Maternal and fetal anaesthesia for fetal surgery

An Evidence-Based Discussion of Fetal Pain and Stress

BACKGROUND

The concept of fetal pain results from procedures conducted without anesthesia in preterm newborns and fetuses, which indicate that it is possible to examine fetal pain based on stress hormone, metabolic, and behavioral changes. Anatomical and physiological data suggest that fetuses become capable of processing nociceptive stimuli around midgestation, although the associated changes in fetal brain development remain unclear. What constitutes fetal pain remains controversial in the light of the definition of pain adopted by the International Association for the Study of Pain (IASP), which posits pain as an "unpleasant sensory and emotional experience."

SUMMARY

Here, we examine the notion that human fetuses cannot "experience" pain and potential implications of this claim. We highlight the key scientific evidence related to fetal pain, including clinical studies on pain in fetuses and preterm newborns. We argue that consistent patterns of stress hormones, metabolic changes, body movements, hemodynamic changes, and pain-related facial expressions in fetuses exposed to invasive procedures overcome the need for subjective proof of pain as articulated in the IASP definition. No study to date has conclusively proven the absence of fetal pain beyond the age of viability.

KEY MESSAGES

Based on the current evidence, we propose that all fetuses receive anesthesia regardless of the invasive procedures being performed to guarantee the least possible pain and physiological, behavioral, or hormonal responses without exposing the mother or her baby to unnecessary complications.

Immediate postdelivery airway management of neonates with prenatally diagnosed micrognathia: A retrospective observational study

INTRODUCTION

Micrognathic neonates are at risk for upper airway obstruction, and many require intubation in the delivery room. Ex-utero intrapartum treatment is one technique for managing airway obstruction but poses substantial maternal risks. Procedure requiring a second team in the operating room is an alternative approach to secure the obstructed airway while minimizing maternal risk. The aim of this study was to describe the patient characteristics, airway management, and outcomes for micrognathic neonates and their mothers undergoing a procedure requiring a second team in the operating room at a single quaternary care children's hospital.

METHODS

This was a retrospective descriptive study. Subjects had prenatally diagnosed micrognathia and underwent procedure requiring a second team in the operating room between 2009 and 2021. Collected data included infant characteristics, delivery room airway management, critical events, and medications. Follow-up data included genetic testing and subsequent procedures within 90 days. Maternal data included type of anesthetic, blood loss, and incidence of transfusion.

RESULTS

Fourteen deliveries were performed via procedure requiring a second team in the operating room during the study period. 85.7% were male, and 50% had a genetic syndrome. Spontaneous respiratory efforts were observed in 93%. Twelve patients (85.7%) required an endotracheal tube or tracheostomy. Management approaches varied. Medications were primarily a combination of atropine, ketamine, and dexmedetomidine. Oxygen desaturation was common, and three patients experienced bradycardia. There were no periprocedural deaths. Follow-up at 90 days revealed that 78% of patients underwent at least one additional procedure, and one patient died due to an unrelated cause. All mothers underwent cesarean deliveries under neuraxial anesthesia. Median blood loss was 700 mL [IQR 700 mL, 800 mL]. Only one mother required a blood transfusion for pre-procedural placental abruption.

DISCUSSION

Procedure requiring a second team in the operating room is a safe and effective approach to manage airway obstruction in micrognathic neonates while minimizing maternal morbidity.

CONCLUSIONS

Though shown to be safe and effective, more data are needed to support the use of procedure requiring a second team in the operating room as an alternative to ex-utero intrapartum treatment for micrognathia outside of highly specialized maternal-fetal centers.

Trends in research related to fetal therapy from 2012 to 2022: a bibliometric analysis

Background

The development of prenatal diagnosis technology allows prompt detection of severe fetal diseases. To address adverse factors that threaten fetal survival, fetal therapy came into existence, which aims to preserve the function after birth to a higher degree and improve the quality of life.

Objective

To conduct a comprehensive bibliometric analysis of studies on fetal therapy in the past decade and explore the research trends and hotspots in this field.

