authors sought to build a predictive algorithm to determine which complex tethered cord patients will develop the symptoms of spinal cord retethering after initial surgical repair with a focus on spinopelvic parameters. METHODS: An electronic medical record database was reviewed to identify patients with complex tethered cord (e.g., lipomyelomeningocele, lipomyeloschisis, myelocystocele) who underwent detethering before 12 months of age between January 1, 2008, and June 30, 2022. Descriptive statistics were used to characterize the patient population. The Caret package in R was used to develop a machine learning model that predicted symptom development by using spinopelvic parameters. RESULTS: A total of 72 patients were identified (28/72 [38.9%] were male). The most commonly observed dysraphism was lipomyelomeningocele (41/72 [56.9%]). The mean ± SD age at index MRI was 2.1 ± 2.2 months, at which time 87.5% of patients (63/72) were asymptomatic. The mean ± SD lumbar lordosis at the time of index MRI was 23.8° ± 11.1°, LSA was 36.5° ± 12.3°, sacral inclination was 30.4° ± 11.3°, and sacral slope was 23.0° ± 10.5°. Overall, 39.6% (25/63) of previously asymptomatic patients developed new symptoms during the mean ± SD follow-up period of 44.9 ± 47.2 months. In the recursive partitioning model, patients whose LSA increased at a rate ≥ 5.84°/year remained asymptomatic, whereas those with slower rates of LSA change experienced neurological decline (sensitivity 77.5%, specificity 84.9%, positive predictive value 88.9%, and negative predictive value 70.9%). CONCLUSIONS: This is the first study to build a machine learning algorithm to predict symptom development of spinal cord retethering after initial surgical repair. The authors found that, after initial surgery, patients who demonstrate a slower rate of LSA change per year may be at risk of developing neurological symptoms.

Cognition and emotional distress in middle-aged and older adults with spina bifida myelomeningocele.

PURPOSE: To investigate cognitive functioning and emotional distress in adults aged 55 to 68 years old with spina bifida myelomeningocele (SBM), both with and without hydrocephalus. A secondary aim was to explore the associations between psychosocial factors in relation to emotional distress. MATERIALS AND METHODS: Cross-sectional study of eleven females and eight males with SBM, five with and twelve without hydrocephalus. Cognitive functioning was investigated with neuropsychological tests and self-report measures. Furthermore, participants completed questionnaires regarding resilience, access to social support, coping, and emotional distress. Descriptive statistics were applied, and Spearman Rho correlation coefficients were used to explore the relationships between psychosocial factors and emotional distress. RESULTS: Eleven exhibited normal cognitive functioning. An observed difference was seen between participants with and without hydrocephalus, where six and five persons reported clinical levels of depression and anxiety, respectively. Positive perceptions of self and future were associated with lower levels of depression and anxiety. CONCLUSION: This study adds important information about cognitive functioning and emotional distress in an understudied population. The results indicated normal cognitive functioning in adults aged 55 to 68 years with SBM without hydrocephalus. Prevalence of emotional distress was comparable with previous studies of younger adults with SBM. There is a need for longitudinal studies investigating cognition and psychological health to fully capture important aspects of the life course of SBM with and without hydrocephalus.

Kyphectomy and sliding growing rod technique in patients with congenital lumbar kyphosis deformity with myelomeningocele.

OBJECTIVE: Neural tube defects are the most common congenital disorders after cardiac anomalies. Lumbar kyphosis deformity is observed in 8-15% of these patients. This deformity severely limits the daily lives of these patients. In our study, we aimed to correct the kyphosis angle of the patients with lumbar kyphosis associated with myelomeningocele (MMC) and allow them to continue their growth without limiting their lung capacity by applying kyphectomy and sliding growing rod technique. PATIENTS AND METHODS: In this study, we retrospectively evaluated 24 patients with congenital lumbar kyphosis deformity associated with MMC, aged between 4 and 9 years, and who applied to Umraniye Training and Research Hospital between the dates of 2018 and 2021. We evaluated preoperative and postoperative kyphosis angles, correction rates, bleeding during operations, operation time, level of instrumentation, number of the resected vertebrae, initial levels of the posterior defects, duration of hospital stays, annual lengthening, and weight of the patients. RESULTS: Mean age was 5.04 (between 4 and 9). Mean preoperative and early postoperative kyphosis angles were 129.8° (87-175°) and 0.79° (- 20-24°), respectively. The kyphotic deformity correction rate was 99.1%. A difference was found regarding kyphosis measurements between preoperative and early period values (p < 0.05). The annual height lengthening of patients was calculated as 0.74 cm/year and 0.77 cm/year between T1-T12 and T1-S1, respectively. Mean preoperative level of hemoglobin (Hgb) was 11.95, postoperative Hgb value was 10.02, and the decrease was significant (p < 0.05). In terms of complications, 50% (12) had broken/loosen screws, 50% (12) had undergone debridement surgery, 37.5% (9) had vacuum-assisted closure therapy, and 33.3% (8) had to get all of their implants removed. CONCLUSION: We believe that our sliding growing rod technique is a new and updated surgical method that can be applied in these patient groups, facilitating the life, rehabilitation process, and daily care of MMC patients with lumbar kyphosis. This technique seems to be a safe and reliable method which preserves lung capacity and allows lengthening.

