Anesthesia for fetal surgery

Fetal Pain in the First Trimester

Fetal pain perception has important implications for fetal surgery, as well as for abortion. Current neuroscientific evidence indicates the possibility of fetal pain perception during the first trimester (<14 weeks gestation). Evidence for this conclusion is based on the following findings: (1) the neural pathways for pain perception via the cortical subplate are present as early as 12 weeks gestation, and via the thalamus as early as 7–8 weeks gestation; (2) the cortex is not necessary for pain to be experienced; (3) consciousness is mediated by subcortical structures, such as the thalamus and brainstem, which begin to develop during the first trimester; (4) the neurochemicals in utero do not cause fetal unconsciousness; and (5) the use of fetal analgesia suppresses the hormonal, physiologic, and behavioral responses to pain, avoiding the potential for both short- and long-term sequelae. As the medical evidence has shifted in acknowledging fetal pain perception prior to viability, there has been a gradual change in the fetal pain debate, from disputing the existence of fetal pain to debating the significance of fetal pain. The presence of fetal pain creates tension in the practice of medicine with respect to beneficence and nonmaleficence.

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.

Fetal heart rate monitoring during fetoscopic repair of open spinal neural tube defects: a single-centre observational cohort study

BACKGROUND

During fetal surgery, the haemodynamic stability of the fetus depends on the haemodynamic stability of the mother. The primary objective of this study was to assess changes in fetal heart rate (FHR) throughout the different stages of surgery. The secondary objective was to assess potential changes in maternal physiological parameters and their association with FHR.

METHODS

This was a single-center observational cohort study conducted between 2015 and 2019 in 26 women undergoing intra-uterine fetoscopic repair of open spina bifida. The primary outcome was FHR. Maternal physiologic parameters were measured at the beginning, during and after surgery. The linear mixed-effects model fitted by maximum likelihood was used to assess changes in each variable at specific times throughout the surgery, and the repeated measures correlation coefficient was used to study the association between FHR and maternal physiological parameters.

RESULTS

One (3.8%) case of fetal bradycardia (FHR <110 beats per minute) required the administration of intramuscular atropine. No other significant FHR changes were observed during surgery. Maternal oesophageal temperature (P <0.001), lactate levels (P=0.002), and mean arterial pressure (P=0.016) changed significantly during surgery, although none of these changes was clinically relevant. The FHR showed a significant association with maternal carbon dioxide tension (r=0.285, 95% CI 0.001 to 0.526) and maternal heart rate (r=0.302, 95% CI 0.025 to 0.535).

CONCLUSION

The FHR remained stable during intra-uterine fetoscopic repair of open spina bifida. Maternal carbon dioxide tension and heart rate may have a mild influence on FHR.

Effects of Maternal Abdominal Surgery on Fetal Brain Development in the Rabbit Model

INTRODUCTION

Anesthesia during pregnancy can impair fetal neurodevelopment, but effects of surgery remain unknown. The aim is to investigate effects of abdominal surgery on fetal brain development. Hypothesis is that surgery impairs outcome.

METHODS

Pregnant rabbits were randomized at 28 days of gestation to 2 h of general anesthesia (sevoflurane group, n = 6) or to anesthesia plus laparoscopic appendectomy (surgery group, n = 13). On postnatal day 1, neurobehavior of pups was assessed and brains harvested. Primary outcome was neuron density in the frontal cortex, and secondary outcomes included neurobehavioral assessment and other histological parameters.

RESULTS

Fetal survival was lower in the surgery group: 54 versus 100% litters alive at birth (p = 0.0442). In alive litters, pup survival until harvesting was 50 versus 69% (p = 0.0352). No differences were observed for primary outcome (p = 0.5114) for surviving pups. Neuron densities were significantly lower in the surgery group in the caudate nucleus (p = 0.0180), but not different in other regions. No differences were observed for secondary outcomes. Conclusions did not change after adjustment for mortality.

