Radiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

DOI: 10.1148/radiol.2381041783
This Article
Right arrow Abstract Freely available
Right arrow Figures Only
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kitami, M.
Right arrow Articles by Takahashi, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kitami, M.
Right arrow Articles by Takahashi, S.
(Radiology 2006;238:156-166.)
© RSNA, 2006

Gastrointestinal Imaging

Types and Frequencies of Biliary Tract Variations Associated with a Major Portal Venous Anomaly: Analysis with Multi–Detector Row CT Cholangiography1

Masahiro Kitami, MD, PhD, Kei Takase, MD, PhD, Gen Murakami, MD, PhD, Saiho Ko, MD, PhD, Masahiro Tsuboi, MD, PhD, Haruo Saito, MD, PhD, Shuichi Higano, MD, PhD, Yoshiyuki Nakajima, MD, PhD and Shoki Takahashi, MD, PhD

1 From the Department of Diagnostic Radiology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-cho, Sendai 980-8574, Japan (M.K., K.T., M.T., H.S., S.H., S.T.); Department of Anatomy, Sapporo Medical University School of Medicine, Sapporo, Japan (G.M.); and First Department of Surgery, Nara Medical University, Kashiwara, Japan (S.K., Y.N.). Received October 18, 2004; revision requested December 22; revision received January 18, 2005; accepted February 16. Address correspondence to M.K. (e-mail: mshkitami{at}rad.med.tohoku.ac.jp).


   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 References
 
Purpose: To retrospectively determine whether major portal venous variation was more frequently associated with biliary variants, with consideration of the types and frequencies of biliary tract variations in the right and left liver lobes.

Materials and Methods: Before undergoing computed tomographic (CT) cholangiography, patients gave informed consent. The retrospective research protocol was approved, and informed consent was waived by the ethics committee. Forty-four patients aged 29–80 years who underwent multi–detector row CT cholangiography had a major portal vein variation in which the main portal vein diverged into the common trunk of the left portal vein and right anterior sectorial portal vein. One hundred fifty-eight consecutive patients aged 26–89 years who did not have this variation served as the control group. Three radiologists retrospectively evaluated the confluence pattern of the bile duct, the relationship between this pattern and the portal vein, and the major branching pattern of the portal vein. Pearson {chi}2 and Fisher exact tests were performed to identify significant differences between the two patient groups.

Results: The classic hilar confluence pattern, where the right posterior sectorial duct connects supraportally with the right anterior sectorial duct, was less frequent in the patients with the portal vein variation than in the control subjects (32% vs 73%, P < .05). The following biliary tract variations were identified more frequently in the variation group than in the control group (P < .05): right posterior sectorial duct joining left hepatic duct with a supraportal course (34% vs 12%), right posterior sectorial duct joining right anterior sectorial duct with an infraportal course (13% vs 4%), right posterior sectorial duct following an infraportal course (23% vs 8%), and left lateral segmental ducts caudal to the umbilical portion of the portal vein (14% vs 3%). The right hepatic duct, which receives all biliary ducts from the right lobe, was significantly less frequently developed in the variation group (46% vs 79%, P < .05). In addition, retroportal bile ducts were seen in four patients with the portal vein variation (P < .05).

Conclusion: Bile duct configurations in patients with portal vein variation were significantly different from those in control subjects.

© RSNA, 2006


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 References
 
During liver surgery, treatment of the bile ducts at the porta hepatis is a critical step to avoiding postsurgical bile leakage and atrophy of the residual liver and/or the graft. For avoiding these complications, precise knowledge of the bile duct anatomy in individual cases has great importance. Although numerous biliary tract variations have been reported, they can be classified into four major categories: (a) variations in the confluence of the right liver lobe ducts with the left hepatic duct (LHD) (1–10); (b) variations in the course of the right posterior sectorial duct (RPSD) formed by the junction of B6 and B7 (bile ducts of hepatic segments VI and VII, respectively) in relation to the right anterior sectorial trunk of the portal vein—that is, the RPSD running on its supraportal (cranial) or infraportal (caudal) side (3,7,9); (c) variations in the confluence of the left lobe ducts (1,4,8,10–13); and (d) variations in the course of the left lateral segmental ducts running cranially or caudad to the umbilical portion of the portal vein (10,14,15).

Major variations in the primary division of the portal vein at the porta hepatis also are well known and include divergence of the main portal vein into the right posterior sectorial trunk and the common trunk of the left portal vein and right anterior sectorial portal vein (hereafter referred to as portal vein variation) (Fig 1). Reported prevalences of this variation range from 6.0% to 11.4% (6,16,17).



View larger version (39K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 1a: Illustrations of (a) common branching pattern of portal vein and (b) portal vein variation. (a) With the common branching pattern, the main portal vein bifurcates into the right and left (Lt) portal veins, and the right portal vein divides into the right anterior (Ant) and right posterior (Post) portal veins. (b) With the portal vein variation, the main portal vein diverges into the right posterior portal vein and the common trunk of the left portal vein and right anterior sectorial portal vein (L+A).

 


View larger version (38K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 1b: Illustrations of (a) common branching pattern of portal vein and (b) portal vein variation. (a) With the common branching pattern, the main portal vein bifurcates into the right and left (Lt) portal veins, and the right portal vein divides into the right anterior (Ant) and right posterior (Post) portal veins. (b) With the portal vein variation, the main portal vein diverges into the right posterior portal vein and the common trunk of the left portal vein and right anterior sectorial portal vein (L+A).

 
Although the spatial relationship between the bile duct and the portal vein (Fig 2), like the infraportal course of the RPSD, has been studied, there have been few reports on the association between portal venous anomalies and biliary variations and the frequency of each type of biliary variation.



View larger version (54K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 2a: Illustrations of (a) supraportal and (b) infraportal courses of RPSD. (a) With the supraportal course, the RPSD (arrow) runs cranially to the right anterior portal vein. Ant = right anterior sectorial portal vein and bile duct, BD = bile duct, Lt = left portal vein and left hepatic duct, Post = right posterior sectorial portal vein and bile duct, PV = portal vein. (b) With the infraportal course, the RPSD (arrow) runs caudad to the right anterior portal vein.

 


View larger version (49K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 2b: Illustrations of (a) supraportal and (b) infraportal courses of RPSD. (a) With the supraportal course, the RPSD (arrow) runs cranially to the right anterior portal vein. Ant = right anterior sectorial portal vein and bile duct, BD = bile duct, Lt = left portal vein and left hepatic duct, Post = right posterior sectorial portal vein and bile duct, PV = portal vein. (b) With the infraportal course, the RPSD (arrow) runs caudad to the right anterior portal vein.

 
In studies involving the use of cast specimens, Kumon et al (3) and Ishiyama et al (7) suggested that the portal vein variation is associated with rare and/or distinct bile ducts variations. Varotti et al (18) recently reported that four of seven patients with the portal vein variation had biliary variations. However, these reports were exploratory, and descriptions of the results were brief. Therefore, the types and frequencies of these biliary variations remain unclear.

Cheng et al (6) studied the association between portal venous and biliary system anomalies by using conventional cholangiography. However, they focused their interest on left hepatectomy, whereas right lobe graft placement is more commonly used in living-donor liver transplantation programs (19), and the clinical importance of this association in relation to right lobe graft placement was not discussed in their study. Furthermore, in their study, they did not examine either the running course (infraportal or supraportal) of the bile ducts, which is crucial for surgical procedures focused on cholangiocarcinoma, or variations in the left lobe ducts, which are important for left lateral segmentectomy and graft placement. Thus, the purpose of our study was to retrospectively evaluate whether major portal vein variation was more frequently associated with biliary variants, with consideration of the types and frequencies of biliary tract variations in the right and left liver lobes.