High-fidelity, low-cost synthetic training model for fetoscopic spina bifida repair.

BACKGROUND: Fetoscopic spina bifida repair is increasingly being practiced, but limited skill acquisition poses a barrier to widespread adoption. Extensive training in relevant models, including both ex vivo and in vivo models may help. To address this, a synthetic training model that is affordable, realistic, and that allows skill analysis would be useful. OBJECTIVE: This study aimed to create a high-fidelity model for training in the essential neurosurgical steps of fetoscopic spina bifida repair using synthetic materials. In addition, we aimed to obtain a cheap and easily reproducible model. STUDY DESIGN: We developed a 3-layered, silicon-based model that resemble the anatomic layers of a typical myelomeningocele lesion. It allows for filling of the cyst with fluid and conducting a water tightness test after repair. A compliant silicon ball mimics the uterine cavity and is fixed to a solid 3-dimensional printed base. The fetal back with the lesion (single-use) is placed inside the uterine ball, which is reusable and repairable to allow for practicing port insertion and fixation multiple times. Following cannula insertion, the uterus is insufflated and a clinical fetoscopic or robotic or prototype instruments can be used. Three skilled endoscopic surgeons each did 6 simulated fetoscopic repairs using the surgical steps of an open repair. The primary outcome was surgical success, which was determined by water tightness of the repair, operation time <180 minutes and an Objective Structured Assessment of Technical Skills score of ≥18 of 25. Skill retention was measured using a competence cumulative sum analysis of a composite binary outcome of surgical success. Secondary outcomes were cost and fabrication time of the model. RESULTS: We made a model that can be used to simulate the neurosurgical steps of spina bifida repair, including anatomic details, port insertion, placode release and descent, undermining of skin and muscular layer, and endoscopic suturing. The model was made using reusable 3-dimensional printed molds and easily accessible materials. The 1-time startup cost was €211, and each single-use, simulated myelomeningocele lesion cost €9.5 in materials and 50 minutes of working time. Two skilled endoscopic surgeons performed 6 simulated, 3-port fetoscopic repairs, whereas a third used a Da Vinci surgical robot. Operation times decreased by more than 30% from the first to the last trial. Six experiments per surgeon did not show an obvious Objective Structured Assessment of Technical Skills score improvement. Competence cumulative sum analysis confirmed competency for each surgeon. CONCLUSION: This high-fidelity, low-cost spina bifida model allows simulated dissection and closure of a myelomeningocele lesion. VIDEO ABSTRACT.

Fetal Spina Bifida Repair in Obese Mothers: Is Maternal and Fetal Safety Compromised?

INTRODUCTION: The Management of Myelomeningocele Study (MOMS) eligibility criteria preclude in utero surgery for fetal spina bifida (fSB) when the maternal body mass index (BMI) is ≥35 kg/m2. Some centers still respect this criterion, while others, like ours, do not. This study aimed to assess whether maternal and fetal safety is compromised with higher maternal BMIs. METHODS: Data of 192 patients with open fSB repair at our center were retrospectively analyzed. According to their BMI, patients were divided into three groups: group 1 (BMI <30 kg/m2), group 2 (BMI 30-35 kg/m2), and group 3 (BMI >35 kg/m2). Subgroup analysis was performed to assess differences in maternal and fetal outcomes. Additionally, complications were divided into grades 1 to 5 according to their severity and outcome consequences and compared among groups. RESULTS: Out of 192 patients, 146 (76.0%) had a BMI <30 kg/m2, 28 (14.6%) had a BMI 30-35 kg/m2, and 18 (9.4%) had a BMI >35 kg/m2. Significant differences occurring more often in either group 2 or 3 compared to group 1 were maternal wound seroma (50% or 56% vs. 32%, p = 0.04), amniotic fluid leakage (14% or 6% vs. 2%, p = 0.01) as well as vaginal bleeding (11% or 35% vs. 9%, p = 0.01). On the contrary, duration of tocolysis with atosiban was shorter in patients with BMI >30 kg/m2 (4 or 5 vs. 6 days, p = 0.01). When comparing severity of maternal or fetal complications, grade 1 intervention-related complications occurred significantly more often in group 3 compared to group 1 or 2 (78% vs. 45% or 57%, p = 0.02). Gestational age at delivery was around 36 weeks in all groups without significant differences. CONCLUSION: This investigation did not identify clinically relevant maternal and/or fetal outcome problems related to BMIs >35 kg/m2. Additional studies are however needed to confirm our results.

