Association between anatomic variations of extrahepatic and intrahepatic bile ducts: Do look up!

Biliary anatomic variations are usually asymptomatic, but they may cause problems in diagnostic investigations and interventional and surgical procedures, increasing both their technical difficulty and their postoperative complication rates. The aim of the present study was to evaluate the prevalence of anatomic variations in the intrahepatic biliary ducts (IHBD) in relation to demographical and clinical characteristics in a large study population requiring magnetic resonance cholangiopancreatography (MRCP) for various clinical conditions. The possible association between IHBD and extrahepatic biliary ducts (EHBD) variants was then explored. From January 2017 to May 2019, 1004 patients underwent MRCP. Demographical and clinical data were collected. IHBD and EHBD anatomy were recorded and the EHBD anatomy was classified using both qualitative and quantitative classifications. The presence of a type 3 EHBD variant (an abnormal proximal cystic duct [CD] insertion) in both qualitative and quantitative classifications and an intrapancreatic CD were associated with the presence of IHBD variants at univariate analysis (p = 0.008, p = 0.019, and p = 0.001, respectively). The presence of a posterior or medial insertion of the CD into the EHBD was a strong predictive factor of the presence of IHBD variants both at uni- and multivariate analysis (p = 0.002 and p = 0.003 for posterior insertion and p = 0.002 and p = 0.002 for medial insertion, respectively). The presence of gallstones on MRCP resulted in a strong predictor of the presence of an anatomical variant of the IHBD both at uni- and multivariate analysis (p = 0.027 and p = 0.046, respectively). In conclusion, the presence of a type 3 variant of the EHBD, an intrapancreatic CD and, especially, a posterior/medial CD insertion into the EHBD represent predictive factors of the concomitant presence of IHBD variants, thus radiologists must be vigilant when encountering these EHBD configurations and always remember to "look up" at the IHBD. Finally, the presence of an IHBD variant is a strong predictive factor of gallstones.

[The new classifications of biliary tract diseases based on actual anatomy]

In order to facilitate the treatment strategies for biliary tract injury, hilar cholangiocarcinoma, bile duct tumor thrombus, cholangiocellular carcinoma and bile duct cystic dilatation, many classifications have been made, even more than 10 types for one disease. Each type is represented by numbers or English alphabet, which are not only confusing but also difficult to remember. The Academician Mengchao Wu divided the liver into five sections and four segments base on its anatomy, this classification is very direct and visual, thus had been using till now. In order to overcome those complicated problems, it is considered to develop a new classification based on actual anatomic location similar to that for liver cancer, which is easy to remember and to directly determine the treatment strategy. All kinds of classifications have their own characteristics and advantages and disadvantages. This practical classifications avoid the complexity and may be useful for clinicians.

Reference limits for hepatic bile duct-to-arteriole and bile duct-to-portal tract ratios in healthy cats

OBJECTIVE To establish reference limits for hepatic bile duct-to-arteriole ratio (BD:A) and bile duct-to-portal tract ratio (BD:PT) in healthy cats and assess whether these parameters could be used to support a diagnosis of biliary ductopenia in cats. SAMPLE Hepatic biopsy samples from healthy cats (n = 20) and cats with ductopenia (2). PROCEDURES Hepatic biopsy samples from healthy cats were used to count the number of bile ducts and hepatic arterioles in 20 portal tracts for each cat. Mean BD:A and mean BD:PT for each cat were calculated, and these values were used to determine reference limits for mean BD:A and mean BD:PT. Results of histologic evaluation, including immunohistochemical staining in some instances, were compared for healthy cats versus cats with ductopenia. RESULTS Of the 400 portal tracts from healthy cats, 382 (95.5%) and 396 (99.0%) had BD:A and BD:PT, respectively, ≥ 1.0, with less variability in BD:A. Mean BD:A and BD:PT were markedly lower in both cats with ductopenia, compared with values for healthy cats. However, only mean BD:A for cats with ductopenia was below the reference limit of 0.59. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that systematic evaluation of BD:A, with a lower reference limit of 0.59 to define biliary ductopenia in cats, may be a discrete and easily applied morphometric tool to enhance detection of ductopenia in cats. However, application of this ratio required evaluation of ≥ 20 portal tracts with cross-sectioned portal elements to determine a mean BD:A value.

Comparison of the Clinicopathologic Characteristics of Intraductal Papillary Neoplasm of the Bile Duct according to Morphological and Anatomical Classifications

BACKGROUND

Intraductal papillary neoplasm of the bile duct (IPNB) is a recently defined entity and its clinical characteristics and classifications have yet to be established. We aimed to clarify the clinical features of IPNB and determine the optimal morphological classification criteria.

METHODS

From 2003 to 2016, 112 patients with IPNB who underwent surgery were included in the analysis. After pathologic reexamination by a specialized biliary-pancreas pathologist, previously suggested morphological and anatomical classifications were compared using the clinicopathologic characteristics of IPNB.

RESULTS

In terms of histologic subtypes, most patients had the intestinal type (n = 53; 48.6%) or pancreatobiliary type (n = 33; 30.3%). The simple "modified anatomical classification" showed that extrahepatic IPNB comprised more of the intestinal type and tended to be removed by bile duct resection or pancreatoduodenectomy. Intrahepatic IPNB had an equally high proportion of intestinal and pancreatobiliary types and tended to be removed by hepatobiliary resection. Morphologic classifications and histologic subtypes had no effect on survival, whereas a positive resection margin (75.9% vs. 25.7%; P = 0.004) and lymph node metastasis (75.3% vs. 30.0%; P = 0.091) were associated with a poor five-year overall survival rate. In the multivariate analysis, a positive resection margin and perineural invasion were important risk factors for survival.

CONCLUSION

IPNB showed better long-term outcomes after optimal surgical resection. The "modified anatomical classification" is simple and intuitive and can help to select a treatment strategy and establish the proper scope of the operation.

Anatomical study of the intrahepatic biliary ducts. Parameters that guide the surgical approach in transplanting the left lobe of the liver

INTRODUCTION

The techniques of split liver transplantation and transplanting organs from living donors require a thorough anatomical knowledge of biliary drainage, and this is an important factor in preventing complications.

METHODS

forty-five human livers were used to perform this study. Measurements were made between the confluence of the right hepatic duct (RHD) and the left hepatic duct (LHD) and among the following structures: the venous ligament, the vertex of the confluence of the duct of segment II (DSll) and the duct of segment III (DSIII), the insertion of the duct of the segment I (DSI) and the duct of segment IV (DSIV). Then the distance between the vertex of the confluence of DSII and DSIII and the ligamentum venosum was checked.

