Long proximal pouch oesophageal atresia with tracheo-oesophageal fistula, a diagnostic dilemma: case report

Oesophageal atresia is a congenital abnormality commonly encountered in neonates. Classification proposed by Gross is the most frequently used. It divides the oesophageal anomalies into five types. Type C—proximal oesophageal atresia and distal tracheo-oesophageal fistula—is the most common. Dafoe and Ross described a rare subtype with a long proximal pouch. Only 11 cases of a long proximal pouch have been reported in the English literature so far. We describe a neonate with long proximal pouch oesophageal atresia with distal tracheo-oesophageal fistula emphasizing the difficulty in arriving at the diagnosis. A 1-week-old neonate presented with feed intolerance and failure to advance orogastric tube into the stomach. Water soluble upper gastrointestinal tract contrast revealed a blind ending proximal oesophagus at the level of the diaphragm. Gastric volvulus was considered as a diagnosis. Patient underwent a laparotomy where a normal stomach was found. Bubbles were seen coming from the fashioned gastrostomy with each inspiration. This prompted us to consider the possibility of a missed oesophageal atresia with distal tracheo-oesophageal fistula. Diagnosis was confirmed on bronchoscopy and right thoracotomy. The tracheo-oesophageal fistula was ligated and a cervical oesophagostomy and Stamm gastrostomy were performed due to irreparable tear in the long upper pouch. This rare subtype of long upper pouch oesophageal atresia poses a diagnostic dilemma that can result in delay in the diagnosis and management. This diagnosis should be suspected if the tip of the orogastric/feeding tube is seen to be far below the level of the carina.


Background
Oesophageal atresia is a rare condition with a frequency of 1.27-4.55 per 10,000 live births with a slight male preponderance of 1.26:1 [1]. Development of the oesophagus seems to be more complex than just the cranio-caudal separation of the foregut into respiratory and oesophageal components. Probably, the middle oesophagus not only separates from the respiratory tract but also fuses with the proximal oesophagus to complete formation of the oesophageal tube. What triggers the length of the upper pouch to vary from a short high pouch in the neck to a long pouch is unknown. Gross described five types of oesophageal atresia with type C-proximal oesophageal atresia and distal tracheo-oesophageal fistula-accounting for about 85% of the anomalies [2].
Postnatal diagnosis is confirmed by the passage of a stiff 10Fr catheter through the nose or mouth. An X-ray is then obtained with downward pressure on the tube. With oesophageal atresia, the tip of the tube is found to be curled in the blind upper pouch. Usually the upper pouch ends around the level of carina which corresponds to the second to fourth thoracic vertebral level. If the tip of the catheter passes below the level of the carina, the diagnosis of oesophageal atresia is usually questioned.

Open Access
Annals of Pediatric Surgery *Correspondence: machaea_s@yahoo.com Walter Sisulu University, Mthatha, South Africa A rare subtype of type C oesophageal atresia was first reported in 1960 [3]. In this variant, the level of the blind upper oesophageal pouch is lower than usual and leads to a diagnostic dilemma. Case reports about this rare entity have described the level of the upper pouch to end around the 6th to the 9th thoracic vertebra. This may give an impression that the tube is in the stomach and may further delay the diagnosis. Our aim is to report a newborn with the long upper pouch oesophageal atresia to emphasize the diagnostic dilemma and the rare complication of a long tear in the long upper pouch.

Case presentation
A 7-day-old newborn baby girl was referred to our centre from a base hospital 100 km away. She was born by caesarean section for foetal distress (birth weight 2.23 kg) and was admitted for respiratory distress. Intravenous antibiotics and feed were started on day 2 of life. She did not tolerate feeds, developed worsening respiratory distress and needed respiratory support. A diagnosis of oesophageal atresia was suspected due to the feed intolerance and inability to pass an orogastric tube into the stomach.
Child arrived at our centre well hydrated, intubated and ventilated with markedly decreased air entry on the right side. Her oxygen saturation was 83% on Fi02 of 90%. There were neither dysmorphic features nor cardiac murmurs on examination. Chest X-ray showed a 'white out' of the right lung with air in the gastrointestinal tract. The aspiration of the orogastric tube did not result in any gastric contents. A Replogle tube inserted and left on continuous low pressure suction (Fig. 1). Her cardiac echo was normal.
Upper gastrointestinal water soluble contrast was performed with a Replogle tube in situ (Fig. 2). It revealed a blind ending oesophagus below the diaphragm, at the level of the 11th thoracic vertebra. With the presumed diagnosis of gastric volvulus, laparotomy was planned on the eighth day of life. On laparotomy, stomach was found to be normal and in the correct position and orientation. This ruled out gastric volvulus. A gastrostomy was performed and an attempt to pass a feeding tube, in a retrograde manner, from the stomach into the distal oesophagus, failed. Bubbles could be seen coming out from the fashioned gastrostomy with each inspiration. This led us to consider the possibility of an oesophageal atresia with distal tracheo-oesophageal fistula.
Bronchoscopy demonstrated copious secretions in the airway and a tracheo-oesophageal fistula at the level of carina. Right posterolateral, muscle sparring thoracotomy through 5th intercostal space, was performed. Long proximal oesophageal pouch, with a large oesophageal tear/perforation (from thoracic inlet to distal stump), was  found. Left cervical oesophagostomy and Stamm gastrostomy were fashioned as the oesophagus was deemed irreparable (Fig. 3). Child recovered from pneumonia and was discharged on D33 of life and is awaiting oesophageal replacement.

Discussion
Oesophageal atresia is a rare condition and the rarer variants present a bigger challenge in making the correct diagnosis. The delay in the diagnosis results in malnutrition due to delayed feeding and lower respiratory tract infections due to aspiration [4]. To our knowledge, only 11 cases have been reported in the English literature so far (Table 1).
Majority of the cases have been reported from the low-to medium-income countries-mainly India. There is a slight male preponderance. With oesophageal atresia, the blind ending proximal pouch normally terminates between the second and the fourth thoracic vertebral level. In most patients with this pathology reported so far, the proximal pouch terminated at the eighth thoracic vertebral level. To our knowledge, our patient had the longest reported proximal pouch, terminating at the 11th thoracic vertebra, making the diagnosis of oesophageal atresia based on imaging, highly unlikely. The majority of patients reported so far had a primary anastomosis of the proximal and distal oesophageal pouch and recovered well. Two patients had demised due to sepsis [7] and lower respiratory tract infection preoperatively [10]. Our patient sustained an irreparable long oesophageal tear/perforation due to vigorous manipulation of the Replogle tube, a similarly uncommon occurrence in oesophageal atresia.
Whether the incidence of this rare type of oesophageal atresia is increasing, it is still to be identified. Careful assessment and preoperative imagining are essential for a successful outcome and in avoiding complications such as oesophageal injury and death [13].

Conclusion
A high index of suspicion is required to suspect and diagnose this rare anomaly as this variant has atypical findings on radiological assessment and poses a serious diagnostic dilemma. Delay in the correct diagnosis can result in morbidity and/or mortality. If diagnosed early, most of the long proximal pouch oesophageal atresia cases can have a good outcome.