Open surgery for in utero repair of spina bifida: Microneurosurgery versus standard technique – A systematic review

Background/objectives Prenatal myelomeningocele (MMC) repair has been shown to improve neurological outcomes. It has been suggested that decreases in the hysterotomy diameter during surgery can improve perinatal outcomes without altering neurologic outcomes. The objective of this study is to describe and compare the main maternal and fetal outcomes of fetuses undergoing open surgery for MMC repair, through the different modifications (standard‐classical, mini‐hysterotomy, and microneurosurgery). Data source MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Ovid, SciELO, LILACS, PROSPERO. Results From a total of 112 studies, seven case series were selected including 399 fetuses with open fetal surgery, five studies using the classical technique (n = 181), one with mini‐hysterotomy (n = 176), and one with the microneurosurgery technique (n = 42). The mini‐hysterotomy and microneurosurgery techniques presented a lower risk of preterm delivery (21.4% and 30%, respectively) compared to the classic technique (47.3%), premature rupture of membranes (78%, 62%, and 72.5 %, respectively), oligohydramnios (0% and 72.5%, respectively), dehiscence of hysterotomy, maintaining the same frequency of Chiari reversion (78%, 62%, and 72.5%, respectively), postnatal correction requirement (0%, 4.8%, and 5.8%, respectively), and lower frequency of requirement for a ventriculoperitoneal shunt placement (13.0%, 7.5%, and 29.1%, respectively). Conclusion The least invasive techniques (minihysterotomy‐microneurosurgery) are possible and reproduceable, as they are associated with better maternal and perinatal outcomes. Key points What’s already known about this topic? Prenatal myelomeningocele repair reverses or corrects the rhombencephalon hernia and reduces the need for ventriculoperitoneal shunt placement and improves the composite score for mental development and motor function at 30 months. What does this study add? This is the first systematic review that compares open techniques for the repair of prenatal myelomeningocele with its different modifications: standard‐classical (6–8 cm), minihysterotomy (3.5 cm) and microneurosurgery (1.5 cm). We describe the main maternal and fetal outcomes.