Clinical Trial: Fetoscopic Meningomyelocele Repair Study

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: Minimally Invasive Fetal Neural Tube Defect Repair Study

Brief Summary:

The purpose of the study is to evaluate the maternal and fetal outcomes of a new technique for the fetoscopic repair of fetal MMC at Texas Children's Hospital Pavilion for Women.

The investigators hypothesis is that this minimally invasive technique is feasible, and that this approach will have the same efficacy as open fetal surgery for MMC, but with significantly less maternal-fetal risk. Both mother and baby will benefit from the surgery. The fetus will have a repaired MMC defect, and the mother will not have a uterine incision (hysterotomy). A hysterotomy increases the risk of uterine rupture and requires that all subsequent deliveries are by cesarean section. There may also be a decreased risk of Pre-term Premature Rupture Of Membranes (PPROM) and prematurity when compared with the current open operation. Finally, a vaginal delivery is possible following the fetoscopic fetal surgery if the baby is shown to have a skin covered repair.


Detailed Summary:

Spina bifida can be a devastating neurological congenital anomaly . It results from incomplete closure of the neural tube between 22 and 28 embryological days. Its incidence is approximately 1-2 per 1,000 births. It is considered the most common congenital anomaly of the central nervous system that is compatible with life.

  1. The most frequent form is myelomeningocele (MMC), characterized by the extrusion of the spinal cord into a sac filled with cerebrospinal fluid (CSF), and is associated with lower limb paralysis and bowel and bladder dysfunction.
  2. The majority of MMCs can be diagnosed between 14 and 20 weeks of gestation. MMC is associated with Chiari II malformation, which includes a constellation of anomalies such as hindbrain herniation, brainstem abnormalities, low-lying venous sinuses and a small posterior fossa.The Chiari II malformation can have deleterious effects on motor, cranial nerve and cognitive functions. Postnatally most MMC patients develop hydrocephalus and require a ventriculoperitoneal shunt. Shunts require lifelong monitoring and have a high failure rate due to infection, obstruction, and fracture.

Experimental studies using animal models have shown that prenatal coverage of a spina bifida-like lesion can preserve neurological function and reduce or reverse hindbrain herniation.These studies suggest a "two-hit" hypothesis in which the ultimate neurologic deficit results from a combination of the failure of normal neural-tube closure (first hit) with secondary spinal cord injury resulting from prolonged exposure of sensitive neural elements to the amniotic fluid (second hit mechanism).

Based on this hypothesis, open fetal surgical repair of MMC was proposed, and the recen
Sponsor: Baylor College of Medicine

Current Primary Outcome: Feasibility [ Time Frame: Time of procedure ]

Whether the minimally invasive technique can be technically performed in human patients (success of primary skin closure) in a safe and effective manner.


Original Primary Outcome: Same as current

Current Secondary Outcome: Reversal of the Chiari II malformation with complete closure of the spinal defect. [ Time Frame: at birth ]

Whether the minimally invasive technique results in an acceptable fetal outcome as defined by reversal of the Chiari II malformation, a reduced need for ventriculoperitoneal shunting or other procedures to avoid or treat hydrocephalus, and complete closure of the spinal defect with protection of the placode. In addition the procedure will be assessed as to whether it prevents loss of neurological level during intra-uterine life.


Original Secondary Outcome: Same as current

Information By: Baylor College of Medicine

Dates:
Date Received: August 22, 2014
Date Started: July 2014
Date Completion: January 2021
Last Updated: September 26, 2016
Last Verified: September 2016