[Maternal-fetal surgery for spina bifida: future perspectives]

Open spina bifida or myelomeningocele (MMC) is a frequent congenital abnormality (450 cases per year in France) associated with high morbidity. Immediate postnatal surgery is aimed at covering the exposed spinal cord, preventing infection, treating hydrocephalus with a ventricular shunt. MMC surgical techniques haven't achieved any major progress in the past decades. Numerous experimental and clinical studies have demonstrated the MMC "two-hit" hypothetic pathogenesis: a primary embryonic congenital abnormality of the nervous system due to a failure in the closure of the developing neural tube, followed by secondary damages of spinal cord and nerves caused by long-term exposure to amniotic fluid. This malformation frequently develops cranial consequences, i.e. hydrocephalus and Chiari II malformation, due to leakage of cerebrospinal fluid. After 30 years of research, a randomized trial published in February 2011 proved open maternal-fetal surgery (OMFS) for MMC to be a real therapeutic option. Comparing prenatal to postnatal surgery, it confirmed better outcomes of MMC children after a follow up of 2.5 years: enhancement of lower limb motor function, decrease of the degree of hindbrain herniation associated with the Chiari II malformation and the need for shunting. At 5 years of age, MMC children operated prenatally seems to have better neurocognitive, motor and bladder-sphincter outcomes than those operated postnatally. However, risks of OMFS exist: prematurity for the fetus and a double hysterotomy at approximately 3-month interval for the mother. Nowadays, it seems crucial to inform parents of MMC patients about OMFS and to offer it in France. Future research will improve our understanding of MMC pathophysiology and evaluate long-term outcomes of OMFS. Tomorrow's prenatal surgery will be less invasive and more premature using endoscopic, robotic or percutaneous techniques. Beforehand, Achilles' heel of maternal-fetal surgery, i.e. preterm premature rupture of membranes, preterm labor and preterm birth, must be solved.