Congenital high airway obstruction syndrome successfully managed with ex-utero intrapartum treatment

Congenital High Airway Obstructive Syndrome (CHAOS) Survival of a Newborn with Laryngeal Atresia

Congenital high airway obstructive syndrome (CHAOS) is a rare congenital anomaly, frequently caused by laryngeal or tracheal atresia, tracheal stenosis, and obstructing laryngeal cysts. This is a congenital malformation, often fatal, with an unknown prevalence. Laryngeal atresia is the most frequent cause. We report a case of an intrauterine diagnosis of CHAOS and ascites in a 17-week fetus delivered at 38 weeks of gestation without other associated malformations. A fetoscopic procedure was performed at 22 weeks of gestation. An attempt was made to perforate the affected area to ensure pulmonary fluid circulation and the ascites' resolution. After birth, a tracheostomy was performed. The patient was mechanically ventilated until 11 months of age, when she was discharged with no cerebral or other complications of immediate postnatal anoxia or episodes of respiratory arrest. A laryngotracheoplasty was performed at 2 years old, but decannulation was not possible due to certain complications. At 5 years old, a new surgical intervention was performed, which allowed decannulation 6 months later.

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.

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.

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.

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.

A rare form of congenital high airway obstruction syndrome and a literature review of ex utero intrapartum treatment

Objective

This is a rare presentation of a fetus with a right mainstem bronchus occlusion leading to congenital high airway obstruction syndrome (CHAOS).

Methods

A review of 15 articles reporting on the use of the ex utero intrapartum treatment (EXIT) procedure.

Results

A total of 22 reported cases of CHAOS had undergone the EXIT procedure from 1994 to 2016. Seventy-seven percent of fetuses that underwent EXIT were alive at the last point of follow-up, but only 36% were alive without any sequelae.

Conclusion

CHAOS is a rare malformation, but after the development of EXIT, survival is a viable option. It is associated with other malformations, but its etiology is entirely unknown.

A Series of Congenital High Airway Obstruction Syndrome - Classic Imaging Findings

Congenital high airway obstruction syndrome (CHAOS) is a very rare entity with very poor prognosis in which upper airway is intrinsically obstructed, the most common reason being laryngeal atresia. In summary prenatal early diagnosis of patients with CHAOS is necessary so that perinatal management can be undertaken successfully or elective termination of pregnancy can be undertaken. The fetoscopic approach may be a life saving modality in a subset of CHAOS patients. Involving a multidisciplinary team comprising of paediatricians, radiologists, obstetricians and anaesthesiologists increases the efficiency of management.

Experimental Evaluation of Tracheo-Amniotic Shunting for Induced Congenital High Airway Obstruction in a Sheep Model

Objective: To evaluate the feasibility of tracheo-amniotic shunting in a sheep model for congenital high airway obstruction syndrome. Material and Methods: High airway obstruction was induced around day 95 (term = 145 days) in 10 lamb fetuses by tracheal clipping. Five days later, ultrasound-guided tracheoamniotic shunting was done using either the Harrison double-pigtail bladder stent (HS) or a double-basket device (BS). Caesarean section (CS) was done around day 110. At each time point, the cardiothoracic index (CTI) was measured. Lung-to-body weight ratio (LBWR) was calculated at fetal necropsy. The primary endpoint was successful shunting defined as anatomically correct placement and functional airway decompression; the secondary endpoint was survival until CS. Results: Two sheep aborted 3 fetuses after tracheal occlusion. Overall, the median CTI at CS was significantly smaller compared to baseline [0.52 (interquartile range, IQR: 0.52-0.54) vs. 0.58 (IQR: 0.54-0.63); p = 0.01]. In the HS group (n = 4), none of the shunts were correctly positioned. In the BS group (n = 3), there was 1 correct shunt placement; however, this fetus was stillborn. Median LBWR suggested pulmonary overgrowth [0.10 (IQR: 0.08-0.11)]. Conclusion: In our hands, using this model with a long and mobile neck and relative oligohydramnios, tracheoamniotic shunting for airway obstruction has a high failure rate. If further pursued, alternative techniques or different models should be considered.

Prenatal Diagnosis and Patient Preferences in Patients with Neural Tube Defects around the Advent of Fetal Surgery in Belgium and Holland

Introduction: We review the characteristics and prenatal choices of patients recently evaluated for neural tube defects (NTD) at two tertiary units. The prenatal diagnosis of NTD allows parents to consider all prenatal options. In selected cases of spina bifida aperta this also includes fetal surgery, which we started offering after combined ‘in-house' and ‘exported' training. Material and Methods: This is a retrospective review of prospectively collected data on NTD diagnosed over the last 8 years and recent fetal surgery referrals. Results: A total of 167 patients were referred for assessment at a median of 19 weeks. Cranial lesions were diagnosed significantly earlier than spinal lesions. Of the open spinal lesions, 77% were isolated. Of these, 22% were managed expectantly and 1 (1%) had fetal surgery. There was no correlation between parental decisions on prenatal management with disease-specific severity markers. We had 14 fetal surgery referrals, all but 1 from beyond our typical referral area; 6 of the assessed patients were operated on, 4 were expectantly managed and 4 requested termination of pregnancy (TOP). These pregnancy outcomes were in the expected range. Discussion: Open spina bifida is mainly diagnosed in the second trimester and 76% of subjects request TOP, irrespective of the severity indicators. The number of local patients considering fetal surgery is low.