RESULTS

The LHD had less anatomical variation than the RHD. Four drainage patterns were established for the left lobe, and pattern l, in which the confluence of DSll and DSIII is to the left of the ligamentum venosum, is considered to be the most constant one. A single duct of the confluence of DSll and DSIII was found 1, 2 and 2.5 cm to the right of the ligamentum venosum in 65%, 80%, and 95% of the cases, respectively.

CONCLUSION

It was possible to show evidence of four drainage patterns of the left anatomical lobe of the liver. Furthermore, it was possible to establish the ligamentum venosum as an anatomical reference for locating the confluences of the ducts of the left liver segments.

Anatomic variations of intrahepatic bile ducts in a European series and meta-analysis of the literature

BACKGROUND

Accurate knowledge of biliary anatomy and its variants is essential to ensure successful hepatic surgery; however, data from European countries are lacking.

METHODS

Two hundred cholangiograms obtained from patients submitted to whole liver transplantation were reviewed; donors' characteristics were related to the prevalence of typical biliary anatomy and its variants. A comprehensive literature search was performed with MEDLINE and EMBASE from 1980 to 2010 to investigate whether geographical origin could be related to biliary abnormalities.

RESULTS

Typical biliary anatomy was observed in 64.5% of cases, but female donors more frequently presented an anatomic variation; typical anatomy was present in 55.0% of females and in 74.0% of males (P = 0.005). Twenty-two reports were identified by the literature search with a total of 7,559 cases, including the present series; heterogeneity was low (Q = 14.60; I2 < 5.0%) after exclusion of three outlier reports. Prevalence of typical biliary anatomy was similar in Europeans and Americans (∼60%); a slightly higher prevalence was observed in Asiatics (∼65%).

CONCLUSIONS

Anatomic variants seem to be more frequent in females, probably as a consequence of different embryologic development. Available data suggest that typical biliary anatomy can be more frequent in Asiatics, but an accurate means of classification is essential to making comparison realistic.

Important biliary drainage variations of left liver lobe

Biliary drainage of the left liver lobe has been examined in view of the current surgical trends for using the left liver lobe of living parent donor for liver transplantation. For this purpose, on 13 acrylic casts of porto-biliary elements of the liver, variations of pattern and level of merging of segmental ducts into a left lobe (lateral) duct were determined in comparison with the main portal trunks. Duplication of ducts was noticed in segments 2 and 3; merging of a duct from the left portion of segment 1 with a duct from segment 2; merging of a double left medial duct with a duct from segment 3 and a magistral pattern of consecutive confluence of segmental ducts from lateral and medial sectors as well as from the left portion of segment 1 into a duct arising from segment 3. Bearing in mind lateral tributaries of the left lobe duct that comprise segment 2, the left portion of segment 1 and subsegment 9 "b" from the right dorsal sector, the disadvantages of obtaining a left lobe graft can be identified.

[Anatomy problems in the radical resection for hilar cholangiocarcinoma]

OBJECTIVE

To analyze the clinical data, surgical strategies and results from the patients with hilar cholangiocarcinoma (HCCA), and to explore the anatomic factors related to the radical resection.

METHODS

The data from 52 patients with HCCA who underwent radical resection between January 1984 to December 2008 were investigated retrospectively, which included clinical diagnosis, Bismuth-Corlette classification, pathologic features, surgical procedures and follow-up results.

RESULTS

According to the Bismuth-Corlette classification, 5, 12, 6, 16 and 13 patients belonged to type I, II, IIIa, IIIb and IV respectively. There were 24 cases underwent combined hepatic lobectomy. The 1-, 3- and 5-year survival rates were 78.8%, 36.4% and 12.1% respectively. Postoperative complications rate was 30.8% with the 3.8% mortality rate. The frequency of surgical complications was significantly higher in patients with higher level of serum total bilirubin (> 340 micromol/L) than that in patients with a relatively lower one (170 micromol/L) before operation (P < 0.05).

CONCLUSIONS

Some anatomical factors should be considered during the radical resection of hilar cholangiocarcinoma, especially evaluation of potential hepatectomy, resection of caudate lobe, hepatic artery resection and/or reconstruction. The prognosis of the patients underwent R(0) radial resection could be significantly improved.

[Anatomy of the liver: what you need to know]

A precise knowledge of arterial, portal, hepatic and biliary anatomical variations is mandatory when a liver intervention is planned. However, only certain variations must be searched when a precise intervention is planned. The basic liver anatomy as well as the most relevant malformations will be precised.

Treatment strategy for hilar cholangiocarcinoma, with special reference to the limits of ductal resection in right-sided hepatectomies

The surgical anatomy of the hepatic hilar region is characterized by the three-dimensional formation of the branches of the bile duct, portal vein, and hepatic artery. The limit of ductal resection in hepatectomy for hilar cholangiocarcinoma is the most peripheral point where the hepatic ducts can be separated from the vasculature. The limit is different for each type of hepatectomy because the portal vein branches that should be preserved or divided vary with the extent of the hepatectomy, and therefore the limit of separation of the hepatic ducts differs. Surgeons are required to understand the surgical anatomy and to identify the precise area of cancer spread on a preoperative cholangiogram so as to choose the appropriate type of hepatectomy, and to ensure that the remnant ductal margin is cancer-negative.

[New possibilities to study biliary tree and gallbladder: functional magnetic resonance cholangiography contrast-enhanced with mangafodipir trisodium (Mn DPDP)]

Mangafodipir trisodium (Teslascan) is a hepatobiliary contrast agent that provides noninvasive opacification of the bile ducts. Using this contrast medium combined with a T1-weighted gradient echo enhanced sequence provides functional imaging of the bile ducts. Second-intention MRI was obtained after the usual morphological study of the bile ducts using heavily T2-weighted sequences (SS-FSE Te eff long and SS FSE Te eff short). This method can detect many biliary duct anomalies: biliary leakage in the postoperative context, mapping of bile ducts and the gallbladder in the search for anatomical variants, analysis of biliodigestive or biliobiliary anastomoses, or a dynamic study of bile secretion and excretion. Opacification of the bile ducts has only been possible until now with invasive tests aggravated by a certain co-morbidity rate and their functional study using biliary scintigraphy limited by mediocre spatial resolution. This new possibility provides access not only to morphological imaging, but also to functional imaging with excellent spatial resolution.

Magnetic resonance cholangiopancreatography of biliary system abnormalities in children

OBJECTIVE

The aim of this study was to assess the usefulness of magnetic resonance cholangiopancreatography (MRCP) with a single-shot fast spin-echo sequence as a noninvasive method to evaluate the biliary system in children.

METHODS

Twenty-five MRCP examinations of 23 patients were evaluated. On the basis of surgical (n=5), endoscopic retrograde cholangiopancreatography (n=4), liver biopsy (n=4), clinical data, and follow-up observation, 6 children were considered to have no significant abnormality. The other 17 children were found to have pancreaticobiliary disease, including choledochal cyst, biliary system dilatation, choledocholithiasis, biliary atresia, multiseptated gallbladder, anomalous pancreaticobiliary union, ruptured hydatic cyst, and biloma. The findings were correlated with the ultrasonography, computed tomography, surgical, and endoscopic retrograde cholangiopancreatography results.

