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

Anesthetic considerations of EXIT procedure: A case report

The ex-utero intrapartum treatment (EXIT) is a rare surgical procedure performed in cases of expected postpartum fetal airway obstruction. This procedure technique lies in a safe establishment of a patent airway during labor in anticipation of a critical respiratory event, without the interruption of maternal-fetal circulation. Anesthetic management in the EXIT procedure is substantially different from that of the standard cesarean delivery and its main goals include uterine relaxation, fetal anesthesia, and placental blood flow preservation. We report the first case of an EXIT procedure performed on a fetus with a prenatal diagnosis of multiple oral masses at King Khalid University Hospital, Riyadh, Saudi Arabia.

Pregnancy hypertension-associated endothelial dysfunction is attenuated by isoflurane anesthesia: Evidence of protective effect related to increases in nitric oxide

AIMS

Pregnancy hypertension-induced endothelial dysfunction associated with impairment of nitric oxide (NO) bioavailability and hemodynamic derangements is a challenging for urgent procedures requiring maternal anesthesia. The volatile anesthetic isoflurane has demonstrated NO-associated protective effects. However, this isoflurane-induced effect is still unclear in pregnancy hypertension. Therefore, the present study examined the potential protective effects of isoflurane anesthesia on endothelial dysfunction and hemodynamic changes induced by hypertensive pregnancy associated with fetal and placental growth restrictions.

MATERIALS AND METHODS

Animals were distributed into four groups: normotensive pregnant rats (Preg), anesthetized pregnant rats (Preg+Iso), hypertensive pregnant rats (HTN-Preg), and anesthetized hypertensive pregnant rats (HTN-Preg+Iso). Systolic and diastolic pressures, mean arterial pressure (MAP), heart rate, fetal and placental weights, vascular contraction, endothelium-derived NO-dependent vasodilation, and NO levels were assessed. The vascular endothelial growth factor (VEGF) levels and endothelial NO synthase (eNOS) Serine (1177) phosphorylation (p-eNOS) expression were also examined.

KEY FINDINGS

Isoflurane produced more expressive hypotensive effects in the HTN-Preg+Iso versus Preg+Iso group, with respective reductions in MAP by 50 ± 13 versus 25 ± 4 mmHg (P < 0.05). Also, HTN-Preg+Iso compared to the HTN-Preg group showed (respectively) preventions against the weight loss of the fetuses (4.0 ± 0.6 versus 2.8 ± 0.6 g, P < 0.05) and placentas (0.37 ± 0.06 versus 0.30 ± 0.06 mg, P < 0.05), hyper-reactive vasocontraction response (1.8 ± 0.4 versus 2.8 ± 0.6 g, P < 0.05), impaired endothelium-derived NO-dependent vasodilation (84 ± 8 versus 50 ± 17 %, P < 0.05), reduced VEGF levels (147 ± 46 versus 25 ± 13 pg/mL, P < 0.05), and decreased p-eNOS expression (0.24 ± 0.07 versus 0.09 ± 0.05 arbitrary units, P < 0.05).

SIGNIFICANCE

Isoflurane anesthesia protects maternal endothelial function in pregnancy hypertension, and possibly endothelium-derived NO is involved.

Changing indications and antenatal prognostic factors for EXIT procedures

OBJECTIVE

In cases of suspected neonatal airway obstruction, the ex-utero intrapartum treatment (EXIT) procedure is used to secure the airway while a fetus remains on placental circulation. We report indications and outcomes from all EXIT procedures at a tertiary obstetric unit between 1997 and 2020.

METHOD

Retrospective cohort study with data collected from maternal and neonatal medical records.

RESULTS

Indications for EXIT procedures were: micrognathia (n=7), lymphatic malformations (n=5), cervical teratomas (n=4), goiters (n=2) and intra-oral epulis (n=1). Infants with a fetal teratoma were delivered earliest due to 75% presenting with preterm premature rupture of membranes or pre-term labor. Low birth weight was found in 75% of these neonates; these did not survive one year. Intubation at EXIT occurred for 58% (n=11) of babies and six neonates required a tracheostomy. In four cases of fetal micrognathia, the inferior facial angle (IFA) was noted to be <5th centile. All but one micrognathia cases had polyhydramnios. Of the total cohort, 75% of neonates were alive at one year.