CONCLUSION

Abdominal surgery in pregnant rabbits at a gestational age corresponding to the end of human second trimester results in limited neurohistological changes but not in neurobehavioral impairments. High intrauterine mortality limits translation to clinical scenario, where fetal mortality is close to zero.

Peri-operative management of percutaneous fetoscopic spina-bifida repair: a descriptive review of five cases from the United Kingdom, with focus on anaesthetic implications

We present a case-based review of the first five percutaneous fetoscopic in-utero spina bifida repair procedures undertaken in the UK. Our focus is on implications of anaesthesia and analgesia for the mother and fetus, provision of uterine relaxation and fetal immobilisation while providing conditions conducive to surgical access. Minimising risks for fetal acidosis, placental and fetal hypoperfusion, maternal and fetal sepsis and maternal fluid overload were the foremost priorities. We discuss optimisation strategies undertaken to ensure fetal and maternal well-being under anaesthesia, shortcomings in the current approach, and possible directions for improvement.

[The multidisciplinary challenge of anesthesia for ex utero intrapartum treatment: a case report]

The Ex- Utero Intrapartum Treatment (EXIT) is a surgical procedure performed in cases of expected postpartum fetal airway obstruction, allowing the establishment of patent airway while maintaining placental circulation. Anesthesia for EXIT procedure has several specific features such as adequate uterine relaxation, maintenance of maternal blood pressure fetal anesthesia and fetal airway establishment. The anesthesiologist should be aware of these particularities in order to contribute to a favorable outcome. This is a case report of an EXIT procedure performed on a fetus with a cervical lymphangioma with prenatal evidence of partial obstruction of the trachea and risk of post-delivery airway compromise.

The multidisciplinary challenge of anesthesia for ex utero intrapartum treatment: a case report

The Ex Utero Intrapartum Treatment (EXIT) is a surgical procedure performed in cases of expected postpartum fetal airway obstruction, allowing the establishment of patent airway while maintaining placental circulation. Anesthesia for EXIT procedure has several specific features such as adequate uterine relaxation, maintenance of maternal blood pressure fetal anesthesia and fetal airway establishment. The anesthesiologist should be aware of these particularities in order to contribute to a favorable outcome. This is a case report of an EXIT procedure performed on a fetus with a cervical lymphangioma with prenatal evidence of partial obstruction of the trachea and risk of post-delivery airway compromise.

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.

Activation of Autophagy Contributes to Sevoflurane-Induced Neurotoxicity in Fetal Rats

Numerous animal studies have demonstrated that commonly used general anesthetics may result in cognitive impairment in the immature brain. The prevailing theory is that general anesthetics could induce developmental neurotoxicity via enhanced apoptosis. In addition, inhibited proliferation induced by anesthetics has also been reported. So far, whether autophagy, a well-conserved cellular process that is critical for cell fate, also participates in anesthesia-induced neurotoxicity remains elusive. Here, we first examined autophagy-related changes after sevoflurane exposure and the effect of autophagy on apoptosis and proliferation, and we also explored the underlying mechanisms of autophagy activation. Pregnant rats were exposed to 2 or 3.5% sevoflurane for 2 h on gestational day 14 (G14); then, markers of autophagy and expression of autophagy pathway components were measured in fetal brains 2, 12, 24, and 48 h after anesthesia. Changes in neural stem cell (NSC) apoptosis, neurogenesis, neuron quantity and learning and memory function were examined after administration of an autophagy or PTEN inhibitor. The expression of microtubule-associated protein 1 light chain 3 (LC3)-II, Beclin-1 and phosphatase and tensin homolog on chromosome 10 (PTEN) were increased in the 3.5% sevoflurane group, while Sequestosome 1 (P62/SQSTM1), phospho-protein kinase B/protein kinase B (p-Akt/Akt) and mammalian target of rapamycin (mTOR) were decreased. 3-methyladenine (3-MA), an inhibitor of autophagy, or dipotassium bisperoxo-(5-hydroxypyridine-2-carboxyl)-oxovanadate (V) (bpV), a PTEN inhibitor, significantly attenuated the activation of autophagy, reversed the decreased expression of B-cell lymphoma-2 (Bcl-2) and reduced the number of terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) positive cells, ameliorated the decline of Nestin expression, Ki67 positive cell rate, neuron quantity and cross platform times, and shortened the prolonged escape latency. Our results demonstrated that 2 h 3.5% sevoflurane exposure at G14 induced excessive autophagy in the fetal brain via the PTEN/Akt/mTOR pathway. Autophagy inhibition reversed anesthesia-induced NSC apoptosis, proliferation decline and memory deficits.

