Gore RM, Ghahremani GG et al. Anomalies and - Department of ...

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Hepatic duct
Accessory ducts
Atresias
Common hepatic duct
Duplications
Atresias
Common bile duct
Duplications
Atresias
Cystic dilation
Figure 78-1. Sites of potential malformation of the gallbladder and
biliary tract. (From Gray SW, Skandalakis JR:Embryology for Surgeons.
Philadelphia, WB Saunders, 1972.)
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of the intrahepatic ducts can be accounted for by the unpredictable
manner in which they wind around preexisting
portal veins.4-6
AGENESIS OF THE GALLBLADDER
Agenesis of the gallbladder is caused by failure of development
of the caudal division of the primitive hepatic diverticulum
or failure of vacuolization after the solid phase of
embryonic development. Atresia or hypoplasia of the gallbladder
also represents aborted development of the organ.7-"
Other congenital anomalies are present in two thirds of these
patients, including congenital heart lesions, polysplenia, imperforate
anus, absence of one or more bones, and rectovaginal
fistula.1O There appears to be a genetic input as well, because
several families with multiple individuals having agenesis
have been identified.1O This malformation is reported in
0.013% to 0.155% of autopsy series, but many of these cases
are in stillborn and young infants. The surgical incidence of
Figure 78-2. Drawings illustrate the normal embryologic development of the pancreas and biliary tract. The ventral pancreatic bud (arrow in A and
B) and biliary system arise from the hepatic diverticulum, and the dorsal pancreatic bud (arrowhead in A and B) arises from the dorsal mesogastrium.
C. After clockwise rotation of the ventral bud around the caudal part of the foregut, there is fusion of the dorsal pancreas (located anterior) and ventral
pancreas (located posterior). D. Finally, the ventral and dorsal pancreatic ducts fuse, and the pancreas is predominantly drained through the ventral
duct, which joins the common bile duct (CBD) at the level of the major papilla. The dorsal duct empties at the level of the minor papilla. (From Mortele
KR, Rochar TC, Streeter JL, et al: Multimodality imaging of pancreatic and biliary congenital anomalies. RadioGraphies 26:715-731, 2006.)