Tracheal agenesis: A report of two cases.

Tracheal agenesis is an extremely rare congenital anomaly involving the respiratory system. It is generally associated with anomalies of other systems. Antenatal diagnosis of this condition is difficult; therefore, it presents as a medical emergency in the labor room. Intubation in these babies is difficult. As many of these babies are born prematurely, respiratory distress syndrome (RDS) adds to the management difficulties. Here, we describe two babies with this lethal anomaly and RDS where esophageal intubation and surfactant therapy proved beneficial. Furthermore, described are other associated anomalies.

Introduction

Tracheal agenesis (TA) is a rare congenital anomaly presenting at birth with respiratory distress and difficult airway management. These pregnancies are associated with polyhydramnios and premature labor, which further complicates the management. The incidence of TA is 1:50,000 live births with male: female ratio of 2:1. So far, approximately 150 cases have been described in literature very few survivals.[1] It was first described in literature by Payne in 1900[2] and further classified by Floyd et al.[3] TA is often associated with other organ system anomalies. TA has been associated with vertebral, anal, cardiovascular, tracheo-esophageal, renal and limb anomalies as in (VACTERL; or with cardiac, renal anomalies and duodenal atresia as in TACRD.[4] There is some evidence to suggest that inactivating mutations of BMP Type 1 receptors may have a role to play in its etiology.[5]

We describe here two cases of TA presenting to our Neonatal Intensive Care Unit (NICU).

Case Reports

Case 1

A male baby was born to a 25-year-old mother at 30 weeks of gestation. The mother had presented in emergency with preterm labor and her antenatal ultrasonography (US) done at 26 weeks was suggestive of polyhydramnios. The baby was delivered vaginally and weighed 1.2 kg. As the baby did not cry immediately, endotracheal intubation was attempted to secure the airway but the vocal cords could not be visualized and there was a single opening corresponding to the esophagus. Resuscitation was hence continued with bag and mask ventilation and baby was shifted to the NICU where a second attempt was made to intubate which failed again. As the baby's condition worsened, the endotracheal tube was passed in the visualized opening, after which the saturations improved. In view of X-ray chest [Figure 1], suggestive of severe respiratory distress syndrome (RDS), natural bovine surfactant with 100 mg/kg of phospholipids was given through the “endotracheal tube,” which showed improvement suggesting that a connection existed between the esophagus and trachea. On invasive ventilation with high-pressure support and 100% FiO2, the saturations were maintained at 85%. The baby also had an imperforate anus, a structurally normal heart on echocardiography, and normal abdominal US. Because of the critical condition of the baby, computed tomography (CT) was not attempted but a water-soluble dye was instilled through the endotracheal tube which showed the esophageal tracheal connection [Figure 2]. The baby further got complicated with a developing pneumoperitoneum, which was drained, but the baby died at 48 h of life.

Figure 1

Evidence of respiratory distress syndrome

Figure 2

Post surfactant and dye study

Case 2

A male baby was born to 32-year-old G3L1A1 mother at 28-week gestation with a birth weight of 930 g. As the baby did not cry at birth, resuscitation with bag and tube was attempted. Failing to visualize the vocal cords, the esophagus was promptly intubated and the baby was gently ventilated before being put on invasive ventilation. RDS evident on X-ray [Figure 3] was treated by giving natural bovine surfactant resulting in X-ray improvement and improvement in saturations. The baby also had an imperforate anus, a patent ductus arteriosus of 2 mm with a structurally normal heart and a solitary right-sided kidney. The baby continued to do well on gentle invasive ventilation, maintaining saturations above 90%. A colostomy was performed on the baby. Although CT could not be done, the dye study delineated the anatomic defect [Figure 4]. Considering the complex nature of the problems and the interventions there on, parents refused to continue further management. The baby succumbed to an evolving pneumonia on day 8 of life.

Figure 3

Respiratory distress syndrome

Figure 4

Dye study showing the anatomical defect

Discussion

TA is a very rare congenital anomaly and antenatal diagnosis of this defect is difficult. In the absence of tracheoesophageal fistula (TOF), it can be suspected as a congenital high airway obstruction syndrome.[6] Definite diagnosis is made on magnetic resonance imaging. Evidence of polyhydramnios with other congenital anomalies along with TOF may be suggestive of possible tracheal anomalies. Postnatal diagnosis is based on specific findings of a severe respiratory distress with no air entry, no audible cry, and difficult intubation.

The severity of TA could be varied and Floyd's classification is widely accepted. It classifies TA into three types: Type 1 - where the distal trachea is connected to the esophagus by a fistula; Type 2 - where the carina is connected to the esophagus by a fistula; and Type 3 - where the two main bronchi arise from the esophagus. The incidence has been 11%, 61%, and 23%, respectively. Both our babies were classified as Type 3 by Floyd's classification. These babies also had an imperforate anus and case 2 also had a solitary right kidney. Thus this series of cases show that TA can be an association of cases of VACTERAL as described previously. We did not find any cardiac or limb anomalies in our cases.

Wilful esophageal intubation can be lifesaving in these babies. As many of these babies are born prematurely, RDS is a major concern besides the anatomical defect and can be a cause of mortality and morbidity by itself. Esophageal intubation not only establishes ventilation but also helps give surfactant, as was given in our cases, and thus help in treating RDS. Although CT is the best modality to delineate the defect postnatally, in settings of its nonavailability or difficulty in transporting the baby, a contrast X-ray with a water-soluble dye can be used to establish the diagnosis and delineate the anatomical defect. Gentle ventilation seems to be the key in managing these patients as our second case survived well till the 1st week of life, giving hope for a long-term survival in these patients which has been rarely reported.[7] Surgical palliation with distal esophageal ligation and gastrostomy has been tried and a novel three-stage surgery for the surviving patients has been attempted.[8] Optimizing postnatal care and planned surgical repair in stages could improve the outcome in this near fatal anomaly.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.