Anesthesia for predelivery procedures: ex-utero intrapartum treatment/intrauterine transfusion/surgery of the fetus

Management and Outcomes of Patients With High-Risk (Congenital Lung Malformation Volume Ratio≥ 1.6) Congenital Lung Malformations

INTRODUCTION

Congenital lung malformations (CLMs) have a variable natural history. Larger lesions with CLM volume ratio (CVR) ≥ 1.6 are associated with hydrops and fetal mortality. The purpose of this study is to describe the management and outcomes of high-risk (CVR ≥ 1.6) CLM patients.

METHODS

A retrospective cohort study was performed for all fetuses evaluated between May 2015 and May 2022. Demographics, prenatal imaging factors, prenatal and postnatal treatment, and outcomes were collected. Descriptive statistics were used to compare the cohorts.

RESULTS

Of 149 fetal CLM patients referred to our fetal center, 21/149 (14%) had CVR ≥ 1.6. One CLM patient had intrauterine fetal demise, and 2 patients were lost to follow-up. Of the remaining 18 patients, 11/18 (67%) received maternal steroids. Seven out of 18 patients (39%) underwent resection at the time of delivery with 1/7 (14%) undergoing exutero intrapartum treatment (EXIT)-to-resection, 5/7 (71%) undergoing EXIT-to-exteriorization-to-resection, and 1/7 (14%) undergoing a coordinated delivery to resection; among those undergoing resection, there were 2 fatalities (28.5%). Seven out of 18 (39%) patients required urgent neonatal open lobectomies, and the remaining 4/18 (22%) patients underwent elective thoracoscopic lobectomies with no mortality.

CONCLUSIONS

The natural history and outcomes of severe CLM patients remain highly variable. The EXIT-to-exteriorization-to-resection procedure may be a safe and effective approach for a subset of CLM patients with persistent symptoms of mass effect and severe mediastinal shift due to the observed decreased operative time requiring placental support observed in our study.

Neuraxial anesthesia in ex utero intrapartum therapy for parturients with fetal congenital diaphragm hernia: a prospective observational study

BACKGROUND

Congenital diaphragmatic hernia (CDH) is characterized by defects in the fetal diaphragm and thoracic herniation of the abdominal viscera. The ex utero intrapartum treatment (EXIT) procedure is used to establish the fetal airway while on placental support. These EXIT procedures are commonly performed under general anesthesia, which increases maternal bleeding and the risk of insufficient placental perfusion subsequently. This study investigated the feasibility of performing neuraxial anesthesia for the EXIT procedure for fetal congenital diaphragmatic hernia to improve outcomes.

METHODS

Parturients with fetal CDH who underwent an EXIT procedure between January 2019 and May 2021 in our institution were recruited. Variables evaluated included gestational age, surgical time, intra-operative blood loss, peri-operative hemoglobin, maternal complications, fetal lung-to-head ratio, time on placental bypass, and postnatal outcome.

RESULTS

Twenty-two cases were included. All procedures were performed under neuraxial anesthesia. The median gestational age at the time of the EXIT procedure was 37 weeks. The median estimated blood loss was 200 mL. There was no report of an adverse maternal event. The placental bypass time was 142.9 ± 72.6 s, and access to the airway was successfully established within the bypass time. Twenty-one neonates reached an Apgar score of 9 at 5 min. In the first two hours after birth, the average pH of neonatal peripheral arterial blood was 7.35 ± 0.07 (n=19), and lactate level 1.85 ± 0.71 mmol/L (n=19).

CONCLUSIONS

In the EXIT procedure to establish an airway for fetal CDH, neuraxial anesthesia proved a feasible technique for maternal anesthesia.

