Maternal anesthesia for fetal surgery

Anesthetic management of fetal pulmonary valvuloplasty: A case report

Anesthesia management of fetal pulmonary valvuloplasty (FPV) is difficult, requiring careful consideration of both the mother and the fetus. Few reports have been published on specific anesthesia implementation and intraoperative management. We report the case of a pregnant woman who was treated with FPV under combined spinal epidural anesthesia (CSEA) with dexmedetomidine in the second trimester of pregnancy. Meanwhile, the application of fetal anesthesia through the umbilical vein was optimal. During the operation, the vital signs of the pregnant woman were stable with no complications and the fetal bradycardia was corrected by intracardiac injection of epinephrine. Four months postoperatively, a boy was born alive by full-term transvaginal delivery. CSEA may be a suitable anesthesia method for FPV surgery. Nevertheless, maternal hemodynamic stability maintenance, effective fetal anesthesia, and timely fetal resuscitation were necessary.

Sevoflurane exposure during the second trimester induces neurotoxicity in offspring rats by hyperactivation of PARP-1

RATIONALE

Fetal exposure to general anesthesia may cause noteworthy neurocognitive impairment, but the mechanisms are unclear.

OBJECTIVES

Our study designed to explore the potential mechanism of neurotoxicity in offspring rats after sevoflurane exposure to the pregnant rats during the second trimester.

METHODS

Pregnant rats (G14 day) were administrated with or without 3.5% sevoflurane, 40 mg/kg 3-aminobenzamide (3-AB), inhibitor of poly ADP ribose polymerase 1 (PARP-1), or 10 mg/kg TC-2153, inhibitor of striatal-enriched phosphatase 61 (STEP61). Afterwards, the effects on expression of β-tubulin (TUJ1), neurite outgrowth inhibitor A (Nogo-A), parthanatos-related and STEP61/proline-rich tyrosine kinase 2 (Pyk2) pathway-associated proteins, and reactive oxygen species (ROS) levels were examined by immunofluorescence staining, Western blot, and dihydroethidium (DHE) staining, respectively. Moreover, morphological changes in the hippocampal CA3 region and neuronal cell death were tested by glycine silver staining and TUNEL and immunofluorescence double staining, respectively. Furthermore, spatial learning and memory functions of rats on postnatal 28-33 days (PND 28-33) were evaluated by morris water maze (MWM).

RESULTS

Mid-pregnancy exposure to sevoflurane led to excessive PARP-1 activation, poly (ADP-ribose) (PAR) polymer accumulation, apoptosis-inducing factor (AIF) nuclear translocation, and Nogo-A accumulation. Besides, sevoflurane significantly inhibited neurite growth and increased cell death in the fetal rat brain. Additionally, sevoflurane activated STEP61/Pyk2 pathway and increased ROS levels. However, 3-AB or TC-2153 significantly alleviated cell death, promoted neurites growth, and improved sevoflurane-induced spatial learning and memory impairment.

CONCLUSION

This study proposes that sevoflurane exposure during the second trimester incudes neurotoxicity in offspring rats by hyperactivation of PARP-1 via STEP61/Pyk2 pathway.

Seguridad de la anestesia neuroaxial en mujeres con embarazo gemelar y síndrome de transfusión feto-fetal, sometidas a fotocoagulación láser. Estudio de cohorte retrospectiva

Objetivo: describir las características clínicas y la frecuencia de complicaciones maternas, fetales y neonatales, según técnica de anestesia neuroaxial (AN) en mujeres con síndrome de transfusión feto-fetal (STFF) tratadas con fotocoagulación láser (FL). Materiales y métodos: estudio de cohorte retrospectiva descriptivo. Se incluyeron gestantes con STFF tratadas con FL y AN en la Fundación Valle del Lili, Cali (Colombia) entre 2013-2017. Se excluyeron pacientes con STFF estadio-V de Quintero. Se usó estadística descriptiva. El protocolo fue aprobado por el Comité de Ética de la institución. Resultados: 32 participantes cumplieron con los criterios de inclusión y de exclusión. La población estuvo constituida por mujeres jóvenes, multíparas. En el 87,5% de los casos se realizó intervención de urgencia. El 43,7% presentaba el estadio-III de Quintero y en el 56,2 % de las gestantes se utilizó anestesia epidural. Las variables hemodinámicas maternas exhibieron un comportamiento similar, acorde al momento de la cirugía y la técnica neuoraxial implementada. El 65,6 % de las gestantes presentó hipotensión sostenida y el 9,3 % desarrolló edema pulmonar. El 65,6 % de las pacientes experimentó parto pretérmino y el 18,7 % ruptura prematura de membranas. Se registraron 14 muertes fetales y cinco neonatales. No se registraron casos de mortalidad materna. Conclusiones: en pacientes con STFF que requieren FL, el uso de la anestesia epidural, espinal o combinada probablemente se asocia con un comportamiento similar al de las variables hemodinámicas maternas, durante los momentos de la cirugía. Los profesionales que brindan atención a estas gestantes deben estar alerta ante la frecuente aparición de complicaciones maternas, fetales y neonatales. Se requieren estudios prospectivos que evalúen la seguridad y la efectividad de las diferentes técnicas de anestesia neuroaxial en pacientes con STFF.