Swedish cohort study found that half of the girls with shunted hydrocephalus had precocious or early puberty.

AIM: We aimed to evaluate the occurrence of, and risk factors for precocious and early puberty in a retrospective cohort study of girls with shunted infantile hydrocephalus. METHODS: The study population comprised 82 girls with infantile hydrocephalus, born between 1980 and 2002, and treated with a ventriculoperitoneal shunt. Data were available for 39 girls with myelomeningocele and 34 without. Medical records were analysed regarding clinical data and timing of puberty. Precocious and early puberty was defined as the appearance of pubertal signs before 8 years and 0 months and 8 years and 9 months, respectively. RESULTS: Median age at last admission was 15.8 years (range 10.0-18.0). In total, 15 girls (21%) had precocious puberty, and another 21 (29%) had early puberty. Three or more shunt revisions had been performed in 26/36 girls with early or precocious puberty and in 3/37 girls without (p = 0.01). The number of shunt revisions correlated negatively with age at the start of puberty in the girls with myelomeningocele (Spearman's correlation coefficient = -0.512, p = 0.001). CONCLUSION: Girls with shunted infantile hydrocephalus have a high risk of precocious or early puberty. Repeated shunt revisions seemed to be associated with early puberty.

Seasonal trend in the occurrence of myelomeningocele in nigeria: a hypothesis of climate-induced oxidative stress.

PURPOSE: Myelomeningocele is the most severe birth defect compatible with long-term survival. It accounts for 5.7% of neurological surgeries in Nigeria. However, the exact cause of this neural tube defect remains unidentified. This study aims to determine if seasonal variation is a potential environmental contributor. METHOD: This study prospectively recruited 242 children diagnosed with myelomeningocele at the University of Nigeria Teaching Hospital (UNTH), Enugu, Nigeria, between January 2010 and December 2022. Our primary outcome was the seasonal occurrence of myelomeningocele, while covariates included gender, birth order, maternal folic acid supplementation (FAS), and parental age. The estimated month of conception was derived from the mother's last menstrual period (LMP), and the occurrence of myelomeningocele across the various seasons in which these babies were conceived was assessed using the Lorenz curve and the Gini coefficient. RESULTS: 242 patients were studied with a male-to-female ratio of 1.26. The majority of cases were lumbosacral (93.4%), and none of the mothers commenced FAS before conception. The highest proportion of cases (39.7%) occurred during the hottest period of the dry season (January-March), while the lowest proportion (15.7%) occurred during the early wet season (April-June). The Gini index of 0.29, and the Gini coefficient derived from 100,000 Monte Carlo simulations of 0.24, indicate a significant variation in the distribution of myelomeningocele cases across different seasons of conception. CONCLUSION: The seasonal occurrence of myelomeningocele with a peak in January-March suggests a potential association with environmental factors including oxidative stress induced by solar radiation.

Intrauterine Correction of Fetal Myelomeningocele Through Minihysterotomy.

Spina bifida is the most common congenital central nervous system anomaly, resulting in lifelong neurologic, urinary, motor, and bowel disability.1 Its most frequent form is myelomeningocele, characterized by spinal cord extrusion into a sac filled with cerebrospinal fluid.1 We report the case of a 28-year-old pregnant female with no comorbidities. At 16 weeks of pregnancy, fetal ultrasound presented ventriculomegaly, cerebellar herniation, and lumbar myelomeningocele. At 22 weeks, intrauterine surgical correction was performed (Video 1). A minihysterotomy spanning approximately 3 cm was performed. The defect was opened, and the neural placode was dissected and released. This was followed by the isolation of the peripheric dura, which was molded into a tube and closed with watertight suture. Finally, the minihysterotomy was sutured and the skin was closed. The pregnancy followed its course with no complications, and the child was born at term with the lesion closed and no necessity of intensive care. Recent studies have demonstrated that infants who undergo open in utero myelomeningocele repair have better neurologic outcomes than those who are treated after birth.1,2 However, maternal morbidity is nonnegligible with the classical open surgery.2 Peralta et al2 propose a modification of the classic 6.0- to 8.0-cm hysterotomy in which the same multilayer correction of the spinal defect is performed through a 2.5- to 3.5-cm hysterotomy. This modification, called minihysterotomy, has been successfully performed outside of its creation center and was associated with reduced risks of preterm delivery and maternal, fetal, and neonatal complications.2,3.