   MATERIALS AND METHODS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
RESULTS
 DISCUSSION
 References
 
Study Subjects
Forty-four consecutive patients with the portal vein variation (9.2%), who were identified from a group of 478 consecutive patients who underwent multi–detector row computed tomographic (CT) cholangiography between May 18, 2000, and July 16, 2003, were included in our study. These patients were 25 men and 19 women aged 29–80 years (mean, 62.6 years). For a control group, we also included 158 consecutive patients—77 men and 81 women aged 26–89 years (mean, 67.8 years)—who did not have the portal vein variation during the period from December 17, 2001, to January 17, 2003. In the control group, which was not matched to the portal vein variation group, 145 patients had the common portal venous pattern and 13 had a trifurcation pattern, in which the main portal vein diverged into the right anterior, right posterior, and left portal veins at the same point. Other anomalies, such as a right umbilical portion, were not identified in our series.

Multi–detector row CT cholangiography had been performed in the 478 patients because of suspected cholelithiasis (454 patients), gallbladder polyp (five patients), or biliary tumor (19 patients). Patients who had undergone hepatectomy, had neoplasms, had inadequate biliary tract depiction, and/or had poor breath-holding capability were excluded from the portal vein variation and control groups. In this study, we performed CT cholangiography to scrutinize the biliary tract because ultrasonography has limitations in terms of objectivity and the depiction of choledocholithiasis and biliary anomalies and magnetic resonance (MR) cholangiography was suboptimal at the institution where we performed CT cholangiography owing to limitations of the available equipment. Before performing multi–detector row CT cholangiography, we obtained informed consent from all patients. The protocol for this retrospective research project was approved by the ethics committee of Ishinomaki Red Cross Hospital, Miyagi, Japan; the requirement for informed consent was waived.

Imaging Evaluation
A multi-detector row helical CT scanner (Aquilion; Toshiba, Tokyo, Japan) was used. Four–detector row (before August 1, 2001) and eight–detector row (after August 1) CT scans were obtained with the following parameters: 0.5 second per rotation, 2-mm (before August 1) or 1-mm (after August 1) collimation, 14 mm/sec table speed (with a beam pitch of 0.875), and a tube current of 120 kV per 300 mA.

Transverse sections were reconstructed with 2-mm-thick (before August 1) or 1-mm-thick (after August 1) sections at 1.0-mm (before August 1) or 0.5-mm (after August 1) intervals. The reconstruction field of view was set to the area around the liver to improve spatial resolution. As a biliary contrast agent, 100 mL of meglumine iotroxate (50 mg/mL Biliscopin; Schering, Berlin, Germany) was administered for 30 minutes, before the initiation of 1 hour of scanning. Before scanning, 200 mL of water was administered to wash out the contrast agent in the duodenum and jejunum, which might have affected the generation of three-dimensional images. The images were processed at a stand-alone workstation (Zio M900; Amin, Tokyo, Japan). A paging method, in which multiple original transverse CT images could be observed by scrolling to the images displayed on the workstation screen, was used. We also used supplementary multiplanar reconstruction images.

We evaluated the following bile duct features by using the paging method: (a) the confluence patterns of the right anterior sectorial duct (RASD), RPSD, and LHD; (b) whether the right hepatic duct (RHD), which was the duct that received all of the biliary ducts from the right liver lobe (ie, B5–B8 [bile ducts of liver segments V–VIII, respectively]), was developed; (c) the confluence patterns of B2–B4 (bile ducts of liver segments II–IV, respectively); and (d) the course of the RPSD and left lateral segmental duct in relation to the portal vein—that is, the supraportal or infraportal course. The major branching patterns of the portal veins also were evaluated by using the paging method.

For visualization of the overall biliary anatomy, volume-rendered images were generated by using the polygonal cutting function on the workstation to eliminate bone structures. The images were evaluated by three radiologists (M.K., M.T., K.T., with 10–16 years experience). In cases of disagreement, interobserver discussion was used to reach a final consensus regarding the interpreted findings.

Two authors (M.K., K.T.) reviewed the patients' medical records to determine whether the subjects had had any contrast agent reactions at presentation and if so, what treatment had been given.

Statistical Analyses
The Pearson {chi}2 test was used to assess the significance of differences in the frequency of bile duct variations between the two patient groups. When a given variation was rarely found (ie, in fewer than five patients), the Fisher exact test was performed. We used SPSS for Windows software, version 11.0.0.1 J (SPSS, Chicago, Ill), to perform statistical analyses. The threshold level for statistical significance was P < .05.


   RESULTS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
DISCUSSION
 References
 
In all cases reviewed, concomitant visualization of the biliary tract and liver parenchyma enabled accurate classification of the bile ducts. Multi–detector row CT cholangiography also yielded hilar portal venous information. Thus, by using the paging method, we were able to evaluate the biliary confluence pattern and the running course of the biliary tract in relation to the portal vein. In our study of 44 patients with and 158 patients without the portal vein variation, three patients (1.5%) reported having mild nausea, abdominal discomfort, or skin reactions in association with contrast agent administration; these side effects did not necessitate treatment. There were no severe reactions.

Biliary Tract Variations in Right Lobe and Hepatic Hilum
The biliary configurations in the right liver lobe were classified as types A–J and are described herein as types Ar–Jr, respectively: In configuration type Ar, the RPSD (B6-B7 junction) joins the RASD (B5-B8 junction) with a supraportal course (classic pattern); in type Br, the RPSD joins the LHD with a supraportal course; type Cr is a triple confluence of the RASD, RPSD, and LHD; in type Dr, the RPSD joins the RASD with an infraportal course; in type Er, the RPSD joins the common hepatic duct with an infraportal course; and types Fr–Jr are other, rare biliary variations (Fig 3, Table 1).



View larger version (47K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 3: Classification of biliary configurations in right liver lobe and hilar region. Biliary configurations in the right lobe and hilar region were classified as types A–J, which are described herein as Ar–Jr, respectively, as shown in the diagram. The individual configuration types are regrouped according to the development, (+), or nondevelopment, (–), of the RHD (columns) and the running course of the RPSD (rows).

 

View this table:
[in this window]
[in a new window]

  		Table 1. Classification of Biliary Configurations in Right Liver Lobe and Hilar Region

 
In the control group, the biliary configuration types were Ar in 73% of the subjects (Fig 4), Br in 12%, Cr in 5%, Dr in 4%, Er in 3%, and other types (ie, Gr and Hr) in 2% (Table 1). In the portal vein variation group, the biliary configuration types were Br in 34% (Fig 5) of the patients, Ar in 32%, Dr in 14% (Fig 6), Cr in 7%, Er in 4%, and other types (ie, Fr, Ir, and Jr) in 9% (Table 1). The frequencies of several biliary configurations differed significantly (P < .05) between the control and variation groups. Compared with the control group, the variation group had (a) a lower frequency of biliary configuration type Ar—the classic pattern (32% vs 73%), (b) a higher frequency of type Br (34% vs 12%), and (c) a higher frequency of type Dr (14% vs 4%).



View larger version (189K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 4a: CT cholangiograms depicting the common portal venous pattern and the type Ar biliary configuration (classic confluence pattern). Transverse images arranged in (a) cranial to (c) caudal order and (d) volume-rendered image in left anterior-cranial view are shown. (a–c) The main portal vein bifurcates into the right portal vein (RPV) and left portal vein (LPV); the right portal vein then bifurcates into the right posterior sectorial portal vein (RPPV) and right anterior sectorial portal vein (RAPV) (b and c). The RPSD runs dorsally (from c to b) and then cranially (a) to the right anterior sectorial portal vein via a supraportal course and joins the RASD (a). (d) Volume-rendered image shows an overview of the bile duct. The RPSD has cranial convexity, which probably corresponds to the site at which the overriding of the right anterior sectorial portal vein occurs. CHD = common hepatic duct, GB = gallbladder.

