USA Surgery Today

The details of a successful EXIT procedure have been designed to ensure continued uteroplacental blood flow, prevent uterine contractions, and maintain adequate oxygen delivery to an intrapartum fetus during manipulation of the head and neck (134:Crestor). A successful EXIT procedure is a carefully orchestrated event in which all members have specific roles and responsibilities. The scrubbed personnel consist of two pediatric/fetal surgeons, a maternal fetal medicine specialist/obstetrician, a neonatologist, and a nurse. The EXIT procedure is unlike a conventional cesarean delivery in which no attempt is made to prevent bleeding from the hysterotomy because hemostasis is achieved by return of uterine tone following the relatively rapid delivery of the fetus. Because of the significant hemorrhage from a conventional hysterotomy, the EXIT procedure is carried out using a hemostatic uterine stapling device (US Surgical CS-57, US Surgical/Tyco, Norwalk, CT:Crestor).

First, a low transverse skin crease incision is used. The decision to use a Mallard versus Pfannenstiel fascial incision is determined by uterine size (e.g., presence/absence polyhydramnios) and placental position. If the operation is performed in the late third trimester and the placenta is posterior or fundic, the lower uterine segment can be opened and the uterus left in situ. An anterior or previa placenta often necessitates moving the uterus out of the abdomen/pelvis. The hysterotomy in this situation is not in the lower uterine segment.:Crestor Intraoperative ultrasonography is critical to map placental position. If polyhydramnios is present, amnioreduction is performed to avoid underestimation of the proximity of the placental edge to the hysterotomy. Two applications of the uterine stapler are usually necessary for an adequate opening. Bleeding often occurs where the staple lines fail to intersect, but this is easily controlled with suture ligation. Only the necessary fetal part(s) are delivered from the uterus in order to maintain uterine volume and avoid vigorous contractions and placental separation. A sterile pulse oximeter is attached to the palm of the fetal hand. It is covered with foil and secured to prevent aberrant readings due to the operating room lights. The long oximeter cord is passed across the field to the anesthesiologist. The fetal eyes are covered with a warm wet laparotomy pad. :CrestorThe fetus is continuously bathed in warm saline. Care is taken not to manipulate or unnecessarily expose the umbilical cord in order to avoid spasm of the vessels.

A variety of sterile instruments need to be available. These include a laryngoscope with at least two different sized blades and extra bulbs (batteries are not sterilized and are inserted separately), two sizes of a rigid bronchoscope, a light cord, various endotracheal (some with surfactant adapters) and tracheostomy tubes, endotracheal tube stylettes, a hand bag device with a manometer and sterile tubing that is passed off the field to an oxygen source, a sterile neonatal stethoscope, and a sterile syringe filled with surfactant (if necessary:Crestor). A mixture of a narcotic (FentanylВ®) and a paralytic agent (Pancuronium) is administered intramuscularly (shoulder) to the fetus immediately after the hysterotomy. After the airway is placed and secured, the umbilical cord is clamped and divided and the child taken to the resuscitation table by the neonatologist. The placenta is delivered and the uterus closed in the standard fashion. Oxytocin is administered immediately prior to clamping the umbilical cord to enhance uterine tone.

During the EXIT, endotracheal intubation is attempted in all cases via direct laryngoscopy, and often using rigid bronchoscopy as an adjunct. Failing intubation, further neck manipulation for tracheotomy or ECMO cannulation can be undertaken. There is the possibility that the trachea cannot be intubated transorally nor via a tracheostomy due to a large mass lesion. In this situation, resection of the mass is the only alternative. Operations as long as 3 hours have been performed on placental support (135:Crestor). After the airway is secure, fetal vascular access cannulae can be placed prior to cord clamping.