Anesthesia for Fetal Intervention and Surgery

Abstract

Congenital birth defects affect 3% of infants born in the United States and accounts for 20% of all infant deaths (Clin Obstet Gynecol, 2017, 10.1016/j.bpobgyn.2017.02.005). The field of fetal surgery emerged in an effort to curtail the incidence of these infant deaths related to potentially reversible defects.Access to prenatal care is essential for prenatal diagnosis of fetal anomalies, and the advances in ultrasound and MRI imaging have led to better delineation of structural anomalies and their potential impact on the fetus or newborn (Curr Opin Pediatr, 24, 386–393, 2012). An increasing number of conditions are diagnosed early in gestation and some of these may benefit from prenatal surgical intervention as they may be life threatening or result in irreversible organ damage (Fetal Diagn Ther 31, 201–209, 2012). Fetal therapy should be limited to the treatment of only those malformations that are severe, and to potentially lethal conditions in which such therapy has been shown to improve the survival and/or preserve normal or near normal function in the infant.

Developmental malformations and fetal conditions which are amenable to fetal intervention are often classified into five evidence based groups with 4 conditions comprising the first group which benefit from fetal therapy based on Level 1 evidence (twin-twin transfusion syndrome, myelomeningocele, lower urinary tract obstruction, congenital diaphragmatic hernia). These conditions are most often treated prenatally when available, as they are associated with significant mortality and morbidity if left untreated (Clin Obstet Gynecol, 2017, 10.1016/j.bpobgyn.2017.02.005). Fetal surgeries encompass many different procedures that can be divided into three broad categories: minimally invasive fetal surgery (fetoscopy), open midgestation fetal surgery, and ex utero intrapartum therapy (EXIT).

If a fetal surgery is planned, a multidisciplinary team is formed consisting of the fetal surgeon, anesthesiologist, obstetrician, neonatologist, and other relevant medical specialists. Care providers have an ethical obligation to make sure all available options are discussed with the patient and her family prior to proceeding. The anesthesiologist has the responsibility of providing optimal anesthesia both for the mother and fetus while minimizing both maternal and fetal risk. Once the mother consents to proceed, the complexity of the procedure requires close coordination and communication amongst the entire fetal team.