 


View larger version (175K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 4b: CT cholangiograms depicting the common portal venous pattern and the type Ar biliary configuration (classic confluence pattern). Transverse images arranged in (a) cranial to (c) caudal order and (d) volume-rendered image in left anterior-cranial view are shown. (a–c) The main portal vein bifurcates into the right portal vein (RPV) and left portal vein (LPV); the right portal vein then bifurcates into the right posterior sectorial portal vein (RPPV) and right anterior sectorial portal vein (RAPV) (b and c). The RPSD runs dorsally (from c to b) and then cranially (a) to the right anterior sectorial portal vein via a supraportal course and joins the RASD (a). (d) Volume-rendered image shows an overview of the bile duct. The RPSD has cranial convexity, which probably corresponds to the site at which the overriding of the right anterior sectorial portal vein occurs. CHD = common hepatic duct, GB = gallbladder.

 


View larger version (161K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 4c: CT cholangiograms depicting the common portal venous pattern and the type Ar biliary configuration (classic confluence pattern). Transverse images arranged in (a) cranial to (c) caudal order and (d) volume-rendered image in left anterior-cranial view are shown. (a–c) The main portal vein bifurcates into the right portal vein (RPV) and left portal vein (LPV); the right portal vein then bifurcates into the right posterior sectorial portal vein (RPPV) and right anterior sectorial portal vein (RAPV) (b and c). The RPSD runs dorsally (from c to b) and then cranially (a) to the right anterior sectorial portal vein via a supraportal course and joins the RASD (a). (d) Volume-rendered image shows an overview of the bile duct. The RPSD has cranial convexity, which probably corresponds to the site at which the overriding of the right anterior sectorial portal vein occurs. CHD = common hepatic duct, GB = gallbladder.

 


View larger version (126K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 4d: CT cholangiograms depicting the common portal venous pattern and the type Ar biliary configuration (classic confluence pattern). Transverse images arranged in (a) cranial to (c) caudal order and (d) volume-rendered image in left anterior-cranial view are shown. (a–c) The main portal vein bifurcates into the right portal vein (RPV) and left portal vein (LPV); the right portal vein then bifurcates into the right posterior sectorial portal vein (RPPV) and right anterior sectorial portal vein (RAPV) (b and c). The RPSD runs dorsally (from c to b) and then cranially (a) to the right anterior sectorial portal vein via a supraportal course and joins the RASD (a). (d) Volume-rendered image shows an overview of the bile duct. The RPSD has cranial convexity, which probably corresponds to the site at which the overriding of the right anterior sectorial portal vein occurs. CHD = common hepatic duct, GB = gallbladder.

 


View larger version (176K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 5a: CT cholangiograms of the portal vein variation associated with the type Br biliary configuration. Transverse images arranged in (a) cranial to (d) caudal order, (e) parasagittal multiplanar reconstruction image of region along the RPSD, and (f) volume-rendered image in the right anterior view are shown. (a–d) The right posterior sectorial portal vein (RPPV) and the common trunk of the left portal vein (LPV) and right anterior sectorial portal vein (RAPV) (ie, L+A) arise from the main trunk of the portal vein (PV) (c, d). The common trunk of the left portal vein and right anterior sectorial portal vein then bifurcates into the right anterior sectorial portal vein and left portal vein (a, b). The RPSD runs dorsally (from c to a) and then cranially (a) to the right anterior sectorial portal vein via a supraportal course and joins the LHD (a). (e) Multiplanar reconstruction image clearly shows that the RPSD runs on the dorsocranial side of the right anterior sectorial portal vein—that is, it takes a supraportal course. (f) Volume-rendered image shows the usual supraportal or cranial course of the RPSD with superior convexity. CHD = common hepatic duct, GB = gallbladder.

 


View larger version (175K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 5b: CT cholangiograms of the portal vein variation associated with the type Br biliary configuration. Transverse images arranged in (a) cranial to (d) caudal order, (e) parasagittal multiplanar reconstruction image of region along the RPSD, and (f) volume-rendered image in the right anterior view are shown. (a–d) The right posterior sectorial portal vein (RPPV) and the common trunk of the left portal vein (LPV) and right anterior sectorial portal vein (RAPV) (ie, L+A) arise from the main trunk of the portal vein (PV) (c, d). The common trunk of the left portal vein and right anterior sectorial portal vein then bifurcates into the right anterior sectorial portal vein and left portal vein (a, b). The RPSD runs dorsally (from c to a) and then cranially (a) to the right anterior sectorial portal vein via a supraportal course and joins the LHD (a). (e) Multiplanar reconstruction image clearly shows that the RPSD runs on the dorsocranial side of the right anterior sectorial portal vein—that is, it takes a supraportal course. (f) Volume-rendered image shows the usual supraportal or cranial course of the RPSD with superior convexity. CHD = common hepatic duct, GB = gallbladder.

 


View larger version (177K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 5c: CT cholangiograms of the portal vein variation associated with the type Br biliary configuration. Transverse images arranged in (a) cranial to (d) caudal order, (e) parasagittal multiplanar reconstruction image of region along the RPSD, and (f) volume-rendered image in the right anterior view are shown. (a–d) The right posterior sectorial portal vein (RPPV) and the common trunk of the left portal vein (LPV) and right anterior sectorial portal vein (RAPV) (ie, L+A) arise from the main trunk of the portal vein (PV) (c, d). The common trunk of the left portal vein and right anterior sectorial portal vein then bifurcates into the right anterior sectorial portal vein and left portal vein (a, b). The RPSD runs dorsally (from c to a) and then cranially (a) to the right anterior sectorial portal vein via a supraportal course and joins the LHD (a). (e) Multiplanar reconstruction image clearly shows that the RPSD runs on the dorsocranial side of the right anterior sectorial portal vein—that is, it takes a supraportal course. (f) Volume-rendered image shows the usual supraportal or cranial course of the RPSD with superior convexity. CHD = common hepatic duct, GB = gallbladder.

 


View larger version (178K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 5d: CT cholangiograms of the portal vein variation associated with the type Br biliary configuration. Transverse images arranged in (a) cranial to (d) caudal order, (e) parasagittal multiplanar reconstruction image of region along the RPSD, and (f) volume-rendered image in the right anterior view are shown. (a–d) The right posterior sectorial portal vein (RPPV) and the common trunk of the left portal vein (LPV) and right anterior sectorial portal vein (RAPV) (ie, L+A) arise from the main trunk of the portal vein (PV) (c, d). The common trunk of the left portal vein and right anterior sectorial portal vein then bifurcates into the right anterior sectorial portal vein and left portal vein (a, b). The RPSD runs dorsally (from c to a) and then cranially (a) to the right anterior sectorial portal vein via a supraportal course and joins the LHD (a). (e) Multiplanar reconstruction image clearly shows that the RPSD runs on the dorsocranial side of the right anterior sectorial portal vein—that is, it takes a supraportal course. (f) Volume-rendered image shows the usual supraportal or cranial course of the RPSD with superior convexity. CHD = common hepatic duct, GB = gallbladder.

 


View larger version (161K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 5e: CT cholangiograms of the portal vein variation associated with the type Br biliary configuration. Transverse images arranged in (a) cranial to (d) caudal order, (e) parasagittal multiplanar reconstruction image of region along the RPSD, and (f) volume-rendered image in the right anterior view are shown. (a–d) The right posterior sectorial portal vein (RPPV) and the common trunk of the left portal vein (LPV) and right anterior sectorial portal vein (RAPV) (ie, L+A) arise from the main trunk of the portal vein (PV) (c, d). The common trunk of the left portal vein and right anterior sectorial portal vein then bifurcates into the right anterior sectorial portal vein and left portal vein (a, b). The RPSD runs dorsally (from c to a) and then cranially (a) to the right anterior sectorial portal vein via a supraportal course and joins the LHD (a). (e) Multiplanar reconstruction image clearly shows that the RPSD runs on the dorsocranial side of the right anterior sectorial portal vein—that is, it takes a supraportal course. (f) Volume-rendered image shows the usual supraportal or cranial course of the RPSD with superior convexity. CHD = common hepatic duct, GB = gallbladder.

