Esophageal atresia type C with overlapping long upper pouch: A rare variant

Highlights • A long upper esophageal pouch extending below T4 level is a rare finding in Esophageal atresia.• This type of esophageal atresia creates confusion on the traditional NG tube and x-ray test, leading to diagnostic dilemma.• The surgery is technically simpler in this variant with good outcome.• Any baby in which the NG tube does not extend below the diaphragm should be considered to have EA until proven otherwise.


Background
Esophageal atresia (EA) is the most common anomaly of the esophagus. There are 5 major types as described by Gross [1]. Type C esophageal atresia with distal fistula (TEF) is by far the most common type accounting for 80% [2]. It is easy to diagnose by resistance to passing a 10Fr orogastric tube [3]. Characteristically the upper segment ends at the level above the tracheal bifurcation (T4) [2]. Radiographs showing the tube coiled around this site confirm the diagnosis [4].
There is a very rare subtype of type-C EA first reported in 1960 [45]. In this variant the level of the upper esophageal pouch is lower than usual, sometimes reaching as far down as the diaphragm [4]. This causes a diagnostic confusion as the traditional feeding tube test gives the false impression of lying in the stomach [3]. Esophagogram can also be mistaken for esophageal stenosis [6]. Some mandate esophagoscopy and bronchoscopy in such cases [4,7]. Still others have failed to diagnose with bronchoscopy, which led them to perform a gastrostomy with retrograde esophagography [6].
There are only a handful of case reports entailing this rare phenomenon worldwide. We recently came across a similar case in our institution causing a diagnostic dilemma. The surgery was delayed to the 22nd day of life with a surprisingly good outcome. Herein we describe our encounter and discuss relevant literature on the subject. The work has been reported in line with the SCARE criteria [8].

Case presentation
A female neonate was referred to our center from the rural parts of Ethiopia. The mother had an uneventful antenatal followup and no abnormality was detected on ultrasound. The child was born term by spontaneous vaginal delivery. Subsequently she went home and was being breastfed when the mother noticed excessive salivation and vomiting after feeding.
The mother took her to a local hospital where the child was admitted in the NICU for 2 weeks for the treatment of sepsis. She was kept NPO, put on intranasal oxygen, maintenance fluid and intravenous antibiotics. However, the respiratory distress and excessive salivation persisted. Referring physicians reported that feeding tube was able to pass down and the x-ray of the child was normal. They had attempted trophic feeding through the NG tube but the child persisted to have vomiting. Finally, she was referred to our center with a suspicion of Type E EA (tracheoesophageal fistula without esophageal atresia) on the 16th day of life.
On presentation at our center, the child had excessive secretions coming out of the mouth and nose. She had some respiratory distress requiring intranasal oxygen but the other vital signs were   stable. Auscultation of the chest revealed crepitations on the right lung, otherwise there was no cardiac murmur. An 8 French NG tube was able to pass more than 20 cm before it met resistance. X-ray taken showed tip of the feeding tube at T8 level. There was also consolidation of the right upper lobe and gas in the stomach (Fig. 1).
Thereafter a barium swallow study was obtained which demonstrated a long dilated upper esophageal pouch reaching the lower chest (Fig. 2). Surgery was planned with the impression of type C TEF with long upper esophageal pouch. The procedure was delayed by 1 week from the child's arrival to our center due to resource constraints in obtaining contrast study as well as operating table.
The child was operated onthe 22nd day of life by pediatric surgery fellows supervised by attendings. Bronchoscopy was not performed as it is not routinely practiced during EA surgery in our setting. The child was put in left lateral position after administration of general anesthesia. A right thoracotomy was performed through the 5th intercostal space and thoracic cavity entered through a muscle sparing approach. We found the upper esophageal pouch redundant, overlapping the distal fistula (Fig. 3). After ligating the fistula, end-to end esophageal anastomosis performed without resecting part of the proximal esophagus.
Postoperatively the child didn't require mechanical ventilation. She had developed postoperative pneumonia requiring  intravenous antibiotics and hospital stay of 2 weeks. However, anastomosis healed well and she tolerated full oral feeds. She was finally discharged in excellent condition.

Discussion and conclusion
Delays diagnosis of tracheoesophageal fistula is a common problem in developing countries, mostly reported from India. It is associated with higher mortality due to malnutrition and pneumonitis [9]. Thus far, there is only 1 report of a survivor operated after the 3rd week (21 days) of life. Gupta reported a surgery delayed to 26th day of life because of delayed presentation to hospital after a home delivery [10]. The case from our report was delayed to the 22nd day of life due to an unusual variant creating a diagnostic dilemma.
Why the upper pouch is markedly elongated in this rare variant is unknown [7]. Older reports have assumed transitory mechanical impingement during aortic development to result in such anomalies [2]. Others suspect it occurs due to the elastic recoil of the dilated upper pouch [4]. We also speculate whether the enlargement was a postnatal occurrence as postulated by John Foker [11]. The late presentation with continued distension of the esophagus could have contributed in our case. However, our review suggests that this is a primary condition as most were diagnosed much earlier (Table 1).
From our literature review we found only 9 previous reports describing this anomaly ( Table 1). Half of the reports were from India. Sex distribution is equal. Most diagnostic delays were for a few days, except for this report. Most reported the coiling of feeding tube >18−20 cm from the lower lip. The level of the upper esophageal pouch on x-ray was around T8 in most of the cases.
Intraoperatively, there was no gap between the esophageal ends as long proximal esophagus overlapped with the distal one. As such, the surgery was described as being simple by most. After division of the fistula, different approaches were used to anastomose esophagus. These included side to side anastomosis and end to end anastomosis with or without resection of proximal redundant esophagus. Except for 2 children, all had favorable outcomes.
In conclusion, physicians need to be aware of this rare variant of EA -TEF with an unusual presentation. Having a high index of suspicion will avoid delays in diagnosis and management. Overall, reported cases show a good survival. Our child was extremely fortunate as she survived her condition even with extremely delayed intervention.

Declaration of Competing Interest
We declare that there is no conflict of interests.

Funding
This study did not receive funding.

Ethical approval
Exemption from ethical approval was obtained from the department of surgery ethics and research committee at Addis Ababa University college of health sciences.

Consent
Written informed consent was obtained from the patient's parent/guardian for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Author contribution
SN and HW collected the data and drafted the manuscript. HGW was involved in the conception of the case report and supervised other authors. All authors read and approved the final manuscript.