Anesthetic Management of Cesarean Delivery Complicated by Ex Utero Intrapartum Treatment of the Fetus

EXIT (ex utero intrapartum treatment) surgery for the management of fetal airway obstruction: A systematic review of the literature

PURPOSE

To provide a comprehensive overview of the perinatal and maternal outcomes of fetuses undergoing EXIT surgery for the management of fetal airway obstruction secondary to cervical or oral tumors.

METHODS

A comprehensive search from inception to September 2018 was conducted on databases including MEDLINE, EMBASE, Cochrane Library and LILACS. All studies that reported an EXIT surgery in singleton were considered eligible. A descriptive analysis was performed.

RESULTS

Out of the 250 full-text study reports, 120 articles reporting 235 cases of EXIT surgery were included. EXIT surgery was performed at 35.1 weeks of gestation on average. The most frequent diagnosis was teratoma (46.4%, n = 109/235). There were 13 adverse maternal events, and the most frequent one was postpartum hemorrhage (4.7%, n = 11/235). No maternal death was reported. Fetal and neonatal death occurred in 17% (40/235) of the cases. There were 29 adverse fetal events (12.2%), and the most frequent one was the failure of intubation or tracheostomy (3.4%, n = 8/235).

CONCLUSION

EXIT surgery could be considered for the management of an oral or cervical tumor that's highly suspicious of blocking the fetal airway. This systematic review reports that EXIT surgery poses substantial risks of maternal and fetal adverse events, including neonatal death.

LEVEL OF EVIDENCE

IV case series with no comparison group.

Anesthesia for EXIT procedure (ex utero intrapartum treatment) in congenital cervical malformation--a challenge to the anesthesiologist

The ex utero intrapartum treatment (EXIT) procedure consists of partial externalization of the fetus from the uterine cavity during delivery, allowing the maintenance of placental circulation. It is indicated in the presence of congenital malformation when difficulty in fetal airway access is anticipated, allowing it to be ensured by direct laryngoscopy, bronchoscopy, tracheostomy, or surgical intervention. Anesthesia for EXIT procedure has several special features, such as the appropriate uterine relaxation, maintenance of maternal blood pressure, fetal airway establishment, and maintenance of postpartum uterine contraction. The anesthesiologist should be prepared for the anesthetic particularities of this procedure in order to contribute to a favorable outcome for the mother and particularly the fetus.

Ex utero intrapartum treatment procedure for management of congenital high airway obstruction syndrome in a vertex/breech twin gestation

Congenital high airway obstruction syndrome (CHAOS) is one indication for the ex utero intrapartum treatment (EXIT), which is used to secure the fetal airway, while fetal oxygenation is maintained by uteroplacental circulation. We report a successful EXIT procedure in a twin gestation in which one child had CHAOS while the other was a healthy child without any congenital abnormalities. After version of Twin B to allow for delivery of Twin A, Twin B underwent airway evaluation and tracheostomy for laryngeal atresia prior to delivery.

Quantification of serum fentanyl concentrations from umbilical cord blood during ex utero intrapartum therapy

Fetal IM injection of fentanyl is frequently performed during ex utero intrapartum therapy (EXIT procedure). We quantified the concentration of fentanyl in umbilical vein blood. Thirteen samples from 13 subjects were analyzed. Medians and ranges are reported as follows. Weight of the newborn at delivery was 3000 g (2020-3715 g). The dose of fentanyl was 60 μg (45-65 μg). The time between IM administration of fentanyl and collection of the sample was 37 minutes (5-86 minutes). Fentanyl was detected in all of the samples, with a median serum concentration of 14.0 ng/mL (4.3-64.0 ng/mL).

Obstetric hemorrhage during an EXIT procedure for severe fetal airway obstruction

PURPOSE

To report a case of massive obstetric hemorrhage occurring during Cesarean delivery for an ex utero intrapartum treatment (EXIT) procedure. Methods to optimize the anesthetic, obstetric, and perinatal management are discussed.

CLINICAL FEATURES

A healthy parturient underwent an urgent EXIT procedure at 32 weeks gestation for a giant fetal neck mass. During the intraoperative period, severe intraoperative hemorrhage occurred from the site of the uterine incision. No evidence of placental bleeding, premature placental separation, or inadequate uterine relaxation was observed during the perioperative period. Placement of a uterine stapling device was unsuccessful in achieving adequate surgical hemostasis. Initial attempts with laryngoscopy and rigid bronchoscopy to secure the fetal airway on placental support were unsuccessful, and early termination of placental support was deemed necessary due to the severity of maternal blood loss. After full delivery of the neonate and termination of placental support, neonatal ventilation with bag-mask ventilation was achieved and successful endotracheal intubation occurred during repeat bronchoscopy.