Methods

We conducted a systematic search on the Web of Science Core Collection to retrieve studies related to fetal therapy published from 2012 to 2022. VOSviewer and CiteSpace were used to analyze the key features of studies, including annual output, countries/regions, institutions, authors, references, research hotspots, and frontiers.

Results

A total of 9,715 articles were included after eliminating duplicates. The annual distribution of the number of articles showed that the number of articles published in fetal therapy had increased in the past decade. Countries and institutions showed that fetal therapy is more mature in the United States. Author analysis showed the core investigators in the field. Keyword analysis showed the clustering and emergence frequency, which helped summarize the research results and frontier hotspots in this field. The cocited references were sorted out to determine the literature with a high ranking of fetal therapy in recent years, and the research trend in recent years was analyzed.

Conclusions

This study reveals that countries, institutions, and researchers should promote wider cooperation and establish multicenter research cooperation in fetal therapy research. Moreover, fetal therapy has been gradually explored from traditional surgical treatment to gene therapy and stem cell therapy. In recent years, fetoscopic laser surgery, guideline, and magnetic resonance imaging have become the research hotspots in the field.

Maternal and obstetric outcomes after Ex-Utero Intrapartum Treatment (EXIT): a single center experience

BACKGROUND

The Ex-utero Intrapartum Treatment (EXIT) is a procedure developed to manage a range of fetal conditions, aiming to ensure the maintenance of neonatal airway and preserving the feto-placental circulation. Its goal is to enhance the neonatal ability to successfully transition and adapt to postnatal life, thereby reducing perinatal morbidity and mortality. However, EXIT has been associated with a high risk of maternal complications. This paper provides an overview of the indications and characteristics of the EXIT procedure, as well as the obstetric outcomes and maternal complications.

METHODS

A retrospective analysis was conducted on a cohort of patients undergoing EXIT at our center between January 2007 and December 2022. Maternal outcomes, including demographic information, data related to the surgical procedure, surgical complications, and postoperative complications were analyzed. To assess the severity of the surgical complications, a modified Clavien-Dindo classification was used. Comparative analysis was performed by randomly selecting a sample from elective cesarean deliveries performed at our center.

RESULTS

A total of 34 EXIT procedures were performed. According to the modified Clavien-Dindo classification, we observed no major complications, while minor maternal complications were present in 2.94% of cases. Compared to elective cesarean deliveries (n = 350), there were no significant differences in terms of maternal complications, highlighting the similarity observed in the mean decrease in postoperative hemoglobin (1.15 g/dL in EXIT vs. 1.2 g/dL in elective cesarean deliveries, p = 0.94). In EXIT group, there was a higher rate of polyhydramnios (26.47% vs 6.59%, p < 0.001), as well as the need for amnioreduction (14.71% vs 0%, p = 0.001) and preterm delivery (32.35% vs 6.02%, p = 0.001). There were no cases of endometritis, post-procedural fever, or abruptio placentae following EXIT.

CONCLUSIONS

EXIT can be considered a safe procedure when performed under adequate conditions, including appropriate uterine access and proper anesthetic management. In our series, EXIT procedure was not associated with a higher incidence of maternal complications when compared to elective cesarean delivery.

TRIAL REGISTRATION

Retrospectively registered.

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.

Ex utero intrapartum technique (EXIT): Indications, procedure methods and materno-fetal complications - A literature review

A congenital malformation of the head, neck or thorax can lead to upper airway compression with a risk of asphyxia or neonatal death. To secure and protect the upper airway, the Ex Utero Intrapartum Therapy (EXIT) procedure has been developed. The procedure allows delivery of the fetus via a hysterotomy while relying on the placenta as the organ of respiration for the fetus prior to clamping of the umbilical cord. A high level of expertise is necessary for successful completion of the EXIT procedure, which is not void of maternal and fetal risks. In this literature review, we present the indications, procedure methods and materno-fetal complications associated with the EXIT procedure.