RESULTS

Magnetic resonance cholangiopancreatography showed the first branch of the intrahepatic duct, the common hepatic duct, the gallbladder, and the common bile duct in 14 children. Cystic duct was not seen in infants, but was partially visible in younger children. Although the main pancreatic duct was visible in head and body portions in 65% of the patients, it was visible in 17% of the patients in the tail. The diagnostic accuracy of MRCP was 100% in patients with choledochal cysts and stenoses. In a patient with hydatic cyst, cystobiliary communication was successfully demonstrated.

CONCLUSION

Magnetic resonance cholangiopancreatography can be used effectively for the evaluation of the biliary system in children.

Contrast-enhanced magnetic resonance cholangiography with Gd-BOPTA and Gd-EOB-DTPA in healthy subjects

PURPOSE

To evaluate the biliary enhancement dynamics of the two gadolinium chelates Gd-BOPTA (MultiHance) and Gd-EOB-DTPA (Primovist) in normal healthy subjects.

MATERIAL AND METHODS

Ten healthy volunteers were evaluated with both agents by magnetic resonance (MR) imaging at 1.5T using a breath-hold gradient-echo T1-weighted VIBE sequence. The relative signal intensity (SI) differences between the common hepatic duct (CHD) and liver parenchyma were measured before and 10, 20, 30, 40, 130, 240, and 300 min after contrast medium injection.

RESULTS

Biliary enhancement was obvious 10 min post-injection for Gd-EOB-DTPA and was noted at 20 min for Gd-BOPTA. At 40 min delay, Gd-BOPTA reached its peak biliary enhancement, but at neither 30 nor 40 min delay was there any significant difference compared with that of Gd-EOB-DTPA. At later delays, the contrast between CHD and liver continued to increase for Gd-EOB-DTPA, whereas it decreased for Gd-BOPTA.

CONCLUSION

The earlier onset and longer duration of a high contrast between CHD and liver for Gd-EOB-DTPA facilitates examination of hepatobiliary excretion. Therefore, Gd-EOB-DTPA may provide adequate hepatobiliary imaging within a shorter time span than Gd-BOPTA and facilitate scheduling at the MR unit. Further studies in patients are required to compare the imaging advantages of Gd-EOB-DTPA and Gd-BOPTA in clinical practice.

Diagnostic and surgical approaches in hilar cholangiocarcinoma

Hilar cholangiocarcinoma is a rare tumor. Surgery remains the only treatment to prolong survival. There is a correlation between the extent of diagnostic work-up and the achieved resection rates. Moreover, diagnostic work-up may contribute to an improvement of the surgical technique. Due to the perihilar fibrosis, the extent of the central lesion may be overestimated, which may lead to exclude the patient from potentially curative surgery. En bloc resection is requested to achieve tumor-free resection margins. The prognosis of the patients treated with surgery is strongly influenced by negative resection margins. According to our experience, 5-year survival of 78/111 patients with tumor resection (resection rate 71%) has been 30%. Forty-eight percent of the patients with curative en bloc resection of tumor and liver survived for more than 5 years. Perioperative mortality was 5.1%. The available data are supposed to reflect the results of centers with high caseload and not the general situation.

A study of the subvesical bile duct (duct of Luschka) in resected liver specimens

BACKGROUND

Injury to the duct of Luschka is associated with biliary fistula from the gallbladder bed after cholecystectomy. However, few studies have reported on the detailed anatomy. We elucidated the anatomy and frequency of the duct of Luschka

METHODS

A total of 128 specimens from patients who underwent right hepatectomy or more extensive right-sided liver resection between February 1992 and December 2003 were examined. Specimens were fixed in formalin, and serial sections were prepared to trace the course of the bile ducts from the subsegmental branch level.

RESULTS

The duct of Luschka was observed in 6 (4.6%) specimens. The sites of confluence were as follows: right anterior inferior dorsal branch (2 patients), right anterior branch (2 patients), right hepatic duct (1 patient), and common hepatic duct (1 patient). The upstream end was located in the liver parenchyma of the right anterior inferior dorsal subsegment (5b) and connective tissue of the gallbladder bed in 4 and 2 specimens, respectively.

CONCLUSIONS

The duct of Luschka never crosses the segmental (5b) border. Therefore, its upstream region may not be injured by segmentectomy or more extensive liver resection. However, it is possible to injure the duct of Luschka at the common hepatic duct, even if right-sided hepatectomy is performed, as the sites of confluence included the common hepatic duct.

Intrahepatic biliary strictures after liver transplantation

Biliary complication has been one of the most common complications after liver transplantation. Nonanastomotic strictures and dilatations involving the intrahepatic biliary tree have been recognized as biliary complications. These lesions were reported to be associated with hepatic artery thrombosis; prolonged preservation time; ABO-incompatible organs; and immunological injury, including injuries to vascular endothelial cells (chronic rejection) and the bile duct (primary sclerosing cholangitis). However, the etiology of these lesions appeared to be mostly related to ischemic injury. Anatomical research on the arterial supply of the bile duct has provided further insights into bile duct blood supply and its surgical implications. The biliary tract is supplied with arterial blood by a vasculature called the peribiliary vascular plexus. Any injury to the peribiliary vascular plexus may contribute to ischemic death of the biliary system mucosa. At many points, the process of liver transplantation exposes the endothelial cells and peribiliary vascular plexus to ischemic injury. The majority of intrahepatic biliary strictures (IHBS) are diffuse or bilateral. A percutaneous or an endoscopic approach has been used as the initial treatment. However, a low threshold for surgical intervention (retransplantation) should be adopted, because these patients demonstrate high mortality. The aim of this article is to review the anatomy, etiology, clinical picture, diagnosis, management, and prognosis of IHBS after liver transplantation.

Congruence between the courses of the biliary ductal and the hepatic arterial systems

The development of diagnostic methods and new surgical techniques means it is increasingly important to have accurate knowledge of the anatomy of the hepatic arterial and biliary systems, including their variations, at extrahepatic and intrahepatic levels. The aim of this study was to determine how often the biliary and arterial systems run together and branch in the same pattern. Fifty corrosion casts of the liver were used to analyse the origin and branching patterns of arteries and the confluences of bile ducts. In addition, both systems were analysed to determine the frequency of normal arrangements and variations. The congruence of the course of both systems was analysed at the porta hepatis and in the left and right hemilivers down to the segmental level. A congruent course of the arterial and the biliary systems was identified in 38% of cases at the porta hepatis, in 32% of cases in the left hemiliver and in 30% of the right hemiliver. The congruence of both systems at the porta hepatis and in the left hemiliver was identified only if both systems were normal. In the right hemiliver, however, the congruence of both systems was identified even when both systems were variable, but only in 10% of cases. The results of the study show that, on the basis of knowledge of the course and branching of one system, the other system cannot be predicted.

