Bile duct duplication

Last revised by Dr Daniel J Bell on 13 Sep 2021

Bile duct duplication, also known as common bile duct duplication (although in some cases this latter terminology would be erroneous), is a rare congenital anomaly of the biliary system. A double bile duct is considered normal during early human development, but by birth, we expect to see the conventional anatomy consisting of a single common hepatic and bile duct 1.


Modified double common bile duct classification proposed by Choi et al. 1:

  • type I: distal septum splitting the bile duct lumen
  • type II: bifurcation of the distal bile duct with each lumen draining independently
  • type III: complete duplication of the bile ducts
    • IIIa: without communicating channels
    • IIIb: with intrahepatic communicating channels
  • type IV: two bile ducts with extrahepatic communicating channel(s) each with a separate opening
  • type V: duplicated proximal bile ducts with single biliary drainage
    • Va: without communicating channels
    • Vb: without communicating channels

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Cases and figures

  • Case 1: type V
    Drag here to reorder.
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