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Background and Objectives: Evolving technologies have influenced the practice of myelomeningocele repair (MMCr), including mandatory folic acid fortification, advances in prenatal diagnosis, and the 2011 Management of Myelomeningocele Study (MOMS) trial demonstrating benefits of fetal over postnatal MMCr in select individuals. Postnatal MMCr continues to be performed, especially for those with limitations in prenatal diagnosis, health care access, anatomy, or personal preference. A comprehensive, updated national perspective on the trajectory of postnatal MMCr volumes and patient disparities is absent. We characterize national trends in postnatal MMCr rates before and after the MOMS trial publication (2000-2010 vs 2011-2019) and examine whether historical disparities persist., Methods: This retrospective, cross-sectional analysis queried Nationwide Inpatient Sample data for postnatal MMCr admissions. Annual and race/ethnicity-specific rates were calculated using national birth registry data. Time series analysis assessed for trends relative to the year 2011. Patient, admission, and outcome characteristics were compared between pre-MOMS and post-MOMS cohorts., Results: Between 2000 and 2019, 12 426 postnatal MMCr operations were estimated nationwide. After 2011, there was a gradual, incremental decline in the annual rate of postnatal MMCr. Post-MOMS admissions were increasingly associated with Medicaid insurance and the lowest income quartiles, as well as increased risk indices, length of stay, and hospital charges. By 2019, race/ethnicity-adjusted rates seemed to converge. The mortality rate remained low in both eras, and there was a lower rate of same-admission shunting post-MOMS., Conclusion: National rates of postnatal MMCr gradually declined in the post-MOMS era. Medicaid and low-income patients comprise an increasing majority of MMCr patients post-MOMS, whereas historical race/ethnicity-specific disparities are improving. Now more than ever, we must address disparities in the care of MMC patients before and after birth., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

Background: Myelomeningocele is associated with hydrocephalus in 35% to 90% of cases. Hydrocephalus is usually treated with insertion of ventriculoperitoneal shunt; however, there is growing evidence that endoscopic third ventriculostomy (ETV) with choroid plexus cauterization (CPC) is an alternative., Objective: To compare the success rate and morbidity of ETV with CPC and ventriculoperitoneal shunt (VPS) as the primary treatment of hydrocephalus in patients with myelomeningocele., Methods: A prospective study from January 2016 to February 2019, involving 46 patients with myelomeningocele who developed hydrocephalus after repair in a tertiary hospital in southwestern Nigeria. Biodata and preoperative features of hydrocephalus were documented. ETV + CPC or VPS was done using standard operative techniques. Patients were followed up monthly for 6 mo., Results: There were 23 patients in the ETV + CPC arm and 22 patients in the VPS arm. Morbidities were cerebrospinal fluid leak, 8.3% in the ETV + CPC arm and 4.5% in the VPS arm, wound dehiscence, 13.6% in the VPS arm, none in the ETV + CPC arm. At 6-mo follow-up, success rate for ETV + CPC was 60.9% and 59.1% for VPS, P = .9., Conclusion: ETV + CPC had similar success rate with VPS at 6 mo with lower morbidity. ETV + CPC should be considered a viable alternative when treating patients with myelomeningocele and hydrocephalus., (© Congress of Neurological Surgeons 2021.)

Background and Importance: Lumbar hyperlordosis in ambulatory children is an uncommon but potentially problematic spinal deformity, and the operative management has not been comprehensively described., Clinical Presentation: We report the case of a 14-yr-old girl presenting with severe progressive lumbar hyperlordosis (-122°) and sagittal imbalance (-6 cm). She had multiple prior surgeries, including myelomeningocele repair at 10 d old, midlumbar meningioma resection at 8 mo old, and posterior lumbar instrumented spinal fusion at 5 yr old. She presented with progressive lumbosacral back pain and intermittent numbness in her left lower extremity, and severe skin contractures over her prior posterior incisions. From an all posterior approach, prior implants and dural scar were removed and then an L5 vertebral column resection (VCR) was performed to disarticulate her lumbar spine from her anteverted pelvis, allowing for slow distraction forces to correct her lumbar hyperlordosis. This was followed by a T7-sacrum fusion using pedicle screws and iliac screws, with autologous bone graft and plastic surgery wound closure. Postoperatively, lumbar lordosis was corrected to -55° and sagittal balance reduced to -0.5 cm. At 10-wk and 14-mo follow-ups, the patient reported resolution of her back pain with no limitations in physical activities. Dramatic improvement was seen in both her preoperative to 14-mo postoperative Oswestry Disability Index (ODI) (54 to 12) and Scoliosis Research Society Scoliosis Research Society (SRS)-22r (54 to 93) scores., Conclusion: This case highlights a rare presentation of severe progressive lumbar hyperlordosis in an ambulatory adolescent after myelomeningocele repair, meningioma resection, and posterior lumbar instrumented spinal fusion with subsequent surgical treatment incorporating important components of both spinal and plastic surgery involvement., (© Congress of Neurological Surgeons 2021.)

Background: Few have explored the safety and efficacy of posterior vertebral column subtraction osteotomy (PVCSO) to treat tethered cord syndrome (TCS)., Objective: To evaluate surgical outcomes after PVCSO in adults with TCS caused by lipomyelomeningocele, who had undergone a previous detethering procedure(s) that ultimately failed., Methods: This is a multicenter, retrospective analysis of a prospectively collected cohort. Patients were prospectively enrolled and treated with PVCSO at 2 institutions between January 1, 2011 and December 31, 2018. Inclusion criteria were age ≥18 yr, TCS caused by lipomyelomeningocele, previous detethering surgery, and recurrent symptom progression of less than 2-yr duration. All patients undergoing surgery with a 1-yr minimum follow-up were evaluated., Results: A total of 20 patients (mean age: 36 yr; sex: 15F/5M) met inclusion criteria and were evaluated. At follow-up (mean: 23.3 ± 7.4 mo), symptomatic improvement/resolution was seen in 93% of patients with leg pain, 84% in back pain, 80% in sensory abnormalities, 80% in motor deficits, 55% in bowel incontinence, and 50% in urinary incontinence. Oswestry Disability Index improved from a preoperative mean of 57.7 to 36.6 at last follow-up (P < .01). Mean spinal column height reduction was 23.4 ± 2.7 mm. Four complications occurred: intraoperative durotomy (no reoperation), wound infection, instrumentation failure requiring revision, and new sensory abnormality., Conclusion: This is the largest study to date assessing the safety and efficacy of PVCSO in adults with TCS caused by lipomyelomeningocele and prior failed detethering. We found PVCSO to be an excellent extradural approach that may afford definitive treatment in this particularly challenging population., (© Congress of Neurological Surgeons 2020.)

