Long-term outcomes after fetal therapy for congenital high airway obstructive syndrome

Medicine and the Law

Congenital high airway obstruction syndrome (CHAOS) is a rare condition that can be diagnosed antenatally by ultrasound. It is usually lethal without immediate intervention at delivery. A 24-year-old woman was diagnosed with fetal CHAOS at 27 weeks' gestation. The couple declined termination of pregnancy. A multidisciplinary team including obstetricians, geneticists, paediatric surgeons, neonatologists and anaesthetists was constituted to plan an ex utero intrapartum treatment (EXIT) procedure. After several simulations, a caesarean section was performed at 38 weeks' gestation under deep inhalational anaesthesia. The fetus was fully delivered with placenta remaining in utero to maintain perfusion. A surgical airway was established via tracheostomy in approximately 5 minutes. The operation was then completed with no maternal complications. The child remains well at 3 years of age. To our knowledge, this is the first EXIT procedure performed for CHAOS in the public sector. This procedure can be lifesaving and is possible with proper planning.

Prenatal and Postnatal Therapies for Down's Syndrome and Associated Developmental Anomalies and Degenerative Deficits: A Systematic Review of Guidelines and Trials

Down's syndrome (DS) is the most common genetic disorder at birth. Multiple developmental abnormalities before birth and early onset of degenerative deficits after birth are features of DS. Early treatment for the manifestations associated with DS in either prenatal or postnatal period may improve clinical outcomes. However, information available from professional bodies and to communities is very limited. We carried out a systematic review and attempted meta-analysis of clinical trials for developmental abnormalities and degenerative deficits in DS. Only 15 randomized controlled trials (RCTs) in 995 (24 days to 65 years old) individuals with DS showed some improvement in cognitive disorders, development and growth, and musculoskeletal problem. However, each trial used different parameters and methods to measure various outcomes. RCTs of prenatal interventions in fetus with DS are lacking. The efficacy and safety of specific interventions in DS are still largely unknown. Proper counseling of the potential treatment for pregnant mothers who wish to continue their pregnancy carrying fetus with DS, and to health care professionals who take care of them are not adequate nowadays.

Acutely presenting congenital chest lesions: a primer for the radiologist

Congenital chest lesions encompass several important entities. Without prompt intervention, many of these can culminate in serious complications. Timely and accurate radiologic interpretation of these entities is integral to patient management. Imaging can help characterize and prognosticate several of these entities, and may both suggest the need for and guide therapy. We overview the clinical presentation, associated complications, imaging characteristics, and prognostic indicators-both postnatal and antenatal-of the spectrum of emergently presenting congenital chest lesions. We also outline current and evolving management strategies, whether fetal, peripartum, or postnatal. The ultimate goal is to help radiologists formulate timely and effective diagnoses of these entities and boost the relevance of their input towards clinical decision-making.

Prenatal Diagnosis and Outcome of Tracheal Agenesis as Part of Congenital High Airway Obstruction Syndrome. Case Presentation and Literature Review

Tracheal atresia is an extremely rare condition whereby a partial or total obstruction of the trachea is seen. It is almost always lethal, with just a handful of cases that ended with a good outcome. In this study we report on a 15-week male fetus, diagnosed with hyperechogenic lungs, midline heart position and inverted diaphragm. Sonographic findings suggest congenital High Airway Obstruction Syndrome (CHAOS) An ultrasound scan and fetal MRI were not able to point out the exact obstruction level. In spite of extensive counselling, the parents opted to carry on with the pregnancy. Fetal demise was noted on a scan at 19 weeks gestation. After the elective termination of pregnancy, a post-mortem examination showed partial tracheal atresia with no other anomalies. Despite technological progress in CHAOS syndrome, a precise diagnosis and accurate prognosis remain elusive.

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.

Risk factor analysis and outcomes of airway management in antenatally diagnosed cervical masses

PURPOSE

To investigate antenatally-determined imaging characteristics associated with invasive airway management at birth in patients with cervical masses, as well as to describe postnatal management and outcomes.

STUDY DESIGN

A retrospective analysis of 52 patients with antenatally diagnosed neck masses was performed using single-center data from January 2008 to January 2019. Antenatal imaging, method of delivery, management, and outcomes data were abstracted from the medical record and analyzed.