CONCLUSION

Risks for neonatal demise with EXIT include fetal teratoma, low birth weight and prematurity. Micrognathia has become an increasingly valid indication for the procedure. The combination of polyhydramnios and IFA <5% correlates well with severe airway obstruction and suggests consideration of EXIT. This article is protected by copyright. All rights reserved.

EXIT-to-airway: Fundamentals, prenatal work-up, and technical aspects

Ex-utero intrapartum treatment (EXIT) is a delivery strategy developed to manage a variety of prenatally diagnosed conditions in the transition to newborn life. This procedure allows control and provides time for intervention in otherwise life-threatening malformations, such as congenital upper airway obstructions. EXIT-to-airway has changed the outcome of fetuses with these anomalies. The main purpose of this intervention is to improve the safety of establishing a reliable airway at birth. Maximal but controlled uterine relaxation to maintain feto-maternal perfusion and thus gas exchange, while keeping the fetal and maternal well-being are the paradigms of any type of EXIT. The most important aspect of fetal airway management is to consolidate a highly trained, well-coordinated, multidisciplinary team that is prepared for every contingency. A comprehensive prenatal assessment, including ultrasound, fetal echocardiogram, fetal MRI, and genetic testing is imperative for patient selection. Extensive preoperative planning, ad-hoc team meetings, and surgical simulations for challenging cases are critical strategies to achieve the best outcomes. This article outlines the prenatal work-up, decision making, technical aspects, and principles for a successful EXIT-to-airway procedure.

Airway management for neonates requiring ex utero intrapartum treatment (EXIT)

In utero congenital malformations in the fetus can occasionally lead to an obstructed airway at birth accompanied by hypoxic injury or peripartum demise, without intervention. Ex utero intrapartum treatment (EXIT) may help reduce morbidity and mortality associated with challenging airways by providing extra time on uteroplacental circulation to secure the airway. Meticulous preparation and planning are crucial for this procedure. Many different types of congenital malformations can result in a difficult airway, but there is no correlation between specific malformations and a required type of airway intervention. Based on our experience and literature review, an airway process flow diagram has been created to help assist teams in decision-making for airway intervention in a neonate during the EXIT procedure. The management of the airway in this scenario involves additional unique considerations that accompany handling a partially delivered newborn in the uterine environment. Extensive preparation and team rehearsal are essential to the success of this procedure.

The EXIT (ex-utero intrapartum treatment) procedure - from the paediatric ENT perspective

The main principle of the EXIT procedure is to maintain uteroplacental circulation with neonatal anaesthesia by controlled uterine hypotonia. This enables securing the foetal airways and decompress or resect large neck and mediastinal foetal masses. The authors present their experience with use of the EXIT procedure in 7 foetuses in whom evaluation and management of the airways were performed. In 4 patients, the neck mass was surgically removed in the neonatal period, in 1 the propranolol treatment was introduced. Two newborns died shortly after the EXIT procedure. The EXIT procedure allows the paediatric otolaryngologist to provide airway patency of newborns during delivery. Both ultrasound and MR imaging are crucial in the prenatal assessment of foetal head and neck masses. Their application in the evaluation of any foetal anomaly is essential for proper prognosis and treatment. Maternal monitoring for complications such as polyhydramnios and preterm labour are important in planning and desirability of the EXIT procedure.

Use of ex utero intrapartum treatment procedure in fetal neck and high airway anomalies - report of four clinical cases

PURPOSE

To present antenatal management and use of ex utero intrapartum treatment (EXIT) in different fetal neck and high airway anomalies.

MATERIAL AND METHODS

We have presented four different cases of fetal neck or airway pathology which were indications for EXIT, at our department.

RESULTS

In three cases of fetal neck tumors, the primary precise antenatal diagnoses of tumors were confirmed after birth. The airways of all three fetuses were properly secured during EXIT by laryngologist. All these newborns survived. In the fourth case, a primary, antenatal diagnosis of congenital high airway obstruction syndrome due to severe trachea obstruction was not confirmed after birth. Finally, due to complete trachea dysgenesis, neither tracheoscopy nor tracheostomy was done during EXIT and the baby died.

CONCLUSION

Despite a failure of intrapartum treatment in the fourth case, we strongly recommend this procedure for deliveries of fetuses with a suspicion of airway obstruction.