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.

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.

Fetal surgery and maternal cortisol response to stress. The myelomeningocele sheep model

BACKGROUND

Prenatal surgery represents a multifactorial stressor event for mother and fetus. The stress response to fetal surgery was evaluated by measuring maternal plasma and amniotic fluid (AF) cortisol levels in the myelomeningocele (MMC) sheep model.

SUBJECTS AND METHODS

Pregnant ewes (n = 8) underwent general anesthesia for MMC-induction (step 1: 75 d gestation), surgical defect repair (step 2: 110 d gestation), and delivery (step 3: 140 d gestation). Maternal blood samples were taken before surgery (surgical stage T1), after laparotomy and uterine exposure (surgical stage T2), at the end of the procedure (surgical stage T3). Fetal stress was evaluated by measuring cortisol levels in AF after hysterotomy at steps 1-3.

RESULTS

Maternal cortisol concentrations at T2 and T3 increased compared with T1 (p = 0.019 and p = 0.046). AF cortisol response increased from 1 to 3 surgical steps and during pregnancy. The AF cortisol level was lower than maternal serum levels (induction p < 0.001; repair p < 0.001; caesarean section p < 0.001).

CONCLUSIONS

Hysterotomy was the most stressful event in the ewes. Fetuses seemed to be partially protected from the high maternal cortisol levels. The fetal stress response to prenatal surgery increased with gestational age. Pain perception development, fetal maturation, and "pain memory" are probably associated with this increase.

Maternal anesthesia for fetal surgery

This article describes the anesthetic management of pregnant women undergoing fetal surgery. Discussion includes general principles common to all fetal surgeries as well as specifics pertaining to open fetal surgery, minimally invasive fetal surgery, and ex utero intrapartum therapy (EXIT) procedures.

[Intrauterine myelomeningocele repair: experience of the fetal medicine and therapy program of the Virgen de Rocío University Hospital]

The most frequent form of spina bifida is myelomeningocele. There is no optimal postnatal treatment for this defect. In addition to the motor or sensory deficits, which depend on the location of the lesion, the defect is usually associated with Chiari ii malformation in affected children. Myelomeningocele has high mortality and, in up to 80% to 90% of patients, can be accompanied by hydrocephalus, which causes severe neurocognitive impairment and requires the patient to be shunted for survival. Intrauterine repair of fetal malformations employing open access through hysterotomy has become a therapeutic option due to improved anesthetic and surgical techniques and instrumentation, which have allowed this type of intervention to become relatively frequent. Anesthetic treatment should focus on both the mother and fetus and the hemodynamic factors regulating placental flow, uterine dynamics, blood loss and fetal well-being must remain well-controlled. Within our Program for Fetal Medicine and Therapy, 21 open fetal interventions have been performed: 17 EXIT procedures and 4 procedures for the intrauterine correction of fetal myelomeningocele. We describe our experience of the intrauterine repair of fetal myelomeningocele through open fetal surgery.

Use of fetal analgesia during prenatal surgery

OBJECTIVE

Recent progresses in fetal surgery have raised concern on fetal pain, its long-term consequences and the risks of sudden fetal movements induced by pain. In several studies, surgeons have directly administered opioids to the fetus, while others have considered sufficient the maternally administered analgesics. We performed a review of the literature to assess the state of the art.

