Postnatal myelomeningocele closure in smallest reported neonate: illustrative case.

Background: Myelomeningocele (MMC) is the most serious form of spina bifida, a congenital defect in neural tube development. Defect closure in a patient with an extremely low birth weight presents unique challenges and risks; lower birth weight is associated with multiple organ system concerns, homeostasis is difficult, and local tissue is underdeveloped. To the authors' knowledge, the present case is the lowest reported weight (490 g) for a neonate with postnatal MMC repair.

Observations: A preterm male with a prenatally diagnosed lumbosacral MMC and associated Chiari malformation type II was born at 23 weeks 1 day to a 29-year-old mother, gravidity 6 parity 4. The patient was medically stabilized and underwent MMC closure on day of life 5. His weight was 490 g at the time of this repair, and he did not have any surgical complications. At age 16 months, he underwent endoscopic third ventriculostomy with choroid plexus cauterization; he has not required any further hydrocephalus treatments since the last follow-up at 30 months of age.

Lessons: To the authors' knowledge, this case is the lowest birth weight ex utero MMC closure reported in the literature. Challenges of prematurity and size required appropriate preoperative stabilization, careful hemostasis and temperature regulation, and meticulous surgical technique.