Feature Type 1 A Type 1 B Type 2 A Type 2 B
Normal carina and tracheobronchial tree Yes (T4/5) Yes ( T4/5) No (pseudo carina T6) No (pseudo carina T6)
Tracheal Right upper lobe bronchus No Yes - usually partialĀ  RUL supply (eg apical lobe of RUL) Yes -usually supplies entire RUL No (absent RUL/Right sided bronchi) with hypoplastic right lung
Bridging bronchus No No Yes - supplies RML and RLL Yes (rudimentary or absent)
Tracheal stenosis (complete rings) Rarely Rarely or short segment Common Common
Imperforate anus Rare Rare Not uncommon Not uncommon