Long-term outcomes and complications of isolated anterior thoracolumbar fusion for neuromuscular scoliosis associated with myelomeningocele.

PURPOSE: Neuromuscular scoliosis associated with myelomeningocele is a difficult clinical dilemma for the treating surgeon. The traditional surgical treatment consists of a posterior spinal instrumented fusion with or without a combined anterior procedure, but this has been associated with high complication rates, mostly related to deep infection. An anterior thoracolumbar fusion is not able to address the entirety of the deformity in many cases but could potentially avoid the devastating infection risks from the posterior approach by avoiding compromised skin. This study aims to evaluate the long-term outcomes and complications associated with isolated anterior thoracolumbar fusion in this high-risk group. METHODS: This study is a retrospective analysis of patients with myelomeningocele-associated scoliosis treated with an isolated anterior spinal fusion over a 20-year time period at a single center. Surgical details, demographics, curve characteristics and complications were recorded. Comparisons were made between patients who required revision surgery and those who did not. RESULTS: Sixteen patients were enrolled with an average age of 12.7 years at the time of surgery and average follow-up of 5.5 years. Patients had on average 7.4 levels fused anteriorly with the most common levels being T10-L4. There were no deep wound infections associated with the anterior surgery. Overall, nine patients (56%) had to be revised posteriorly due to adding-on or junctional deformity at an average of 3.7 years after index procedure. Four patients were revised due to proximal adding-on, while 1 was extended distally. Four additional patients were extended both proximally and distally. Of the posterior revisions, 2 patients developed deep wound infections, and both of these were in patients extended distally. Preoperative lumbar lordosis was higher in patients who required distal extension (100 vs. 69 degrees; p = 0.035). CONCLUSIONS: Patients undergoing isolated anterior fusion for scoliosis associated with myelomeningocele have low infection rates but often require posterior revision. The majority of patients can avoid the deep infection risk associated with distal posterior surgery at long-term follow-up. LEVEL OF EVIDENCE: IV.

Allogenic umbilical cord-derived mesenchymal stromal cells improve motor function in prenatal surgical repair of myelomeningocele: An ovine model study.

OBJECTIVE: To investigate the effects of an adjuvant allogenic umbilical cord mesenchymal stromal cell (UC-MSC) patch applied during fetal surgery on motor and sphincter function in the ovine MMC model. DESIGN: MMC defects were surgically created at 75 days of gestation and repaired 14 days later. POPULATION: Ovine MMC model: fetal lambs. METHODS: We compared lambs that received a UC-MSC patch with a control group of lambs that received an acellular patch. MAIN OUTCOME MEASURES: Clinical neurological assessment was performed at 2 and 24 hours of life and included determination of the Sheep Locomotor Rating scale (SLR), which has been validated in the ovine MMC model. Electrophysical examinations, spine scans and histological analyses were also performed. RESULTS: Of the 13 operated lambs, nine were born alive: five had of these had received a UC-MSC patch and four an acellular patch. At 24 hours of life, lambs in the UC-MSC group had a significantly higher score (14 versus 5, P = 0.04). Amyotrophy was significantly more common in the control group (75% versus 0%, P = 0.02). All the lambs in the control group and none of those in the UC-MSC group were incontinent. No significant differences were observed between the UC-MSC and control groups in terms of the presence of spontaneous EMG activity, nerve conduction or spinal evoked potentials. In the microscopic examination, lambs in the UC-MSC group had less fibrosis between the spinal cord and the dermis (mean thickness, 453 versus 3921 µm, P = 0.03) and around the spinal cord (mean thickness, 47 versus 158 µm, P < 0.001). Examination of the spinal cord in the area of the MMC defect showed a higher large neuron density in the UC-MSC group (14.5 versus 5.6 neurons/mm2, P < 0.001). No tumours were observed. CONCLUSIONS: Fetal repair of MMC using UC-MSC patches improves motor and sphincter function as well as spinal preservation and reduction of fibrosis.