ANESTHESIA FOR FETAL SURGERY - PRINCIPLES AND CONSIDERATIONS: A CONCISE REVIEW

Fetal surgery, an integral part of fetal therapy has undergone evolution since is conception, which was possible due to continuous refinements in surgical as well as anesthetic techniques The fetal surgery can be done in various stages of the gestation for corrective treatment. Time tested criteria have been laid down for patient selection which help improve the outcome of the whole exercise. The anesthesia concerns and considerations are unique as are the ethical issues involved in this treatment modality involving two patients with contrasting physiological needs. This article reviews salient aspects of fetal physiology in detail. Anesthesia for the fetal interventions is curated as per the invasive nature of surgical interventions. The type of fetal interventions are classified as minimally invasive procedures, Open mid gestation procedures and Ex-utero intrapartum treatment (EXIT) procedures. Preoperative evaluation is dictated by extent of gestation, and invasiveness of the surgical procedure apart from medical status of mother and fetus. This review also tries to enumerate number of clinically useful pharmacological agents in fetal anesthesia including essential tocolytic agents, in addition to management of common fetal complications with a separate section on fetal bradycardia

Protocolo para el manejo anestésico del binomio materno fetal en el proyecto EXIT para neonatos con hernia diafragmática / Protocol for the anesthetic management of the maternal-fetal binomial in the EXIT project for neonates with diaphragmatic hernia

Resumen: EXIT (tratamiento ex útero intraparto). El manejo anestésico para esta cirugía es significativamente diferente del manejo anestésico de una cesárea convencional, involucra anestesia general profunda con halogenados, administración de narcóticos, relajación uterina adecuada y preservación del flujo útero placentario hacia el feto durante la anestesia y al mismo tiempo tiene el beneficio de la anestesia general para que el producto obtenga anestesia y facilite el acceso a la vía aérea del neonato antes del pinzamiento del cordón umbilical. El fin de mantener la oxigenación a través de la placenta es efectuar la maniobra de intubación sin el riesgo de hipoxia. En el Hospital Infantil de México «Federico Gómez¼ se lleva a cabo este tipo de cirugías desde junio de 2007; sin embargo, aún no se cuenta con un manejo homogéneo. Material y métodos: A través de un reporte de casos se hizo una revisión perioperatoria de las pacientes embarazadas, a las cuales se les dio manejo anestésico para cirugía EXIT en el período comprendido entre junio de 2007 y mayo de 2018. Resultados: De los 43 casos manejados, la información anestésica perioperatoria obtenida permitió homologar el manejo anestésico del binomio materno fetal para poder realizar un protocolo intrahospitalario. Conclusión: El poder realizar un protocolo para el manejo anestésico del binomio materno fetal en el proyecto EXIT permite disminuir las complicaciones y la morbimortalidad ofreciendo mejor calidad en la atención.

Abstract: The anesthetic management for this procedure is quite different from the anesthetic management of a conventional caesarean section. It includes deep general anesthesia with halogenated and narcotic administration, to get adecuate uterine relaxation and preservation of best uteroplacental flow to the fetus during anesthesia and the benefit of general anesthesia to aim the neonate show effects of of anesthetic medication by this way facilitate airway access before umbilical cord clamping. The aim to mantain placental oxigenation to neonate is avoid hypoxia risk during intubation technique. In the Hospital Infantil de Mexico «Federico Gómez¼ this procedures have been carried out since June 2007, however, there is still no homogeneous management. Material and methods: Through a case report, a perioperative files review was made of pregnant patients who were given anesthetic management for EXIT procedure in June 2007 to May 2018 period. Results: Of the 43 cases, the perioperative anesthetic information obtained allowed to standardize the anesthetic management of the maternal fetal binomial in order to perform an intrahospital protocol. Conclusion: The ability to perform a protocol for the anesthetic management of the maternal fetal binomial in the exit project allows to reduce complications and morbidity and mortality in the binomial, offering better quality of care.

The multidisciplinary challenge of anesthesia for ex utero intrapartum treatment: a case report / O desafio multidisciplinar da anestesia para procedimento intraparto extra-uterino: relato de caso

Abstract 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.

Resumo O procedimento Intraparto Extra-Uterino (EXIT) é procedimento cirúrgico realizado em casos de previsão de obstrução de via aérea fetal no pós-parto, que permite estabelecer via aérea patente enquanto a circulação placentária é mantida. A anestesia para o procedimento EXIT apresenta várias características específicas, tais como relaxamento uterino adequado, manutenção da pressão arterial materna, anestesia fetal e estabelecimento da via aérea fetal. O anestesiologista deve estar ciente dessas especificidades para contribuir para desfecho favorável. Trata-se de relato de caso de procedimento EXIT realizado em feto com linfangioma cervical e evidência pré-natal de obstrução parcial de traqueia e risco de comprometimento de via aérea pós-parto.