Myelomeningocele (MMC) is the most common open neural tube defect associated with long-term survival. In 2011, The Management of Myelomeningocele Study (MOMS) trial demonstrated that fetal repair for MMC reduced the rate of shunted hydrocephalus and improved developmental, motor, and ambulation outcomes at 30 mo compared to postnatal intervention.1 Recent studies have demonstrated the safety and feasibility of fetoscopic MMC repair as well as reduction in preterm birth, lower risk of uterine dehiscence, and the option of vaginal delivery with this approach compared to open fetal repair.2-4 The patient is a 25-yr-old female, G4 P2, who presented at 20 wk's gestation with ultrasound findings concerning for MMC and Chiari II malformation. These findings were further corroborated with fetal magnetic resonance imaging. After extensive prenatal counseling in a multidisciplinary fashion and discussion regarding risks and benefits of prenatal closure of the MMC, the patient chose to undergo prenatal repair and surgical consent was obtained. At 25 wk's gestation, the patient underwent a fetoscopic multilayer closure with dural patch repair using a standardized, 3-port, carbon dioxide insufflation technique for the intrauterine treatment of MMC without any postoperative complications. The duration of the entire procedure was 275 min. At 36 wk's and 1 d's gestational age, the patient had a spontaneous vaginal delivery, resulting in a healthy male newborn. The surgical site was well healed without complications, and follow-up radiographic imaging was reassuring. This edited, 2-dimensional operative video highlights the key steps of the fetoscopic closure with follow-up postnatal clinical and radiographic outcomes., (Copyright © 2020 by the Congress of Neurological Surgeons.)

