EXIT-to-resection: resection of fetal thoracic or mediastinal mass
EXIT-to-extracorporeal membrane oxygenation (E(MO): congenital diaphragmatic hernia he Agency for Healthcare Research and Quality stresses that when considering fetal surgery, the overriding concern must be maternal and fetal safety. Accomplishing the fetal goals of the procedure is secondary (Walsh, 2011).
Some abnormalities amenable to fetal surgical treatment, antepartum or intrapartum, are shown in Table 16-2. An overview of these procedures, their indications, and complications is provided here to assist with initial patient evaluation and counseling. Additional content is also found in Cunningham and Gilstrap s Operative Obstetrics, 3rd edition.
These procedures require extensive preoperative counseling and multidisciplinary care. he mother must undergo general endotracheal anesthesia to suppress both uterine contractions and fetal responses. Using intraoperative sonographic guidance to avoid the placental edge, a low-transverse hysterotomy incision is made with a stapling device that seals the edges for hemostasis. To replace amnionic fluid losses, warmed luid is continuously infused into the uterus thorough a rapid infusion device. he fetus is gently manipulated to permit pulse oximetry monitoring and to establish venous access, in case luids or blood are emergently needed. The surgical procedure is then performed. After completion, the hysterotomy is closed and tocolysis begun. T ocolysis typically includes intravenous magnesium sulfate for 24 hours, oral indomethacin for 48 hours, and, at some centers, oral nifedipine until delivery (Wu, 2009). Prophylactic antibiotics are also administered and generally continued for 24 hours following the procedure. Cesarean delivery is needed later in gestation and for all future deliveries.
Morbidities associated with fetal surgery are well characterized. In a review of 87 open procedures, Golombeck and coworkers (2006) reported the following morbidities: pulmonary edema-28 percent, placental abruption-9 percent, blood transfusion-13 percent, premature rupture of membranes-52 percent, and preterm delivery-33 percent. Wilson and associates (2010) reviewed subsequent pregnancy outcomes following open fetal surgery and reported that 14 percent of women experienced uterine rupture and 14 percent had uterine dehiscence. Morbidities identiied in the recent Management of Myelomeningocele Study (MOMS) are shown in Table 16-3 (Adzick, 2011). Other potential risks include maternal sepsis and fetal death during or following the procedure, particularly if hydrops is present.
Even with postnatal repair, children with myelomeningocele generally have varying degrees of paralysis, bladder and bowel dys function, developmental delays, and brainstem dysfunction from the Arnold-Chiari II malformation (Chap. 10, p. 193). Damage is postulated to result from abnormal embryonic neurulation and from ongoing exposure of neural elements to amnionic luid (Adzick, 2010; Meuli, 1995, 1997). Fetal myelomeningocele meets the criteria listed in Table 16-1 and is the first nonlethal birth defect for which fetal surgery has been ofered (Fig. 16-2).