CONCLUSIONS

The risk of obstetric hemorrhage due to uterine relaxation and inadequate surgical hemostasis in patients undergoing EXIT procedures is poorly reported. To reduce adverse maternal and neonatal outcomes, the premature termination of placental support during EXIT procedures may be required in the setting of severe obstetric hemorrhage.

Ex utero intrapartum treatment procedure in a patient with arthrogryposis multiplex congenita, using continuous spinal anesthesia and intravenous nitroglycerin for uterine relaxation

The ex utero intrapartum treatment procedure allows for the controlled management of a potentially life-threatening difficult airway in the newborn. General anesthesia has previously been reported for the management of this procedure. We report the use of continuous spinal anesthesia in conjunction with intravenous nitroglycerin for the ex utero intrapartum treatment procedure in a woman with arthrogryposis multiplex congenita, a rare syndrome characterized by rigid joints and limb contractures.

Advances in obstetric anesthesia: anesthesia for fetal intrapartum operations on placental support

Fetal intrapartum operations on placental support (OOPS), also known as ex-utero intrapartum treatment (EXIT) procedures, are very rare (and often challenging) surgical techniques designed to allow partial delivery (cesarean section) of a fetus with a potentially difficult airway, with subsequent management of the neonatal airway (direct laryngoscopy, fiberoptic bronchoscopy, or tracheostomy) while oxygenation is continuously maintained via the placenta (on placental support). The peripartum management of pregnant women and their fetuses undergoing OOPS is very complex and multidisciplinary, and differs greatly from that of standard cesarean sections. The goal of this article is to review the current recommendations for the peripartum anesthetic management of pregnant women carrying fetuses with fetal congenital malformations undergoing OOPS.

Case series: Combined spinal epidural anesthesia for Cesarean delivery and ex utero intrapartum treatment procedure

PURPOSE

To report the use of regional anesthesia and iv nitroglycerin to provide anesthesia and uterine relaxation for three Cesarean deliveries (CD) involving ex utero intrapartum treatment (EXIT) of potentially life-threatening airway obstruction in the newborn.

CLINICAL FEATURES

Case 1--a 36-yr-old woman at 38 weeks' gestation was scheduled for an elective CD for fetal skeletal dysplasia and micrognathia. Case 2--a 34-yr-old woman at 35 weeks gestation had a fetal ultrasound revealing fixed neck flexion and micrognathia consistent with fetal arthrogryposis. Case 3--a 27-yr-old woman presented at 38 weeks gestation for CD for severe fetal micrognathia, with mandibular growth below the fifth percentile. For each case, a combined spinal epidural anesthetic was performed with 0.75% bupivacaine, fentanyl and morphine intrathecally followed by placement of a multiorifice epidural catheter. Prior to uterine incision patients received a loading dose followed by an iv infusion of nitroglycerin. Uterine relaxation was sufficient in all cases for delivery of the fetus, and allowed for evaluation by direct laryngoscopy and intubation while maintaining fetal-placental circulation. The surgical procedures were completed without incident.

CONCLUSIONS

Anesthesia and uterine relaxation for CD and EXIT procedures can be safely provided with regional anesthesia and iv nitroglycerin.

The Effects of Volatile Anesthetics on Spontaneous Contractility of Isolated Human Pregnant Uterine Muscle: A Comparison Among Sevoflurane, Desflurane, Isoflurane, and Halothane

We examined the effects of equianesthetic concentrations of sevoflurane, desflurane, isoflurane, and halothane on the spontaneous contractility of isolated human pregnant uterine muscles. We also determined if their action was related to potassium channels. Uterine specimens were obtained from normal full-term pregnant women undergoing elective lower-segment cesarean delivery. Longitudinal muscle strips were mounted vertically in tissue chambers. Their isometric tension was recorded while they were exposed to 0.5-3 minimum alveolar concentration (MAC) of volatile anesthetics in the absence and presence of the high conductance calcium-activated potassium channel blocker, tetraethylammonium, or the adenosine triphosphate-sensitive potassium channel (K(ATP))-blocker, glibenclamide. The anesthetics examined produced a dose-dependent depression of contractility. The inhibitory potency of sevoflurane and desflurane was comparable to, whereas that of isoflurane was smaller than, that of halothane: concentrations causing 50% inhibition of the contractile amplitude (ED(50)) were 1.72, 1.44, 2.35, and 1.66 MAC (P < 0.05), respectively. Tetraethylammonium and glibenclamide did not affect the uterine response to the anesthetics, except for glibenclamide, which attenuated the response to isoflurane. These results indicate that the volatile anesthetics have inhibitory effects on the contractility of the human uterus. The inhibitory effect of isoflurane may in part be mediated through activation of K(ATP) channels.