Anesthesia for fetal surgery

Fetal therapy is an exciting and growing field of medicine. Advances in prenatal imaging and continued innovations in surgical and anesthetic techniques have resulted in a wide range of fetal interventions including minimally invasive, open mid-gestation, and ex-utero intrapartum treatment procedures. The potential for maternal morbidity is significant and must be carefully weighed against claimed benefits to the fetus. Appropriate patient selection is critical, and a multidisciplinary team-based approach is strongly recommended. The anesthetic management should focus on maintaining uteroplacental circulation, achieving profound uterine relaxation, optimizing surgical conditions, monitoring fetal hemodynamics, and minimizing maternal and fetal risk.

Management of the critical airway when an EXIT procedure is not an option: A case report

Perinatal imaging facilitates detection of congenital head and neck masses to plan fetal procedures which secure the airway. Ex utero intrapartum therapy (EXIT) procedures are preferred to protect the neonatal airway. Herein we present a case in which a neonate with a large oropharyngeal lymphovascular malformation was delivered and the airway successfully managed without an EXIT procedure using a multidisciplinary approach. Preparations for the non-EXIT delivery and critical airway management are described.

Prenatal diagnosis of obstructive head and neck masses and perinatal airway management: the ex utero intrapartum treatment procedure

Advances in prenatal imaging in the last 20 years have enabled prenatal diagnosis of obstructive head and neck masses. These advances, coupled with improvements in maternal-fetal anesthesia, have made possible the development of the ex utero intrapartum treatment (EXIT) procedure for management of obstructive head and neck masses, during which the airway is managed in a controlled fashion while maintaining fetal circulation for oxygenation. This review addresses the preoperative and perioperative assessment and management of patients with prenatally diagnosed airway obstruction, indications and contraindications for the EXIT procedure, technical details of the procedure, and outcomes.

Obstetric anesthesia: not just for cesareans and labor

The scope of obstetric anesthesia practice ranges far beyond the delivery of care to women for vaginal and cesarean deliveries. Increasingly, obstetric anesthesiologists are involved in the management of anesthetics for new procedures and for new indications. Anesthesia is frequently needed for maternal procedures, as well as fetal procedures, and at varying times in the intrapartum period. Maternal-specific procedures include cerclage, external cephalic version (ECV), postpartum bilateral tubal ligation (BTL), and dilation and evacuation (D and E). Fetus-specific procedures include fetoscopic laser photocoagulation and ex-utero intrapartum treatment (EXIT). This review will not include discussion of the anesthetic management of non-obstetric surgery during pregnancy, such as appendectomy or cholecystectomy.

The ex utero intrapartum treatment (EXIT) procedure: application of a new therapeutic paradigm

The ex utero intrapartum treatment (EXIT) procedure is a term given to a technique that can transform a potentially fatal neonatal emergency to a controlled intervention with an improved outcome. It has revolutionised the care of prenatally diagnosed congenital malformations in which severe upper airway obstruction is anticipated. An extended period of utero-placental circulation can be utilised to avoid profound cardiopulmonary compromise. Its therapeutic applications have been broadened to include fetuses with congenital diaphragmatic hernia after tracheal plugging, high-risk intrathoracic masses, severe cardiac malformations and conjoined twins. It requires the co-ordination of a highly skilled and experienced multidisciplinary team. The recent enthusiasm for the EXIT procedure needs to be balanced against maternal morbidity. Specific indications and guidelines are likely to be refined as a consequence of ongoing advances in fetal intervention and antenatal imaging.

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.

The new challenging pediatric patient

The 'new' challenging pediatric patients are those who could be called 'the survivors' and neonates undergoing birth under materno-fetal circulation. Their anesthetic management is complex because their initial pathology was previously lethal: the physiologic, pharmacologic, and or technical aspect of their management is presently unknown or hypothetical. Some examples are described. Communication with the pediatrician in charge of the child is the key to safe and effective anesthetic care of these cases.

