The EXIT procedure: experience and outcome in 31 cases.
BACKGROUND
The EXIT (ex utero intrapartum treatment) procedure, although initially designed for reversal of tracheal occlusion in fetuses with congenital diaphragmatic hernias (CDH), has been adapted to treat a variety of fetal conditions.


METHODS
A retrospective chart review of all consecutive EXIT procedures since 1996 was conducted.


RESULTS
Thirty-one women underwent the EXIT procedure, with an average maternal age of 29 years (range, 20 to 38), and average gestational age of 34 weeks (range, 29 to 40). The indication was airway obstruction from fetal neck mass in 13, and reversal of tracheal occlusion from in utero clipping in 13. Singular indications included an EXIT-to-ECMO (extracorporeal membrane oxygenation) procedure for a fetus with CDH and a cardiac defect (n = 1), congenital high airway obstruction syndrome (CHAOS, n = 1), resection of a very large congenital cystic adenomatoid malformation of the lung (CCAM) on uteroplacental bypass (n = 1), unilateral pulmonary agenesis (n = 1), and thoracoomphalopagus conjoined twins. The mean duration on uteroplacental bypass (from uterine incision to umbilical cord clamping) was 30.3 plus minus 14.7 minutes (range, 8 to 66). No fetus experienced hemodynamic instability during uteroplacental bypass as recorded by fetal heart rate (FHR), pulse oximeter, and fetal echocardiography, except for one instance of reversible bradycardia from umbilical cord compression. The mean FHR and fetal saturation were 153.0 plus minus 38.5 beats per minute and 71.2% plus minus 19.9%, respectively. Five fetuses required a tracheostomy. Only 1 death occurred during an EXIT procedure because of inability to secure the airway secondary to extensive involvement by a lymphangioma. The average cord pH and pCO(2) were, respectively, 7.20 plus minus 0.11 and 63.2 plus minus 14.6. Two maternal complications occurred: bleeding from a hysterotomy site and dehiscence of an old hysterotomy scar noticed at a subsequent cesarean section. The average maternal blood loss was 848.3 plus minus 574.1 mL.


CONCLUSIONS
The EXIT procedure was used successfully to ensure uteroplacental gas exchange and fetal hemodynamic stability during a variety of surgical procedures performed to secure the fetal airway or ensure successful transition to postnatal environment.
Bouchard
Sarah
S
Division of Pediatric General, The Center for Fetal Diagnosis and Treatment, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
Johnson
Mark P
MP
Flake
Alan W
AW
Howell
Lori J
LJ
Myers
Laura B
LB
Adzick
N Scott
NS
Crombleholme
Timothy M
TM
D000328:Adult; D000402:Airway Obstruction / Q000601:surgery; D001201:Ascites / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000601:surgery; D002585:Cesarean Section; D015615:Cystic Adenomatoid Malformation of Lung, Congenital / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000601:surgery; D015199:Extracorporeal Membrane Oxygenation; D005260:Female; D005315:Fetal Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D005865:Gestational Age; D006258:Head and Neck Neoplasms / Q000401:mortality / Q000601:surgery; D006801:Humans; D018191:Lymphangioma, Cystic / Q000401:mortality / Q000601:surgery; D008279:Magnetic Resonance Imaging; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012189:Retrospective Studies; D014139:Tracheostomy; D016896:Treatment Outcome; D014428:Twins, Conjoined / Q000601:surgery; D016216:Ultrasonography, Prenatal