 


View larger version (177K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 5f: CT cholangiograms of the portal vein variation associated with the type Br biliary configuration. Transverse images arranged in (a) cranial to (d) caudal order, (e) parasagittal multiplanar reconstruction image of region along the RPSD, and (f) volume-rendered image in the right anterior view are shown. (a–d) The right posterior sectorial portal vein (RPPV) and the common trunk of the left portal vein (LPV) and right anterior sectorial portal vein (RAPV) (ie, L+A) arise from the main trunk of the portal vein (PV) (c, d). The common trunk of the left portal vein and right anterior sectorial portal vein then bifurcates into the right anterior sectorial portal vein and left portal vein (a, b). The RPSD runs dorsally (from c to a) and then cranially (a) to the right anterior sectorial portal vein via a supraportal course and joins the LHD (a). (e) Multiplanar reconstruction image clearly shows that the RPSD runs on the dorsocranial side of the right anterior sectorial portal vein—that is, it takes a supraportal course. (f) Volume-rendered image shows the usual supraportal or cranial course of the RPSD with superior convexity. CHD = common hepatic duct, GB = gallbladder.

 


View larger version (183K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 6a: CT cholangiograms of the portal vein variation associated with the type Dr biliary configuration and the infraportal course of B3. Transverse images arranged in (a) cranial to (e) caudal order, (f) parasagittal multiplanar reconstruction image of region along the RPSD, and (g) volume-rendered image in the right anterior-cranial view are shown. (a–e) B3 runs medially and dorsally and courses caudad to the umbilical portion of the left portal vein (UP)—that is, it takes an infraportal course (a, b). The right posterior sectorial portal vein (RPPV) and the common trunk of the left portal vein (LPV) and right anterior sectorial portal vein (RAPV) (ie, L+A) arise from the main trunk of the portal vein (PV) (d, e). The common trunk of the left portal vein and right anterior sectorial portal vein then bifurcates into the right anterior sectorial portal vein and left portal vein (c). The left portal vein continues to the umbilical portion via an anterior course (a–c). The RPSD runs caudad (from e to d) and then anteriorly (c) to the right anterior sectorial portal vein via an infraportal course (in contrast to the dorsocranial course [ie, supraportal course] seen in Figs 4 and 5). (f) Multiplanar reconstruction image clearly shows that the RPSD runs on the anterior-caudal side of the right anterior sectorial portal vein—that is, it takes an infraportal course. (g) Volume-rendered image shows that the RPSD follows a straight course without cranial convexity. CHD = common hepatic duct, GB = gallbladder.

 


View larger version (187K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 6b: CT cholangiograms of the portal vein variation associated with the type Dr biliary configuration and the infraportal course of B3. Transverse images arranged in (a) cranial to (e) caudal order, (f) parasagittal multiplanar reconstruction image of region along the RPSD, and (g) volume-rendered image in the right anterior-cranial view are shown. (a–e) B3 runs medially and dorsally and courses caudad to the umbilical portion of the left portal vein (UP)—that is, it takes an infraportal course (a, b). The right posterior sectorial portal vein (RPPV) and the common trunk of the left portal vein (LPV) and right anterior sectorial portal vein (RAPV) (ie, L+A) arise from the main trunk of the portal vein (PV) (d, e). The common trunk of the left portal vein and right anterior sectorial portal vein then bifurcates into the right anterior sectorial portal vein and left portal vein (c). The left portal vein continues to the umbilical portion via an anterior course (a–c). The RPSD runs caudad (from e to d) and then anteriorly (c) to the right anterior sectorial portal vein via an infraportal course (in contrast to the dorsocranial course [ie, supraportal course] seen in Figs 4 and 5). (f) Multiplanar reconstruction image clearly shows that the RPSD runs on the anterior-caudal side of the right anterior sectorial portal vein—that is, it takes an infraportal course. (g) Volume-rendered image shows that the RPSD follows a straight course without cranial convexity. CHD = common hepatic duct, GB = gallbladder.

 


View larger version (182K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 6c: CT cholangiograms of the portal vein variation associated with the type Dr biliary configuration and the infraportal course of B3. Transverse images arranged in (a) cranial to (e) caudal order, (f) parasagittal multiplanar reconstruction image of region along the RPSD, and (g) volume-rendered image in the right anterior-cranial view are shown. (a–e) B3 runs medially and dorsally and courses caudad to the umbilical portion of the left portal vein (UP)—that is, it takes an infraportal course (a, b). The right posterior sectorial portal vein (RPPV) and the common trunk of the left portal vein (LPV) and right anterior sectorial portal vein (RAPV) (ie, L+A) arise from the main trunk of the portal vein (PV) (d, e). The common trunk of the left portal vein and right anterior sectorial portal vein then bifurcates into the right anterior sectorial portal vein and left portal vein (c). The left portal vein continues to the umbilical portion via an anterior course (a–c). The RPSD runs caudad (from e to d) and then anteriorly (c) to the right anterior sectorial portal vein via an infraportal course (in contrast to the dorsocranial course [ie, supraportal course] seen in Figs 4 and 5). (f) Multiplanar reconstruction image clearly shows that the RPSD runs on the anterior-caudal side of the right anterior sectorial portal vein—that is, it takes an infraportal course. (g) Volume-rendered image shows that the RPSD follows a straight course without cranial convexity. CHD = common hepatic duct, GB = gallbladder.

 


View larger version (177K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 6d: CT cholangiograms of the portal vein variation associated with the type Dr biliary configuration and the infraportal course of B3. Transverse images arranged in (a) cranial to (e) caudal order, (f) parasagittal multiplanar reconstruction image of region along the RPSD, and (g) volume-rendered image in the right anterior-cranial view are shown. (a–e) B3 runs medially and dorsally and courses caudad to the umbilical portion of the left portal vein (UP)—that is, it takes an infraportal course (a, b). The right posterior sectorial portal vein (RPPV) and the common trunk of the left portal vein (LPV) and right anterior sectorial portal vein (RAPV) (ie, L+A) arise from the main trunk of the portal vein (PV) (d, e). The common trunk of the left portal vein and right anterior sectorial portal vein then bifurcates into the right anterior sectorial portal vein and left portal vein (c). The left portal vein continues to the umbilical portion via an anterior course (a–c). The RPSD runs caudad (from e to d) and then anteriorly (c) to the right anterior sectorial portal vein via an infraportal course (in contrast to the dorsocranial course [ie, supraportal course] seen in Figs 4 and 5). (f) Multiplanar reconstruction image clearly shows that the RPSD runs on the anterior-caudal side of the right anterior sectorial portal vein—that is, it takes an infraportal course. (g) Volume-rendered image shows that the RPSD follows a straight course without cranial convexity. CHD = common hepatic duct, GB = gallbladder.

 


View larger version (153K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 6e: CT cholangiograms of the portal vein variation associated with the type Dr biliary configuration and the infraportal course of B3. Transverse images arranged in (a) cranial to (e) caudal order, (f) parasagittal multiplanar reconstruction image of region along the RPSD, and (g) volume-rendered image in the right anterior-cranial view are shown. (a–e) B3 runs medially and dorsally and courses caudad to the umbilical portion of the left portal vein (UP)—that is, it takes an infraportal course (a, b). The right posterior sectorial portal vein (RPPV) and the common trunk of the left portal vein (LPV) and right anterior sectorial portal vein (RAPV) (ie, L+A) arise from the main trunk of the portal vein (PV) (d, e). The common trunk of the left portal vein and right anterior sectorial portal vein then bifurcates into the right anterior sectorial portal vein and left portal vein (c). The left portal vein continues to the umbilical portion via an anterior course (a–c). The RPSD runs caudad (from e to d) and then anteriorly (c) to the right anterior sectorial portal vein via an infraportal course (in contrast to the dorsocranial course [ie, supraportal course] seen in Figs 4 and 5). (f) Multiplanar reconstruction image clearly shows that the RPSD runs on the anterior-caudal side of the right anterior sectorial portal vein—that is, it takes an infraportal course. (g) Volume-rendered image shows that the RPSD follows a straight course without cranial convexity. CHD = common hepatic duct, GB = gallbladder.