Cirugía fetal en teratoma sacrococcígeo

Sacrococcygeal teratoma is the most common neonatal tumor. In a large number of cases, fetuses are born at term and the teratoma can be resected without complications. However, in another group, prematurity, hydrops and cardiac failure do not allow pregnancy interruption without consequences for the fetus. Here is where fetal surgery has a place. We conducted a search of the literature related to sacrococcygeal teratoma and case reports where surgery was performed, including those with details on the patient's preparation, surgery, and the postoperative period. The average gestational age of presentation in ultrasound is 23 weeks. There is more literature on open surgery, and the main indication is hydrops or imminent cardiac failure. The reported cases with minimally invasive therapy are the least, with controversial results. Sacrococcygeal teratoma in the newborn is an entity with very good prognosis depending on the case, time of diagnosis, type of tumor, and malignancy potential. However, those of prenatal diagnosis are at high risk of complications and death. There are several reports of open surgery and EXIT procedure (special delivery technique where the sacrococcygeal teratoma is exposed through a limited incision in the uterus) with good surgical results but with high maternal and fetal comorbidity. Therefore, minimally invasive techniques have emerged to reduce the potential risks of open surgery; nevertheless, there are contradictory results.

El teratoma sacrococcígeo es el tumor neonatal más común. En un gran número de los casos los fetos llegan al término y pueden ser resecados sin complicaciones. Sin embargo, en otro grupo de pacientes, su prematuridad, el hidrops y la falla cardiaca no permiten interrumpir el embarazo sin consecuencias para el feto. Aquí es donde la cirugía fetal tiene cabida. Se realizó una búsqueda de la literatura relacionada al teratoma sacrococcígeo y reportes de casos donde se practicó cirugía. Se incluyeron también aquellos en donde se detallaba la preparación de la paciente, el transoperatorio y postoperatorio. La edad gestacional de la presentación usualmente fue durante la ecografía estructural, con una media de las 23 semanas. Se encuentra más literatura acerca de cirugías abiertas y la principal indicación es el hidrops y/o la falla cardiaca inminente. Los casos reportados realizados con mínima invasión son los menos, con resultados controversiales. El teratoma sacrococcígeo en el recién nacido es una entidad con muy buen pronóstico dependiendo del caso, tiempo del diagnóstico, tipo del tumor y potencial de malignidad del mismo. Sin embargo, el diagnosticado prenatalmente, cursa con alto riesgo de complicaciones y muerte. Hay varios casos reportados de cirugía abierta y procedimiento EXIT (técnica especial en la que el tumor es expuesto a través de una pequeña incisión) con buenos resultados quirúrgicos, pero con alta comorbilidad materna y fetal. Por ende, han surgido técnicas mínimamente invasivas para disminuir los riesgos potenciales de la cirugía abierta; a pesar de esto hay resultados contradictorios.

Two cases of Ex utero intrapartum treatment (EXIT) in UP-PGH

The survival rate and prognosis for neonates with airway obstruction is poor if not managed immediately after delivery. Ex utero intrapartum treatment (EXIT) is indicated for cases in which airway obstruction is anticipated. The procedure establishes the fetal airway prior to complete delivery while maintaining an intact uteroplacental circulation. Maintaining uteroplacental circulation, ensuring uterine relaxation, and temporizing placental detachment during the EXIT procedure are achieved by administering a higher dose of inhalation anesthetic and intravenous nitroglycerine. However, this can lead to maternal hypotension and compromised feto-placental perfusion, reduced fatal cardiac output and acidosis. It is therefore essential that these be managed using vasopressors and inotropes. This paper reports the first institutional experience with the EXIT procedure in the Philippines, presenting two cases of neonates with large cystic hygroma. One case was performed as an elective procedure, the other as emergency treatment.

Anesthesia for EXIT procedure (ex utero intrapartum treatment) in congenital cervical malformation - a challenge to the anesthesiologist / Anestesia para procedimento EXIT (tratamento extraútero intraparto) em malformação congênita cervical - um desafio para o anestesiologista

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.

O procedimento EXIT (tratamento extraútero intraparto) consiste na exteriorização parcial do feto da cavidade uterina durante o parto para permitir a manutenção da circulação fetoplacentária. Está indicado na presença de malformações congênitas em que se antecipa a dificuldade no acesso da via aérea fetal e permite que essa seja assegurada por laringoscopia direta, broncoscopia, traqueostomia ou intervenção cirúrgica. A anestesia para procedimento EXIT apresenta várias particularidades. O relaxamento uterino adequado, a manutenção da pressão arterial materna, o estabelecimento de via aérea fetal e a manutenção da contração uterina pós-parto são alguns exemplos. O anestesiologista deve estar preparado para as particularidades anestésicas desse procedimento, de modo a contribuir para um desfecho favorável para a mãe e particularmente para o feto.

