Fetoscopic spina bifida repair.

INTRODUCTION: Spina bifida is the most common non-lethal congenital birth defect of the central nervous system that causes chronic disability due to the combined effects of local nerve damage and the sequelae of non-communicating hydrocephalus. This abnormality can be identified early in gestation and the damage can be progressive over the course of pregnancy. Advances in fetal treatment have made minimally invasive prenatal surgery a realistic consideration for spina bifida in order to improve the outcome for children affected this condition.

EVIDENCE ACQUISITION: Prenatal surgery for spina bifida via open fetal surgery with hysterotomy decreases the rate of ventriculoperitoneal shunt placement and improves motor function compared to standard postnatal surgery. Maternal risks of open fetal surgery are primarily related to complications of the hysterotomy including thinning or rupture that begins in the index pregnancy but persists for every future pregnancy. Minimizing maternal risks is the largest impetus to explore and optimize a minimally invasive fetoscopic alternative. Techniques vary from using a complete percutaneous approach to open fetoscopy, which requires laparotomy but is minimally invasive to the uterus. This allows vaginal delivery at term and no scar complications are reported thus far. Fetal short-term neurosurgical outcomes compare favorably with improvement in hindbrain herniation >70% and decreased need for treatment for hydrocephalus between 40-45% after prenatal surgery performed either fetoscopically or through open fetal surgery.

EVIDENCE SYNTHESIS: Maternal obstetric outcomes are superior for fetoscopic spina bifida repair compared to open fetal surgery and avoids the ongoing risk in future pregnancy. Neonatal and infant benefits appear equivalent. The open fetoscopic approach minimizes the risk of ruptured membranes and subsequent preterm delivery as opposed to a completely percutaneous procedure. International collaboration is ongoing to share experience and assess long term treatment effects.

CONCLUSIONS: Continued refinement of a minimally invasive strategy for prenatal treatment of spina bifida is necessary to maximize benefits to the child and further minimize maternal risks and preterm birth.