In Utero Fetoscopic Repair Program for Sacral Myelomeningoceles and Mye-LDM

Myelomeningocele and Myelic limited dorsal myeloschisis (MyeLDM) correspond to neural tube defects which lead to lifelong disabilities including lower extremity paralysis, sphincters deficiency, and cerebral complications (Chiari 2 malformation and hydrocephalus). It is demonstrated that fetal surgery repair of MMC with upper limit between the first thoracic vertebra (T1) and the first sacral vertebra (S1) improves motor and cerebral prognosis. Nowadays, this fetal surgery is performed either after maternal laparotomy and hysterotomy (open fetal surgery) or using fetoscopy. the investigators, at Trousseau Hospital (APHP, Paris), initiated an open fetal surgery of MMC program called PRIUM1 and 16 fetuses has been currently operated.

Fetoscopic repair of MMC is proposed by several international groups in order to prevent from maternal and obstetric morbidity related to the hysterotomy and improve the mother's obstetrical prognosis by allowing vaginal delivery. Results of fetoscopic MMC repair are very satisfying, both in terms of repair surgery efficacy and in terms of obstetrical prognosis. The research team believe that it is justified to propose this minimally invasive repair technique using fetoscopy, for represented by sacral MMC (level S1 and lower) as well as for intermediate forms between open and closed dysgraphisms, represented by MyeLDM. Indeed, these dysraphism are associated with the same cerebral complications than MMC with upper limit between T1 and S1 which could be corrected with prenatal repair. In addition, the spinal cord protection offered by prenatal surgery could prevent from the neuroepithelium destruction observed during pregnancy, with a potential motor benefit for the children.

The main objective of PRIUM 2 is to evaluate the success of fetoscopic surgical repair of sacral MMC or MyeLDM with a birth after 32 weeks of gestation and without severe perinatal morbidity and mortality.

The secondary objectives of PRIUM 2 are to evaluate the complications of pregnancy related to fetoscopic surgery as well as to evaluate the prenatal and postnatal evolution of the cerebral complications (Chiari 2 malformation and hydrocephalus) after fetoscopic repair surgery of the dysraphism (up to 12 months of age).

In this protocol, fetal sacral MMC/ MyeLDM repair surgery will be performed using gas fetoscopy before 26 weeks. After an exteriorization of the uterus through a laparotomy, humidified and warmed gas will be insufflated with low pressure (6 to 8mmHg mmHg). Fetoscopic repair surgery will be performed by a multidisciplinary team (maternal fetal medicine specialists, pediatric neurosurgeons, pediatric surgeons).

After discharge, patients will be followed weekly by a midwife and every two weeks by a referring obstetrician who will perform a clinical examination and a fetal ultrasound.A post procedure MRI will be performed 4 weeks after the surgery. If there is no obstetrical contraindication, vaginal delivery will be authorized.

The children will be followed according to the conventional management of children with dysraphisms and consultations at 8 weeks of life and 12 months of life will be scheduled at Trousseau Hospital, with the multidisciplinary team (pediatric neurosurgeons, physical medicine and rehabilitation specialists, pediatric orthopedic surgeons). During these two consultations, the children will have a complete clinical examination, a cerebral and spinal MRI and an ultrasound of the urinary tract.

Inclusion criteria

Inclusion criteria

• Pregnant women age 18 years and older who are able to consent
• Singleton pregnancy before 26 weeks of gestation,
• Sacral MMC (upper level S1 or below) or MyeLDM diagnosed on ultrasound and MRI, 4. Absence of associated malformation apart from the anomalies usually observed in cases of open dysraphisms (i.e. feet malpositions, associated cerebral signs) or chromosomal anomaly if verification of the karyotype was desired by the couple
• Affiliated to health insurance, understanding and speaking French
• Written consent of the patient for the surgery and representatives of the parental authority for the postnatal follow-up of the child
• Patient who made the choice to continue the pregnancy

Exclusion criteria

• Abnormal angulation of the fetal spine,
• risk factors for prematurity: cervical length less < 15mm, history of late miscarriage before 22 weeks, pre-existing rupture of the membranes at inclusion,
• Placenta praevia,
• BMI greater than 35 kg / m2,
• Abnormality of the uterus: large fibroid, uterine malformation, history of uterine body surgery
• Maternal infection at risk of maternal-fetal transmission: HIV, HBV, HCV,
• Surgical or anesthetic contraindication.
• Participation in another interventional research protocol,
• Patients under legal protection (guardianship, curatorship).
• Allergies to drugs used in the research