RESULTS

Antenatal diagnosis of neck masses in this cohort consisted of 41 lymphatic malformations (78.8%), 6 teratomas (11.5%), 3 hemangiomas (5.8%), 1 hemangioendothelioma (1.9%), and 1 giant foregut duplication cyst (1.9%). Mean gestational age at time of diagnostic imaging was 29 weeks 3 days (range: 19w4d - 37w). Overall, 22 patients (42.3%) required invasive airway management at birth, specifically 18 patients (34.6%) required endotracheal intubation and 4 (7.7%) required tracheostomy. 15 patients (28.8%) underwent ex-utero intrapartum treatment (EXIT) for the purposes of securing an airway. Polyhydramnios, tracheal deviation and compression, and anterior mass location on antenatal imaging were significantly associated with incidence of invasive airway intervention at birth, EXIT procedure, and tracheostomy during the neonatal hospitalization (p < 0.025; Fisher's exact test). Logistic regression analysis demonstrated statistically significant association between increasing antenatally-estimated mass volume and incidence of invasive airway management at birth (p = 0.02). Post-natal cervical mass management involved surgical excision (32.7%), sclerotherapy (50%), and adjuvant therapy with rapamycin (17.3%). Demise in the neonatal period occurred in 4 (7.7%) patients.

CONCLUSION

This series documents the largest single-center experience of airway management in antenatally diagnosed cervical masses. Fetal imaging characteristics may help inform the appropriate method of delivery, airway management strategy at birth, and prenatal counseling.

Prenatal diagnosis of congenital high airway obstruction syndrome

Congenital high airway obstruction syndrome (CHAOS) is a rare sequence due to a complete obstruction of the fetal airway that blocks the larynx or trachea, either intrinsic atresia or extrinsic compression (e.g., congenital neck mass). Despite the true incidence of CHAOS is unknown, an incidence of 1 per 50,000 newborns is described. If any obstruction occurs in the tracheobronchial airway, this secretion cannot be extricated. Because of this situation, a knock-on effect starts: the enlargement of the lungs squeezes the heart and great veins, what results in a replacement of the heart to the center of the chest becoming small and dysfunctional. Decreased venous return and the failure of cardiovascular system end in ascites and hydrops. The diaphragm planes or inverts according to the severity of the process. In case of unrecognized syndrome during the prenatal period, it usually results in stillbirth or death shortly after delivery. The overall prognosis remains fatal, and long-term medical and surgical challenges for survivors remain considerable even after overcoming fetal intervention.

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.

Perinatal outcome of fetuses with congenital high airway obstruction syndrome: a single-center experience

Objective

To report our experience with management of fetuses with congenital high airway obstruction syndrome (CHAOS).

Methods

We retrospectively reviewed the cases of fetuses who were prenatally diagnosed and postnatally confirmed with CHAOS between 2010 and 2019 at Asan Medical Center, Seoul, Korea.

Results

Of 13 fetuses prenatally diagnosed with CHAOS, 7 were lost to follow-up and 6 were postnatally confirmed as having CHAOS. All fetuses, except one were delivered via cesarean section with an ex utero intrapartum treatment (EXIT) procedure. Two patients had coexisting congenital heart diseases requiring several cardiac surgeries following birth. Both of these patients demonstrated developmental delay; however, the remaining 4 had a normal development except for expressive language. Two infants died of respiratory complications, and the remaining 4 were alive at the end of the follow-up period. All 4 live patients underwent tracheostomy with planned reconstruction surgery. Three children are now able to phonate, and 1 can maintain a conservation.

Conclusion

The proper management of CHAOS using the EXIT procedure results in high survival and low hypoxemia-induced complication rates. Therefore, an accurate prenatal diagnosis is necessary for an appropriate perinatal management.

International Pediatric Otolaryngology Group (IPOG): Consensus recommendations on the prenatal and perinatal management of anticipated airway obstruction

OBJECTIVE

To make recommendations on the identification, routine evaluation, and management of fetuses at risk for airway compromise at delivery.