Background: The Management of Myelomeningocele Study (MOMS) demonstrated that fetal myelomeningocele (fMMC) closure results in improved hydrocephalus and hindbrain herniation when compared to postnatal closure., Objective: To report on the outcomes of a single institution's experience in the post-MOMS era, with regard to hydrocephalus absence and hindbrain herniation resolution., Methods: A single-center retrospective study of a subset of post-MOMS patients who underwent fetal/postnatal myelomeningocele closure was performed. Primary outcomes included cerebrospinal fluid (CSF) diversion status and hindbrain herniation resolution. Families were contacted via telephone for outcome information if care was transitioned to outside institutions. Univariate/multivariable analyses were performed using several prenatal and postnatal variables., Results: From January 2011 to May 2016, data were reviewed from families of 62 postnatal and 119 fMMC closure patients. In the postnatal group, 80.6% required CSF diversion compared to 38.7% fetal cases (P < .01). Hindbrain herniation resolution occurred in 81.5% fetal repairs compared to 32.6% postnatal (P < .01). In the fetal group, fetal/premature neonatal demise occurred in 6/119 (5.0%) patients. There was a 42.0% decrease (95% CI -55.2 to -28.8) and 48.9% increase (95% CI 33.7 to 64.1) in risk difference for CSF diversion and hindbrain herniation resolution, respectively, in the fetal group. On univariate analysis for both groups, prenatal atrial diameter, frontal-occipital horn ratio, and hindbrain herniation resolution were significantly associated with the absence of clinical hydrocephalus. The treatment of hydrocephalus was significantly delayed in the fetal group compared to the postnatal group (10 mo vs 13.8 d)., Conclusion: This study demonstrates the benefits of fMMC closure with regard to CSF dynamics., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Background: The effect of modifications in fetal myelomeningocele (fMMC) closure techniques has not been extensively studied., Objective: To study the effect of a modified closure technique on fMMC postnatal patient outcomes: hydrocephalus, hindbrain herniation, and cyst development., Methods: We performed single-center retrospective study of a subset of post-MOMS (Management of Myelomeningocele Study) trial patients who underwent fMMC closure. After January 2015, the fetal myofascial closure technique was modified. Needlepoint monopolar cautery was used to raise dural lined myofascial flaps to create a more robust closure. Outcomes between the pre- and postmodification groups were compared with regard to hindbrain herniation, hydrocephalus, and cyst development. Families who transitioned care to local institutions were contacted via telephone for outcome information., Results: From January 2011 to May 2016, data were reviewed from 119 fMMC closure patients. Patients without full follow-up data were excluded from the final analysis. Cerebrospinal fluid diversion was seen in 32 of 74 patients with the standard technique compared to 14 of 45 with the modified closure and was significantly decreased in postmodification when compared to that of the MOMS trial (P = .01). Hindbrain herniation resolution was significantly decreased in both the pre- and postmodification groups compared to that of the MOMS trial (P < .01). Prior to January 2015 with standard closure, 23 cysts required resection whereas no cysts required resection in the modified repair group (P < .01)., Conclusion: Modified myofascial closure for fMMC closure is safe and feasible. The new approach reflects a decreased rate of cyst development requiring surgical resection, and a trend for improved rates of hindbrain herniation and hydrocephalus., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Background: The incidence of spina bifida (SB) is higher in the developing world as compared to the United States because of folic acid deficiency during pregnancy. Advances in technology have made prenatal repair of myelomeningocele (MM) possible., Objective: The objective of this guideline was to determine if there is a difference in the rate of development of tethered cord syndrome (TCS) in infants who had prenatal closure compared to infants who had MM repair after birth., Methods: The Guidelines Task Force developed search terms and strategies to search PubMed and Embase for the relevant literature published between 1966 and September 2016. Strict inclusion/exclusion criteria were used. Full text articles were reviewed and, when appropriate, included as evidence., Results: A total of 261 abstracts were reviewed. Fifty-four full-text articles were selected for further analysis. Three studies met inclusion criteria., Conclusion: There was Class II evidence from 1 study and Class III evidence from another 2 studies demonstrating that TCS develops in infants with prenatal MM closure at an equal or higher rate than with postnatal closure. There was an increased risk of development of inclusion cysts in infants who underwent in utero closure. Continued surveillance for TCS and/or the development of inclusion cysts in children with prenatal and postnatal closure of MM is indicated (Level II). Differences between prenatal and postnatal repair with respect to the development of TCS and/or inclusion cysts should be considered alongside other relevant maternal and fetal outcomes when deciding upon a preferred method for MM closure.The full guideline can be found at https://www.cns.org/guidelines/guidelines-spina-bifida-chapter-6., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Background: Myelomeningocele (MM) is an open neural tube defect treated by pediatric neurosurgeons with prenatal or postnatal closure., Objective: The objective of this systematic review was to answer the question: What is the evidence for the effectiveness of prenatal vs postnatal closure of MM regarding short and long-term ambulatory status? Treatment recommendations were provided based on the available evidence., Methods: The National Library of Medicine PubMed database and Embase were queried using MeSH headings and keywords relevant to ambulatory status after prenatal or postnatal closure of MM. Abstracts were reviewed to identify which studies met the inclusion criteria. An evidence table was assembled summarizing the studies and the quality of evidence (Classes I-III). Based on the quality of the literature, a recommendation was rendered (Level I, II, or III)., Results: One randomized controlled trial (Class II) and 3 retrospective cohort studies (Class III) were included as evidence. Initial ambulatory status depended on anatomic level of the neural tube defect. In the short term, prenatal closure may improve ambulatory status compared to postnatal closure. Spinal cord tethering or dermoid inclusion cyst has been associated with neurologic deterioration in infants closed in utero and after birth. Ambulation may cease in both groups over time. No long-term studies evaluated whether there is a difference in the ability to ambulate upon reaching adulthood., Conclusion: Prenatal closure of MM may improve ambulatory status in the short term (Level II). Spinal cord tethering in both groups caused deterioration in the ability to walk. Evaluation and treatment of spinal cord tethering may help maintain ambulatory status (Level III). No studies evaluate whether prenatal or postnatal repair provides improved ability to ambulate upon reaching adulthood.The full guideline can be found at https://www.cns.org/guidelines/guidelines-spina-bifida-chapter-3., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Background: Appropriate timing for closure of myelomeningocele (MM) varies in the literature. Older studies present 48 h as the timeframe after which infection complication rates rise., Objective: The objective of this guideline is to determine if closing the MM within 48 h decreases the risk of wound infection or ventriculitis., Methods: The Guidelines Task Force developed search terms and strategies used to search PubMed and Embase for relevant literature published between 1966 and September 2016. Strict inclusion/exclusion criteria were used to screen abstracts and to develop a list of relevant articles for full-text review. Full text articles were then reviewed and when appropriate, included in the evidentiary table. The class of evidence was evaluated, discussed, and assigned to each study that met inclusion criteria., Results: A total of 148 abstracts were identified and reviewed. A total of 31 articles were selected for full text analysis. Only 4 of these studies met inclusion criteria., Conclusion: There is insufficient evidence that operating within 48 h decreases risk of wound infection or ventriculitis in 1 Class III study. There is 1 Class III study that provides evidence of global increase in postoperative infection after 48 h, but is not specific to wound infection or ventriculitis. There is 1 Class III study that provides evidence if surgery is going to be delayed greater than 48 h, antibiotics should be given.The full guideline can be found at https://www.cns.org/guidelines/guidelines-spina-bifida-chapter-4., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Background: Myelomeningocele (MM) is the most common congenital anomaly to affect the nervous system and affects 1500-2000 newborn infants per year in the United States. It is accompanied by symptomatic hydrocephalus in approximately 70%-80% of patients. Different treatment strategies for hydrocephalus characteristically result in different effects on the size of the ventricles., Objective: The objective of this systematic review was to determine whether persistent ventricular enlargement adversely impacts neurocognitive development in patients with MM., Methods: The PubMed National Library of Medicine Medline database and Embase were queried using MeSH headings and keywords relevant to neurocognitive or intellectual development and ventricular size or morphology. Abstracts were reviewed by the authors to identify which studies met strict inclusion criteria. An evidence table was constructed that summarized the included studies and reflected the quality of evidence (Classes I-III) that each represented. A recommendation was made that is based on the quality of the evidence., Results: An initial abstract review utilizing strict inclusion/exclusion criteria yielded 48 studies, 9 of which underwent full-text review. There is limited and conflicting Class III evidence from 2 studies., Conclusion: Currently, there is insufficient data to conclude that ventricular size and morphology impact neurocognitive development.The full guideline can be found at https://www.cns.org/guidelines/guidelines-spina-bifida-chapter-5., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Background: Myelomeningocele (MM) is a condition that is responsible for considerable morbidity in the pediatric population. A significant proportion of the morbidity related to MM is attributable to hydrocephalus and the surgical management thereof. Postnatal repair remains the most common form of treatment; however, increased rates of prenatal diagnosis, advances in fetal surgery, and a hypothesis that neural injury continues in utero until the MM defect is repaired have led to the development and evaluation of prenatal surgery as a means to improve outcomes in afflicted infants., Objective: The objective of this guideline is to systematically evaluate the literature to determine whether there is a difference in the proportion of patients who develop shunt-dependent hydrocephalus in infants who underwent prenatal MM repair compared to infants who had postnatal repair., Methods: The Guidelines Task Force developed search terms and strategies used to search PubMed and Embase for relevant literature published between 1966 and September 2016. Strict inclusion/exclusion criteria were used to screen abstracts and to develop a list of relevant articles for full-text review. Full-text articles were then reviewed, and when appropriate, included as evidence., Results: A total of 87 abstracts were identified and reviewed by 3 independent reviewers. Thirty-nine full-text articles were selected for analysis. Three studies met selection criteria and were included in the evidence table., Conclusion: Class I evidence from 1 study and class III evidence from 2 studies suggest that, in comparison to postnatal repair, prenatal surgery for MM reduces the risk of developing shunt-dependent hydrocephalus. Therefore, prenatal repair of MM is recommended for those fetuses who meet specific criteria for prenatal surgery to reduce the risk of developing shunt-dependent hydrocephalus (level I). Differences between prenatal and postnatal repair with respect to the requirement for permanent cerebrospinal fluid diversion should be considered alongside other relevant maternal and fetal factors when deciding upon a preferred method of MM closure. The full guideline can be found at https://www.cns.org/guidelines/guidelines-spina-bifida-chapter-2., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Background: The structural complexity of terminal myelocystocele (TMC) precludes a recognizable link to spinal cord development and therefore a plausible embryogenetic theory., Objective: To demystify TMC using clinical, imaging, surgical, electrophysiological, and histopathological data and to propose a theory of embryogenesis., Methods: Our series consisted of 4 newborns and 6 older children. All had preoperative magnetic resonance imagings and surgical repair of the myelocystocele with electrophysiological monitoring., Results: TMC can be deconstructed into essential and nonessential features. Essential features are present in all TMCs and constitute the core malformation, comprising an elongated spinal cord extending extraspinally into a cerebrospinal fluid--filled cyst that is broadly adherent to the subcutaneous fat. The functional conus resides in the proximal cyst or within the intraspinal cord, and the caudal myelocystocele wall is nonfunctional fibroneural tissue. Nonessential features include variable measures of hydromyelia, caudal meningocele, and fat, present in only some patients. The core structure of TMC strikingly resembles a transitory stage of late secondary neurulation in chicks in which the cerebrospinal fluid-filled bleblike distal neural tube bulges dorsally to fuse with the surface ectoderm, before focal apoptosis detaches it from the surface and undertakes its final dissolution. We theorize that TMC results from a time-specific paralysis of apoptosis just before the dehiscence of the cystic distal cord from the future skin, thereby preserving the embryonic state., Conclusion: Besides tethering, the myelocystocele may show early rapid expansion causing precipitous deterioration. We recommend early repair with resection of the nonfunctional caudal cyst wall, reconstruction of the proximal neural placode, and duraplasty.