Anesthesia for Maternal-Fetal Interventions: A Consensus Statement From the American Society of Anesthesiologists Committees on Obstetric and Pediatric Anesthesiology and the North American Fetal Therapy Network

Maternal-fetal surgery is a rapidly evolving specialty, and significant progress has been made over the last 3 decades. A wide range of maternal-fetal interventions are being performed at different stages of pregnancy across multiple fetal therapy centers worldwide, and the anesthetic technique has evolved over the years. The American Society of Anesthesiologists (ASA) recognizes the important role of the anesthesiologist in the multidisciplinary approach to these maternal-fetal interventions and convened a collaborative workgroup with representatives from the ASA Committees of Obstetric and Pediatric Anesthesia and the Board of Directors of the North American Fetal Therapy Network. This consensus statement describes the comprehensive preoperative evaluation, intraoperative anesthetic management, and postoperative care for the different types of maternal-fetal interventions.

Effects of Pregnancy Anesthesia on Fetal Nervous System

The effects of general anesthesia on the developing brain remain a great concern in the medical field and even in the public, and most researches in this area focus on infancy and childhood. In recent years, with the continuous development of medical technology, the number of operations during pregnancy is increasing, however, studies on general anesthesia during pregnancy are relatively lacking. The mid-trimester of pregnancy is a critical period, and is regarded as a safe period for surgery, but it is a fragile period for the development of the central nervous system and is particularly sensitive to the impact of the environment. Our research group found that general anesthesia may have adverse effects on fetal neurodevelopment during the mid-trimester. Therefore, in this review, we summarize the characteristics of anesthesia during pregnancy, and the related research of the anesthesia’s impacts on the development of central nervous system were introduced.

Anesthesia-Related Factors Associated with Preterm Labor and Delivery after Open Fetal Surgery

BACKGROUND

Fetal surgery, such as for meningomyelocele repair, has a clear clinical fetal benefit. In patients who undergo in utero repair of meningomyelocele, for example, there is reduced long-term disease morbidity. However, despite the beneficial effects of early intervention, women who undergo fetal interventions have an increased risk of preterm labor and delivery. Several surgery-related factors have been described but no specific anesthesia-related factors.

OBJECTIVE

The aim of this study was to determine if any aspects of the perioperative anesthetic management influenced maternal complications following in utero surgery.

METHODS

This was a retrospective chart review of the anesthetic management of mothers and fetuses who presented for open and fetoscopic myelomeningocele repair, between 2011 and 2015, at Texas Children's Fetal Center®.

RESULTS

Forty-six women underwent open or fetoscopic repair of neural tube defects at our institution. We found the maternal heart rate in the postoperative period to be associated with a higher likelihood of preterm labor, but not delivery. The odds of having preterm delivery was higher for nulliparous patients and those with lower intraoperative diastolic pressure.

CONCLUSIONS

Our findings confirm what has been previously reported regarding the association of nulliparity with preterm delivery. Additionally, this study highlights the importance of maintaining stable perioperative hemodynamics during the intraoperative and postoperative phases of care for patients undergoing in utero surgery.