METHODS

Recommendations are based on expert opinion by members of the International Pediatric Otolaryngology Group (IPOG). A two-iterative Delphi method questionnaire was distributed to all members of the IPOG and responses recorded. The respondents were given the opportunity to comment on the content and format of the survey, which was modified for the second round. "Consensus" was defined by >80% respondent affirmative responses, "agreement" by 51-80% affirmative responses, and "no agreement" by 50% or less affirmative responses.

RESULTS

Recommendations are provided regarding etiologies of perinatal airway obstruction, imaging evaluation, adjunct evaluation, multidisciplinary team and decision factors, micrognathia management, congenital high airway obstruction syndrome management, head and neck mass management, attended delivery procedure, and delivery on placental support procedure.

CONCLUSIONS

Thorough evaluation and thoughtful decision making are required to optimally balance fetal and maternal risks/benefits.

Congenital High Airway Obstruction Syndrome (CHAOS): No Intervention, No Survival-A Case Report and Literature Review

Congenital high airway obstruction syndrome (CHAOS) is complete or partial obstruction of the fetal upper airway. CHAOS is a rare and fatal condition if no perinatal intervention is done. Antenatal sonographic imaging has typical findings that can help in an early diagnosis, which is important in deciding elective termination of the pregnancy or successful planning of appropriate perinatal management.

A Technical Look at Fetoscopic Laser Ablation for Fetal Laryngeal Surgical Recanalization in Congenital High Airway Obstruction Syndrome

Background: Congenital high airway obstruction syndrome (CHAOS) is a rare condition characterized by complete obstruction of the upper fetal airways. Left untreated, it is uniformly fatal. Ex utero intrapartum treatment (EXIT) has been used to establish a surgical airway in affected fetuses during delivery. While this procedure benefits those fetuses that survive to delivery, high mortality in the prenatal period necessitates earlier innovative strategies. Herein, we report a novel technique for in utero intervention. Methods: A fetoscopic intervention was performed at 28 weeks on a 35-year-old G1P0 woman with fetal CHAOS from a laryngeal obstruction measuring 11 mm in length on prenatal imaging. Under ultrasound guidance, a 3.3-mm curved fetoscope was used to access the uterine cavity through a single subcentimeter maternal skin incision. The scope was driven through the fetal oral cavity and manipulated to attain a view of the vocal cords. A subglottic obstruction was observed. A 600-micron laser fiber was passed through the working channel of the scope and used to ablate the obstructed airway. Using the laser fiber and a guidewire, the ablated opening was traversed with the fetoscope to the level of the carina. Results: Postoperatively, the lungs became less hyperinflated. There was improvement in ascites and diaphragmatic eversion. At 31 1/7 weeks' gestation, the mother experienced preterm premature rupture of membranes with active labor and the fetus was delivered through EXIT to tracheostomy. The infant was managed on mechanical ventilation and is currently thriving at home with a tracheostomy at 2 years of age. Conclusion: Fetoscopy with laser ablation of the airway obstruction is an effective prenatal management strategy that offers the potential to alter the devastating natural course of CHAOS.

Causes of death shortly after delivery and medical malpractice claims in congenital high airway obstruction syndrome: Review of the literature

Congenital High Airway Obstruction Syndrome is a rare pathology that may conduct the baby to death shortly after delivery. This outcome may cause emotional distress in the parents but it may also generate expensive medical malpractice claims about the reasons why the syndrome was not identified and/or correctly treated. The authors conducted a review of the cases in which Congenital High Airway Obstruction Syndrome caused death of the baby shortly after delivery. Then, they pointed out these ultrasonographic and anatomical reasons why the syndrome may be not identified and/or correctly treated: negative prenatal ultrasonography, recurrence of non-specific findings at prenatal ultrasonography, connection of respiratory and gastrointestinal tracts, tracheal agenesis or atresia, parent's refuse of post-partum therapeutic procedures, multiple malformations of the fetus/child. In conclusion, the authors highlighted that death shortly after delivery is usually caused by specific conditions that are not influenced by healthcare team's practice.