 


View larger version (173K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 6f: CT cholangiograms of the portal vein variation associated with the type Dr biliary configuration and the infraportal course of B3. Transverse images arranged in (a) cranial to (e) caudal order, (f) parasagittal multiplanar reconstruction image of region along the RPSD, and (g) volume-rendered image in the right anterior-cranial view are shown. (a–e) B3 runs medially and dorsally and courses caudad to the umbilical portion of the left portal vein (UP)—that is, it takes an infraportal course (a, b). The right posterior sectorial portal vein (RPPV) and the common trunk of the left portal vein (LPV) and right anterior sectorial portal vein (RAPV) (ie, L+A) arise from the main trunk of the portal vein (PV) (d, e). The common trunk of the left portal vein and right anterior sectorial portal vein then bifurcates into the right anterior sectorial portal vein and left portal vein (c). The left portal vein continues to the umbilical portion via an anterior course (a–c). The RPSD runs caudad (from e to d) and then anteriorly (c) to the right anterior sectorial portal vein via an infraportal course (in contrast to the dorsocranial course [ie, supraportal course] seen in Figs 4 and 5). (f) Multiplanar reconstruction image clearly shows that the RPSD runs on the anterior-caudal side of the right anterior sectorial portal vein—that is, it takes an infraportal course. (g) Volume-rendered image shows that the RPSD follows a straight course without cranial convexity. CHD = common hepatic duct, GB = gallbladder.

 


View larger version (145K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 6g: CT cholangiograms of the portal vein variation associated with the type Dr biliary configuration and the infraportal course of B3. Transverse images arranged in (a) cranial to (e) caudal order, (f) parasagittal multiplanar reconstruction image of region along the RPSD, and (g) volume-rendered image in the right anterior-cranial view are shown. (a–e) B3 runs medially and dorsally and courses caudad to the umbilical portion of the left portal vein (UP)—that is, it takes an infraportal course (a, b). The right posterior sectorial portal vein (RPPV) and the common trunk of the left portal vein (LPV) and right anterior sectorial portal vein (RAPV) (ie, L+A) arise from the main trunk of the portal vein (PV) (d, e). The common trunk of the left portal vein and right anterior sectorial portal vein then bifurcates into the right anterior sectorial portal vein and left portal vein (c). The left portal vein continues to the umbilical portion via an anterior course (a–c). The RPSD runs caudad (from e to d) and then anteriorly (c) to the right anterior sectorial portal vein via an infraportal course (in contrast to the dorsocranial course [ie, supraportal course] seen in Figs 4 and 5). (f) Multiplanar reconstruction image clearly shows that the RPSD runs on the anterior-caudal side of the right anterior sectorial portal vein—that is, it takes an infraportal course. (g) Volume-rendered image shows that the RPSD follows a straight course without cranial convexity. CHD = common hepatic duct, GB = gallbladder.

 
The RHD was developed (types Ar, Dr, and Gr) significantly more frequently in the control group (79%) than in the portal vein variation group (45%) (P < .05) (Fig 3, Table 2).


View this table:
[in this window]
[in a new window]

  		Table 2. Regrouping of Biliary Tract Configurations in Right Liver Lobe and Hilar Region

 
The running course of the RPSD in relation to the right anterior sectorial portal vein, irrespective of the terminal junction, could be classified into three patterns: a supraportal course, an infraportal course, and other courses (Fig 3, Table 2). The supraportal course (types Ar–Cr) was significantly less frequent in the portal vein variation group (73%) than in the control group (91%) (P < .05), whereas the infraportal course (types Dr–Fr) was significantly more frequent in the portal vein variation group (23%) than in the control group (8%) (P < .05). The frequency of the type Dr biliary configuration—that in which the RPSD infraportally joins RASD (Fig 6)—was particularly high (14%) in the portal vein variation group.

In two cases, the B2 or the B2-B3 junction took a retroportal course and drained into the RPSD, although the RPSD took an infraportal course (type Fr). In one case, the RPSD took neither a supraportal nor an infraportal course; rather, it took a retroportal course to join the common hepatic duct (type Jr). In three cases, B6 and B7 did not join to form a common trunk of the RPSD (types Gr–Ir). In two of these cases (types Gr and Hr), B6 and B7 took infraportal and supraportal courses, respectively. In the remaining case, B7 took a retroportal course and drained into the LHD and B6 took an infraportal course (type Ir).

Biliary Tract Variations in Left Lobe
The confluence patterns in the left liver lobe were mainly classified as types A–C, which are described herein as types Al–Cl, respectively (Table 3, Fig 7): In confluence pattern type Al, the common trunk of B2 and B3 joins B4; type Bl is a triple confluence of B2, B3, and B4; in type Cl, B2 drains into the common trunk of B3 and B4; and the other types include a pattern in which two ducts from one segment take two different drainage paths, Fr, and other patterns.


View this table:
[in this window]
[in a new window]

  		Table 3. Biliary Configurations in Left Liver Lobe

 


View larger version (50K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 7a: Illustrations of major biliary confluence patterns in the left liver lobe, as viewed from the caudal perspective. The confluence patterns in the left lobe were mainly classified as types A–C, which are described herein as Al–Cl, respectively. (a) The common trunk of B2 and B3 joins B4 (type Al). BD = bile duct, PV = portal vein. (b) Triple confluence of B2, B3, and B4 (type Bl). (c) B2 joins the common trunk of B3 and B4 (type Cl).

 


View larger version (41K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 7b: Illustrations of major biliary confluence patterns in the left liver lobe, as viewed from the caudal perspective. The confluence patterns in the left lobe were mainly classified as types A–C, which are described herein as Al–Cl, respectively. (a) The common trunk of B2 and B3 joins B4 (type Al). BD = bile duct, PV = portal vein. (b) Triple confluence of B2, B3, and B4 (type Bl). (c) B2 joins the common trunk of B3 and B4 (type Cl).

 


View larger version (43K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 7c: Illustrations of major biliary confluence patterns in the left liver lobe, as viewed from the caudal perspective. The confluence patterns in the left lobe were mainly classified as types A–C, which are described herein as Al–Cl, respectively. (a) The common trunk of B2 and B3 joins B4 (type Al). BD = bile duct, PV = portal vein. (b) Triple confluence of B2, B3, and B4 (type Bl). (c) B2 joins the common trunk of B3 and B4 (type Cl).

 
In the control group, the drainage pattern types were Al in 73% of the subjects, Cl in 18%, Bl in 5%, and other types in 4%. The drainage pattern types in the portal vein variation group were Al in 54% of the patients, Cl in 27%, Bl in 9%, and other types in 9%. Type Cl was seen more frequently in the variation group (27%) than in the control group (18%), but the difference was not significant.

The running courses of the lateral segmental ducts of the left lobe were generally supraportal (ie, running on the cranial side of the umbilical portion of the portal vein), and the frequencies of complete supraportal duct were 97% (153 of 158 patients) in the control group and 86% (38 of 44 patients) in the portal vein variation group. In contrast, infraportal ducts were noted in only a few cases (Fig 8). The infraportal duct was noted, at least partially, in five (3%) control subjects. The infraportal duct was the duct formed by the B2-B3 junction in one control subject, B3 in two subjects, the accessory duct of B3 in one subject, and the accessory duct of B2 in one subject. In the variation group, this duct was seen in 14% (six of 44 patients) of cases. In this group, the infraportal duct was the duct formed by the B2-B3 junction in one patient, B3 in three patients, the inferior branch of B3 in one patient, and the accessory duct of B3 in one patient (Fig 6). The infraportal duct was observed significantly more frequently in the portal vein variation group than in the control group (P < .05).



View larger version (55K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 8: Diagram of the infraportal left lateral segmental duct, as viewed from the caudal perspective, with the common trunk of B2 and B3 running on the caudal side of the umbilical portion of the portal vein. The diagrams in Figure 7 show the supraportal course of the left lateral segmental ducts. BD = bile duct, PV = portal vein.