Objective: Cervical myelomeningocele is an extremely rare condition, accounting for only 1 to 5% of all neural tube defects. These lesions are usually diagnosed in childhood. Here, we report a case of a cervical myelomeningocele diagnosed and treated in adulthood., Clinical Presentation: A 52-year-old man presented with a 3-year history of progressing weakness and paresthesia in his upper limbs. Physical examination revealed a posterior midline neck mass covered with normal skin. Magnetic resonance imaging showed a soft-tissue mass tethering the cord by a stalk extending from the dorsal spinal cord to the dome of the lesion. Syrinx was evident cranially and caudally to the origin of the posterior stalk., Intervention: Surgical resection of the sac and intradural exploration were performed. The subdural space was explored, and the tethered structures were released. Histological examination showed small foci of meningothelial cells with psammoma bodies and rare thin fascicle of glial tissue dispersed in hyaline tissue. Immunohistochemical stains against glial fibrillary acidic protein and S100 confirmed the presence of bands of astrocytic tissue. The patient demonstrated early improvement of neurological deficits. Six months after surgery, he was asymptomatic and magnetic resonance imaging showed resolution of the syrinx., Conclusion: We believe the syrinx in this patient was caused by a blockade of flow in the central canal and around the spinal cord as a result of the tethered cord. The untethering procedure resulted in the collapse of the syrinx followed by resolution of neurological deficits.

Objective: Transient paraplegia in the immediate postoperative period after lipomyelomeningocele repair is uncommon and is not discussed in the literature. We present the unique case of a patient who developed transient paraplegia 48 hours after lipomyelomeningocele repair attributable to the acute development of a thoracic syrinx., Clinical Presentation: At birth, the patient was noted to have a large skin-covered mass in the lumbosacral region. On neurological examination, both iliopsoas and quadriceps exhibited 3/5 motor function, and the plantar flexors and dorsiflexors exhibited 1/5 motor function. Urodynamic studies were normal. Magnetic resonance imaging demonstrated the presence of a lipomyelomeningocele associated with tethering of the spinal cord in the lumbosacral region., Intervention: At 5 months of age, the patient underwent repair of the lipomyelomeningocele. After surgery, the patient developed progressive paraplegia along with bowel and bladder dysfunction. Given the concern about a postoperative hematoma resulting in cauda equina syndrome, the patient returned to the operating room for a wound exploration. No compressive lesion such as a hematoma was found at surgery. A postoperative magnetic resonance imaging scan obtained afterward, however, demonstrated the presence of a large thoracic syrinx., Conclusion: Syrinx formation can occur as early as 48 hours after lipomyelomeningocele repair, leading to progressive lower extremity weakness and bowel and bladder incontinence. In the immediate postoperative period, an acute syrinx can mimic cauda equina syndrome, and a magnetic resonance imaging scan is necessary to distinguish between these two entities. In this patient, the syrinx was transient and resolved without a shunting procedure.