Ex utero intrapartum treatment (EXIT) procedures

Ex Utero Intrapartum Treatment (EXIT) is a technique developed to safely and efficiently establish cardiopulmonary support at delivery while maintaining placental bypass. Indications for the EXIT approach are expanding and currently include EXIT-to-airway, EXIT-to-resection, EXIT-to-extracorporeal membrane oxygenation (ECMO), and EXIT-to-separation of conjoined twins. The EXIT technique involves planned partial delivery of the fetus via hysterotomy while maintaining uterine relaxation and placental support, allowing for the establishment of neonatal cardiopulmonary stability in a controlled manner. Fetal interventions performed during EXIT can include endotracheal intubation, tracheostomy, mass excision, removal of a temporary tracheal occlusive device, ECMO cannulation, and others. The most important aspect of an EXIT procedure is the formation of a multi-disciplinary team with broad expertise in fetal intervention to collaborate throughout the pre, intra, and post-partum periods. This chapter reviews the prenatal workup, decision making, surgical indications, and operative considerations associated with EXIT procedures.

Fetoscopy-Assisted Percutaneous Decompression of the Distal Trachea and Lungs Reverses Hydrops Fetalis and Fetal Distress in a Fetus with Laryngeal Atresia

We present a case of prenatal hydrops secondary to congenital high airway obstruction syndrome (CHAOS) that was treated with fetoscopy-assisted needle decompression. A 22-year-old G3P2 woman presented after a 21-week ultrasound demonstrated CHAOS. The fetus developed hydrops at 25 weeks, characterized by abdominal ascites, pericardial effusion, and scalp edema. Fetal MRI showed complete obstruction of the glottis and subglottic airway, suggestive of laryngeal atresia. At 27 weeks, due to the progression of the hydrops, operative fetoscopy was proposed and performed. Fetal laryngoscopy confirmed fusion of the vocal cords and laryngeal atresia. The atretic segment was a solid cartilaginous block, preventing intubation. Using the fetoscope to stabilize the fetal head and neck, we performed ultrasound-guided percutaneous needle drainage of the cervical trachea through the anterior fetal neck. We removed 17 mL of viscous fluid from the lower trachea, resulting in immediate lung decompression. Two weeks later, ultrasound confirmed hydrops resolution. The patient was delivered and tracheostomy performed at 30 weeks via an ex utero intrapartum treatment (EXIT) procedure after progression of preterm labor. At 27 days of life, the infant was stable on minimal ventilator support. To our knowledge, this is the first successful report of an ultrasound-guided percutaneous tracheal decompression through the anterior neck of a fetus with CHAOS secondary to laryngeal atresia.

Congenital high airway obstruction syndrome (CHAOS): Natural history, prenatal management strategies, and outcomes at a single comprehensive fetal center

PURPOSE

Congenital high airway obstruction syndrome (CHAOS) is a devastating fetal condition of complete airway discontinuity resulting in significant hydrops and extreme lung hyperplasia. It is universally fatal with survival reported only in the rare spontaneous fistulization or EXIT intervention (Ex Utero Intrapartum Treatment). Even in these cases, mortality remains high, and current investigations are targeting prenatal interventions. This report describes our experience with management and fetal interventions for CHAOS, including laser laryngotomy.

METHODS

We retrospectively reviewed all patients diagnosed with CHAOS at a single academic institution between 2006 and 2017.

RESULTS

Fifteen patients were identified. Eight had obstruction at the trachea and seven at the larynx. In the laryngeal obstructions, three expired shortly after birth, and one survived after spontaneous fistulization and subsequent EXIT to tracheostomy. The remaining three underwent in-utero treatment with laser laryngotomy. One had preterm premature rupture of membranes (PPROM), delivered 3 days post-operatively, and died. Two underwent EXIT to tracheostomy with one surviving to discharge and is currently 2 years old.

CONCLUSION

Our study demonstrates the outcomes of a large series of patients diagnosed with CHAOS. While mortality remains high, options for fetal intervention are being explored to allow alterations in the prenatal natural history and improve postnatal outcomes.

TYPE OF STUDY

Retrospective Treatment Study.

LEVEL OF EVIDENCE

Level IV.

