Anesthetic Management of Ex Utero Intrapartum Treatment (EXIT) and Fetal Surgery

In recent years, the significant advancement in imaging techniques has led to the early and detailed diagnoses of fetal abnormalities in utero. Some of these conditions may result in significant irreversible damage to an organ or sometimes even death if not corrected before birth. Therefore, surgical intervention is required to correct these abnormalities when the fetus is still in utero during mid-gestation or immediately after delivery when the fetus is still on placental circulation (EXIT: Ex Utero Intrapartum Treatment procedure).  Fetal surgeries, better termed maternal-fetal surgery, need a varying degree of analgesia, sedation, or anesthesia to both the mother and fetus for optimal operating conditions and favorable outcomes. Unlike conventional cesarean sections, they often need general anesthetic together with profound uterine relaxation, which is often continued after the procedure. Also, the fetus needs to be maintained on placental support for varying lengths of time. These surgeries should pose minimal risk to the parturient, which is often termed as “Innocent Bystander,” as she is exposed to the risk of surgery and anesthesia from which she receives no direct benefit. There should be sufficient data that the fetus will benefit from the surgery, and any other lethal fetal abnormality should be ruled out to qualify for the fetal surgeries. These procedures pose a special challenge to the anesthesiologist, having to consider the unique maternal physiology as well as the fetal physiology. Hence a complete understanding of maternal and fetal physiology, anesthetic principles, and anesthesia techniques are essential. This review article presents a brief overview of the various fetal surgeries and the anesthetic considerations specific to them.