The challenging airway: Tracheal agenesis in the newborn

1 Introduction

Tracheal agenesis (TA) is a rare congenital airway malformation that is often incompatible with life [1]. Newborns with TA present specific challenges with initial airway placement, ventilation, and oxygenation [1, 2]. Additional congenital malformations of the cardiac, gastrointestinal, and genitourinary systems are also frequently present [3, 4].

There are several types of TA, first described by Floyd et al as three distinct anatomic classifications varying by severity [5]. Faro et al expanded those classifications to include seven subtypes [6]. Here we report a case of type II tracheal agenesis. The newborn underwent tracheal reconstruction that was ultimately unsuccessful.

2 Case report

An 1800 gram premature female was born at 32 weeks’ gestation to a G7P2234 mother by emergent Cesarean section secondary to preterm premature rupture of membranes and a non-reassuring fetal heart rate pattern. The pregnancy had been complicated by polyhydramnios, gestational diabetes, rheumatoid arthritis, and lymphocytic colitis. Maternal serologic tests were unremarkable. Prenatal ultrasonography was significant for a left-sided superior vena cava (SVC), dilated coronary sinus without a ventricular septal defect (VSD), but no other obvious malformations.

At delivery, Apgar scores were 2, 6, and 6 at one, five, and ten minutes, respectively. The infant was cyanotic, hypotonic with no respiratory effort, and bradycardic. Positive pressure ventilation was immediately initiated with resolving bradycardia, and spontaneous breaths were noted around 4 minutes. Despite being placed on continuous positive airway pressure (CPAP), she had significant suprasternal and subcostal retractions with ongoing hypoxia and a decision was made to intubate. Three providers (a neonatologist and two anesthesiologists) were unable to pass an endotracheal tube (ETT) beyond the vocal cords. A laryngeal mask airway was placed, but the infant continued to be hypoxic and was manually mask ventilated and taken to the operating room for emergent bronchoscopy.

She was found to have nearly complete agenesis of the trachea and a tracheoesophageal fistula (TEF) was identified. A stoma was created in the cervical esophagus for ventilation, and the proximal cervical esophagus was ligated to create a diversionary cervical esophagostomy for salivary drainage. An esophagogastric disconnection, open gastrojejunostomy tube placement, and pyloromyotomy were also performed. Additionally, on initial examination she was found to have an anorectal malformation with perineal fistula, and an evaluation for the VACTERL association did not show any vertebral, renal, or limb anomalies.

Over the next several days she continued to stru-ggle with hypoxemia, respiratory acidosis, and hypercarbia despite implementation of high frequency jet ventilation. There were concerns for a tethered spinal cord, and an echocardiogram showed an atrial septal defect (ASD), a large patent ductus arteriosus (PDA), and bilateral SVCs with a variant left SVC connected to a dilated coronary sinus. A computed tomographic scan of the chest (Fig. 1) demonstrated a small anterior TEF that branched from a short trachea/carina and connected to two main bronchi. The infant underwent tracheal reconstruction consisting of repair of her stenotic TEF and splint placement on day eight. She was found to have a 1.2 mm TEF and tracheal agenesis to the level of the carina. An extensive tracheal reconstruction was performed. Though she tolerated the procedure, she became acutely hypotensive, hypoxemic, and difficult to ventilate when removed from bypass. She subsequently had a cardiac arrest and was urgently placed on veno-arterial extracorporeal membrane oxygenation (ECMO). She continued to struggle with hypotension and hypercarbia and was found to have significant bilateral intraparenchymal cerebral hemorrhages. The infant’s family agreed to redirection of care, and she expired on day nine. The family declined permission for a postmortem examination.

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Fig. 1

Left: CT chest demonstrating a small anterior TEF which communicates with a very short trachea/carina connecting the two main bronchi. Center: CT chest in 3D rendition demonstrating the anatomy in the left picture. Right: Lateral image from preoperative CT chest demonstrating a tracheotomy tube in position into the esophagus with the atretic trachea and TEF.

Tracheal agenesis is a rare congenital airway malformation that occurs in about 1 in 50,000 to 1 in 100,000 live births and occurs twice as frequently in males [1, 2]. It develops within the first 7 weeks of gestation during the embryonic phase of fetal development and results from delayed lung bud outgrowth as well as delayed tracheal, bronchi, and lung formation from the laryngotracheal groove [7]. Early prenatal findings of TA include polyhydramnios, bilaterally enlarged echogenic lungs (secondary to intrapulmonary fluid retention), flattened diaphragms, and ascites [8]. After birth, infants present with severe respiratory distress with cyanosis, apnea, dyspnea, and hypoxia [3].

There are three main anatomic classifications of TA [5]. Type I (20%) is characterized by agenesis of the proximal trachea, a normal bronchus, and the presence of a TEF [1, 8]. Type II (60%) involves TA, a normal bronchus, and a communication between the esophagus and carina before it bifurcates [1, 8]. Type III (20%) consists of TA with bronchi originating from the distal part of esophagus [1, 8]. In this case, the newborn met criteria for type II with a small anterior TEF that branched from a short trachea/carina and connected to two main bronchi. In this type, endotracheal tube insertion into the tracheoesophageal fistula and airway maintenance is more challenging [9]. Though there are several strategies to address TA ventilation and tracheal reconstruction, there are still only a few documented survivors.

The timing of repair varies, as there is a wide spectrum of TA types. Individual risk factors such as birthweight and gestational age must also be considered. Tracheal reconstruction can be managed in three different ways. The first is conservative management with follow-up imaging and bronchoscopy; the second is direct insertion of an endotracheal tube into the fistula to optimize ventilation; the third is external stent placement after resection of the stenotic area and anastomosis [9]. In this case, the third option was used. Park et al described a similar case of a premature infant who underwent stenting of his TEF [10]. However, in both cases there was continued respiratory failure secondary to a narrowed TEF. Additionally, our patient underwent a brief course of ECMO, which poses its own unique set of medical and ethical dilemmas in bridging patients to further tracheal reconstruction.

4 Conclusion

TA is a rare congenital airway malformation with type II being the most common. Mortality remains high among all types despite advances in surgical techniques. Additional research aimed at ventilation strategies and growth management in premature infants with TA might provide more insight for future tracheal reconstruction.

Conflict of interests

The authors report no conflicts of interest.

Grant information

The authors received no specific funding for this work.