Management of CHAOS by intact cord resuscitation: case report and literature review

Background: Congenital high airway obstruction syndrome (CHAOS) is a near fatal condition, except when the ex utero intrapartum treatment (EXIT) procedure is performed as rescue. After antenatal diagnosis of the condition, counseling regarding prognosis and outcome needs to be provided.Case: We describe here a case with CHAOS due to isolated fetal laryngeal atresia, presented at our center at 33-week gestation. After counseling regarding the uncertain outcome, consent for elective caesarean was not given. Intact cord resuscitation (ICR) was done as a rescue by a well-coordinated team during delivery. Tracheostomy was performed successfully under local anesthesia within five minutes, while the cord was still attached to the placenta. The baby had supraglottic stenosis on CT scan. Reconstructive surgery is planned after 8 months. The literature review showed 24 reports of 28 cases with intrinsic airway obstruction managed by EXIT, laryngeal atresia was the most common cause (18/28). The outcome was poor in tracheal agenesis (1/4 survived) whereas those having laryngeal web or small communication (4/4 survived) had better outcome. Tracheal reconstruction was done in 3/28 cases only.Conclusions: The case emphasizes that ICR and tracheostomy during vaginal delivery can rescue the baby. The literature reviewed provided insight into the outcome of CHAOS cases in world literature.

Perinatal Care of Infants with Congenital Birth Defects

Prenatal diagnosis has changed perinatal medicine dramatically, allowing for additional fetal monitoring, referral and counseling, delivery planning, the option of fetal intervention, and targeted postnatal management. Teams participating in the delivery room care of infants with known anomalies should be knowledgeable about specific needs and expectations but also ready for unexpected complications. A small number of neonates will need rapid access to postnatal interventions, such as surgery, but most can be stabilized with appropriate neonatal care. These targeted perinatal interventions have been shown to improve outcome in selected diagnoses.

Maternal and Fetal Immune Response to in Utero Stem Cell Transplantation

Purpose of Review

In Utero Hematopoietic Cellular Transplantation (IUHCT) is a promising intervention for the non-toxic treatment of congenital disease that hinges on the assumption of fetal immunologic immaturity and an inability to reject a hematopoietic allograft. However, clinical IUCHT has failed except in cases where the fetus is severely immunocompromised. The current review examines recent studies of engraftment barriers stemming from either the fetal or maternal immune system.

Recent Findings

New reports have illuminated roles for maternal humoral and cellular immunity and fetal innate cellular immunity in the resistance to allogeneic IUHCT. These experimental findings have inspired new approaches to overcome these barriers. Despite these advances, postulates regarding a maternal immune barrier to IUHCT provide an inadequate explanation for the well-documented clinical success only in the treatment of fetal immunodeficiency with normal maternal immunity.

Summary

Characterization of the maternal and fetal immune response to allogeneic IUHCT provides new insight into the complexity of prenatal tolerance. Future work in this area should aim to provide a unifying explanation for the observed patterns of success and failure with clinical IUHCT.

EXIT (ex utero intrapartum treatment) in a growth restricted fetus with tracheal atresia

Congenital high airway obstruction syndrome (CHAOS) encompasses a heterogeneous group of pathologies leading to poor lung development and difficulty oxygenating the newborn after delivery. While previously uniformly fatal, the ex utero intrapartum therapy (EXIT) procedure has provided a method to treat these patients and provide an airway to potentiate survival. We present a patient diagnosed prenatally with CHAOS secondary to tracheal atresia complicated by severe intra-uterine growth restriction (IUGR) who was successfully delivered via an EXIT procedure at 33-weeks. Multidisciplinary care and planning is paramount.

Congenital tracheobronchial stenosis

Congenital tracheobronchial stenosis is a rare disease characterized by complete tracheal rings that can affect variable lengths of the tracheobronchial tree. It causes high levels of morbidity and mortality both due to the stenosis itself and to the high incidence of other associated congenital malformations. Successful management of this complex condition requires a highly individualized approach delivered by an experienced multidisciplinary team, which is best delivered within centralized units with the necessary diverse expertise. In such settings, surgical correction by slide tracheoplasty has become increasingly successful over the past 2 decades such that long-term survival now exceeds 88%, with normalization of quality of life scores for patients with non-syndrome-associated congenital tracheal stenosis. Careful assessment and planning of treatment strategies is of paramount importance for both successful management and the provision of patients and carers with accurate and realistic treatment counseling.

