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Case Reports Indian Pediatrics 2000;37: 665-667 |
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Tracheal Agenesis |
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Agenesis, aplasia or atresia of the trachea is a rare congenital anomaly that to date seems incompatible with life. Tracheal atresia is a congenital absence of a normal passage that does not imply a particular length of involvement. Tracheal atresia encompasses cases of agenesis (total absence of trachea) as well as varying lengths of tracheal mal-development(1). We describe here a case who had tracheal agenesis with anorectal mal-formation.
A female baby born at term to a primigravida by LSCS at a private Nursing Home in Delhi, weighing 1930 grams was admitted to the Referral Neonatal Unit of Lok Nayak Hospital. The baby had respiratory distress and had not cried since birth. Bag and mask ventilation was started initially and subsequently, the baby was intubated with 2.5 mm endotracheal tube and referred to us on IPPV with self inflating bag. At admission the baby was 4 hours old and was pink on room air. The perineum was bulging and anus was imperforate. In order to put an appropriate (3 mm) sized endotracheal tube, the baby was extubated. Attempted intubation was difficult. Laryngoscopy revealed absence of glottic opening. Only one opening was visualized, and was intubated. On ventilation, oxygenation improved and the baby was put on ventilator (Drager Babylog 8000) on SIMV mode. Through the same orifice, Ryle’s tube could be passed into the stomach. On the basis of these findings a diagnosis of tracheal agenesis was entertained. On withdrawing the nasogastric tube gradually, air bubbled out from the open end of the nasogastric tube kept under water surface. Fibre optic bronchoscopy revealed rudi-ments of epiglottis with no glottic opening and a single posterior opening. On advancing the bronchoscope the endotracheal tube was seen going anteriorly and Ryle’s tube posteriorly. Spiral CT thorax revealed a single passage (esophagus) containing the endotracheal tube and Ryle’s tube. Trachea was not visualized. Endotracheal tube entering the broncho-esophageal fistula which ended in bifurcation was visualized. A cut back of the anorectal malformation was performed. The baby expired at 84 hours of life. Autopsy was refused by the parents.
Tracheal agenesis is a rare malformation and a recent review identified only 87 cases reported in world literature(2). Diagnostic features include respiratory distress at birth, absent cry, failure to intubate and successful ventilation with accidental esophageal intubation. The textbook of Neonatal Rsuscitation, which is the basis of Neonatal Resuscitation training program, does not mention tracheal agenesis at all(3). Awareness of utility of esophageal intubation as a simple life saving measure in tracheal agenesis needs to be generated through modifying the neonatal resuscitation training program. The embryogenesis of tracheal agenesis is controversial. Kluth et al.(4) showed that the esophagus and trachea develop as the foregut decreases in size by infolding, without formation of a fused septum. They proposed that tracheal atresia with fistula may result from a ventral deformation of the foregut and a concomitant dorsal dislocation of the tracheo-esophageal space, which differentiates into the esophagus and from which the trachea and bronchi take their origin. Many of these cases have associated laryngeal anomalies. In 1962 Floyd et al.(5) identified 3 types of anomaly. In type 1 (10%) there is a normal carina and except for a small distal part, the whole trachea is absent. In type 2 (59%) the whole trachea is lacking but bronchi join in the midline. In type 3 (31%) both bronchi arise separately from esophagus. In 1979, Faro et al.(6) described 7 types of tracheal agenesis. Recently, at least 9 forms of tracheal atresia have been described in more than 60 reported cases(1). The most common form of the anomaly consists of agenesis of the trachea, with the 2 bronchi joined together to communicate with the esophagus(6) as in our case. This anomaly accounts for 55% of the reported cases (5,6). The next most common anomaly is the agenesis in which the bronchi do not join together but communicate with the esophagus separately, and account for 20% of cases. Varying lengths of trachea may form that communicate with the esophagus; these make up approximately 10% of the malforma-tions(5,6). Other forms of the anomaly are tracheal agenesis in which a fibrous band connects the larynx to the distal trachea or combined main bronchi(6); atresia of the proximal trachea and an intact distal trachea without esophageal fistula(6); a short segment of tracheal atresia with a normal proximal and distal trachea and no esophageal commu-nication(6); mid tracheal atresia and esophageal atresia with a blind proximal esophagus and distal tracheoesophagal fistula(7); distal tracheal atresia with a proximal tracheoesophageal fistula and a bronchoesophageal fistula(8); and total agenesis of the tracheobroncheal tree and lungs(6). Most infants with tracheal agenesis die within 24 hours of birth. Death occurs because of pneumonia from retained secretions. Associated anomalies include complex congenital heart lesions, genitourinary, gastro-intestinal, pulmonary, central nervous system and musculoskeletal anomalies. Long term survival with corrective surgery has been achieved in 3 children with very short tracheal atresia(7,8). Correction of long length tracheal atresia requires some form of conduit that would be flexible with bending of the neck yet rigid enough to maintain a wide open airway. The airway must be lined by ciliated epithelium that would convey mucoid secretions to the level of the larynx or a tracheostomy. No such artificial conduit has thus far been possible(1).
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