Ex utero intrapartum treatment procedure for management of congenital high airway obstruction syndrome in a vertex/breech twin gestation

Congenital high airway obstruction syndrome (CHAOS) is one indication for the ex utero intrapartum treatment (EXIT), which is used to secure the fetal airway, while fetal oxygenation is maintained by uteroplacental circulation. We report a successful EXIT procedure in a twin gestation in which one child had CHAOS while the other was a healthy child without any congenital abnormalities. After version of Twin B to allow for delivery of Twin A, Twin B underwent airway evaluation and tracheostomy for laryngeal atresia prior to delivery.

Ultrasound evaluation of congenital cervical teratoma and therapeutic management (ex utero intrapartum treatment)

The ultrasound evaluation of the fetal neck has a high importance as a key point of the airway and digestive tract. We report the case of a fetus diagnosed with a cervical teratoma by ultrasound, which generated a compressive effect on airway, requiring a surgical approach EXIT (ex utero intrapartum treatment) to ensure the extrauterine viability.

Prenatal diagnosis and outcome of echogenic fetal lung lesions

OBJECTIVE

To describe the antenatal findings and outcome of fetuses with echogenic lung lesions.

METHODS

This was a retrospective study of the prenatal sonographic features, antenatal management and outcome of 193 fetuses with an echogenic lung lesion diagnosed at 18-35 weeks of gestation. There were nine cases of congenital high airway obstruction syndrome (CHAOS), 170 cases of cystic adenomatoid malformation (CAM) and 14 cases of pulmonary sequestration (PS). A literature search was also carried out to compare our data with those of previous series.

RESULTS

The prognosis in our series of fetuses with CHAOS was invariably poor, but the literature describes a handful of survivors after delivery by Cesarean section and ex-utero intrapartum therapy (EXIT). Of the cases in our series with PS and no pleural effusions, more than 95% survived; in half of these cases the lesion resolved antenatally and in the other half sequestrectomy was carried out postnatally. In cases with PS and pleural effusions, successful treatment was provided by the placement of thoracoamniotic shunts or occlusion of the feeding blood vessel by ultrasound-guided laser coagulation or injection of sclerosants. In cases with CAM and no hydrops, there was more than 95% survival and in up to half of the cases there was sonographic evidence of spontaneous antenatal resolution of the hyperechogenic lesion, which was confirmed by postnatal imaging in about 60% of the cases. Of the cases with CAM with hydrops managed expectantly, more than 95% died before or after birth. Of the cases with macrocystic CAM with hydrops, two-thirds survived after placement of a thoracoamniotic shunt. In cases with microcystic CAM with hydrops, there is some evidence that open fetal surgery with lobectomy could improve survival but such treatment is highly invasive for the mother.

CONCLUSIONS

CHAOS is a severe abnormality, whereas CAM and PS are associated with a good prognosis. In a high proportion of fetuses with hyperechogenic lung lesion, there is spontaneous antenatal resolution and the underlying pathology may be transient bronchial obstruction.

Congenital laryngeal atresia associated with esophageal atresia and tracheoesophageal fistula: a case of long-term survival

Congenital laryngeal atresia (LA) is a life-threatening anomaly in which appropriate perinatal management is essential for survival. The authors report a neonate with LA associated with esophageal atresia (EA) and tracheoesophageal fistula (TEF) who was successfully resuscitated by emergent tracheostomy. Before birth, the patient had a diagnosis of EA based on the findings of polyhydramnios and absent stomach bubble. Immediately after birth, severe respiratory distress, cyanosis, and sternal retraction were evident. Because either endotracheal or esophageal intubation was unsuccessful, an emergent tracheostomy was performed. A direct laryngoscope revealed a subglottic atresia with normal appearance of the vocal cords. Repair of EA with TEF was performed on the third day of life, and the postoperative course was uneventful. In 2 years follow-up, the patient has no mental retardation nor central nervous impairment. Because of the presence of TEF, the antenatal ultrasonogram did not demonstrate the characteristic findings of the congenital high airway obstruction syndrome. This case represents one of the very few reported cases of successful resuscitation of a neonate with an unanticipated LA in which emergent airway management is required immediately after birth.

Current consequences of prenatal diagnosis of congenital diaphragmatic hernia

BACKGROUND

Today, the diagnosis of congenital diaphragmatic hernia (CDH) can readily be made in the prenatal period during screening ultrasound examination. Patients ought to be referred to rule out associated anomalies, and in isolated cases, prognosis is poor when the liver is intrathoracic and the lung-to-head ratio (LHR) is less than 1. In these patients, prenatal intervention aiming to reverse pulmonary hypoplasia can be considered.