 

   DISCUSSION
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
References
 
In our study, the frequency of various biliary configurations differed significantly between the portal vein variation group and the control group. The following features were observed more frequently in the variation group than in the control group: infraportal course of the RPSD (types Dr–Fr), RPSD joining the LHD with a supraportal course (type Br), lack of development of the RHD (types Br, Cr, Er, Fr, Hr–Jr), retroportal bile ducts (types Fr, Ir, and Jr), and infraportal left lateral segmental ducts. Of the infraportal courses of the RPSD, that in which the RPSD joined the RASD (type Dr) predominated. In contrast, the supraportal course of the RPSD (type Ar–Cr) and development of the RHD (types Ar, Dr, and Gr) were less common in the variation group. In the control group, the RPSD joining the RASD with a supraportal course (type Ar) predominated (73% of subjects) and can be regarded as the classic pattern. The frequency of this pattern was only 32% in the variation group. Regarding the confluence patterns in the left lobe, type Cl occurred more frequently in the variation group than in the control group, but the difference was not significant.

To our knowledge, the work of Cheng et al (6) was the first, and to date the only, study in which the relationship between hilar biliary configuration and portal venous anomaly was investigated. Although their classifications are not identical to those described in our study, they found that the cases of portal vein variation always involved anomalous confluence patterns of the hilar bile ducts. Similarly, we observed a frequent occurrence of hilar bile duct variation in the portal vein variation group, although the frequency of the classic confluence pattern was greater than 30% in this group. This discrepancy can be attributed in part to the difference in the number of examined patients with the portal vein variation between our study and the Cheng et al study (6)—44 and 24 patients, respectively.

Regarding the clinical importance of the hilar confluence, the Cheng et al study (6) was focused exclusively on left hepatectomy (resection of liver segments II–IV). Right lobe graft placement was not discussed, although this has recently become the more commonly used procedure in living-donor liver transplantation programs (19). Furthermore, the bile duct configurations in the left lobe were not studied in their study. The confluence pattern in the left lobe duct is important for left lateral segmentectomy or graft placement (resection of liver segments II and III, leaving segment IV). The supraportal and infraportal courses of the right and left lobe ducts constitute another crucial factor in surgery for the treatment of cholangiocarcinoma. Cheng et al, however, did not address the spatial relationship between the bile duct and the portal vein, since they mainly used conventional cholangiographic techniques such as percutaneous transhepatic cholangiography and endoscopic retrograde cholangiography.

Clinical Importance of Portal Vein Variation in the Liver
During harvesting of the right liver lobe, the confluence patterns of the hilar biliary ducts are quite important, since multiple stumps must be reconstructed in cases in which the RHD is not developed (types Br, Cr, Er, Fr, Hr–Jr) (5,6,10). The portal vein variation in the liver generally has been considered a contraindication to living-donor right liver lobe transplantation because of the difficulties associated with portal venous reconstruction (20). However, technical improvements now enable the use of right lobe liver grafts from donors who have portal venous anomalies (20–23). In this situation, not only the portal vein but also the bile duct must be carefully reconstructed, because the portal vein variation is associated—at a surprisingly high frequency (>50%)—with absence of the RHD, which complicates reconstruction. For this reason, presurgical biliary evaluation is critically important for right lobe transplantation in which the donor has the portal vein variation.

The bile duct of the left lateral segment usually courses supraportally (in 97% of control subjects and 86% of patients with the portal vein variation in the current study). In cases in which the rarely seen variation of infraportal left lateral segmental duct is not recognized preoperatively, this configuration may be inadvertently injured during left lateral segmentectomy (10,14,15). Furthermore, during harvesting of the lateral segment by means of dissection on the hilar side of the umbilical portion of the portal vein, injury to B4 may occur in residual livers with the type Cl variation, as commented on by some authors (8,12).

Conversely, a high frequency of the infraportal course of both right lobe and left lobe ducts is probably advantageous in that it allows more radical surgery for cholangiocarcinoma to be performed (24,25). During partial resection of the liver, visualization of the complete infraportal bile duct to as far as the distal segment is more easily achieved than visualization of the supraportal bile duct. Visualization of the complete infraportal bile duct facilitates partial resection, including trisegmentectomy. However, in cases of an incomplete form of the infraportal left lateral segmental duct—that is, when B2 and B3 follow courses that are partially infraportal and partially supraportal—the benefits of a complete infraportal bile duct are lost.

Regarding left lobe graft placement, Cheng and co-workers, as well as other authors (5,6,10), have stated that reconstruction of the RPSD in the residual liver is necessary in cases in which the RPSD joins the LHD (type Br). In terms of the frequent association between portal vein and bile duct variations, we agree with the opinion of Cheng and colleagues (6) that biliary injury may occur in livers with anomalous portal veins. This type of injury could be particularly frequent during routine left hepatectomy, because the so-called Glissonian approach has been widely adopted (26–28). In this approach, the Glisson pedicle is transected together, without separation of the artery, portal vein, and bile duct. Blind handling of bile ducts that follow unusual courses can result in biliary injury.

Embryologic Considerations
Our study revealed that the biliary configurations in patients with the portal vein variation are quite different from those in patients without this variation. Consequently, portal vein variation appears to be strongly associated with anomalous development of the bile ducts. In embryos, development of the hepatic duct occurs later than development of the primary divisions of the portal vein (29,30). Thus, the bile ducts tend to follow a roundabout course between the portal vein divisions. Therefore, portal venous anomalies are frequently accompanied by biliary variations.

Comparisons between CT Cholangiography and Other Modalities and Safety of Intravenous Biliary Contrast Agents
In our study, intravenous CT cholangiography was performed by administering meglumine iotroxate, which is considered to be a newer-generation intravenous biliary contrast agent (31). Use of this agent enables clear visualization of the biliary tree and yields information about the liver parenchyma and portal vein. We believe that the concomitant visualization of these compartments enables accurate classification of the bile ducts and reliable definition of their supraportal and infraportal courses. In contrast, endoscopic retrograde cholangiography and percutaneous transhepatic cholangiography do not yield portal venous information and are relatively invasive. The option of CT cholangiography performed with contrast media administered through a percutaneous transhepatic cholangiographic tube could compensate for the limitations of intravenous CT cholangiography, which facilitates poor visualization of the biliary tree in patients with high serum bilirubin levels (32,33).

MR cholangiography also enables good visualization of the biliary tract noninvasively (34–36). Although MR cholangiography itself does not depict the portal venous branching pattern, this anatomic system can be easily evaluated with other MR imaging sequences (37–39).

Intravenous CT cholangiography (36,40), oral contrast agent–enhanced CT cholangiography (40), MR cholangiography (34–36), and mangafodipir trisodium–enhanced MR cholangiography (36,41,42) have been evaluated for depiction of the biliary tract. According to the recent report of Yeh et al (36), who compared all of these techniques except oral contrast agent–enhanced CT cholangiography, intravenous CT cholangiography enabled significantly better visualization than the other methods.

Although the meglumine iotroxate agent used in our study is not available in some countries, it is widely used in European (43–46) and Asian countries (47–52), mainly because it has a relatively low negative reaction rate. Nilsson (53) reported a negative reaction rate of 3.5% (3.0% minor, 0.3% moderate, and 0.2% severe reactions) after a 30-minute infusion of meglumine iotroxate for 30 minutes in 1446 patients. Lindsey et al (54) reported minor reactions at a frequency of only 0.7% in their study involving 1000 patients. In our study, three (1.5%) of 202 patients reported having mild complications and there were no cases of severe reactions.