Airway tissue engineering for congenital laryngotracheal disease

Regenerative medicine offers hope of a sustainable solution for severe airway disease by the creation of functional, immunocompatible organ replacements. When considering fetuses and newborns, there is a specific spectrum of airway pathologies that could benefit from cell therapy and tissue engineering applications. While hypoplastic lungs associated with congenital diaphragmatic hernia (CDH) could benefit from cellular based treatments aimed at ameliorating lung function, patients with upper airway obstruction could take advantage from a de novo tissue engineering approach. Moreover, the international acceptance of the EXIT procedure as a means of securing the precarious neonatal airway, together with the advent of fetal surgery as a method of heading off postnatal co-morbidities, offers the revolutionary possibility of extending the clinical indication for tissue-engineered airway transplantation to infants affected by diverse severe congenital laryngotracheal malformations. This article outlines the necessary basic components for regenerative medicine solutions in this potential clinical niche.

Fetal surgery: principles, indications, and evidence

Since the first human fetal surgery was reported in 1965, several different fetal surgical procedures have been developed and perfected, resulting in significantly improved outcomes for many fetuses. The currently accepted list of fetal conditions for which antenatal surgery is considered include lower urinary tract obstruction, twin-twin transfusion syndrome, myelomeningocele, congenital diaphragmatic hernia, neck masses occluding the trachea, and tumors such as congenital cystic adenomatoid malformation or sacrococcygeal teratoma when associated with developing fetal hydrops. Until recently, it has been difficult to determine the true benefits of several fetal surgeries because outcomes were reported as uncontrolled case series. However, several prospective randomized trials have been attempted and others are ongoing, supporting a more evidence-based approach to antenatal intervention. Problems that have yet to be completely overcome include the inability to identify ideal fetal candidates for antenatal intervention, to determine the optimal timing of intervention, and to prevent preterm birth after fetal surgery. Confronting a fetal abnormality raises unique and complex issues for the family. For this reason, in addition to a maternal-fetal medicine specialist experienced in prenatal diagnosis, a pediatric surgeon, an experienced operating room team including a knowledgeable anesthesiologist, and a neonatologist, the family considering fetal surgery should have access to psychosocial support and a bioethicist.

Postmortem magnetic resonance appearances of congenital high airway obstruction syndrome

BACKGROUND

Congenital high airway obstruction syndrome (CHAOS) is a rare life-threatening condition characterised by complete or near-complete developmental obstruction of the foetal airway. Although antenatal imaging findings have been described, the postmortem MRI findings have not been reported.

OBJECTIVE

To present postmortem MRI features of CHAOS.

MATERIALS AND METHODS

We retrospectively reviewed our hospital pathology and imaging databases for cases of CHAOS over a 2-year period.

RESULTS

We identified two cases of CHAOS. In both cases, postmortem plain radiographs demonstrated gross abdominal distension with distortion and splaying of the rib cage. Both foetuses had characteristic postmortem MRI findings including large-volume fluid-filled lungs on T2-weighted imaging, diaphragmatic eversion, fluid-filled airway dilatation below the level of obstruction, centrally positioned and compressed heart, and massive ascites. One foetus had an associated limb abnormality.

CONCLUSION

Postmortem MRI in foetuses suspected of having CHAOS allows confirmation of the diagnosis, determination of the anatomical level of the atresia or stenosis, and identification of associated abnormalities without the need for invasive autopsy.

Prenatal diagnosis of obstructive head and neck masses and perinatal airway management: the ex utero intrapartum treatment procedure

Advances in prenatal imaging in the last 20 years have enabled prenatal diagnosis of obstructive head and neck masses. These advances, coupled with improvements in maternal-fetal anesthesia, have made possible the development of the ex utero intrapartum treatment (EXIT) procedure for management of obstructive head and neck masses, during which the airway is managed in a controlled fashion while maintaining fetal circulation for oxygenation. This review addresses the preoperative and perioperative assessment and management of patients with prenatally diagnosed airway obstruction, indications and contraindications for the EXIT procedure, technical details of the procedure, and outcomes.