EXIT Llyod Davies

The EXIT (Ex utero intrapartum treatment) procedures have been, with a high degree of success, employed to treat a myriad types of fetal airway obstruction most commonly neck masses such as cystic hygroma and lymphangioma with ample plan including prenatal diagnosis by ultrasound scan or MRI. Before the advent of EXIT, formal documentations had been published with descriptions of intubation during intrapartum period and fetal airway protection either during normal or operative delivery. We report a 28-year-old gravida 2 para 1 who was referred to our Maternal Fetal Medicine (MFM) unit at 26 weeks and 3 days gestation with a foetal neck mass. We present a case of an successful EXIT procedure performed in the Lloyd Davies position with the hips abducted and flexed at 15 degrees as is employed during gynecologic laparoscopy surgery minus the Trendelenburg tilt. Both mother and baby are well. The benefits of this position are discussed.

E X I T (ex-utero intrapartum therapy) en linfangioma cervical fetal / EXIT procedure (ex-utero intra-partum therapy) for fetal neck lymphangioma

Se presenta un caso clínico de una embarazada primigesta de 17 años, con un feto con gran masa cervical a las 20 semanas, se diagnostica como linfangioma cervical. La evaluación prenatal concluye que existe gran riesgo de asfixia perinatal por obstrucción de la vía aérea superior, se resuelve el parto mediante procedimiento EXIT (ex-utero intrapartum therapy) a las 37 semanas. Se logra realizar intubación con larin-goscopia directa, con un tiempo de by-pass uteroplacentario de 7 minutos. Se obtiene un recién nacido de 3300 g, al segundo día se opera del tumor con buenos resultados. Se revisa el protocolo del procedimiento EXIT en sus aspectos anestésicos, obstétricos, quirúrgicos y neonatológicos. Se concluye que el EXIT debe ser planteado en todo caso en que se sospeche obstrucción de la vía aérea superior y puede ser realizado en hospitales que cuenten con equipamiento habitual y un equipo médico multidisciplinario.

We report a case of primigravida patient, 17 years old, with a fetus showing a large cervical mass at 20 weeks of gestation and was diagnosed as a cervical lymphangioma. The prenatal evaluation concludes that there exists a great risk of perinatal asphyxia due to obstruction of the upper airway and therefore it is decided to perform a cesarean section at 37 weeks of gestation, using an EXIT procedure (ex-utero intra-partum therapy). We perform intubation with a semi- rigid tube having a by-pass time utero-placental of 7 minutes, obtaining a newborn of 3300 g at birth. The newborn is operated two days after birth removing the cervical tumor with good results. We review the protocol of the EXIT procedure concerning aspects related to anesthesia, obstetrics, surgery and neonatal care. We conclude that EXIT should be considered in all cases in which obstruction of the upper airway is suspected, and can be performed in hospitals that have basic surgical facilities and a multidisciplinary team.

Anesthetic Management during an Ex Utero Intrapartum Treatment (EXIT) Procedure of the Agnathic Fetus : A case report / 대한마취과학회지

We report our experience of the anesthetic management of an ex utero intrapartum treatment (EXIT) procedure that was performed on a fetus with a mandible anomaly (agnathia) for airway management. The EXIT procedure is a method for maintaining the feto-placental circulation during a cesarean section using deep inhalation anesthesia. In the EXIT procedure, the anesthetic goal is the profound relaxation of the uterus to maintain the feto-placental circulation. High dose inhalation agents are used maintain the level of uterine relaxation. Anesthesia was induced with rapid sequence intubation and maintained with 2 vol% isoflurane and nitrous in oxygen (50:50) combined with intermittent boluses of fentanyl and atracurium. The fetus was not given any drugs other than those as a result of placental transfer and was monitored with pulse oximeter. The mother and fetus were maintained hemodynamically stable with a preserved feto-placental circulation. After delivery, the uterine tone improved soon after discontinuing the isoflurane, and the pitocin infusion was begun. There were no signs of uterine atony in the postoperative period.

Anesthesia for fetal procedures and surgery

Many of the anesthetic considerations for fetal procedures and surgery are identical to those for nonobstetric surgery during pregnancy, including concern for maternal safety, avoidance of both teratogenic drugs and fetal asphyxia, and the prevention of preterm labor and delivery. Anesthesia is required for the mother and quite often the fetus to perform many fetal procedures. Fetal procedures and surgery can be divided into subgroups according to their anesthetic requirements. For example: procedures that only require a needle insertion into the uterus but not into the fetus, such as intrauterine infusions; laser surgical photocoagulation of the communicating placental circulation for twin-twin transfusion syndrome (TTTS) and radio-frequency umbilical cord ablation for managing twin reversed arterial perfusion (TRAP), which are not really fetal procedures, rather they are placental or cord procedures; surgical procedures performed directly on the fetus; and the EX-utero Intrapartum Treatment (EXIT) procedure. Anesthetic considerations also depend on other factors, such as the location of the placenta. Unlike maternal surgery, for fetal procedures, the fetus is not an innocent bystander for whom the least anesthetic interference is used. Instead, the fetus can be the primary patient and may benefit from anesthesia, with close monitoring of the anesthetic effects to ensure well-being. Fetal asphyxia, hypoxia, or distress can be most effectively recognized, predicted, and avoided by fetal monitoring. Monitoring is also crucial for assessing the fetal response to corrective maneuvers.