Fetal surgery for myelomeningocele and the incidence of shunt-dependent hydrocephalus

Abstract

Context: Intrauterine closure of exposed spinal cord tissue prevents secondary neurologic injury in animals with a surgically created spinal defect; however, whether in utero repair of myelomeningocele improves neurologic outcome in infants with spina bifida is not known.

Objective: To determine whether intrauterine repair of myelomeningocele improves patient outcomes compared with standard care.

Design: Single-institution, nonrandomized observational study conducted between January 1990 and February 1999.

Setting: Tertiary care medical center.

Participants: A sample of 29 study patients with isolated fetal myelomeningocele referred for intrauterine repair that was performed between 24 and 30 gestational weeks and 23 controls matched to cases for diagnosis, level of lesion, practice parameters, and calendar time. All infants were followed up for a minimum of 6 months after delivery.

Main outcome measures: Requirement for ventriculoperitoneal shunt placement, obstetrical complications, gestational age at delivery, and birth weight for study vs control subjects.

Results: The requirement for ventriculoperitoneal shunt placement for decompression of hydrocephalus was significantly decreased among study infants (59% vs 91%; P = .01). The median age at shunt placement was also older among study infants (50 vs 5 days; P = .006). This may be explained by the reduced incidence of hindbrain herniation among study infants (38% vs 95%; P<.001). Following hysterotomy, study patients had an increased risk of oligohydramnios (48% vs 4%; P = .001) and admission to the hospital for preterm uterine contractions (50% vs 9%; P = .002). The estimated gestational age at delivery was earlier for study patients (33.2 vs 37.0 weeks; P<.001), and the birth weight of study neonates was less (2171 vs 3075 g; P<.001).

Conclusions: Our study suggests that intrauterine repair of myelomeningocele decreases the incidence of hindbrain herniation and shunt-dependent hydrocephalus in infants with spina bifida, but increases the incidence of premature delivery.