Biliary architecture of livers exhibiting right-sided ligamentum teres: an indication for preoperative cholangiography prior to major hepatectomy

Abstract

ObjectiveTo obtain information about the basic biliary anatomy of livers with right-sided ligamentum teres (RSLT).Summary of background dataRSLT is a relatively rare anomaly with a reported incidence of 0.2–1.2%. Although the portal/hepatic venous and arterial anatomy of livers with RSLT has already been established, the biliary architecture of such livers remains unclear.MethodsRSLT was detected in 48 patients during 12,071 consecutive image readings (0.4%). Of these patients, the cholangiograms of 46 patients were analyzed, and their intrahepatic biliary tree confluence patterns were classified.ResultsThe following four unique biliary confluence patterns were identified in livers with RSLT: the symmetrical type (23/46), independent right lateral type (13/46), total left type (6/46), and total right type (1/46). Analyses of the portal and arterial branching patterns of these livers showed that there were no correlations between their biliary confluence patterns and their portal or arterial ramification patterns.ConclusionThe basic biliary architecture of livers with RSLT was clarified. As the RSLT patients' anomalous biliary confluences differed from those seen in normal livers and were difficult to predict, preoperative cholangiography should be performed prior to complex hepatobiliary surgery involving livers with RSLT to ensure patient safety.

Hepatectomy for gallbladder-cancer with unclassified anomaly of right-sided ligamentum teres: A case report and review of the literature

“…In the most common cases ( e.g ., an independent ramification of the right lateral portal pedicle), a surgeon’s misunderstanding and ligation of the left portal trunk result in a lack of portal flow in two-thirds of the whole liver during left hepatectomy[ 3 ]. Therefore, awareness of the type of anomaly is important before planning hepatectomy for patients with RSLT[ 1 , 3 , 4 ]. In 1997, Nagai et al[ 1 ] reported two types of portal vein classifications of RSLT, and later, Shindoh et al[ 3 ] and Nishitai et al[ 4 ] demonstrated the classification of arterial, portal, and biliary ramifications.…”

“…Therefore, awareness of the type of anomaly is important before planning hepatectomy for patients with RSLT[ 1 , 3 , 4 ]. In 1997, Nagai et al[ 1 ] reported two types of portal vein classifications of RSLT, and later, Shindoh et al[ 3 ] and Nishitai et al[ 4 ] demonstrated the classification of arterial, portal, and biliary ramifications. Portal ramification patterns were classified into three types: Independent right lateral, bifurcation, and trifurcation.…”

“…No specific relationship has been reported among the patterns of the biliary, portal, and arterial ramifications in RSLT livers[ 4 ]. Embryologically, the portal ramifications induce restructuring of the ductal plate that surrounds them in the future intrahepatic ducts, which results in a periportal position of the intrahepatic bile ducts[ 19 ].…”

“…Preoperative simulation has become a common practice in Japan because simulation software has been developed and has become commercially available, and the cost of preoperative liver simulation has been covered by national health care insurance since 2012[ 25 ]. The fusion image of the portal vein and bile duct is useful for hepatectomy with RSLT because both the symmetrical type and the total left type of bile duct confluence patterns are similar to the ramification pattern of the normal liver, and cholangiography alone may provide misleading information for the operation[ 4 ]. The fusion image from one examination modality is referred to as an “all-in-one” (bile ducts, arteries, and portal veins) 3D image, in which MDCT is performed after cholangiography using carbon dioxide or iodine[ 24 ].…”

Hepatectomy for Hilar Cholangiocarcinoma with Right-Sided Ligamentum Teres Using a Hepatectomy Simulation System

“…In 2016, Nishitai et al [ 10 ] identified 4 intrahepatic biliary tree confluence patterns in their analysis of cholangiograms in 46 patients with RSLT. They found that the symmetrical type, in which the right hepatic duct drains Segment 6 + 7 plus the dorsal area of Segment 5 + 8 and the left hepatic duct drains the ventral area of Segment 5 + 8 and the left hemiliver, was the most frequent pattern.…”