Newly discovered variant of oesophageal atresia: ‘Type Y’

Abstract

Multiple variations of oesophageal atresia (OA) have been described. We present two cases of a new variant of OA (‘Type Y’) where the fistula enters the trachea in a Y-shaped configuration. Awareness of this is important. Bronchoscopy will reveal a single fistula opening and therefore there will initially be no suspicion of anatomical variation. It may be that only one bifurcation of the ‘Y’ fistula is patent which poses a risk of incomplete fistula closure.

Background

The incidence of oesophageal atresia (OA) and/or tracheo-oesophageal fistula (TOF) ranges from 1 in 2500 to 1 in 3000.¹ The Gross classification and previous Ladd and Vogt classifications are well defined (figure 1). We describe a new variant of oesophageal atresia with distal fistula (‘Type Y’). Awareness of this variant reduces the risk of incomplete fistula closure.

Figure 1.

Vogt, Ladd and Gross classifications of oesophageal atresia and/or tracheo-oesophageal fistula.

Case presentation

We present two cases of OA with a new variant TOF (‘Type Y’).

The first case was a male infant born at 42 weeks by emergency caesarean section at his local hospital due to failure to progress. There was a history of premature rupture of membranes for 48 hours. Antenatal history and scans were unremarkable. Birth weight was 3.64 kg. He was born in good condition with Apgar scores of 8, 10 and 10 at 1, 5 and 10 min, respectively. At 14 hours of age, he developed tachypnoea (respiratory rate of 90–100), tachycardia (heart rate 180 bpm) and saturations of 90% in air. Auscultation of the chest revealed poor air entry and crackles bilaterally.

The baby was transferred to the neonatal unit where he was initially screened and treated for suspected sepsis. Blood gas showed a respiratory acidosis with a lactate of 4.7. A nasogastric (NG) tube was unable to be advanced beyond 10 cm. Chest and abdominal radiographs were taken confirming the NG tube was coiled at the level of T2/T3 with air visualised in the stomach and small bowel. OA with distal TOF was diagnosed. A replogle tube was sited and placed on continuous suction. Blood tests including a full blood count, coagulation screen, urea and electrolytes were normal. Echocardiogram was normal.

On day 1 of life, the baby proceeded to surgery. Under general anaesthesia, a flexible bronchoscopy was performed first. This confirmed one fistula in the mid trachea. The operation was performed via a right thoracotomy (extrapleural approach). The distal pouch and fistula were identified above the azygous vein. The distal fistula was transfixed at the base with 5–0 polydioxanone (PDS) sutures and ligated. The upper pouch was then identified and mobilisation commenced; however, a further portion of the fistula was found to enter the trachea superiorly in a ‘Y-shaped’ configuration connecting with the previously identified distal fistula (figure 2). The superior portion of this fistula was also transfixed with 5–0 PDS and ligated. Following dissection, the gap between the upper and lower oesophageal pouches was approximately one vertebral body. Oesophageal anastomosis was completed with 4–0 vicryl interrupted sutures with a size 6fr transanastmotic tube (TAT) left in situ.

Figure 2.

Original illustration of ‘Type Y’ oesophageal atresia. Blue arrow shows fistula entering in ‘Y-configuration’.

On day 1 postoperatively, the baby developed a right pneumothorax. This did not require any intervention and resolved completely on chest X-ray by day 7. The baby was extubated day 2 postoperatively. Feeds were commenced at 10 mL/kg/day via TAT from day 2 postoperatively and gradually increased. Full feeds were established on day 4 via TAT. Oral feeds were commenced on day 5, and the TAT was removed. The baby was discharged day 8 postoperatively.