Prenatal sevoflurane exposure causes neuronal excitatory/inhibitory imbalance in the prefrontal cortex and neurofunctional abnormality in rats

The balance of excitatory and inhibitory neurons in the central nervous system is critical for maintaining brain function and sevoflurane, a general anesthetic and an GABA receptor modulator, may change the balance of excitatory and inhibitory neurons in the cortex during early brain development. Herein, we investigated whether prenatal sevoflurane exposure (PSE) disturbs cortical neuronal development and brain function. Pregnant rats at the gestational day 14.5 were subjected to sevoflurane exposure at 3.0% for 3 h and their offspring were studied thereafter. We found a significant increase of parvalbumin-positive neurons, vesicular GABA transporter (VGAT) and GAD67 expression, and GABA neurotransmitter, and a significant decrease of vesicular glutamate transporter 1 (VGLUT1) expression and glutamate in the medial prefrontal cortex (mPFC) of offspring. Pyramidal neurons showed atrophy with shorter dendrites, less branches and lower spine density visualized by Golgi stain and a decrease of excitability with the increased miniature inhibitory postsynaptic current (mIPSC) frequency and amplitude, the decreased miniature excitatory postsynaptic current (mEPSC) frequency and excitation/inhibition (E/I) ratio using whole-cell recording in offspring. There was a significant increase of inhibitory synapse in the mPFC detected by electron microscopy. Furthermore, PSE animals showed hypo-excitatory phenotype including depression-like behaviors and learning deficits. Thus, our studies provide novel evidence that PSE causes the persisted imbalance of excitatory and inhibitory neurons in the mPFC, and this is very likely the mechanisms of the sevoflurane-induced brain functional abnormalities.

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.

The first national survey of anesthesia techniques for fetal therapies in Japan

PURPOSE

The aim of this study was to survey the frequency of various anesthetic techniques used in the anesthetic management of both the mother and fetus during fetal therapies in Japan.

METHODS

We sent a postal survey to the institutions with physicians who held membership of the Japan Society of Fetal Therapy to describe maternal and fetal anesthetic management during fetal therapies performed from January 2016 to March 2017. The therapies included were thoracoamniotic shunting (TAS), intrauterine transfusion (IUT), radiofrequency ablation (RFA), fetoscopic laser photocoagulation (FLP), fetoscopic endotracheal occlusion (FETO), and ex utero intrapartum treatment (EXIT). Survey respondents were asked to specify the standard anesthetic technique used in each of these procedures done during the study period.

RESULTS

The most common anesthetic techniques used in each therapy were sedation/analgesia with local anesthesia in TAS (31%), local anesthesia alone in IUT (47%), neuraxial anesthesia in RFA (50%), FLP (66%) and FETO (100%), and general endotracheal anesthesia in EXIT. Fetal analgesia was utilized in 61% of TAS, 33% of IUT, 10% of RFA, 22% of FLP, 100% of FETO, and 50% of EXIT. In all fetal therapies, the most common route of administration for fetal anesthesia was maternal administration.

CONCLUSION

In this first published description of the frequency of various anesthetic techniques used during fetal therapies in Japan, we found that anesthetic techniques varied depending on the degree of invasiveness to the mother and fetus. Fetal anesthesia was not always performed, and the most common route for fetal anesthesia was maternal administration.

Dexmedetomidine Ameliorates the Neurotoxicity of Sevoflurane on the Immature Brain Through the BMP/SMAD Signaling Pathway

Numerous studies have demonstrated that general anesthetics might damage the nervous system, thus, the effect of general anesthetics on the developing brain has attracted much attention. Dexmedetomidine (Dex) exhibits a certain neuroprotective effect, but the mechanism is obscure. In our study, pregnant rats on gestational day 20 (G20) were exposed to 3% sevoflurane for 2 h or 4 h, and the neuronal apoptosis in hippocampal CA1 region of the offspring rats was detected by quantification of TUNEL positive cells and cleaved-caspase3 (cl-caspase3). Different doses of Dex were intraperitoneally injected before sevoflurane anesthesia; then, the expression of apoptotic-related proteins including BCL-2, BAX and cl-caspase3 as well as amyloid precursor protein (APP, a marker of axonal injury), p-CRMP-2 and CRMP-2 were measured at postnatal days 0, 1and 3 (P0, P1, and P3, respectively). As an antagonist of the bone morphgenetic proteins (BMP) receptor, DMH1 was co-administered with sevoflurane plus Dex to investigate whether BMP/SMAD is associated with the neuroprotective effects of Dex. The results showed that prenatal sevoflurane anesthesia for 4 h activated apoptosis transiently, as manifested by the caspase3 activity peaked on P1 and disappeared on P3. In addition, the expressions of APP and p-CRMP-2/CRMP-2 in postnatal rat hippocampus were significantly increased, which revealed that prenatal sevoflurane anesthesia caused axonal injury of offspring. The long-term learning and memory ability of offspring rats was also impaired after prenatal sevoflurane anesthesia. These damaging effects of sevoflurane could be mitigated by Dex and DMH1 reversed the neuroprotective effect of Dex. Our results indicated that prenatal exposure to 3% sevoflurane for 4 h increased apoptosis and axonal injury, even caused long-term learning and memory dysfunction in the offspring rats. Dex dose-dependently reduced sevoflurane- anesthesia-induced the neurotoxicity by activating the BMP/SMAD signaling pathway.