Objective: Cervical myelomeningocele (cMMC) is a rare disease. Only a few series have been published regarding cMMC. Different issues regarding the etiology, classification, clinical, surgical, and pathological aspects of cMMC are still a matter of conflict., Methods: Sixteen children operated on for cMMC between July 2000 and 2003 were followed by the neurosurgical service at Children's Hospital Medical Center in Tehran. The patients were followed up for 2 to 5 years (median, 3 yr)., Results: The studied patients were nine boys and seven girls, ages 1 day to 4 months. Neurological examination was normal in all but two patients. All children had a normal anal fold, could void spontaneously, and showed no evidence of gross orthopedic deformity. We found eight patients with hydrocephalus, four patients with Chiari II malformation, two patients with syringomyelia, one patient with diastematomyelia at the level of cervical hemimyelomeningocele, and one patient with associated sacral myeloschisis. A thorough urological evaluation was planned for 13 patients, which confirmed bladder dysfunction in 10 (71%) patients. All infants had midline lesions, which consisted of a protruding sac from the back of neck, covered with purplish rudimentary or dysplastic skin at the dome. All patients underwent surgical resection of the sac and intradural exploration to release any adhesion and to exclude other associated anomalies., Conclusion: Cervical myelomeningocele differs structurally and clinically from myelomeningocele in distal areas and has a more favorable outcome. We think that some trivial neurological deficits in cMMC are caused by the late and limited neurulation abnormality during its development. We advise thorough preoperative evaluation of the brain, spinal column, and urinary system. Intradural exploration to release any potential adhesion bands as well as correcting associated anomalies is recommended in all cMMC operations.

Objective and Importance: To describe an alternative approach to the operative management of large meningomyeloceles, in which primary closure is not possible., Clinical Presentation: Two full-term infants presented with very large meningomyeloceles for closure after an uncomplicated delivery., Technique: An allogeneic skin graft was used in both cases to approximate the skin defect that remained after removal of the large meningomyelocele sacs. The surgical site was treated with dressing changes only during the postoperative period., Conclusion: The independent use of allogeneic skin grafts can lead to a successful cosmetic result for the treatment of large meningomyeloceles without the use of complicated skin incisions or flap advancements.

ALTHOUGH ADVANCES IN prenatal care and diagnosis have reduced the incidence of spina bifida, repair of neural tube defects remains one of the standard cases encountered by pediatric neurosurgeons. The operative techniques used in closure of these congenital defects have remained essentially unchanged during the past 2 decades; however, the operative nuances for closure often are based on the variability in configuration and size of the open defects, which can present a challenge. Repair of the open spinal dysraphism may require only a simple closure, but extensive dissection and reconstruction of the neural, meningeal, fascial, and epidermal tissues, including the use of specialized vascularized flaps, may be required in some cases. In this article, we briefly describe the preoperative evaluation, decision process, and standard techniques for the repair of myelomeningocele and myeloschisis.

Objective: The purpose of this study was to describe the natural history of tethered cord in patients who have undergone meningomyelocele repair., Methods: We performed a retrospective review of 45 patients with a history of neonatal meningomyelocele repair who subsequently developed symptoms of tethered cord. Symptoms of tethered cord in this cohort consisted of the development of bladder spasticity or orthopedic foot deformity. None of these patients were treated with cord untethering; instead, they were treated symptomatically., Results: On follow-up, 40 (88.9%) of these patients subsequently required additional orthopedic or urological procedures because of further symptoms of tethered cord. The incidence of progression of tethered cord syndrome is 27.5, 40, and 60% at 1, 2, and 5 years, respectively., Conclusion: Although this study does not address the question whether cord untethering will prevent further symptom development, these results do provide a strong rationale for consideration of an untethering procedure in patients with repaired meningomyelocele at the time of the onset of symptoms of tethered cord.

Objective and Importance: We report a case of a child with terminal myelocystocele (TMC). This case exemplifies the importance of performing a multidisciplinary evaluation and magnetic resonance imaging in the patient with suspected meningomyelocele when fetal surgery is being considered., Clinical Presentation: This patient was evaluated at the Center for Fetal Diagnosis and Treatment and considered for fetal surgery to repair meningomyelocele., Technique: A follow-up based on both ultrasound and magnetic resonance imaging was performed throughout pregnancy., Conclusion: Although a definitive diagnosis of TMC was not established prenatally, the patient was not offered fetal surgery, based on multiple selection criteria. We correlate the pathophysiology of TMC with the radiographic and amniocentesis findings. TMC must be considered in the differential diagnosis in a fetus with a dysraphic defect.

Objective: Invasive urological procedures, commonly performed on patients with myelodysplasia, may contribute to the occurrence of cerebrospinal fluid shunt complications. Shunt complications that occurred after urological procedures in children with myelodysplasia were studied., Methods: Shunt complications occurring after urological procedures were examined in 29 patients. Differences between patients with or without complications were studied. Complications were analyzed according to the location of abnormality, the treatment, and the timing after shunt and urological surgery., Results: The 1-year incidence of shunt complications after a urological procedure had been performed was 31% (overall incidence, 41.4%). Shunt complications were observed only after intraperitoneal urological procedures. Most complications were distal, occurring more than 1 year after the preceding shunt surgery. The patients in the shunt complications group had significantly more intraperitoneal urological procedures (3.2 versus 0.8, P = 0.004) and previous shunt revisions (2.0 versus 0.9, P = 0.015) than had the group without complications. As compared with the group of patients with extraperitoneal complications, the intraperitoneal group experienced significantly more infections (4 of 9 versus 0 of 10, P = 0.014) requiring more complex treatment, and their complications occurred significantly earlier in the follow-up period after the urological procedure had been performed (7.2 versus 27.3 mo, P = 0.006). The patients in the group with extraperitoneal complications experienced significantly more mechanical shunt malfunctions than did the intraperitoneal group (9 of 10 versus 4 of 9, P = 0.016), which required simple shunt revisions., Conclusion: Patients with spina bifida and shunted hydrocephalus may have an increased risk of developing intraperitoneal shunt complications after intraperitoneal urological procedures have been performed. These intraperitoneal shunt complications usually occur a few months after urological surgery and require complex treatment.

