The prospect of treating severe fetal anomalies in utero has been a topic of intense interest for more than two decades. Pioneering work in animals led to the development of open fetal surgery, in which maternal hysterotomy and partial exteriorization of the fetus are performed to permit surgery for selected life-threatening anomalies. Currently, such expertise is available at only a few centers in the United States and for only a few fetal conditions. Because it entails substantive fetal and maternal risks, these procedures are considered only when they might reasonably be expected to improve fetal outcome and when withholding them would undoubtedly be catastrophic.
Although the indications for open fetal surgery are limited, the number of conditions amenable to less invasive therapy has expanded, particularly during the past decade. These procedures are not without risk, but maternal morbidity and fetal preterm delivery may be reduced. For any fetal therapy, it is important that appropriate selection criteria be established and verified, that each procedure be perfected and tested successfully in experimental animals, and that its efficacy in human pregnancy be rigorously evaluated prior to widespread implementation.
These procedures require a highly skilled team from different disciplines, as well as extensive case management with education and counseling. To gain fetal access, the mother must undergo general endotracheal anesthesia to suppress both uterine contractions and fetal responses. Using sonographic guidance to avoid the placental edge, a hysterotomy incision is made with a stapling device that seals the edges to permit hemostasis. Warmed fluid is continuously infused into the uterus thorough a rapid infusion device. The fetus is gently manipulated to permit pulse oximetry monitoring and venous access in case fluids or blood are emergently needed. At this point, fetal surgery is performed. The hysterotomy is then closed and tocolysis begun. Later in the pregnancy, delivery is completed by cesarean.
In a review of 87 open fetal surgery procedures from the Fetal Treatment Center of the University of California, San Francisco, Golombeck and colleagues (2006) reported the following morbidities: maternal pulmonary edema—28%, maternal blood transfusion—13%, preterm labor and delivery—33%, prematurely ruptured membranes—52%, chorion-amnion separation—20%, chorioamnionitis—9%, and placental abruption—9%. Other potential risks include later uterine rupture, maternal sepsis, and fetal death during or following the procedure.
Some conditions for which open fetal surgery is offered include thoracic masses with hydrops, such as congenital cystic adenomatoid malformation (CCAM) and extralobar pulmonary sequestration; spina bifida; and sacrococcygeal teratoma (SCT) with evidence of high-output cardiac failure. For fetuses with CCAM, once hydrops had developed, none of 25 fetuses survived without treatment, whereas 8 of 13 survived with fetal lobectomy.
Unlike open fetal surgery for other abnormalities, surgery for spina bifida is controversial, because the condition itself is not lethal. However, isolated open spinal defects usually result in permanent neurological damage, and in utero repair can potentially limit the damage ...