Neurosurgical Management of Myelomeningocele in Premature Infants: A Case Series.

Introduction: Myelomeningocele (MMC) is the most common neural tube defect, but rarely seen in premature infants. Most centers advocate for closure of MMC within 24 hours of birth. However, this is not always possible in severely premature infants. Given the rarity of this patient population, we aimed to share our institutional experience and outcomes of severely premature infants with MMC. Methods: We performed a retrospective, observational review of premature infants (≤ 32 weeks gestational age) identified through our multidisciplinary spina bifida clinic (1995-2021) and surgical logs. Descriptive statistics were compiled about this sample including timing of MMC closure and incidence of adverse events such as sepsis, CSF diversion, meningitis, and death. Results: Eight patients were identified (50% male) with MMC who were born ≤ 32 weeks gestational age. Mean gestational age of the population was 27.3 weeks (SD 3.5). Median time to MMC closure was 1.5 days (IQR = 1 -80.8). Five patients were taken for surgery within the recommended 48 hours of birth; 2 patients underwent significantly delayed closure (107 and 139 days); and one patient's defect epithelized without surgical intervention. Six of eight patients required permanent cerebrospinal fluid (CSF) diversion (2 patients were treated with ventriculoperitoneal shunting (VPS), three were treated with endoscopic third ventriculostomy (ETV) with choroid plexus cauterization (CPC) and 1 patient treated with ETV; mean of 3 years after birth, ranging from 1 day to 16 years). Two patients required more than one permanent CSF diversion procedure. Two patients developed sepsis (defined as meeting at least 2/4 SIRS criteria), and 2 patients had intraventricular hemorrhage (both grade III). No patients developed meningitis (defined as positive CSF cultures) prior to MMC closure. Median follow up duration was 9.7 years. During this time epoch, 3 patients died: Two before 2 years of age of causes unrelated to surgical intervention. One of the two patients with grade III IVH died within 24 hours of MMC closure. Conclusions: In our institutional experience with premature infants with MMC, some patients underwent delayed MMC closure. The overall rate of meningitis, sepsis, and mortality for preterm children with MMC was similar to MMC patients born at term.