Limitations
A major limitation of our study was the fact that the biliary configurations, portal venous anatomy, and relationships between these entities were not confirmed at dissection or surgery. Nevertheless, multi–detector row CT cholangiography facilitates excellent visualization of the second-order branches of the biliary tract and good visualization of the third-order branches, as noted previously (36). In addition, concomitant visualization of the biliary tract and liver parenchyma allows accurate classification of the bile ducts. Multi–detector row CT cholangiography appears to be satisfactory for identifying at least the first-order branching of hilar portal pedicles, although the differences in opacity between the portal vein and liver parenchyma are not large. Therefore, we believe that intravenous multi–detector row CT cholangiography is an appropriate modality for presurgical evaluation of biliary configurations and the portal venous anatomy.

Our control group consisted of 158 consecutive patients who lacked the portal vein variation and included 13 patients with a portal venous trifurcation. We did not specifically search for patients with this trifurcation among the 478 patients, so we did not analyze them as an independent group. Also, we did not apply age matching between the portal vein variation and control groups because the biliary anatomy is not thought to change with age. Similarly, we did not apply sex matching between the two groups because we found no reports that the frequency of biliary variation differs according to sex.

In our study, we identified the types and frequencies of biliary configurations in patients with and those without the portal vein variation in the right and left liver lobes. Anomalies of the confluence and running course of the biliary tract were significantly more frequent in livers with the portal vein variation.


   FOOTNOTES
 

Abbreviations: LHD = left hepatic duct • RASD = right anterior sectorial duct • RHD = right hepatic duct • RPSD = right posterior sectorial duct

Authors stated no financial relationship to disclose.

Author contributions: Guarantor of integrity of entire study, M.K.; study concepts/study design or data acquisition or data analysis/interpretation, all authors; manuscript drafting or manuscript revision for important intellectual content, all authors; approval of final version of submitted manuscript, all authors; literature research, M.K., G.M., S.K., H.S.; clinical studies, M.K., K.T., M.T.; statistical analysis, M.K., S.H.; and manuscript editing, M.K., K.T., G.M., S.K., Y.N., S.T.


