Update in fetal anesthesia for the ex utero intrapartum treatment (EXIT) procedure

Multiple sevoflurane exposures during mid-trimester induce neurotoxicity in the developing brain initiated by 15LO2-Mediated ferroptosis

AIMS

Mid-gestational sevoflurane exposure may induce notable long-term neurocognitive impairment in offspring. This study was designed to investigate the role and potential mechanism of ferroptosis in developmental neurotoxicity induced by sevoflurane in the second trimester.

METHODS

Pregnant rats on day 13 of gestation (G13) were treated with or without 3.0% sevoflurane, Ferrostatin-1 (Fer-1), PD146176, or Ku55933 on three consecutive days. Mitochondrial morphology, ferroptosis-relative proteins, malondialdehyde (MDA) levels, total iron content, and glutathione peroxidase 4 (GPX4) activities were measured. Hippocampal neuronal development in offspring was also examined. Subsequently, 15-lipoxygenase 2 (15LO2)-phosphatidylethanolamine binding protein 1 (PEBP1) interaction and expression of Ataxia telangiectasia mutated (ATM) and its downstream proteins were also detected. Furthermore, Morris water maze (MWM) and Nissl's staining were applied to estimate the long-term neurotoxic effects of sevoflurane.

RESULTS

Ferroptosis mitochondria were observed after maternal sevoflurane exposures. Sevoflurane elevated MDA and iron levels while inhibiting GPX4 activity, and resultant long-term learning and memory dysfunction, which were alleviated by Fer-1, PD146176, and Ku55933. Sevoflurane could enhance 15LO2-PEBP1 interaction and activate ATM and its downstream P53/SAT1 pathway, which might be attributed to excessive p-ATM nuclear translocation.

CONCLUSION

This study proposes that 15LO2-mediated ferroptosis might contribute to neurotoxicity induced by maternal sevoflurane anesthesia during the mid-trimester in the offspring and its mechanism may be ascribed to hyperactivation of ATM and enhancement of 15LO2-PEBP1 interaction, indicating a potential therapeutic target for ameliorating sevoflurane-induced neurotoxicity.

Intraoperative management for ex-utero intrapartum treatment: focusing on the fetus

Ex-utero intrapartum treatment (EXIT) is a method of securing the airway of a fetus while maintaining umbilical circulation for newborns who are experiencing life-threatening airway obstruction. Cesarean section is completed only after ensuring the neonate's safety. However, managing the airway of a neonate while maintaining umbilical circulation is a major challenge for anesthesiologists. Anesthesiologists must understand the physiology of both the mother and fetus, and extensive discussions with obstetricians, pediatricians, otolaryngologists, and nursing staff prior to the procedure are essential. This review provides an overview of the EXIT and details of airway management for neonates.

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.

Monitored Anesthesia Care versus General Anesthesia for Intrauterine Fetal Interventions: Analysis of Conversions and Complications for 480 Cases

INTRODUCTION

Fetal intervention/surgery constitutes a relatively new field of maternal-fetal medicine in which monitored anesthesia care (MAC) or general anesthesia (GA) are utilized as anesthetic techniques when feasible. In this study, we sought to calculate the usage of MAC and GA in various fetal procedures as well as investigate any anesthetic complications and conversions from MAC to GA.

METHODS

All intrauterine fetal intervention cases performed at the Texas Children's Hospital Pavilion for Women from 2012 to 2016 were retrospectively analyzed and categorized by mode of anesthesia. Anesthetic complications, conversions to GA, preoperative patient physical status, average number of intraoperative medications required, and average duration of procedure were compared between the MAC and GA groups.

RESULTS

A total of 480 fetal interventions were performed with 432 under MAC (90%) and 37 under GA (7.7%). There were 11 conversions from MAC to GA (2.3%). These conversions were due to poor visualization with ultrasound and change of surgical approach to laparoscopic-assisted technique (n = 5), inability to lay flat due to back pain (n = 3), persistent vomiting (n = 2), and unresponsiveness after a spinal block (n = 1). One anesthetic complication occurred due to a medication administration error and did not require conversion to GA. The average preoperative American Society of Anesthesiologists (ASA) physical status classification was 1.97 for the MAC group and 1.87 for the GA group (p = 0.23). Duration of the interventions averaged 129 min under MAC and 138 min under GA (p = 0.23). An average of 7.8 different medications were administered during MAC cases compared to 13.1 during GA cases (p < 0.0001).

DISCUSSION

This analysis suggests that MAC is the most commonly used anesthetic option for fetal interventions with a low complication rate and minimal conversion rates to GA. It is therefore preferable to use MAC when feasible due to the low complication rate and decreased drug exposure.

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.

Novel multidisciplinary approach to monitor and treat fetuses with gastroschisis using the Svetliza Reducibility Index and the EXIT-like procedure

OBJECTIVE

To describe our initial experience with a novel approach to follow-up and treat gastroschisis in "zero minute" using the EXITlike procedure.

METHODS

Eleven fetuses with prenatal diagnosis of gastroschisis were evaluated. The Svetliza Reductibility Index was used to prospectively evaluate five cases, and six cases were used as historical controls. The Svetliza Reductibility Index consisted in dividing the real abdominal wall defect diameter by the larger intestinal loop to be fitted in such space. The EXIT-like procedure consists in planned cesarean section, fetal analgesia and return of the herniated viscera to the abdominal cavity before the baby can fill the intestines with air. No general anesthesia or uterine relaxation is needed. Exteriorized viscera reduction is performed while umbilical cord circulation is maintained.

RESULTS

Four of the five cases were performed with the EXIT-like procedure. Successful complete closure was achieved in three infants. The other cases were planned deliveries at term and treated by construction of a Silo. The average time to return the viscera in EXIT-like Group was 5.0 minutes, and, in all cases, oximetry was maintained within normal ranges. In the perinatal period, there were significant statistical differences in ventilation days required (p = 0.0169), duration of parenteral nutrition (p=0.0104) and duration of enteral feed (p=0.0294).

CONCLUSION

The Svetliza Reductibility Index and EXIT-like procedure could be new options to follow and treat gastroschisis, with significantly improved neonatal outcome in our unit. Further randomized studies are needed to evaluate this novel approach.

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.

Three-dimensional ultrasound of massive macroglossia in a fetus with Beckwith-Wiedemann syndrome

We present the prenatal ultrasound findings of massive macroglossia in a fetus with prenatally diagnosed Beckwith-Wiedemann syndrome. Three-dimensional surface mode ultrasound was utilized for enhanced visualization of the macroglossia.