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Paper text:
biliary drainage has long been called achilles heel liver transplantion , and biliary complications compromise the succese of liver transplantation .
a precise understanding of general anatomic principles and common variations is the key to safe living donor liver transplantation .
this procedure requires not only a precise understanding of liver anatomy but also the means of assessing them .
one of the most important challenges is that of managing the biliary duct during liver lobe resection and reimplantation .
olos biliary anatomy variants are associated with an increased risk of postoperative complications , including biliary leaks and strictures , in both the donor and recipient [ 3 , 4 ] .
one cause of complications is unrecognized anomalous biliary anatomy ( 24%57% of individuals have variant biliary patterns ) [ 58 ] .
although anomalous anatomy is not always a contraindication for liver donation , knowledge of variant anatomy is critical to ensuring the safety of donors and aids selection of suitable candidates [ 9 , 10 ] .
, heloury et al . , soares et al . , and cheng et al . noted intrahepatic transposition of bile ducts in 1 to 22% of cases [ 1013 ] .
intrahepatic transposition of bile ducts is manifested by the fact that bile ducts originating from the right liver lobe may end in the left liver duct ( ductus hepaticus sinister ) ; that is , bile ducts of the left liver lobe may end in the right liver duct ( ductus hepaticus dexter ) .
main research methods were anatomical macrodissection and statistics . as a criterion for determination of variations in some parts of bile tree
, we used the classification segmentatio hepatis according to couinaud ( 1957 ) according to terminologia anatomica , thieme stuugart : federative committee on anatomical terminology , 1988 .
after the researches have been completed , intrahepatic transposition of bile ducts was found in two cases ( 2% ) ; out of total examined cases ( 100 ) right - left transposition and left - right intrahepatic transposition were found . in one case we found right - left intrahepatic transposition , where the right segmental bile duct ( rsbd ) , originating from the segment viii , joins the left liver duct ( lld ) .
newly evolved duct is distally united to ductus hepaticus dexter and they form common liver duct ( ductus hepaticus communis ) ( figure 1 ) . in the second case ( 1% ) , left - right intrahepatic transposition was observed .
left segmental bile duct ( lsbd ) originating from the segment iv ends in right liver duct ( rld ) ( figure 2 ) .
variability of form , of position in space , and of topographic relations of bile ducts is immense .
some of the rare variations of bile ducts are in the focus of surgical anatomy in this area .
the key problem in research of variable anatomy of bile ducts is heterogeneity of the sample , as well as the case of a small sample . because of all the cited ,
significant disagreements are present concerning the findings of different researchers in the field of bile ducts anatomy , what is contributed by lacking of uniformity of methods and criteria of the research .
results of this research to a great extent confirm the other authors ' results presented in the literature available .
the right - left transposition of intrahepatic bile ducts , observed in 1% of cases in our research material , is a more frequent variation and is found , according to the literature available , in 222% of cases ( bile ducts originating out of segments
, heloury et al . , and cheng et al . found the left - right transposition in 13% of cases , what corresponds to the results of our researches [ 7 , 11 ] .
safety and success in liver transplantation to great extent depends on knowledge of anatomy and some common embryological anomalies in bile tree .
variations in bile tree were found in 2443% of cases , out of which 122% are the variations of intrahepatic bile ducts .
therefore , good knowledge on ductal anatomy enables good planning , safe performance of therapeutic and operative procedures , and decreases the risk of intraoperative and postoperative complications .
objective . to describe the intrahepatic bile duct transposition ( anatomical variation occurring in intrahepatic ducts ) and to determine the frequency of this variation . 
 material and methods . 
 the researches were performed randomly on 100 livers of adults , both sexes . 
 main research methods were anatomical macrodissection . as a criterion for determination of variations in some parts of bile tree 
 , we used the classification of segmentatio hepatis according to couinaud ( 1957 ) according to terminologia anatomica , thieme stuugart : federative committee on anatomical terminology , 1988 . 
 results . 
 intrahepatic transposition of bile ducts was found in two cases ( 2% ) , out of total examined cases ( 100 ) : right - left transposition ( right segmental bile duct , originating from the segment viii , joins the left liver duct - ductus hepaticus sinister ) and left - right intrahepatic transposition ( left segmental bile duct originating from the segment iv ends in right liver duct - ductus hepaticus dexter ) . 
 conclusion . 
 safety and success in liver transplantation to great extent depends on knowledge of anatomy and some common embryological anomalies in bile tree . 
 variations in bile tree were found in 2443% of cases , out of which 122% are the variations of intrahepatic bile ducts . 
 therefore , good knowledge on ductal anatomy enables good planning , safe performance of therapeutic and operative procedures , and decreases the risk of intraoperative and postoperative complications .