Three-dimensional vasculature of the bovine liver

To clarify anatomical distribution of Fasciola infection, the vascular and ductal architectures of the liver were studied by means of corrosion cast technique using synthetic resin. The arteria hepatica propria (AP) passes as the arteria gastroduodenalis (AG); AP becomes the left trunk after the porta hepatis; AP passes on the right side of vena porta communis (VPC) and projects AG while curving in a U-shape below the portal vein. Hepatic veins located between the vena hepatica media (HM) and vena hepatica dextra (HD) varied widely among specimens and were irregular, including the vena hepatica dorso-lateralis sinistra (Hds), vena hepatica dorso-lateralis dextra (Hdd), vena hepatica lobi caudati (Hlc), venae hepaticae processus caudati (Hpc), venae hepaticae processus papillaris (Hpp), and the hepatic vein to the dorsal intermediate part, which directly or indirectly drained into the vena cava caudalis. The courses of the bovine hepatic veins were markedly diverse, and anastomoses between vena hepatica sinistra (HS) and Hds were observed in about a half of the livers. The portal vein entered the liver as VPC slightly above the centre of the right lobe on the visceral surface. The intermediate or transverse part [pars transversa trunci sinistri (PTS)] of truncus sinister (TS), which extends from the entry of the portal vein into the left lobe of the liver, was slightly arched downward [pars umbilicalis trunci sinistri (PUS)]. The portal vein further arched from the distal end of TS to the umbilical vein and ran towards the inter-lobar incision between the left lobe and quadrate lobe. Based on these branches, hepatic segments were determined as 13 or 14 areas. A total of 15 bile ducts were derived from various lobes. The hepatic duct was about 2.6-6 cm long from the confluence of the right and left hepatic ducts to the division of the cystic duct and the common hepatic duct.

Clinical and anatomical basis for the classification of the structural parts of liver

Progress of diagnostic human's liver imaging (ultrasound, computerized tomography, magnetic nuclear resonance, etc.) stimulates development of modern liver surgery. Therefore, before and during the operation, surgeons and radiologists can determine the site and extent of liver damage, its relationship with blood vessels and ascertain which part of the liver should be resected. For this reason, physicians have to know anatomical and clinical peculiarities of the liver. Naming of the parts of this complex inner organ is still highly varied: parts, halves, lobes, divisions, sectors, segments, and subsegments. Our understanding and explanation of liver composition are still defined differently among anatomists, surgeons, and radiologists, thus not only confusing less experienced specialists, but also increasing probability of mistakes. Such lack of communication aggravates the design of an operation plan and its documentation, which frequently may even result in undesirable legal consequences. Unified terms among surgeons and radiologists are of importance not only in clinical settings of one country, but also on the international level (e.g. when comparing results of surgery). The smallest parts of the liver are defined using C. Couinaud's segmentation system, allowing for a precise identification of the site of liver damage, as well as to plan methods of segment resection that would protect the remaining hepatic tissue. The classification that best meets the needs of surgeons and radiologists was the one proposed by H. Bismuth. We suggest that this classification should also be used by our physicians who are engaged in diagnostics and treatment of hepatic diseases in their practice. We also discuss other classifications used worldwide (those proposed by J. Healey and P. Schroy, N. Goldsmith and R. Woodburne, C. Couinaud, and H. Bismuth) and present recommendations of global societies of anatomists and surgeons.

The intrahepatic biliary epithelium is a target of the growth hormone/insulin-like growth factor 1 axis

BACKGROUND/AIMS

We evaluated the role and mechanisms by which the GH/IGF1 axis modulates cholangiocyte proliferation.

METHODS

GH-receptors (GH-R), IGF1, IGFBP3 (binding protein 3), IGF1-R and receptor substrates (IRS) were evaluated in cholangiocytes of normal or bile duct-ligated (BDL) rat livers. The effects of GH and IGF1 on proliferation of normal quiescent cholangiocytes and the transduction pathways involved were investigated.

RESULTS

IGF1, GH-R, IGF1-R, IRS-1/2 were expressed in normal cholangiocytes and overexpressed in cholangiocytes proliferating after BDL which also secrete IGF1 in a higher amount than normal cells. IGFBP3, which may counter-regulate IGF1 effects, was decreased in BDL cholangiocytes. IGF1 promoted cholangiocyte proliferation in association with overexpression of p-IGF1R, IRS1, IRS-2, p-ERK1/2 and p-AKT. GH induced IGF1 expression and release in isolated cholangiocytes, and reproduced the effects of IGF1 but GH effects were abolished by IGF1-R blocking antibody, suggesting IGF1 as a mediator of GH. Finally, IGF1 and 17beta-estradiol reciprocally potentiated their proliferative effects on cholangiocytes, and by interacting at both receptor and post-receptor levels.

CONCLUSIONS

Cholangiocytes respond to GH with production and release of IGF1 that modulates cell proliferation by transduction pathways involving IGF1-R, IRS1/2 and both ERK and PI3-kinase pathways. The biliary epithelium is a target of GH/IGF1 liver axis.

Heterogeneity of subvesical ducts or the ducts of Luschka: a study using drip-infusion cholangiography-computed tomography in patients and cadaver specimens

The objective of this study was to examine the heterogeneity of the subvesical duct or the ducts of Luschka as well as the reliability of drip-infusion cholangiography with computed tomography (DIC-CT) for their identification. DIC-CT was used in 277 consecutive patients (135 men, 142 women) and for the dissection and histologic study of 10 cadaver livers. We found 32 subvesical ducts in 28 (10.1%) of 277 patients. Irrespective of whether the terminals were extra- or intraparenchymal, the subvesical ducts often (17/32 ducts, 15/28 patients) drained into a subsegmental duct of S5 or S4. Notably, some displayed an "intermediate" course along the gallbladder fossa with an intraparenchymal origin and terminated at S5. Such ducts tended to be seen in the elderly. Another 15 ducts drained into a thick, centrally located duct, such as the right sectorial or hepatic duct. The anatomic study demonstrated that the subvesical duct likely included the cystic vein-concomitant duct. A major type of subvesical duct, characterized by an intermediate course along its bed, appeared to result from degenerative exposure of a peripheral duct with aging. The subvesical duct draining into the thick duct included both a "daughter branch," such as seen in the lung, and the so-called anomaly. Such ducts can be demonstrated with DIC-CT, but the incidence might be limited. However, the cystic vein/concomitant duct was difficult to identify radiologically. Consequently, although presurgical radiology is useful for avoiding bile leakage after laparoscopic cholecystectomy, surgeons should be aware of its limitations.

