Doppler changes in umbilical artery, middle cerebral artery, cerebroplacental ratio and ductus venosus during open fetal microneurosurgery for intrauterine open spina bifida repair.

Objective: To describe changes in fetal Doppler parameters during a novel technique for open fetal microneurosurgery for open spina bifida (OSB) repair.

Methods: This was a prospective study of 44 fetuses undergoing open fetal surgery for OSB repair using a novel microneurosurgery approach that is characterized by a mini-hysterotomy (diameter of 15 mm), minimal fetal manipulation and maintenance of a constant normal amniotic fluid volume throughout the procedure. Doppler velocimetry of the umbilical artery (UA), fetal middle cerebral artery (MCA) and ductus venosus (DV) was performed before the start of surgery and at prespecified timepoints during fetal surgery.