Tracheoesophageal fistula (TEF) with esophageal atresia is caused by a developmental error in the partitioning of the foregut. Which embryological structure forms abnormally to produce the most common type (Type C — proximal esophageal atresia with distal TEF)?

• A Failure of recanalization of the esophageal lumen after solid epithelial proliferation
• B Excessive anterior deviation of the tracheoesophageal septum
• C Failure of the tracheoesophageal septum to grow posteriorly, causing aberrant posterior fistula from trachea to distal esophagus ✓
• D Absence of neural crest cells in the distal esophagus

Explanation

The primitive foregut is divided into the ventral respiratory system and dorsal esophagus by the tracheoesophageal septum growing caudally. In the most common type of TEF (Type C, ~85%), there is a posteriorly directed fistulous connection from the trachea (usually at the carina) to the distal esophageal segment, with the proximal esophagus ending in a blind pouch. This is due to failure of the septum to grow straight posteriorly, leaving a persistent communication. The clinical hallmark is polyhydramnios (in utero) and inability to pass NGT past 10-12 cm.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.