How hydrocephalus rates and brain development differ between myelomeningocele (MMC; with overlying sac) and myeloschisis (without overlying sac) is poorly understood. In this study, the authors compare rates of and age at CSF diversion as well as brain anatomy in patients with MMC and myeloschisis after prenatal and postnatal repair. Demographic and clinical data were retrospectively collected from open spinal dysraphism patients who underwent prenatal or postnatal repair between 2015 and 2024 at Washington University in St. Louis. The need for and timing of permanent CSF diversion and brain imaging characteristics on the first postnatal MRI examination were compared by lesion type (myeloschisis vs MMC). The following imaging characteristics were examined: ventricular anatomy; corpus callosum, massa intermedia, tectum, and septum pellucidum morphology; the presence of gray matter heterotopias; hindbrain herniation; and medullary kinking/compression/displacement below foramen magnum. A total of 98 patients (48% female, 88% Caucasian) were included. There were 21 (21%; 9 prenatal repair, 12 postnatal repair) myeloschisis and 77 (79%; 29 prenatal repair, 48 postnatal repair) MMC patients with similar distribution of lesion levels (p = 0.115). After both prenatal (relative risk [RR] 2.17, 95% CI 1.14-5.62) and postnatal (RR 1.33, 95% CI 1.07-1.65) repair, more patients with myeloschisis than MMC required CSF diversion. Those with prenatally repaired MMC (median 94 days, range 15-154 days) underwent CSF diversion earlier than those with myeloschisis (median 210 days, range 13-357 days) (Hodges-Lehmann Δ114, 95% CI 2-226). However, this was no longer significant after adjusting for fetal atrial diameter, the presence of hindbrain herniation, and medullary compression (β = 75 days, 95% CI -78 to 229). There were minimal differences in brain imaging characteristics except for an increased presence of hindbrain herniation (4 [44%] myeloschisis patients vs 6 [21%] MMC patients; Δ23.8, 95% CI -11.9 to 59.4) and a decreased presence of posterior fossa crowding (2 [22%] myeloschisis patients vs 15 [52%] MMC patients; Δ30.3, 95% CI 3.0-62.1) in patients with myeloschisis versus MMC that was repaired prenatally. Patients with myeloschisis have an increased need for CSF diversion after both prenatal and postnatal repair compared to those with MMC, which may be a consequence of increased rates of hindbrain herniation. The timing of CSF diversion after prenatal repair occurs later in patients with myeloschisis, which may be a consequence of lower rates of medullary compression. These findings suggest that there may be differences in pathophysiology between lesion types and may help with patient counseling.

Myelomeningocele is defined by the presence of a fluid-filled sac that contains the neural placode and cerebrospinal fluid (CSF) at the level of the spinal defect. Alternatively, the term myeloschisis is used when the neural placode is not contained within a CSF-filled sac. While both are eligible for prenatal closure, few studies have characterized the impact of the type of lesion on postnatal outcomes. This study compares the outcomes of these 2 types of open spinal dysraphism using data from the Fetal Myelomeningocele Consortium registry sponsored by the North American Fetal Therapy Network. The prospective observational Fetal Myelomeningocele Consortium registry was used to extract deidentified data corresponding to patients who underwent fetal closure of myelomeningocele vs myeloschisis. Demographics, operative characteristics, perioperative complications, and postnatal outcomes were collected. A total of 1327 patients were identified, including 991 (74.7%) with myelomeningocele and 336 (25.3%) with myeloschisis. Compared with myelomeningocele, myeloschisis was associated with lower rates of prenatal talipes (11% vs 24%, P < .001) and higher rates of favorable prenatal movement (94% vs 86%, P < .001). Postnatally, myeloschisis conferred higher rates of leg movement (97% vs 90%, P = .002) and an increased likelihood of ambulation in the household (10.4% vs 4.1%, P = .009) and outside (7.2% vs 1.9%, P = .004) at 1 year. However, myeloschisis was also linked to greater use of skin patches during closure (49% vs 27%, P < .001), higher CSF leak rates among those with wound dehiscence (26% vs 8%, P = .014), and more frequent CSF diversion and tethered cord surgeries at follow-up. Myeloschisis and myelomeningocele demonstrate distinct clinical profiles. Although patients with myeloschisis may have favorable motor outcomes, they are also characterized by higher rates of CSF leakage, CSF diversion, and tethered cord surgery. These findings highlight the need for lesion-specific prognostication and may inform surgical planning and parental counseling in the context of prenatal spina bifida closure.

To provide an updated overview of international clinical practice in prenatal repair of open spinal dysraphism (OSD), focusing on evolving eligibility criteria, surgical techniques, and diagnostic standards. A structured online survey was distributed to 83 fetal surgery centers worldwide. The questionnaire addressed surgical techniques, maternal and fetal eligibility and diagnostic standards. Descriptive analyses were performed to identify current trends and practice variations. 38 centers from 16 countries participated in the survey (response rate 45.8%). Open fetal surgery remains the most common approach (51.4%) though 47.4% reported offering multiple techniques, including fetoscopic methods. Compared with the MOMS criteria, 42.4% performed surgery beyond 25.6 weeks of gestation, 52.4% accepted a BMI 35%-40% and 28.6% acc epted even a BMI of 41%-45%, and 42.4% treated women with prior uterine surgery. Most centers (87.9%) combined ultrasound and MRI for preoperative imaging. Genetic evaluation was heterogeneous: 66.7% required karyotyping, 63.6% required chromosomal microarray, 18.2% non-invasive testing, and 6.1% required none. Prognostic indicators such as ventriculomegaly and motor function increasingly influence selection decisions. International practice in prenatal OSD repair shows broadening maternal eligibility, diversification of surgical approaches, and variable diagnostic strategies. These findings highlight a shift toward individualised care and emphasise the need for further studies to evaluate the impact of practice adaptations.

Aperta lipomyelomeningocele (LMMC) is a form of open spinal dysraphism often associated with Chiari II malformation. Infantile hypertrophic pyloric stenosis (IHPS), the leading surgical cause of gastric-outlet obstruction in early infancy, has rarely been reported alongside LMMC and Chiari II. We present a term male neonate who underwent early repair of lumbosacral LMMC and later ventriculo-peritoneal (VP) shunting for post-haemorrhagic hydrocephalus. Persistent non-bilious vomiting despite functional shunting led to imaging that confirmed IHPS. The infant required a phased surgical approach, combining Ramstedt pyloromyotomy with simultaneous VP shunt revision, followed by extended multidisciplinary rehabilitation. The coexistence of these three distinct congenital anomalies produced overlapping symptoms and delayed IHPS diagnosis. This case emphasises the need for vigilant reassessment of ongoing gastrointestinal symptoms in children with neural tube defects and explores embryological links between these conditions. Recognising such rare associations is vital for timely intervention and improved outcomes.