METHODS

We present our current algorithm for counselling patients presenting with CDH. Patients with a poor prognosis are offered percutaneous fetal endoluminal tracheal occlusion (FETO) with a balloon, inserted at 26 to 28 weeks. We report on the evolution of technique and results in a consecutive homogeneous case series and compare outcome in cases with similar severity managed in the postnatal period.

RESULTS

Within a period of 28 months, FETO was performed between 26 and 28 weeks in 24 fetuses with severe left-sided CDH. Under general (n = 5), epidural (n = 17) or local (n = 2) anesthesia, the balloon was successfully positioned at first surgery (23/24) with a mean operation time of 20 minutes (range, 3-60 minutes). There were no serious maternal complications or direct fetal adverse effects. In the first 2 weeks after FETO, LHR increased from 0.7 to 1.7. Premature prelabour rupture of the membrane (PPROM) occurred in 16.7% and 33.3% at 28 and 32 weeks or earlier, respectively. Gestational age at delivery was 33.5 weeks. Patency of airways was restored either in the prenatal (n = 12) or perinatal period (n = 12). Early (7 days) and late (28 days) survival, and survival at discharge were 75% (18/24), 58.3% (14/24) and 50% (12/24), respectively. Half of nonsurvivors (n = 6) died of pulmonary hypoplasia and hypertension, in combination with PPROM and preterm delivery (n = 4) and balloon dislodgement (n = 2), which coincided with a short tracheal occlusion (TO) period (12 days). In the other 6, TO period was comparable to that in the 12 survivors (47 vs 42 days, respectively). In that group of 6 babies, only 2 died of pulmonary problems. Late neonatal survival (28 days) was higher with prenatal vs perinatal balloon retrieval 83.3% vs 33.3% (P = .013). In a multicentre study validating the criteria, survival till discharge in 37 comparable cases was 9% (3/32) and 13% (5/37) of parents opted for termination.

CONCLUSION

Fetuses with isolated left-sided CDH, liver herniation, and LHR of less than 1 have a poor prognosis. Percutaneous FETO is minimally invasive and may improve the outcome in these highly selected cases. Airways can be restored before birth, allowing vaginal delivery and return to the referring tertiary unit and may improve survival rate. The procedure carries a risk for PPROM, although that may decrease with experience.

Fetoscopic and ultrasound-guided decompression of the fetal trachea in a human fetus with Fraser syndrome and congenital high airway obstruction syndrome (CHAOS) from laryngeal atresia

Congenital high airway obstruction syndrome (CHAOS) from laryngeal atresia bears a poor prognosis for hydropic fetuses owing to cardiac failure. We attempted percutaneous fetoscopic and ultrasound-guided tracheal decompression in a hydropic human fetus with CHAOS associated with Fraser syndrome. Percutaneous fetoscopic and ultrasound-guided tracheal decompression was performed using three trocars under general materno-fetal anesthesia at 19 + 5 weeks of gestation. Abnormal fetoplacental blood flow normalized within hours as a result of the intervention. Furthermore, a normalization of lung : heart size and lung echogenicity was observed within days. Resolution of hydrops was complete within 3 weeks. Premature rupture of membranes and premature contractions prompted emergency delivery of the fetus by ex-utero intrapartum treatment (EXIT) at 28 + 2 weeks of gestation. Following delivery, the lungs could be ventilated at low pressures and ambient oxygen concentration. Weaning from ventilation was achieved at 18 days of postnatal life. Our experience indicated that percutaneous fetoscopic and ultrasound-guided decompression of the fetal trachea is feasible and may permit normalization of hemodynamics in hydropic human fetuses with CHAOS from laryngeal atresia. The procedure may also result in normalization of heart : lung size and provide the time needed to regain the function of the overstretched diaphragm in this grave fetal condition.

Fetoscopic surgery: where are we today?

PURPOSE OF REVIEW

Since the early 1990s, advances in endoscopic equipment and the commercial availability of micro-catheters, mini-balloons, tiny laser fibers and other ingenious tools have set the trend toward the development of minimally invasive fetoscopic surgical techniques for the treatment of some congenital malformations that progress in severity over the course of gestation and may destroy entire organ systems of the unborn. The purpose of this review is to provide a state-of-the-art overview of these new procedures for the anesthesiologist.

RECENT FINDINGS

Procedures like diagnostic fetoscopies, laser coagulation of inter-twin placental vascular connections in twin-twin transfusion syndrome, fetal tracheal balloon occlusion in diaphragmatic hernia, laser perforation of posterior urethral valves, vocal cord division in congenital high-airway obstruction syndrome and most recently even coverage of spina bifida aperta can be performed entirely percutaneously using minimally invasive fetoscopic techniques. Careful selection of anesthetic methods and intensive maternal monitoring by the anesthesiology team are paramount to the success of these procedures, particularly in hemodynamically unstable fetuses or procedures that employ gas insufflation of the amniotic cavity.

SUMMARY

An increasing spectrum of congenital malformations can be treated by fetoscopic surgery. Compared to open fetal surgery, fetoscopic surgery results in significantly less maternal trauma. Like the open procedures, the efficacy of the fetoscopic procedures to improve fetal outcome over postnatal treatment strategies will have to be assessed in further studies under close supervision of committees for human research.