Contribution of magnetic resonance cholangiography to the anatomic study of bile ducts

BACKGROUND/AIMS

Until recently, in-depth anatomic study of the biliopancreatic ducts was only possible with injection-corrosion techniques or peroperative radiology. These were tedious and tributary of the quality of anatomic specimens. Since 1990, a new minimally invasive technique has been available: nuclear magnetic resonance cholangiography (NMRCP). The aim of the study was to evaluate the feasibility and the results of NMRCP applied to the study of the biliopancreatic tract.

METHODOLOGY

NMRCP was performed in 50 healthy volunteers and results were interpreted by two readers in consensus.

RESULTS

NMRCP showed the common bile, left hepatic and paramedian ducts in 100% of cases. The right hepatic duct was seen in 78% of cases. The lateral duct was seen in 98% of cases. Segmental ducts were found in 68 to 78% of cases for segments II, III, VI, VII and VIII. Only 18% of ducts for segment I were found. The gallbladder was seen in only 72% of cases. The cystic duct was clearly seen in 64% of cases. The hepato-pancreatic duct was seen in 82% of cases. In 70% of cases, distribution of the hepatic ducts was modal. The remaining 30% displayed variations.

CONCLUSIONS

The anatomic and radiological results reported in our study of 50 cases demonstrate the excellent feasibility and reliability of magnetic resonance cholangiography applied to the anatomic study of the bile ducts. We suggest that a wide scale multicenter study in living healthy individuals may be worth considering.

Defining intrahepatic biliary anatomy in living liver transplant donor candidates at mangafodipir trisodium-enhanced MR cholangiography versus conventional T2-weighted MR cholangiography

PURPOSE

To compare three-dimensional (3D) mangafodipir trisodium-enhanced T1-weighted magnetic resonance (MR) cholangiography with conventional T2-weighted MR cholangiography for depiction and definition of intrahepatic biliary anatomy in liver transplant donor candidates.

MATERIALS AND METHODS

One hundred eight healthy liver transplant donor candidates were examined with two MR cholangiographic methods. All candidates gave written informed consent, and the study was approved by the institutional review board. First, breath-hold transverse and coronal half-Fourier single-shot turbo spin-echo and breath-hold oblique coronal heavily T2-weighted turbo spin-echo sequences were performed. Second, mangafodipir trisodium-enhanced breath-hold fat-suppressed 3D gradient-echo sequences were performed through the ducts (oblique coronal plane) and through the entire liver (transverse plane). Interpretation of biliary anatomy findings, particularly variants affecting right liver lobe biliary drainage, and degree of interpretation confidence at both 3D mangafodipir trisodium-enhanced MR cholangiography and T2-weighted MR cholangiography were recorded and compared by using the Wilcoxon signed rank test. Then, consensus interpretations of both MR image sets together were performed. Intraoperative cholangiography was the reference-standard examination for 51 subjects who underwent right lobe hepatectomy. The McNemar test was used to compare the accuracies of the individual MR techniques with that of the consensus interpretation of both image sets together and to compare each technique with intraoperative cholangiography.

RESULTS

Biliary anatomy was visualized with mangafodipir trisodium enhancement in all patients. Mangafodipir trisodium-enhanced image findings agreed with findings seen at combined interpretations significantly more often than did T2-weighted image findings (in 107 [99%] vs 88 [82%] of 108 donor candidates, P < .001). Confidence was significantly higher with the mangafodipir trisodium-enhanced images than with the T2-weighted images (mean confidence score, 4.5 vs 3.4; P < .001). In the 51 candidates who underwent intraoperative cholangiography, mangafodipir trisodium-enhanced imaging correctly depicted the biliary anatomy more often than did T2-weighted imaging (in 47 [92%] vs 43 [84%] donor candidates, P = .14), whereas the two MR imaging techniques combined correctly depicted the anatomy in 48 (94%) candidates.

CONCLUSION

Mangafodipir trisodium-enhanced 3D MR cholangiography depicts intrahepatic biliary anatomy, especially right duct variants, more accurately than does conventional T2-weighted MR cholangiography.

Spiegel?s Lobe Bile Ducts Often Drain into the Right Hepatic Duct or Its Branches: Study Using Drip-Infusion Cholangiography-Computed Tomography in 179 Consecutive Patients

Using drip-infusion cholangiography-computed tomography (DIC-CT), we successfully identified the bile ducts draining the caudate lobe in 138 of 179 consecutive patients with extrahepatic cholelithiasis (179 ducts from Spiegel's lobe and 154 from the paracaval portion; 1-5 ducts per patient). The dorsal subsegmental duct of S8 (B8c) was often identified and could be discriminated from the paracaval caudate ducts, thus acting as a landmark for the right margin of the caudate lobe. Notably, in more than one-third of the 138 patients, at least one of the Spiegel's lobe ducts drained into the right hepatic duct or its branches (30.2% of the 179 ducts overall; all ducts joined branches of the right lobe in 25 patients). Similarly, 34.4% of the 154 paracaval caudate lobe ducts drained into the left hepatic duct or its branches. These "anatomical left/right dissociations" between the drainage territory and route were much more frequent than previously reported. Our results confirm the effectiveness of DIC-CT as a classical, noninvasive method for presurgical evaluation of the biliary system, but they also suggest that anatomical partial resection of the dorsal liver in patients with hilar cholangioma is often impossible because of contralateral biliary drainage.

Direct bile duct visualization during the preparation of split livers

The split-liver technique is an important means to alleviating donor shortage. Its development is, at least in part, hindered by the risk of biliary complications, particularly when splitting is performed ex situ. We present a simple technique aimed at improving the identification of the biliary anatomy at the hilar level and the safety of the procedure.

Intrahepatic segmental bile duct patterns in hepatolithiasis: a comparative cholangiographic study between Taiwan and Japan

BACKGROUND/PURPOSE

We analyzed confluence patterns of intrahepatic segmental bile ducts, seeking to relate hepato-lithiasis to anatomic variation. The comparative study was completed patients with hepatolithiasis in Taiwan and Japan.

METHODS

Direct cholangiography was performed in 103 hepatolithiasis patients in Taiwan and 77 in Japan. Segmental ducts patterns were classified as type I, normal configuration; type II, "triad" confluence; type III, posterior segmental duct joining left hepatic duct; or type IV, distal confluence of the right posterior segmental duct.

RESULTS

Taiwanese patients had only calcium bilirubinate or black stones, and were mostly female. As overall analysis, types I, II, III, and IV were found in 61, 26, 13, and 3 patients, respectively. In Japanese, types I, II, III, and IV were found in 52, 10, 13, and 2, respectively. There was no difference between the two institutes. Since no patients in Taiwan had cholesterol calculi, Japanese patients were reanalyzed including only 58 patients with calcium bilirubinate or black stones. Differences in those populations remained insignificant.