Complex Pathology and Management in the Obstetric Patient: A Narrative Review for the Anesthesiologist

Pregnant patients may present with multiple complex comorbidities that can affect peripartum management and anesthetic care. The preanesthesia clinic is the ideal setting for early evaluation of high-risk pregnant patients. Comorbidities may include cardiovascular pathology such as valvular abnormalities, septal defects, aortopathies, arrythmias and cardiomyopathies. Additional comorbidities include pulmonary conditions such as obstructive sleep apnea as well as preexisting neuromuscular and skeletal disorders that may impact anesthetic management. Hematologic conditions involving both bleeding diathesis and thrombophilias may present unique challenges for the anesthesiologist. Patients may also present with endocrinopathies including diabetes and obesity. While not as common, high-risk patients may also have preexisting gastrointestinal conditions such as liver dysfunction, renal failure, and even post-transplant status. Ongoing and prior substance abuse, obstetric conditions such as placenta accreta spectrum disorders, and fetal conditions needing ex utero Intrapartum treatment also require advanced planning. Preanesthesia evaluations also help address important ethical and cultural considerations. Counseling patients regarding anesthetic considerations as well as addressing concerns will play a role in reducing racial and ethnic disparities. Anticipatory guidance by means of pre-anesthetic planning can facilitate multidisciplinary communication and planning. This can allow for an impactful and meaningful role in the care provided, allowing for safe maternal care and optimal outcomes.

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.

Analgesia for fetal pain during prenatal surgery: 10 years of progress

Some doubts on the necessity and safety of providing analgesia to the fetus during prenatal surgery were raised 10 years ago. They were related to four matters: fetal sleep due to neuroinhibitors in fetal blood, the immaturity of the cerebral cortex, safety, and the need for fetal direct analgesia. These objections now seem obsolete. This review shows that neuroinhibitors give fetuses at most some transient sedation, but not a complete analgesia, that the cerebral cortex is not indispensable to feel pain, when subcortical structures for pain perception are present, and that maternal anesthesia seems not sufficient to anesthetize the fetus. Current drugs used for maternal analgesia pass through the placenta only partially so that they cannot guarantee a sufficient analgesia to the fetus. Extraction indices, that is, how much each analgesic drug crosses the placenta, are provided here. We here report safety guidelines for fetal direct analgesia. In conclusion, the human fetus can feel pain when it undergoes surgical interventions and direct analgesia must be provided to it. IMPACT: Fetal pain is evident in the second half of pregnancy. Progress in the physiology of fetal pain, which is reviewed in this report, supports the notion that the fetus reacts to painful interventions during fetal surgery. Evidence here reported shows that it is an error to believe that the fetus is in a continuous and unchanging state of sedation and analgesia. Data are given that disclose that drugs used for maternal analgesia cross the placenta only partially, so that they cannot guarantee a sufficient analgesia to the fetus. Safety guidelines are given for fetal direct analgesia.

Fetal anesthesia: intrauterine therapies and immediate postnatal anesthesia for noncardiac surgical interventions

PURPOSE OF REVIEW

This review describes maternal and fetal anesthetic management for noncardiac fetal surgical procedures, including the management of lower urinary tract obstruction, congenital diaphragmatic hernia (CDH), myelomeningocele, sacrococcygeal teratoma, prenatally anticipated difficult airway and congenital lung lesions.

RECENT FINDINGS

Fetal interventions range from minimally invasive fetoscopic procedures to mid-gestation open surgery, to ex-utero intrapartum treatment procedure. Anesthetic management depends on the fetal intervention and patient characteristics. Anesthesia for most minimally invasive procedures can consist of intravenous sedation and local anesthetic infiltration in clinically appropriate maternal patients. Open fetal and ex-utero intrapartum treatment procedures require maternal general anesthesia with volatile anesthetic and other medications to maintain uterine relaxation. Tracheal balloons are a promising therapy for CDH and can be inserted via minimally invasive techniques. Management of the prenatally anticipated difficult airway during delivery and removal of tracheal balloons from patients with CDH during delivery can be clinically dynamic and require flexibility, seamless communication and a high-functioning, multidisciplinary care team.

SUMMARY

Maternal and fetal anesthetic management is tailored to the fetal intervention and the underlying health of the fetus and mother.