Upper Biliary Confluence: Merging Pattern and Disposition Associated with Main Plane of Liver Functional Division

The aim of this study was to establish the merging patterns and dispositions of upper biliary confluence and to compare our findings with those of other investigators as applied to liver transplantation. We put our emphasis on the interpretation of our results in relation with the main plane of liver functional division. On 30 postmortem, adult human liver specimens, of subjects of both sexes, the injection-corrosive method was applied. By using magnifying lens, 27 acrylic porto-biliary casts of proper quality were observed to determine a merging pattern of right and left hemiliver ducts and disposition of upper biliary confluence related with main portal branches at bifurcation, as well as the disposition of main plane of liver functional division and presence or crossing with biliary ducts. Merging patterns of upper biliary confluence were statistically analyzed, by using of Kolmogorov-Smirnov’s test of agreement for one sample. Summarized results of other anatomists and clinicians as well as our results are presented in a table. Some findings by their relative frequencies were compared. Our results for upper biliary confluence revealed a formation of common hepatic duct in 15 cases-55.6%, whereas in 11 cases-40.7% the right sectoral ducts separately joined opposite site and one case-3.704% was with extrahilar confluence of right and left sectoral ducts. Our summarized results and the results of other investigators have shown that the normal upper biliary confluence anatomy varied from 25 to 98% and variant or aberrant ones from 2 to 93.3%. They point out the absence only of right hepatic duct, right or left and absence of both right and left hepatic ducts at the same time. There was interauthors agreement only to the upper biliary confluence disposition. We have noted the difference within the dispositions of upper biliary confluence versus main plane of division and important crossing of this plane with biliary ducts. Upper biliary confluence anatomy appears in very variable degree of normal, variant or aberrant anatomy. Aberrant confluence of sectoral or segmental ducts from right or left hemilivers to duct of opposite site as applied to liver transplantation is in dependence not only by merging pattern, but also by interdisposition of upper biliary confluence and main plane of liver functional division.