METHODS

We performed a PubMed search to retrieve the papers that in the last 10 years reported studies of human fetal surgery and that described whether any fetal analgesia was administered.

RESULTS

We retrieved 34 papers. In three papers, the procedure did not hurt the fetus, being performed on fetal annexes, in two papers, it was performed in the first half of pregnancy, when pain perception is unlikely. In 10 of the 29 remaining papers, fetal surgery was performed using direct fetal analgesia, while in 19, analgesia was administered only to the mother. In most cases, fetal direct analgesia was obtained using i.m. opioids, and muscle relaxant. Rare drawbacks on either fetuses or mothers due to fetal analgesia were reported.

CONCLUSION

Fetal direct analgesia is performed only in a minority of cases and no study gives details about fetal reactions to pain. More research is needed to assess or exclude its possible long-term drawbacks, as well as the actual consequences of pain during surgery.

Tongue cancers during pregnancy: Case reports and review of literature

BACKGROUND

Due to its rarity, there is no standard treatment for tongue cancers that concur with pregnancy. Treatment depends on the stage of cancer, gestational age of the pregnancy, and the wish of the mother to maintain the pregnancy. The purpose of this study was to review the literature and to report 5 new cases.

METHODS

Twelve cases of tongue cancer during pregnancy were already reported between 1987 and 2009. We report 5 new cases and first administration of concomitant radiochemotherapy for tongue cancer.

RESULTS

Median age of the patients was 29 years, 65% of diagnoses were made after the first trimester of pregnancy. Different treatment modalities are used to treat tongue cancer during pregnancy.

CONCLUSION

We hypothesize that tongue cancer treatment adhering to standard protocols provides the best guarantee to cure the mother. Based on a growing experience and insight taking fetal safety into consideration, the available data suggest that standard treatment is a realistic option.

General anesthesia for cesarean delivery at a tertiary care hospital from 2000 to 2005: a retrospective analysis and 10-year update

BACKGROUND

Complications from general anesthesia for cesarean delivery are a leading cause of anesthesia-related mortality. As a consequence, the overall use of general anesthesia in this setting is becoming less common. The impact and implications of this trend are considered in relation to a similar study performed at our institution 10 years ago.

METHODS

The hospital database for all cesarean deliveries performed during six calendar years (January 1, 2000 through December 31, 2005) was reviewed. The medical records of all parturients who received general anesthesia were examined to collect personal details and data pertinent to the indications for cesarean delivery and general anesthesia, mode of airway management and associated anesthetic complications.

RESULTS

Cesarean deliveries accounted for 23.65% to 31.51% of an annual total ranging from 8543 to 10091 deliveries. The percentage of cases performed under general anesthesia ranged from 0.5% to 1%. A perceived lack of time for neuraxial anesthesia accounted for more than half of the general anesthesia cases each year, with maternal factors accounting for 11.1% to 42.9%. Failures of neuraxial techniques accounted for less than 4% of the general anesthesia cases. There was only one case of difficult intubation and no anesthesia-related mortality was recorded.

CONCLUSION

The use of general anesthesia for cesarean delivery is low and declining. These trends may reflect the early and increasing use of neuraxial techniques, particularly in parturients with co-existing morbidities. A significant reduction in exposure of trainees to obstetric general anesthesia has been observed.

FETAL ANAESTHESIA: IS THIS NECESSARY FOR FETOSCOPIC THERAPY?

Since Robinson and Gregory demonstrated the need to administer analgesia to preterm infants and the safety of such anaesthestic techniques in this specific patient population, pain in neonates and adequate analgesia have drawn more and more attention. Thanks to the outstanding work by Anand et al, it became increasingly clear that premature infants experience stress during invasive procedures and that as a consequence long-term neurodevelopmental status may be affected. Fetuses also demonstrate a stress response. Fetal analgesia can be administered efficiently, eliminating the fetal stress response. However, it remains unclear whether this results in improved neurodevelopment and improved long term outcome.

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.