CONCLUSION

Anatomic variations in segmental ducts apparently do not contribute to pathogenesis of hepatolithiasis.

Surgical anatomy of the bile ducts at the hepatic hilum as applied to living donor liver transplantation

OBJECTIVE

To evaluate anatomic variations of the biliary tree as applied to living donor liver transplantation.

SUMMARY BACKGROUND DATA

Anatomic variability is the rule rather than the exception in liver surgery. However, few studies have focused on the anatomic variations of the biliary tree in living donor liver transplantation in relation to biliary reconstruction.

METHODS

From November 1992 to June 2002, 165 patients underwent major hepatectomy with extrahepatic bile duct resection; right-sided hepatectomy in 110 patients and left-sided hepatectomy in 55. Confluence patterns of the intrahepatic bile ducts at the hepatic hilum in the surgical specimens were studied.

RESULTS

Confluence patterns of the right intrahepatic bile ducts were classified into 7 types. The right hepatic duct was absent in 4 of the 7 types and in 29 (26%) of the 110 livers. Confluence patterns of the left intrahepatic bile ducts were classified into 4 types. The left hepatic duct was absent in 1 of the 4 types and in 1 (2%) of the 55 livers.

CONCLUSIONS

In harvesting the right liver from a donor without a right hepatic duct, 2 or more bile duct stumps will be present in the plane of transection in the graft in 3 patterns based on their relation to the portal vein. Accurate knowledge of the variations in the hepatic confluence is essential for successful living donor liver transplantation.

Is cholangiography required for ex situ splitting of cadaveric livers?

Anomalous biliary anatomy is encountered frequently and, if not considered at the time of ex situ splitting of a cadaveric liver into left lateral segment and right lobe grafts, right-sided second-order ducts that enter the left system, or the segment IV duct, may be damaged, leading to biliary complications in the recipients. Bench cholangiography facilitates delineation of these anomalies, but if one considers the commonly encountered variations in biliary anatomy, in relation to the correct plane of division of the left hepatic duct (away from the hilum, close to the umbilical fissure), it is possible to avoid inadvertent injury to right-sided sectoral ducts. This approach, combined with careful probing of the ducts and absolute identification of the segment IV duct negates the contribution of cholangiography.

Radiological anatomy of the medial segmental bile duct of the liver assessed by CT cholangiography

BACKGROUND/AIMS

To analyze drainage areas and points of confluence of the medial segmental bile ducts of the liver, 72 patients with obstructive jaundice underwent computed tomography cholangiography.

METHODOLOGY

We divided the medial segmental ducts into the following three subsegmental branches: B4a was defined as the inferior branch, B4b as the superior branch, and B4c as the dorsal branch.

RESULTS

In 62 (86%) of the 72 patients, each B4a and B4b branches joined to form a single medial segmental duct, which joined the left hepatic duct in 25 patients (35%), the confluence of the lateral inferior (B3) and superior (B2) branches in 18 patients (25%), B3 in 15 patients (20%), the confluence of the right and left hepatic ducts in 4 patients (6%). In addition, these medial segmental ducts primarily entered the left hepatic duct in the final half of its length or more distant portion from the hepatic hilum in 43 (77%) of the 62 patients.

CONCLUSIONS

Thus, in most cases the inferior area of the medial segment should be preserved when right-sided resection of the liver is indicated for hilar bile duct cancer.

Clinicoanatomical studies on the dorsal subsegmental bile duct of the right anterior superior segment of the human liver

BACKGROUND

The dorsal subsegmental intrahepatic bile duct in the right anterior superior segment (B8c) sometimes joins the posterior sectorial duct. In such cases it can be misidentified as the right posterior superior segmental duct (B7). However, there are no published studies on the confluent pattern of B8c.

MATERIALS AND METHODS

We studied B8c in the resected liver of 107 patients (65 with bile duct carcinoma and 42 with gallbladder carcinoma) who had undergone right hepatectomy or more extensive right-sided liver resection.

RESULTS

B8c was identified in all cases. It joined the right posterior sectorial duct or B7 in 18 cases (16.8%). In 12 cases B8c joined independently the posterior sectorial duct or B7. In 6 cases B8c joined the posterior sectorial duct after making the common duct with the lateral subsegmental duct in the anterior superior or anterior inferior segment (B8b or B5c).

CONCLUSIONS

B8c does not join the anterior sectorial bile duct in every sixth case.

Variations of intrahepatic and proximal extrahepatic bile ducts

BACKGROUND/AIMS

The modern segmental concept of the liver with a segmental bile duct distribution is of practical importance for biliary specialists and should include information on variations of intrahepatic and extrahepatic bile ducts. The aim of this study was to find biliary variations, especially on a segmental and sectorial level, and to try to arrange them into types.

METHODOLOGY

We analyzed 51 corrosion casts of the human liver, which enabled the three-dimensional study of extrahepatic, sectorial, segmental and subsegmental bile ducts, their variations in course and confluencing, and the relationship between the structures of the portal pedicle.

RESULTS

The types of confluence and their frequency were determined separately for the left, right, right anterior sectorial, right posterior sectorial and common hepatic ducts. "Normal" left confluence was formed in 82% and three variations in 18%. "Normal" right confluence was formed in 75% and four variations in 25%. A complete ("normal") anterior sectorial duct was present in 35% and four variations in 65%. A complete ("normal") posterior sectorial duct was present in 61% and four variations in 39%.

CONCLUSIONS

The study showed that the biliary tree variations are quite frequent, and therefore clinically important, and that they could be arranged into several types.

Anatomic variation in intrahepatic bile ducts: an analysis of intraoperative cholangiograms in 300 consecutive donors for living donor liver transplantation

OBJECTIVE

To describe the anatomical variation occurring in intrahepatic bile ducts (IHDs) in terms of their branching patterns, and to determine the frequency of each variation.

MATERIALS AND METHODS

The study group consisted of 300 consecutive donors for liver transplantation who underwent intraoperative cholangiography. Anatomical variation in IHDs was classified according to the branching pattern of the right anterior and right posterior segmental duct (RASD and RPSD, respectively), and the presence or absence of the first-order branch of the left hepatic duct (LHD), and of an accessory hepatic duct.

RESULTS

The anatomy of the intrahepatic bile ducts was typical in 63% of cases (n=188), showed triple confluence in 10% (n=29), anomalous drainage of the RPSD into the LHD in 11% (n=34), anomalous drainage of the RPSD into the common hepatic duct (CHD) in 6% (n=19), anomalous drainage of the RPSD into the cystic duct in 2% (n=6), drainage of the right hepatic duct (RHD) into the cystic duct (n=1), the presence of an accessory duct leading to the CHD or RHD in 5% (n=16), individual drainage of the LHD into the RHD or CHD in 1% (n=4), and unclassified or complex variation in 1% (n=3).