   References
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 References
 

  1. Healey JE Jr, Schroy PC. Anatomy of the biliary ducts within the human liver: analysis of the prevailing pattern of branchings and the major variations of the biliary ducts. AMA Arch Surg 1953;66:599–616.[Abstract/Free Full Text]
  2. Couinaud C. Intrahepatic biliary ducts. In: Couinaud C, ed. Surgical anatomy of the liver revisited. Paris, Pa: Couinaud, 1989; 61–74.
  3. Kumon M, Matushima M, Itahara T, et al. Gross anatomy of the liver hilus and caudate lobe using corrosion casts of the liver [in Japanese]. Tan to Sui 1989;10:1417–1422.
  4. Yoshida J, Chijiiwa K, Yamaguchi K, Yokohata K, Tanaka M. Practical classification of the branching types of the biliary tree: an analysis of 1094 consecutive direct cholangiograms. J Am Coll Surg 1996;182:37–40.[Medline]
  5. Cheng YF, Huang TL, Chen CL, Chen YS, Lee TY. Variations of the intrahepatic bile ducts: application in living related liver transplantation and splitting liver transplantation. Clin Transplant 1997;11:337–340.[Medline]
  6. Cheng YF, Huang TL, Chen CL, et al. Anatomic dissociation between the intrahepatic bile duct and portal vein: risk factors for left hepatectomy. World J Surg 1997;21:297–300.[CrossRef][Medline]
  7. Ishiyama S, Yamada Y, Narishima Y, Yamaki T, Kunii Y, Yamauchi H. Surgical anatomy of the hilar bile duct [in Japanese]. Tan to Sui 1999;20:811–820.
  8. Hribernik M, Gadzijev EM, Mlakar B, Ravnik D. Variations of intrahepatic and proximal extrahepatic bile ducts. Hepatogastroenterology 2003;50:342–348.[Medline]
  9. Kamiya J, Nagino M, Uesaka K, Sano T, Nimura Y. Clinicoanatomical studies on the dorsal subsegmental bile duct of the right anterior superior segment of the human liver. Langenbecks Arch Surg 2003;388:107–111.[Medline]
  10. Ohkubo M, Nagino M, Kamiya J, et al. Surgical anatomy of the bile ducts at the hepatic hilum as applied to living donor liver transplantation. Ann Surg 2004;239:82–86.[Medline]
  11. Kawarada Y, Das BC, Onishi H, et al. Surgical anatomy of the bile duct branches of the medial segment (B4) of the liver in relation to hilar carcinoma. J Hepatobiliary Pancreat Surg 2000;7:480–485.[CrossRef][Medline]
  12. Onishi H, Kawarada Y, Das BC, et al. Surgical anatomy of the medial segment (S4) of the liver with special reference to bile ducts and vessels. Hepatogastroenterology 2000;47:143–150.[Medline]
  13. Cho A, Okazumi S, Yoshinaga Y, Ishikawa Y, Ryu M, Ochiai T. Relationship between left biliary duct system and left portal vein: evaluation with three-dimensional portocholangiography. Radiology 2003;228:246–250.[Abstract/Free Full Text]
  14. Kitamura H, Mori T, Arai M, Tsukada K, Numata M, Kawasaki S. Caudal left hepatic duct in relation to the umbilical portion of the portal vein. Hepatogastroenterology 1999;46:2511–2514.[Medline]
  15. Ozden I, Kamiya J, Nagino M, Uesaka K, Sano T, Nimura Y. Clinicoanatomical study on the infraportal bile ducts of segment 3. World J Surg 2002;26:1441–1445.[CrossRef][Medline]
  16. Yamane T, Mori K, Sakamoto K, Ikei S, Akagi M. Intrahepatic ramification of the portal vein in the right and caudate lobes of the liver. Acta Anat (Basel) 1988;133:162–172.[Medline]
  17. Ko S, Murakami G, Kanamura T, Sato TJ, Nakajima Y. Cantlie's plane in major variations of the primary portal vein ramification at the porta hepatis: cutting experiment using cadaveric livers. World J Surg 2004;28:13–18.[CrossRef][Medline]
  18. Varotti G, Gondolesi GE, Goldman J, et al. Anatomic variations in right liver living donors. J Am Coll Surg 2004;198:577–582.[CrossRef][Medline]
  19. Ito T, Kiuchi T, Egawa H, et al. Surgery-related morbidity in living donors of right-lobe liver graft: lessons from the first 200 cases. Transplantation 2003;76:158–163.[CrossRef][Medline]
  20. Thayer WP, Claridge JA, Pelletier SJ, et al. Portal vein reconstruction in right lobe living-donor liver transplantation. J Am Coll Surg 2002;194:96–98.[CrossRef][Medline]
  21. Marcos A, Orloff M, Mieles L, Olzinski A, Sitzmann J. Reconstruction of double hepatic arterial and portal venous branches for right-lobe living donor liver transplantation. Liver Transpl 2001;7:673–679.[CrossRef][Medline]
  22. Chen YS, Cheng YF, De Villa VH, et al. Evaluation of living liver donors. Transplantation 2003;75(3 suppl):S16–S19.[CrossRef][Medline]
  23. Lee SG, Hwang S, Kim KH, et al. Approach to anatomic variations of the graft portal vein in right lobe living-donor liver transplantation. Transplantation 2003;75(3 suppl):S28–S32.[CrossRef][Medline]
  24. Yoshifumi K, Yamagiwa K. Operation for gallbladder cancer [in Japanese]. Gastroenterol Surg 1997;20(7):1088–1105.
  25. Nagino M. Knack of anterior segment resection and caudate lobe resection. In: Nimura Y, ed. Knack and pitfalls of surgery for hilar cholangiocarcinoma [in Japanese]. Tokyo, Japan: Bunkodo, 2002; 270–271.
  26. Fong Y, Blumgart LH. Useful stapling techniques in liver surgery. J Am Coll Surg 1997;185:93–100.[CrossRef][Medline]
  27. Nakai T, Koh K, Funai S, Kawabe T, Okuno K, Yasutomi M. Comparison of controlled and Glisson's pedicle transections of hepatic hilum occlusion for hepatic resection. J Am Coll Surg 1999;189:300–304.[CrossRef][Medline]
  28. Figueras J, Lopez-Ben S, Llado L, et al. Hilar dissection versus the "glissonean" approach and stapling of the pedicle for major hepatectomies: a prospective, randomized trial. Ann Surg 2003;238:111–119.[CrossRef][Medline]
  29. Couinaud C. Embryology. In: Couinaud C, ed. Surgical anatomy of the liver revisited. Paris, Pa: Couinaud, 1989; 11–24.
  30. Skandalakis JE, Gray SW. Embryology for surgeons. 2nd ed. Baltimore, Md: Williams & Wilkins, 1994; 282–295.
  31. Taenzer V, Volkhardt V. Double blind comparison of meglumine iotroxate (Biliscopin), meglumine iodoxamate (Endobil), and meglumine ioglycamate (Biligram). AJR Am J Roentgenol 1979;132:55–58.[Abstract]
  32. Stockberger SM, Wass JL, Sherman S, Lehman GA, Kopecky KK. Intravenous cholangiography with helical CT: comparison with endoscopic retrograde cholangiography. Radiology 1994;192:675–680.[Abstract/Free Full Text]
  33. Takahashi M, Saida Y, Itai Y, Gunji N, Orii K, Watanabe Y. Reevaluation of spiral CT cholangiography: basic considerations and reliability for detecting choledocholithiasis in 80 patients. J Comput Assist Tomogr 2000;24:859–865.[CrossRef][Medline]
  34. Fulcher AS, Turner MA. Orthotopic liver transplantation: evaluation with MR cholangiography. Radiology 1999;211:715–722.[Abstract/Free Full Text]
  35. Limanond P, Raman SS, Ghobrial RM, Busuttil RW, Lu DS. The utility of MRCP in preoperative mapping of biliary anatomy in adult-to-adult living related liver transplant donors. J Magn Reson Imaging 2004;19:209–215.[CrossRef][Medline]
  36. Yeh BM, Breiman RS, Taouli B, Qayyum A, Roberts JP, Coakley FV. Biliary tract depiction in living potential liver donors: comparison of conventional MR, mangafodipir trisodium–enhanced excretory MR, and multi-detector row CT cholangiography—initial experience. Radiology 2004;230:645–651.[Abstract/Free Full Text]
  37. Leyendecker JR, Rivera E Jr, Washburn WK, Johnson SP, Diffin DC, Eason JD. MR angiography of the portal venous system: techniques, interpretation, and clinical applications. RadioGraphics 1997;17:1425–1443.[Abstract]
  38. Carr JC, Nemcek AA Jr, Abecassis M, et al. Preoperative evaluation of the entire hepatic vasculature in living liver donors with use of contrast-enhanced MR angiography and true fast imaging with steady-state precession. J Vasc Interv Radiol 2003;14:441–449.[Medline]
  39. Amano Y, Takahama K, Nozaki A, Amano M, Kumazaki T. Magnetic resonance portography using contrast-enhanced fat-saturated three-dimensional steady-state free precession imaging. J Magn Reson Imaging 2004;19:238–244.[CrossRef][Medline]
  40. Chopra S, Chintapalli KN, Ramakrishna K, Rhim H, Dodd GD 3rd. Helical CT cholangiography with oral cholecystographic contrast material. Radiology 2000;214:596–601.[Abstract/Free Full Text]
  41. Kapoor V, Peterson MS, Baron RL, Patel S, Eghtesad B, Fung JJ. Intrahepatic biliary anatomy of living adult liver donors: correlation of mangafodipir trisodium-enhanced MR cholangiography and intraoperative cholangiography. AJR Am J Roentgenol 2002;179:1281–1286.[Abstract/Free Full Text]
  42. Goldman J, Florman S, Varotti G, et al. Noninvasive preoperative evaluation of biliary anatomy in right-lobe living donors with mangafodipir trisodium-enhanced MR cholangiography. Transplant Proc 2003;35:1421–1422.[CrossRef][Medline]
  43. Sajjad Z, Oxtoby J, West D, Deakin M. Biliary imaging by spiral CT cholangiography: a retrospective analysis. Br J Radiol 1999;72:149–152.[Abstract]
  44. Breen DJ, Nicholson AA. The clinical utility of spiral CT cholangiography. Clin Radiol 2000;55:733–739.[CrossRef][Medline]
  45. Schroeder T, Malago M, Debatin JF, et al. Multidetector computed tomographic cholangiography in the evaluation of potential living liver donors. Transplantation 2002;73:1972–1973.[CrossRef][Medline]
  46. Cabada Giadas T, Sarria Octavio de Toledo L, Martinez-Berganza Asensio MT, et al. Helical CT cholangiography in the evaluation of the biliary tract: application to the diagnosis of choledocholithiasis. Abdom Imaging 2002;27:61–70.[CrossRef][Medline]
  47. Kwon AH, Uetsuji S, Ogura T, Kamiyama Y. Spiral computed tomography scanning after intravenous infusion cholangiography for biliary duct anomalies. Am J Surg 1997;174:396–401.[Medline]
  48. Kinami S, Yao T, Kurachi M, Ishizaki Y. Clinical evaluation of 3D-CT cholangiography for preoperative examination in laparoscopic cholecystectomy. J Gastroenterol 1999;34:111–118.[CrossRef][Medline]
  49. Toyoda H, Hayakawa K, Kikkawa M, et al. Usefulness of three-dimensional CT cholangiography for patients prior to laparoscopic cholecystectomy. Radiat Med 2000;18:161–166.[Medline]
  50. Nambu A, Ichikawa T, Katoh K, Araki T. A case of abnormal pancreaticobiliary junction evidenced by 3D drip infusion cholangiography CT. J Comput Assist Tomogr 2001;25:653–655.[CrossRef][Medline]
  51. Kobayashi M, Matsuura K, Araki K, et al. Three-dimensional demonstration of cystic duct by helical CT scanning. Hepatogastroenterology 2002;49:1491–1495.[Medline]
  52. Takeuchi M, Hishiyama H, Kondo S, Katoh H. Efficacy of cholangiography under helical computed tomography for laparoscopic cholecystectomy. Surg Today 2002;32:387–391.[CrossRef][Medline]
  53. Nilsson U. Adverse reactions to iotroxate at intravenous cholangiography: a prospective clinical investigation and review of the literature. Acta Radiol 1987;28:571–575.[Medline]
  54. Lindsey I, Nottle PD, Sacharias N. Preoperative screening for common bile duct stones with infusion cholangiography: review of 1000 patients. Ann Surg 1997;226:174–178.[CrossRef][Medline]



This article has been cited by other articles:


Home page
 RadiologyHome page
R. Sugita, T. Yamazaki, N. Fujita, T. Naitoh, M. Kobari, and S. Takahashi
Cystic Artery and Cystic Duct Assessment with 64-Detector Row CT before Laparoscopic Cholecystectomy
Radiology, July 1, 2008; 248(1): 124 - 131.
[Abstract] [Full Text] [PDF]

Home page
 RadioGraphicsHome page
M. Hashimoto, K. Itoh, K. Takeda, T. Shibata, T. Okada, Y. Okuno, and M. Hino
Evaluation of Biliary Abnormalities with 64-Channel Multidetector CT
RadioGraphics, January 1, 2008; 28(1): 119 - 134.
[Abstract] [Full Text] [PDF]

Home page
 RadiologyHome page
B. M. Yeh, F. V. Coakley, A. C. Westphalen, B. N. Joe, C. E. Freise, A. Qayyum, R. A. McTaggart, and J. P. Roberts
Predicting Biliary Complications in Right Lobe Liver Transplant Recipients according to Distance between Donor's Bile Duct and Corresponding Hepatic Artery
Radiology, January 1, 2007; 242(1): 144 - 151.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Figures Only
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kitami, M.
Right arrow Articles by Takahashi, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kitami, M.
Right arrow Articles by Takahashi, S.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
RADIOLOGY RADIOGRAPHICS RSNA JOURNALS ONLINE