Objective and Importance: Distal ventriculoperitoneal shunt failure has been associated with absorption failure secondary to previous peritonitis. This assumption has caused surgeons to seek alternate sites for distal catheter placement. We propose that the absorptive potential of the peritoneal cavity should be assessed before that site is discounted for catheter placement., Clinical Presentation: The case of a 14-month-old male patient is presented, demonstrating multiple ventriculoperitoneal shunt placement procedures and a diagnostic dilemma with respect to distal shunt placement. Peritoneography was performed to demonstrate peritoneal fluid absorption, allowing subsequent placement of a new distal shunt catheter with good clinical results., Technique: Using aseptic technique, a 24-gauge spinal needle was inserted in the midline of the abdomen and water-soluble contrast material was instilled. Delayed radiographs delineated peritoneal adhesions and demonstrated renal excretion of the contrast material, confirming peritoneal absorption., Conclusion: The peritoneal cavity remains the site of choice for distal shunt catheter placement. If failure of peritoneal cerebrospinal fluid absorption is suspected as a cause of shunt failure, then peritoneography with water-soluble contrast material may be safely used to demonstrate the adequacy of fluid absorption before a secondary site is chosen.

Objective and Importance: We describe three cases in which ventrally situated cervical arachnoid cysts led to spinal cord or cervicomedullary compression after repeat craniocervical decompression for Chiari II malformations., Clinical Presentation: All three patients underwent craniocervical decompression when their Chiari malformations became symptomatic. The first patient developed chronic vertiginous spells and headache and was treated with repeated craniocervical decompression procedures during several years. Seven months after undergoing her third decompression procedure, she developed severe dizzy spells, which were determined to be of brain stem origin. The second patient had a small, asymptomatic arachnoid cyst anterior to the brain stem discovered at age 6 years. After undergoing repeat craniocervical decompression for headaches 8 years after undergoing his first procedure, the patient developed severe neck pain and acute quadraparesis. A third patient underwent repeat craniocervical decompression at age 14 years for cranial nerve dysfunction. Postoperatively, he acutely developed paresis of extraocular movements and incoordination of the upper extremities. All three patients were found to have anteriorly situated arachnoid cysts compressing the brain stem and/or cervical spinal cord., Intervention and Technique: Fenestration of the arachnoid cyst or drainage with cystoperitoneal shunting adequately treated acute brain stem or cervical spinal cord compression. All three patients had achieved satisfactory relief from their acute symptoms of neural compression at their follow-up examinations., Conclusion: An association between spinal arachnoid cysts and neural tube defects has previously been reported. However, the development of previously undetected spinal arachnoid cysts after craniocervical decompression was unexpected. We hypothesize that extensive craniocervical decompression may alter the cerebrospinal fluid pressure dynamics in such a way that the anterior subarachnoid space, previously compressed, may dilate. Occasionally, because of perimedullary arachnoiditis, the cerebrospinal fluid may become loculated and act as a mass. Direct fenestration or shunting may successfully treat this problem, and less extensive craniocervical decompression may avoid it.

Objective and Importance: Meningoceles associated with defects of the abdominal wall are exceedingly rare. One such complex case is presented along with a review of the relevant literature. The current pathophysiological theories and surgical management are discussed., Clinical Presentation: A case of a patient with an anterolateral lumbar lipomyelomeningocele associated with multiple congenital anomalies, including defects in the abdominal wall and urogenital system, is presented. The lipomyelomeningocele presented as an expanding abdominal mass., Intervention: Ventriculoatrial shunting and two operations to repair the myelomeningocele were performed to control the expanding abdominal mass., Conclusion: This report illustrates that the surgical management of complex lipomyelomeningoceles is similar to the more common types. It also demonstrates that in the infant in whom the intra-abdominal cerebrospinal fluid collection is the primary cause of the symptoms, cerebrospinal fluid shunting may be used to delay the definitive repair until the dura strengthens, thus avoiding the complications of complex repairs of dura with low tensile strength.

Objective and Importance: This report describes an important technical modification in ventriculoperitoneal shunting., Clinical Presentation: A young woman presented with shunt malfunction caused by occlusion of the peritoneal catheter. Conventional sites for placement of distal catheter were unavailable or had been used up., Intervention: After the installation of a ventriculopleural shunt resulted in pleural effusion, it was converted to a transdiaphragmatic ventriculoperitoneal shunt, resulting in an excellent clinical outcome., Conclusion: The suprahepatic subdiaphragmatic space can be directly accessed in some selected patients with extensive peritoneal adhesions, resulting in successful ventriculoperitoneal shunting.

Objective: We report our experience with a previously undescribed method of myelomeningocele closure, which is the use of bilateral lumbar periosteal flaps as an additional tissue layer in complex cases. These flaps reinforce the dural repair, act to protect the spinal cord, and may help to contain any potential cerebrospinal fluid leak from the primary repair of the cord, thereby preventing pseudomeningocele formation., Methods: The repair involves the development of bilateral thoracolumbar fascial flaps in conjunction with periosteal flaps, which are elevated from adjacent lumbar pedicles and transverse processes, thus forming a composite tissue flap. These periosteally based flaps may be closed in a "pants over vest" fashion to completely cover the spinal defect, reinforcing the neurosurgical repair. The flap anatomy and dissection are detailed., Results: Two representative cases in which the lumbar periosteal turnover flap procedure was used are reported. One patient was operated on during the early neonatal period for primary myelomeningocele repair; the other was operated on at age 5 years after a tethered cord release. Durable, stable soft tissue coverage of the spinal cord was obtained in both patients, with a postoperative follow-up period of at least 12 months. There was no recurrence of the pseudomeningocele noted preoperatively in the second patient., Conclusion: The lumbar periosteal turnover flap may be used to reinforce tenuous spinal cord and dural repairs in the myelomeningocele patient. This method provides a secure and watertight closure over the primary repair of the cord, may help to contain potential cerebrospinal fluid leaks, and adds an additional autologous tissue layer to standard skin or muscle flap repairs.