CONCLUSION

The branching pattern of IHDs was atypical in 37% of cases. The two most common variations were drainage of the RPSD into the LHD (11%) and triple confluence of the RASD, RPSD and LHD (10%).

Human liver caudate lobe and liver segment

Recently, the caudate lobe has seemed to be the final target for aggressive cancer surgery of the liver. This lobe has five surfaces: the dorsal, left and hilar-free surfaces and the right and ventral-border planes. Surgeons have divided the caudate lobe into three parts: Spiegel's lobe, which is called the 'caudate lobe and papillary process' by anatomists, the caudate process, viewed as almost the same entity by anatomists, and the paracaval portion corresponding to the dorsally located parenchyma in front of the inferior vena cava. All three parts are supplied by primary branches originating from the left and right portal veins, including the hilar bifurcation area. The hilar bifurcation branch often (50%) supplies the paracaval portion and it sometimes (29%) extends its territory to Spiegel's lobe. It was postulated by Couinaud that the paracaval portion or the S9 is not defined by its supplying portal vein branch but by its 'dorsal location' in the liver. Couinaud's caudate lobe or dorsal-liver concept cause, and still now causes, great logical confusion for surgeons. We attempt here to describe the margins of the lobe, border branches of the portal vein, the left/right territorial border of the portal vein or Cantile's line and other topics closely relating to the surgery within these contexts. Finally, the caudate lobe as a liver segment will be discussed.

Clinicoanatomical study on the infraportal bile ducts of segment 3

In some patients, bile ducts of segments 2 and 3 (B2 and B3) run caudally to the umbilical portion of the left portal vein (UP)--an infraportal course. We aimed to evaluate the frequency and clinical implications of this variation. Between January 1992 and October 2000, 108 patients underwent resection for hilar cholangiocarcinoma. The records of the 6 patients with infraportal left hepatic ducts were evaluated. An infraportal B3 was diagnosed in 6 patients (6%). No patient had an infraportal B2. An infraportal B3 could be demonstrated by computed tomography (CT) before biliary drainage, percutaneous transhepatic or endoscopic cholangiography, portography after percutaneous transhepatic biliary drainage (PTBD) via B3 and CT after PTBD via B3. Four patients (4/6) had a liver bridge covering Rex's recess (B3 not in the bridge). The incidence of the bridge in 75 comparable patients was 9/75. In conclusion, common radiologic methods are sufficient for diagnosis of abnormal biliary anatomy. The presence of a liver bridge over Rex's recess is suggestive of this variation. Separate biliary reconstruction for an infraportal branch is mandatory in an extended right hepatectomy for biliary tract cancer and may be necessary in liver transplantation with segments 2+3 grafting.

Functional heterogeneity of cholangiocytes

The objective of this article is to summarize the findings related to the notion that cholangiocytes, within small and large intrahepatic ducts, are heterogeneous regarding (1) morphology; (2) secretion in response to hormones and peptides and to bile acids; and (3) proliferation in response to injury or toxins, including bile duct ligation (BDL), acute carbon tetrachloride (CCl 4 ) administration, chronic feeding of bile salts (i.e., taurocholate [TC] or taurolithocholate [TLC]) or alpha-naphthylisothiocyanate (ANIT). After an overview of the morphology of the biliary epithelium, we provide a summary of cholangiocyte function, the in vivo models, and the in vitro experimental tools (i.e., small and large cholangiocytes or small and large intrahepatic bile duct units [IBDU]), which allowed us to demonstrate cholangiocyte heterogeneity. After a discussion on the receptors, transporters, and channels that are heterogeneously expressed by cholangiocytes, we discuss the different-sized ducts that differentially respond to injury and toxins. Finally, we review the human diseases that selectively target specific-sized ducts.

[Biliary and vascular anatomy of the liver]

This paper is a review of the anatomy of the bile ducts and the vascular anatomy of the liver. This anatomy is subject of numerous variations which can be explained by the embryology of the liver and its vessels. The perfect knowledge of this anatomy is useful for an accurate interpretation of the conventional and slice imaging techniques of the liver. It is also of major importance for an appropriate management of all kinds of hepatic vascular and biliary percutaneous procedures.

Right lobe living donor liver transplantation: preoperative evaluation of the donor with MR imaging

OBJECTIVE

The purpose of this study was to report our experience in preoperative evaluation of right hepatic lobe donors with a comprehensive MR examination and to compare abdominal MR images, MR cholangiograms, and MR angiograms with findings at surgery, intraoperative cholangiography, and digital subtraction angiography.

MATERIALS AND METHODS

Twenty-eight right hepatic lobe donors underwent preoperative evaluation with MR imaging, MR cholangiography, and MR angiography. Two abdominal radiologists independently and randomly reviewed these studies. Points of assessment included focal and diffuse liver disease, calculation of right lobe volumes, depiction of the biliary tract and ductal anomalies, and depiction of the liver vasculature and vascular anomalies. Comparison was made with intraoperative cholangiograms (n = 20) and digital subtraction angiograms (n = 28).

RESULTS

MR imaging revealed and characterized focal liver lesions in eight of 28 patients. Calculated right lobe volumes agreed with surgically determined volumes within 7% for reviewer 1 and within 15% for reviewer 2. Intrahepatic bile ducts were depicted completely with MR cholangiography in 25 of 28 patients and with intraoperative cholangiography in nine of 20 patients. MR cholangiography revealed ductal anomalies in six patients. MR imaging and MR angiography depicted the portal veins more completely than digital subtraction angiography. MR imaging and MR angiography correctly excluded portal venous anomalies in all patients and revealed surgically confirmed accessory hepatic veins in six of 28 patients. Angiographically confirmed arterial anomalies were correctly detected in three of 28 patients by at least one reviewer on MR imaging and MR angiography.

CONCLUSION

MR imaging, MR cholangiography, and MR angiography provide a comprehensive, accurate means of evaluating donors for factors that may preclude or complicate right hepatic lobe donation.

alpha-Amylase expressed in human liver is encoded by the AMY-2B gene identified in tumorous tissues

BACKGROUND

An alpha-Amylase in human liver is detected with an anti-human salivary amylase antibody, but the enzyme activity is very low. We previously found that the rat liver contained an amylase which differed from the enzyme of mice. In this study, we characterized the human liver amylases biochemically and immunohistochermically.