Mid-gestational sevoflurane exposure inhibits fetal neural stem cell proliferation and impairs postnatal learning and memory function in a dose-dependent manner

Advancements in fetal intervention procedures have led to increases in the number of pregnant women undergoing general anesthesia during the second trimester-a period characterized by extensive proliferation of fetal neural stem cells (NSCs). However, few studies have investigated the effects of mid-gestational sevoflurane exposure on fetal NSC proliferation or postnatal learning and memory function. In the present study, pregnant rats were randomly assigned to a control group (C group), a low sevoflurane concentration group (2%; L group), a high sevoflurane concentration group (3.5%; H group), a high sevoflurane concentration plus lithium chloride group (H + Li group), and a lithium chloride group (Li group) at gestational day 14. Rats received different concentrations of sevoflurane anesthesia for 2 h. The offspring rats were weaned at 28 days for behavioral testing (i.e., Morris Water Maze [MWM]), and fetal brains or postnatal hippocampal tissues were harvested for immunofluorescence staining, real-time PCR, and Western blotting analyses in order to determine the effect of sevoflurane exposure on NSC proliferation and the Wnt/β-catenin signaling pathway. Our results indicated that maternal exposure to 3.5% sevoflurane (H group) during the mid-gestational period impaired the performance of offspring rats in the MWM test, reduced NSC proliferation, and increased protein levels of fetal glycogen synthase kinase-3 beta (GSK-3β). Such treatment also decreased levels of β-catenin protein, CD44 RNA, and Cyclin D1 RNA relative to those observed in the C group. However, these effects were transiently attenuated by treatment with lithium chloride. Conversely, maternal exposure to 2% sevoflurane (L group) did not influence NSC proliferation or the Wnt signaling pathway. Our results suggest that sevoflurane exposure during the second trimester inhibits fetal NSC proliferation via the Wnt/β-catenin pathway and impairs postnatal learning and memory function in a dose-dependent manner.

Foetal surgery: Anaesthetic implications and strategic management

Intrauterine surgery is being performed with increasing frequency. Correction of foetal anomalies in utero can result in normal growth of foetus and a healthier baby at delivery. Intrauterine surgery can also improve the survival of babies who would have otherwise died at delivery, or in the neonatal period. There are three commonly used approaches to correct foetal anomalies: open surgery, where the foetus is exposed through hysterotomy; percutaneous approach, where needle or foetoscope is inserted through the abdominal wall and the uterine wall; finally, ex utero intrapartum treatment (EXIT) surgery, where the intervention is performed on the baby before terminating the maternal umbilical support to the baby. Anaesthetic management of the mother and the foetus requires good understanding of maternal physiology, foetal physiology, and pharmacological and surgical implications to the foetus. Uterine relaxation is a critical requisite for open foetal procedures and EXIT procedures. General anaesthesia and/or regional anaesthesia can be used successfully depending on the nature of foetal intervention. Foetal surgery poses complications not only to the foetus but also to the mother. Therefore, the decision for undertaking foetal surgery should always consider the risk to the mother versus benefit to the foetus.

Minimally Invasive Fetal Surgery

Fetal surgery corrects severe congenital anomalies in utero to prevent their severe consequences on fetal development. The significant risk of open fetal operations to the pregnant mother has driven innovation toward minimally invasive procedures that decrease the risks inherent to hysterotomy. In this article, we discuss the basic principles of minimally invasive fetal surgery, the general history of its development, specific conditions and procedures used to treat them, and the future of the field.

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.