Anesthésie maternofœtale pour « ex utero intrapartum » traitement (EXIT) procédure : à propos de deux cas

The ex utero intrapartum treatment (EXIT) procedure is a surgical procedure maintaining utero-placental circulation during caesarean section. Anaesthetic implications are described: foetal transplacental anaesthesia to avoid first breathing and to permit surgical procedure on obstructed foetal airway, deep maternal haemodynamically stable anaesthesia to relax uterine smooth muscle during a long caesarean procedure but avoiding post-partum haemorrhage. Volatile anaesthesia with sevoflurane seems to be adequate for these aims. Two cases are described.

Verifying Correct Endotracheal Intubation by Measurement of End-Tidal Carbon Dioxide During an Ex Utero Intrapartum Treatment Procedure

The ex utero intrapartum treatment (EXIT) procedure provides time to secure the airway of the fetus while utero-placental circulation supplies the fetus with oxygen. We report the anesthetic management of a fetus with a large neck mass during an EXIT procedure in which the confirmation of correct endotracheal intubation was hampered by parts of the mass, blood, and other fluids. The use of a standard end-tidal carbon dioxide probe provided a reliable signal and proved the endotracheal position of the tube while utero-placental circulation was still intact.

Ex utero intrapartum surgery (EXIT): indications and anaesthetic management

The ex utero intrapartum treatment (EXIT) procedure is a technique for safely managing airway obstruction at birth, in which placental support is maintained until the airway is evaluated and secured. In addition to the usual considerations of anaesthesia in obstetrics there are special considerations relating to the EXIT procedure: maintaining fetoplacental circulation by profound uterine relaxation and achieving fetal anaesthesia for airway manipulations. This chapter focuses on the key issues involved in managing this procedure: the indications, preoperative concerns, organization of a multidisciplinary team, problems of maternal and fetal anaesthesia, maintenance of the uterine relaxation and control of fetal airway.

Fetal surgery, anaesthesiological considerations

PURPOSE OF REVIEW

Refined techniques and skills have enabled sophisticated prenatal diagnosis in utero and resulted in the newly evolving specialty of fetal surgery in a few centres worldwide. Most of the procedures performed today have been preceded by extensive experimental research in animals, whereas fetal anaesthesia is mainly based on clinical experience and a few studies performed in pregnant sheep.

RECENT FINDINGS

Major limitations of fetal surgery include the high frequency of preterm labour and delivery which may offset any fetal benefit of the surgical procedure. The development of more potent tocolytic drugs than the drugs currently available may thus be compared to the meaning of potent immunosuppressive agents in organ transplantation. Fetal mortality and maternal morbidity consequently lead to a more cautious way of treatment, as with the development of endoscopic fetal surgery.

SUMMARY

The invasive fetal surgery is still considered as being in a research stage in most cases. Therefore most procedures are performed as minimally invasive, avoiding substantial risks by accessing the uterus through minimal openings. Some new devices are under investigation for monitoring the myometrial electrical activity and mechanical contractility and the fetal electroencephalogram, the continuous monitoring of the fetal arterial oxygen saturation, PO2 and PCO2, and for monitoring fetal cerebral oxygenation, blood volume and blood flow by near infrared spectroscopy.

Anesthesia for fetal surgery

Fetal surgery is a rapidly growing and evolving area. Fetal surgery is based on years of animal and clinical research. In contrast, anesthesia techniques for fetal surgery are based on clinical experience. The techniques that have emerged are safe for mother and fetus. In this review, the authors describe current techniques for anesthetic management of fetal surgery patients. General anesthesia is the primary technique used for hysterotomy based surgical correction of midgestation fetuses and ex utero interpartum corrections of end-gestation fetuses. Epidural analgesia, with general anesthesia as back-up, is the primary technique used for fetoscopic cases in which anesthetic care is required. Because of the myriad of anesthetic and surgical issues these cases generate, it is essential to have good communication and cooperation between surgeons and anesthesiologists from the preoperative period to the postoperative period. This will allow development of a cohesive anesthetic and surgical plan that can be used for the safe perioperative management of the fetal surgery patient.