The indications for hindbrain decompression in neonates and young infants with spinal dysraphism who experience brain stem dysfunction in association with Chiari II malformations have remained controversial. This largely reflects the fact that the postoperative outcome in such patients has often been poor, which has supported the belief that much of the brain stem compromise in these patients is congenital and inherently irreversible. However, in a previous retrospective review of our operative results between 1975 and 1989, we noted that a significant component of the brain stem dysfunction in these children was an acquired phenomenon that potentially was reversible with prompt operative intervention. Accordingly, we hypothesized that with early craniocervical decompression, excellent functional outcome could be achieved in a majority of neonates and young infants with symptomatic Chiari II malformations. On the basis of this premise, we prospectively treated all such patients since 1989 with urgent brain stem decompression after other potential causes for brain stem dysfunction, such as progressive hydrocephalus, had been ruled out. All children underwent limited suboccipital craniectomies, cervical laminectomies extending beneath the inferior extent of the cerebellar tissue, and dural decompressions. The outcome in these patients has been favorable in comparison with previous studies. Ten of the 13 children treated according to this protocol recovered normal or nearly normal brain stem function shortly after decompression; 1 child had mild residual unilateral lower cranial nerve paresis. None of these children required a tracheostomy for ventilatory support, and only one required a temporary gastrostomy. The other three children all exhibited bilateral vocal cord paralysis and severe central hypoventilation by the time decompression was performed and failed to have any meaningful recovery of function. We conclude that early recognition of the symptoms of brain stem compromise in neonates and young infants with spinal dysraphism coupled with urgent evaluation and decompression are effective in producing prompt resolution of the brain stem dysfunction in most affected patients. Conversely, the prognosis for recovery is poor in children who exhibit bilateral vocal cord paralysis by the time of decompression.

Cervical myelomeningoceles are rare dysraphic lesions. Nine cases of cervical myelomeningoceles are reported. The external features of all nine myelomeningoceles were strikingly similar: They were sturdy, tubular protuberances from the back of the infants' necks, covered at the base by full-thickness skin and covered on the dome by thick squamous epithelium. Internally, these were tethered cord lesions in which fibroneural bands or sagittal midline fibrous septa were tightly tethering the cervical spinal cord to the adjacent dural or intrasaccular soft tissues. Six of our early cases (Group 1) were initially treated with simple subcutaneous resection of the sac and ligation of the dural fistula without release of the internal tethering structures. Five of these children subsequently deteriorated 13 months to 8 years later, all with worsening hand function and spastic legs. All five were reexplored, and the tethering bands and septa were excised; all showed improvement. The other three neonates (Group 2) treated in the last 4 years underwent initial intradural exploration of the lesions; in one case, the tethering fibrous elements were only partially eliminated and the patient deteriorated 4 years later, but improved after a second operation for resection of a missed ventral fibrous septum. The other two Group 2 infants had a thorough release of the fibroneural stalks initially, and both were neurologically stable 3 years later. We recommend that cervical myelomeningoceles should be studied preoperatively with magnetic resonance imaging and computed tomographic myelography to identify the internal structures. The minimum initial surgical treatment should be a two-level laminectomy, intradural exploration, and excision of all tethering bands and septa, in addition to resection of the sac. If a split cord is revealed by imaging studies, both the ventral and dorsal surfaces of the hemicords must be carefully inspected to locate the median septum.

An animal model for intrauterine surgical treatment of myelomeningocele is described using sheep. We report the technical feasibility of endoscopic intrauterine skin graft placement over surgically induced defects, including over exposed spinal cord. These grafts exclude amniotic fluid from the underlying lesion and provide a matrix for fetal skin growth below the graft. The potential for human application is discussed.

In 47 patients with Chiari malformations (41 with Type I, 6 with Type II) diagnosed by magnetic resonance imaging, syringomyelia was found significantly more frequently in those who had a herniation of 9 to 14 mm (9 of 16, 56%) than in those who had a smaller (2 of 15, 13%) or larger (2 of 16, 13%) herniation. Syringomyelia associated with the Chiari malformation is generally considered to be due to mechanical factors induced by altered cerebrospinal fluid hydrodynamics. On the basis of the present study, one may speculate whether these mechanical factors affect the cord most efficiently at an intermediate level of herniation, which may prove to be a risk factor for the development of syringomyelia.

Selective treatment of infants with myelomeningocele is said to be beneficial to the infants, their parents, and to society. One group of arguments intended to support this point of view is analyzed. Recent data do not support the factual basis on which these arguments rest; moreover, the moral assumptions that lie behind them should be emphasized. The values held by participants in a discussion of allowing infants to die are as important as facts about treatment options.

A silicone, dual cuffed catheter designed for the control of nasal hemorrhage was used for rectal sphincter pressure monitoring. Patients with lipomyelomeningocele and tethered spinal cord were monitored during their operative procedures to aid in distinguishing sacral nerve roots from other tissues. Stimulation of sacral nerve roots was done with a disposable nerve stimulator. The use of a catheter with two balloons helps to keep the outer balloon placed against the rectal sphincter.

The occurrence of a myelomeningocele completely embodied within a lumbosacral teratoma is extremely rare. We report on the clinical presentation, radiological appearance, surgical treatment, and histological make up of such a lesion.

A case of invasive squamous cell carcinoma arising in the skin overlying a large lumbar meningomyelocele is reported. This case is unique in that a chronic neurocutaneous fistula was not present. It is proposed that chronic irritation of the meningomyelocele was the primary factor in the pathogenesis of the cancer.

Between October 1982 and August 1987, 20 patients underwent magnetic resonance imaging (MRI) and subsequent surgical release of a tethered spinal cord. The tethering was caused by a thick filum terminale in 6 patients. On MRI scans, the conus medullaris was at L4 in 2 patients, at L2 in 3 patients, and the filum terminale appeared thick in 1 patient. The spinal cord was tethered to an intradural lipoma correctly demonstrated by MRI in 6 patients. Increased epidural fat was misdiagnosed as an intradural lipoma in one patient and a lipomatous stalk was not identified in 2 other patients. Scar tissue resulting from repair of a meningocele had tethered the cord in the remaining 8 patients. On MRI scans, the conus medullaris was located between L3 and S3; in 5 of the patients, scar tissue was apparent on the MRI scan. This correlative study supports the use of MRI as the initial, and possibly the only, imaging modality when a tethered spinal cord is suspected. Improved or more recent MRI techniques will help demonstrate these anomalies better.