The second case, presenting 17 months later, was a female infant born at 38+5 weeks via vaginal delivery with a birth weight of 3.2 kg. Antenatal investigations were normal. The baby was discharged home 6 hours following delivery. She then presented to the local emergency department on day 1 of life due to cyanotic episodes and respiratory distress. An NG tube was unable to be advanced beyond 10 cm and a diagnosis of OA with distal TOF was made. The patient was referred to the paediatric surgical team at a nearby hospital and transferred. On day 2 of life, the patient proceeded to surgery. Flexible bronchoscopy revealed normal vocal cords, proximal posterior trachealis prolapse with dynamic collapse and the fistula was identified in the mid trachea. A posterolateral thoracotomy via an extrapleural approach was performed. The fistula was also identified entering via a ‘Y-shaped’ configuration (figure 2), and in this case only the distal portion of this fistula was patent. The fistula was transfixed with 5–0 prolene and ligated. After mobilisation, the gap between the upper and lower oesophageal pouches was 2 cm. Oesophageal anastomosis was completed with 6–0 PDS and a 6fr TAT was left in situ. The patient recovered well and was extubated on day 1 postoperatively. Feeds were commenced via TAT on day 1 postoperatively and progressed to oral feeds following this. The patient was discharged on day 4; however, presented back the next day due to increased work of breathing and tachypnoea. Chest X-ray showed evidence of aspiration pneumonia for which 5 days of intravenous antibiotics were given. Flexible bronchoscopy was repeated and showed mild tracheomalacia at site of previous TOF. A CT scan of the chest showed mild narrowing of the left main bronchus with no extrinsic compression. Nasoendoscopy showed a left vocal cord palsy with good movement of the right. The baby recovered well and was discharged home 11 days later.

Differential diagnosis

Differential diagnosis for this condition would include:

A ‘Type D’ OA/TOF with a fistula from both the upper and lower oesophageal pouches connecting to the trachea very close to each other, but this can be excluded by the preoperative bronchoscopies both showing only one opening in the trachea.

An ‘H type’ OA/TOF with oesophageal continuity and a single TOF but in both cases a nasogastric tube could not be passed and there was a gap seen between the lower and upper oesophagus with only the fistulous tract to the trachea.

Overlapping pouches that had adhered to each other with just one fistula to the trachea. This can be excluded as there was a clear connection from both proximal and distal pouches to the trachea but to the same point in the trachea.

Outcome and follow-up

Case 1 completed follow-up at 1 month where he was feeding well and thriving. Case 2 was progressing along the 50th centile for weight at 3-week review, and cry was improving.

Discussion

Vogt described the original classification of OA and/or TOF in 1929.² Ladd then developed a classification in 1945 and Gross revised this in 1953. The Gross classification divides types in an A–E categorisation (figure 1).^{3 4}

Multiple variations of OA and/or TOF have been described. Kluth reported several of these in 1976.⁵ Within type IIIb (Gross type C), there were 20 different subtypes, and five were described within type IIIc (Gross type D). Sinha et al identified a case where the fistula extended from lower oesophageal pouch and the trachea with cystic dilatation in the mid portion and a concurrent type III duodenal atresia.⁶ Harne et al described oesophageal atresia with a fistula and a long segment of congenital oesophageal stenosis in the distal pouch.⁷ Luo had an oesophageal atresia with distal tracheoantral and congenital intrathoracic stomach.⁸ Ozcan reported a case of oesophageal atresia with an obliterated distal fistula and heterotopic pancreatic tissue in the distal pouch.⁹ An oesophageal atresia with an abnormally long lower segment that entered the trachea in the upper thoracic aperture with a long atretic proximal portion and a further membrane in the lower segment has also been reported.¹⁰

To our knowledge, this is the first description of this ‘Type Y’ variation. We describe these two cases to raise awareness. On bronchoscopy, the appearance is identical to a standard single fistula, and intraoperatively there is a potential for incomplete fistula closure. Based on these findings, we do not believe that any additional preoperative investigations such as upper pouch oesophagoscopy would be necessary or helpful as this is unlikely to delineate this variant type fistula. We would continue to advise routine preoperative bronchoscopy prior to repair and that this variant of fistula be considered intraoperatively.

Learning points.

• This is a new variant of oesophageal atresia (‘Type Y’) where the fistula enters the trachea in a Y-configuration.

• Bronchoscopy findings will identify a fistula with a single opening; therefore, the surgeon will not be expecting any anatomical variation.

• Knowledge of this variation reduces the risk of incomplete fistula closure.