Airway management on placental support (AMPS)--the anaesthetic perspective

Neonatal airway obstruction has been reported to have a high mortality. Antenatal diagnosis of this condition is now possible. Anaesthetic and surgical techniques have been developed that allow neonatal airway obstruction to be managed at delivery, while the fetus remains oxygenated via the placental circulation. Three case studies are presented, and the anaesthetic issues for mother and fetus/neonate are discussed with reference to previously published cases of airway management on placental support. In particular, techniques for uterine relaxation and maintenance of placental circulation are explored. The history of these procedures and issues of planning and logistics are also discussed.

The effects of sevoflurane on isolated gravid human myometrium

The volatile anaesthetic agents are known to influence uterine muscle tone. All of the agents studied to date have been found to produce uterine relaxation. This property has been used to produce therapeutic uterine relaxation for difficult obstetric deliveries and the Ex Utero Intrapartum Treatment (EXIT) procedure. This study describes the effects of sevoflurane on isolated human myometrium at concentrations of 0.1, 0.25, 0.5, 0.75, 1.0, 1.5, 2.5 and 3.5 MAC. Sevoflurane produces dose-dependent depression of uterine muscle contractility with an ED50 of 0.94 MAC. Frequency of contraction was increased at concentrations of 2.5 MAC and greater. At concentrations of 3.5 MAC and above, uterine activity was virtually abolished.

Management of fetal airway obstruction: an innovative strategy

This article describes a planned ex utero intrapartum treatment (EXIT) procedure at the Children's Hospital of Philadelphia for a fetus with an airway obstruction resulting from a giant neck mass. The EXIT procedure is a technique that establishes a fetal airway while the utero-placental circulation is maintained for up to 1 hour. As a part of the planned EXIT procedure, a multidisciplinary, highly skilled team was developed to care for both mother and baby. This team consisted of obstetric and surgical personnel to care for the mother during the procedure, the birth, and the recovery, and a neonatal surgical team to care for the newborn. Nursing expertise necessary to conduct this procedure and safely care for the woman and fetus are discussed.

Anesthesia for fetal surgery

Fetal surgery is the antenatal treatment of fetal malformations that cannot be adequately corrected after birth. Anesthesia for fetal surgery involves two patients, and issues of maternal safety, avoidance of fetal asphyxia, adequate fetal anesthesia and monitoring, and uterine relaxation are important. Communication with the surgeon to determine the surgical approach and need for uterine relaxation allows the anesthesiologist the ability to vary the anesthetic technique. Lessons learned from fetal surgery may help other neonates with life-threatening anomalies and may help understand the complex issues related to preterm labor.

The ex utero intrapartum treatment (EXIT) procedure in fetal neck masses: a case report and review of the literature

Large fetal neck masses can cause airway obstructions with potential fetal demise after delivery. The relationship of the neck mass to airway structures can be defined prenatally with ultrasound and magnetic resonance imaging (MRI). The ex utero intrapartum treatment (EXIT) procedure can be used to obtain a fetal airway while feto-maternal circulation is preserved to optimise fetal outcome. We present a case in which prenatally a large fetal neck mass was diagnosed on ultrasound and a successful EXIT procedure was performed. A review of the literature is given and the prenatal use of ultrasonography and MRI in case of fetal neck masses is discussed.

Anesthetic management of the exit (ex utero intrapartum treatment) procedure

The EXIT (ex utero intrapartum treatment) procedure is used to maintain fetal-placental circulation during partial delivery of a fetus with a potentially life-threatening upper airway obstruction. We performed the EXIT procedure on a fetus with a large intra-oral cyst. Sevoflurane was used as the anesthetic because of its rapid titratability. Sevoflurane provided excellent maternal and fetal anesthesia. Modifications to previously described monitoring techniques for the EXIT procedure were also used.

Anesthetic considerations for fetal surgery

This article outlines the perioperative management of the parturient who presents for fetal surgery. Anesthetic considerations include the physiological changes of pregnancy, preterm labor, the consequences of tocolytic drugs, maternal and fetal anesthesia, and postoperative analgesia.