Cerebrospinal fluid (CSF) eosinophilia is a rare finding most often associated with central nervous system inflammatory processes, including parasitic, bacterial, and mycotic infections. It has also been seen as an allergic phenomenon. We present two cases of CSF eosinophilia occurring concurrently with sterile shunt malfunction. We speculate that CSF eosinophilia in our patients might have resulted from an allergic response to a foreign material such as suture, surgical glove powder, hair, cotton fibers, antibiotics, or silicone rubber. The incidence of sterile CSF eosinophilia after shunting is not known. Information concerning the role of eosinophilia in the development of shunt malfunctions is also lacking. An increased awareness of this possibility and further investigation are warranted.

Infants afflicted with meningomyelocele are paralyzed as a result of the physiological disconnection of the neural plate from the spinal cord. Intact neural elements within the placode often maintain segmental reflex innervation of the paralyzed lower extremity muscles. It was hypothesized that bridging this central-peripheral gap with vaible intercostal nerves would restore limited voluntary movement to the paralyzed muscles. This procedure has been performed on four infants and seems promising.

Terminal myelocystoceles constitute approximately 5% of skin-covered lumbosacral masses and are especially common in patients with cloacal exstrophy. Pathologically, terminal myelocystocele consists of (a) a skin-covered lumbosacral spina bifida (b) an arachnoid-lined meningocele that is directly continuous with the spinal subarachnoid space; and (c) a low-lying, hydromyelic spinal cord that traverses the meningocele and then expands into a large terminal cyst. The terminal cyst bulges into the extraarachnoid compartment caudal to the meningocele and forms a distal sac that does not communicate with the subarachnoid space. The terminal cyst is lined by ependyma and dysplastic glia, is directly continuous with the dilated central canal of the cord, and probably represents a ballooned terminal ventricle. Patients with terminal myelocystocele have normal intellectual potential and are usually born without neurological deficit, so these defects must be identified and repaired early, before the onset or progression of lower extremity pareses.

Spinal surgery for the various dysraphic malformations is generally indicated to arrest disease progression. The results of the present study suggest that certain clinical conditions and presentations are associated with an exceptionally good surgical prognosis. Sixty-nine procedures were done in 55 patients. The diagnoses included hydromyelia and tethered cord related to diastematomyelia, lipoma, lipomeningocele, previous operation, and thickened filum terminale. The operative results were evaluated for significant functional neurological and urological improvement, as well as for the relief of pain. Pain relief was achieved in 92% of patients with preoperative pain. Significant functional return was seen in 67% of hydromyelia patients. On the other hand, surgical treatment of tethered cord caused improvement in 24% (lipoma) to 46% (thickened filum and diastematomyelia). These results suggest that patients with hydromyelia and patients with a dysraphic malformation and pain have an excellent prognosis after operation. A re-evaluation of the indications for surgery for these patients may be necessary.

During the years 1975 to 1985, 10 patients underwent simultaneous repair of myelomeningocele and insertion of a ventriculoperitoneal shunt at the Hospital for Sick Children in Toronto. The technique for carrying out these procedures in the same operative setting will be described. None of the patients developed shunt infections or myelomeningocele repair breakdown in the follow-up period of 1 to 9 years. One patient died 9 days after operation secondary to aspiration. The remaining patients underwent neuropsychological testing during their follow-up periods and over 70% were found to have normal or slightly below normal intelligence and psychosocial development. The technique of simultaneous repair of a myelomeningocele and insertion of a ventriculoperitoneal shunt in infants with a myelomeningocele and concomitant hydrocephalus overt at birth is safe and should be carried out to decrease the risk of myelomeningocele repair breakdown and cerebrospinal fluid leak in such patients.

The closure of myelorachischisis defects has been difficult and at times complicated. Over the past 2 decades, the use of rotational advancement flaps has been increasingly popular, but can be attended by instances of skin ischemia and necrosis. The development of the myocutaneous and muscle flap concept has aided reconstructive surgery. Extensive experience with the useful latissimus dorsi flap with and without overlying skin has been obtained for the reconstruction of a variety of truncal defects. We describe the use of bilateral "reverse" latissimus dorsi muscle flaps based on the paraspinal perforators for the closure of myelorachischisis defects in two patients. Coverage was uneventful in both instances. A 2-year follow-up revealed no compromise of upper extremity function due to sacrifice of the latissimus dorsi muscles. We offer an approach to the problem of closure of large myelorachischisis defects: bilateral reverse latissimus dorsi muscle flaps and delayed skin coverage. This approach seems to offer a good muscle layer over the dural closure and to provide long-standing durable coverage without apparent compromise of upper extremity function.

It is suggested that the application of nitroglycerin ointment to neurosurgical wound closure exhibiting skin pallor or cyanosis can minimize necrosis and dehiscence. Examples of the use of this agent in patients undergoing myelomeningocele closure as well as in a premature infant undergoing ventriculoperitoneal shunting are described.

Two primary lumbosacral tumors arising at the site of neural tube defects are presented. One was a teratoma diagnosed in an infant with myelomeningocele. The other was an ependymoma that developed in an adult with meningocele. It is postulated that these cases represent a neoplastic transformation of heterotopic primordial elements that have been incorporated within the defect, supporting the view that overgrowth of neural tissue may be the result rather than the cause of neural tube deformity. Such rare occurrences may be due to interaction between intrauterine teratogenic factors and familial predisposition in affected patients.

The operative and magnetic resonance image (MRI) findings of 25 patients with the diagnosis of lipomyelomeningocele and/or tethered cord were compared. Postoperative MRI scans of eight patients, five of whom were in stable condition, were also compared with the preoperative studies. In this review there was one false negative MRI scan and four MRI scans in which the relationship of the lipoma to the conus or filum was not demonstrated accurately. In six patients, incidental intramedullary cystic lesions at the conus were identified by MRI scan. All eight postoperative (1 month to 2 years) scans demonstrated no change in the level of the conus from the preoperative study. MRI is an accurate screening modality in the initial diagnosis of occult spinal dysraphism. MRI was not useful in the postoperative evaluation of lipomyelomeningocele and the tethered cord, since the caudal, posterior displacement of the conus was unchanged in all studies.