A Rare Case Report of Esophageal Lung Associated with VACTERL Anomaly

    

    

    Figure 3: Contrast study through gastrostomy tube showing the retrograde
flow of contrast into right lower bronchus clearly showing bronchial markings.
    
    

Discussion

Broncho-pulmonary foregut malformation is a term is described initially by Gerle [2]. He used this term to describe pulmonary sequestration communicating with the Gastro-intestinal tract. Since there are much more variations in these category, Srikanth et al coined the term Communicating Broncho-Pulmonary Foregut Malformation (CBPFM) to indicate communication between esophagus or stomach with the respiratory tract or a part of the lungs [3]. When there an anomalous origin of bronchus from esophagus it is termed as the esophageal lung. CBPFM is commonly associated with esophageal atresia, Tracheo-Esophageal Fistula (TEF) to the distal esophagus, duodenal stenosis with the annular pancreas, imperforate anus, vertebral anomalies, and ambiguous genitalia [1,4].

CBPFM arises when cells of respiratory potential arise from esophagus distal to normal lung bud or a part of lung bud originating from esophagus instead of the ventral laryngotracheal tube. This group of cells is invaginated into adjacent normal pulmonary tissue, often maintaining a communication with esophagus or stomach by a pedicle. As pedicle outgrows its vascular supply, it disconnects with the respiratory tissue and forming a sequestration, but instead if the pedicle fails to disconnect it will form CBPFM [5]. Srikanth et al, with their own experience and literature review of 57 patients proposed an anatomical classification system [3]. Group I: anomaly is associated with esophageal atresia and tracheo-esophageal fistula; Group Ia: if entire lung arises from esophagus; Group Ib: if part of lung arises from esophagus; Group II: one lung originates from the lower esophagus; Group III: an isolated anatomic lung lobe or segment communicates with the esophagus or stomach. Group IV: A portion of the normal bronchial system communicates with the esophagus. Based on their classification our case report falls under type 1B wherein portion of lung arises from the esophagus. In their review of 57 patients, only 2 of them had type 1B and our case report is further unique with its association of VACTERAL anomalies.

VACTERL are non-randomly occurring group of malformations like Vertebral defects, Anal atresia, Tracheo-Esophageal Fistula (TEF) with esophageal atresia, cardiac, Renal dysplasia and limb deformities, out of which at least three should be there to make a diagnosis of VACTERL. More importantly, there should not be any clinical or laboratory evidence of the alternative diagnosis. The probable explanation for this association is probably due to developmental field defects that occur in blastogenesis. Of these vertebral anomalies are more common (60-80%) and in our case we had multiple fused and segmented thoracic vertebrae.Clinical presentation of CBPFM depends on the type of malformation and associated anomalies. It could be asymptomatic, recurrent respiratory tract infection and respiratory failure. Diagnosis is usually difficult due to its rarity and uncommon presentation. Investigations would include radiography, upper GI contrast and CT scan of thorax along with angiogram. In our case we considered differential diagnosis of Congenital Pulmonary Airway Malformations (CPAM) especially Congenital Cystic Adenomatoid Malformation (CCAM), pleural effusion, chylothorax, lung atelectasis, accidental ligation of right main bronchus or leakage from the ligated fistula, all of which were ruled out by USS thorax, needle aspiration and CT scan. Contrast study of the esophagus (esophagram) can be useful, but in cases of esophageal atresia, contrast study through gastrostomy tube with suspected lung in dependent lesion will help us in making the diagnosis. A cardiac angiogram may be essential to identify the supplying vessel to the sequestrated lung, which helps in surgery.In our case report, Initial chest radiograph taken at birth showed completely collapsed lung and then subsequent x-rays showed adequately inflated right lung. This is probably due to retrograde flow of air from the stomach, draining into right lungs through broncho-esophageal fistula (during positive pressure ventilation at resuscitation at the time of birth). Immediately after the surgical ligation of trachea-esophageal fistula, there is no air draining from stomach to the right lung, which led to complete collapse of the right lung. Complete anatomy is illustrated in (Figure 4).In our literature search, we found only three case reports of the right esophageal lung associated with VACTERL/VATER anomaly [6-8]. This case report is to emphasize the importance of considering CBPFM as one of the diagnoses in any infant with persistent unilateral lung opacification, especially worsening with feeding should raise the suspicion of this rare anomaly [1].

    

    

    Figure 4: Illustration of complete anatomy showing esophageal atresia,
tracheo- esophageal fistula, gastrostomy tube and right broncho-esophageal
communication.