Anesthetic management of the ex utero intrapartum treatment (EXIT) procedure -A case report-

The ex utero intrapartum treatment (EXIT) procedure is a very rare technique performed in cases of fetal congenital malformations. The EXIT procedure increases the rate of survival at delivery by maintaining the uteroplacental circulation until the airway of the fetus is secured. To maintain the uteroplacental circulation, a higher dose of inhalational anesthetics and/or intravenous nitroglycerin can be used as compared to conventional Cesarean section. The aim of this report is to share our anesthetic experience during the EXIT procedure with members of the Korean society of anesthesiology for the first time, and to highlight the maternal implications of the use of inhalational anesthetics and nitroglycerin during Cesarean section for the EXIT procedure.

Early resection and reconstruction of head and neck masses in infants with upper airway obstruction

OBJECTIVE

Congenital airway obstruction can be caused by tumors or lesions arising from the neck, tongue and oral cavity. Neonates may require prolonged intubation or tracheostomy before curative resection and reconstruction. The aim of the study was to carry out surgical resection and reconstruction with locoregional flap and free bone graft in the neonatal and early infantile period for definitive management of head and neck masses and treatment of potential airway obstruction.

METHODS

Newborns with obstructive head and neck masses in Queen Mary Hospital, University of Hong Kong Medical Centre between 2006 and 2009 were operated on in the neonatal period.

RESULTS

There were one obstructive neck teratoma, two intraoral teratomas and one neuroglial heterotopia. All tumors were resected within the first 3 months of life without major complication. A local cervical cutaneous flap was first used to reconstruct the lateral pharyngeal wall defect in a neonate with a huge neck teratoma, followed by another infant with a neuroglial heterotopia. A piece of cranial bone was used for reconstruction of the skull base defect. None of them required tracheostomy or prolonged intubation. Oral feeding was resumed in the early postoperative period.

CONCLUSION

Surgical resection and reconstruction with locoregional flap and bone graft can be performed safely in neonatal and early infantile period as management of head and neck masses and treatment of upper airway obstruction.

Approaches to the management of antenatally diagnosed congenital tumours

Congenital fetal tumours are rare, but current imaging modalities including US and MRI facilitate antenatal diagnosis and investigation, allowing a presumptive diagnosis and management strategy. Although the prevalence of fetal tumours is difficult to ascertain, an incidence of 7.2 per 100,000 live births has previously been reported, with the incidence of neonatal malignancy estimated at 36.5 per million births. Teratomas and neuroblastomas are the most common solid tumours described. Tumours may be very large or associated with severe hydrops leading to significant dystocia with the potential for difficult vaginal or caesarean delivery. Once the diagnosis of a fetal tumour is made, optimal management incorporates a multidisciplinary approach including obstetrician, neonatologist, paediatric surgeon and paediatric oncologist so that counselling is appropriate and a clear management plan is in place for parents.

The ex utero intrapartum treatment procedure: anesthetic considerations

The ex-utero intrapartum treatment (EXIT) procedure is an uncommon operation indicated for fetal lesions with the potential to cause life-threatening airway obstruction immediately after delivery. By maintaining utero-placental circulation, the fetal airway can be evaluated and secured prior to delivery. The anesthetic goals for the EXIT procedure differ significantly from a cesarean delivery and include profound uterine relaxation, fetal anesthesia and maintenance of the maternal-fetal circulation. We present a case of an uneventful EXIT procedure and include a discussion of the anesthetic goals for this operation.

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.

Airway management of three cases of congenital cervical teratoma

Cervical teratomas are rare congenital tumors derived from all three germ cell layers. The vast majority are histologically benign, but the significant size they may attain can potentiate life-threatening upper airway obstruction. All cases require the specialist airway skills of the pediatric anesthetist. This may be planned, in the case of antenatally diagnosed lesions, when the pediatric anesthetist is part of a multidisciplinary team involved in an EX utero Intrapartum Treatment (EXIT) or Operation On Placental Support (OOPS) procedure, or when a neonate is undergoing elective excision in the early neonatal period as definitive treatment. Alternatively the anesthetist may be called upon urgently to secure a compromised airway immediately postpartum when no antenatal diagnosis has been made. Furthermore, after elective surgical excision, airway compromise is possible, which may again require anesthetic intervention. The aim of this study is to report the authors' experience in managing the airway in three cases of congenital cervical teratoma in the study institution over the last 24 months. These cases highlight the possible airway scenarios that may confront the anesthetist in the immediate postpartum, elective surgery and postoperative stages and the variety of techniques that may be employed in order to overcome the potential difficulties encountered.

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.