METHODS AND RESULTS

Although the amylase activity of human liver was much lower than that of rat, protein moiety and sugar chains of the human amylase were identified as similar to the rat liver enzyme with an anti-human salivary amylase antibody and by concanavalin A (Con A) affinity chromatography. Liver amylases from human and rat were the same size, 50 kDa, on Western blot analysis and had the same isoelectric points. The cytoplasm of hepatocytes was moderately stained immunohistochemically with the anti-human salivary amylase antibody. Intrahepatic bile ducts were also stained weak-to-moderately. RT-PCR, with a specific primer for the consensus sequence of human amylases, amplified a single 474-bp product from the human liver total RNA. The PCR product was sequenced and referred to the homology. Thirteen bases in the 434-bp fragment of the human liver amylase differed from the corresponding region of the AMY-1 gene transcript and the deduced amino acid sequence differed at five residues. The human liver amylase cDNA sequence was identical to the corresponding cDNA of the AMY-2B, which was known to expressed in tumorous tissues. In situ hybridization revealed the expression of AMY-2B mRNA in non-tumorous human liver.

CONCLUSIONS

The present results suggest the possibility that a novel amylase detected in tumorous tissues and encoded by the AMY-2B gene is a liver-specific amylase expressed in the human liver.

Quantitative assessment of the rat intrahepatic biliary system by three-dimensional reconstruction

The anatomical details of the biliary tree architecture of normal rats and rats in whom selective proliferation was induced by feeding alpha-naphthylisothiocyanate (ANIT) were reconstructed in three dimension using a microscopic-computed tomography scanner. The intrahepatic biliary tree was filled with a silicone polymer through the common bile duct and each liver lobe embedded in Bioplastic; specimens were then scanned by a microscopic-computed tomography scanner and modified Feldkamp cone beam backprojection algorithm applied to generate three-dimensional images. Quantitative analysis of bile duct geometry was performed using a customized software program. The diameter of the bile duct segments of normal and ANIT-fed rats progressively decreased with increasing length of the biliary tree. Diameter of bile ducts from ANIT-fed rats (range, 21 to 264 microm) was similar to that of normal rats (22 to 279 microm). In contrast, the number of bile duct segments along the major branch reproducibly doubled, the length of the bile duct segments decreased twofold, and the length of the biliary tree remained unchanged after ANIT feeding. Moreover, the total volume of the biliary tree of ANIT-fed rats was significantly greater (855 microl) than in normal rats (47 microl). Compared with normal rats, the total surface area of the biliary tree increased 26 times after ANIT-induced bile duct proliferation. Taken together, these observations quantitate the anatomical remodeling after selective cholangiocyte proliferation and strongly suggest that the proliferative process involves sprouting of new side branches. Our results may be relevant to the mechanisms by which ducts proliferate in response to hepatic injury and to the hypercholeresis that occurs after experimentally induced bile duct proliferation.

Surgical anatomy of the bile duct branches of the medial segment (B4) of the liver in relation to hilar carcinoma

In some patients, hilar bile duct carcinoma can easily spread to the bile duct branches of the caudate lobe (B1) as well as to the bile duct branches of the medial segment (B4), and resection of the inferior portion of the medial segment (S4a) is then required. It is therefore important to understand the detailed anatomy of the B4, its confluence patterns, and its relation to the B1 in order to be able to identify such patients. The confluence pattern of the B4 was studied in 141 specimens (68 adult cadavers and 73 liver casts) and the distance between the left bile duct branches of the caudate lobe (B11) and the B4 was measured in 56 of the 73 casts in which both B11 and B4 were present. Two main gross types of B4 were recognized: type I, in which B4 joined the left hepatic duct (LHD) close to the hilar confluence (35.5%), and type II, in which B4 joined the LHD far from the hilar confluence (54.6%). Analysis of the relationship between B11 and B4 revealed a mean distance between B11 and B4 of 8 mm in type 1, and 17 mm in type II. When the distance is less than 10 mm, B11 and B4 are considered to be located very close to each other, and in such individuals hilar bile duct carcinoma can infiltrate the B4 easily, thereby necessitating the resection of S4a, together with a caudate lobectomy for curative resection. Also, the confluence pattern of the B4 often creates a problem when the LHD is divided and reconstructed during hepatectomy, because of the numerous anatomical variations of the B4 itself. We therefore concluded that a good anatomical knowledge of the B4 and its relation to the B11 is essential in making the decision to perform S4a resection in selected patients with hilar bile duct carcinoma with the aim of curative resection.

Anatomy of the porta hepatis as a basis for extended hepatoporto-enterostomy for extrahepatic biliary atresia--a new surgical technique

Reports on long-term survival rates after Kasai's HPE reveal that 23% of patients are healthy ten and more years after surgery. Therefore we studied again the anatomy and histology of the porta hepatis and the portal tracts in order to improve this surgical procedure.

METHODS

Autopsied livers of 6 children with and 6 without EHBA were investigated with regard to the topographical and histological anatomy of the major intra- and extrahepatic bile ducts.

RESULTS

On the basis of anatomical findings we have modified the conventional Kasai's HPE and developed an extended exploration of the porta hepatis. The procedure and surgical technique is described in this paper.

[Anatomic and surgical aspects of intrahepatic segmentation]

This article presents anatomical and surgical patterns of hepatovenous and portal segmentation in the human liver. Special attention was drawn to the significance of portal fissures, their projections and surgical approach to large blood vessels. The anatomical variations of hepatic veins and the constituents of the portal triad (with particular surgical importance) were also included. Finally, the study gives a brief description of the perivascular fibrous capsule morphology and its relations to the portal bifurcation.

[Anatomy of the liver]

Over the past decades, great progress has been made in surgery on the liver. Technical achievements and the strict application of anatomical knowledge to surgical practice have added a new dimension to the field of liver surgery. In some cases, new facts about the anatomy of the liver needed considerable time before being implemented. Surgery of liver metastases, primary tumours of the liver and not least liver transplantation have focussed the interest of visceral surgeons more and more on this organ. Segment-orientated liver anatomy, a knowledge and consideration of vascular structures, and the observance of anatomical landmarks are the prerequisites for successful surgery on the liver.

[Surgical anatomy of the hepatic hilar area]

It is important to understand the main variations of the biliary and vascular elements inside the plate system for hilar bile duct carcinoma because all variations of these elements occur in this plate system. The plate system consists of the hilar plate, cystic plate, and umbilical plate which cover the extrahepatic vascular system and are fused with the hepatoduodenal ligament. The bile duct and vascular system that penetrate the plate system form Glisson's capsule in the liver, but the caudate branch and the medial segmental branch are exceptions. The bile duct and hepatic artery accompanying the plate system can be exfoliated from the portal vein with numerous lymph ducts and nerves. The bile ducts in the right hepatic lobe are classified into 4 types, and the standard type is present in 53-72% of cases. In the left bile duct, the medial segmental bile duct is connected in the vicinity of the hilar area in 35.5% of cases, and these cases should be treated the same as the caudate lobe in hilar bile duct carcinoma. Generally, there is little main variation of the portal vein (16-26%), but more variation in the hepatic artery (31-33%). During surgery for hilar bile duct carcinoma, it is important to observe the plate system and the many variations of the bile duct and vascular system.

The anatomical basis for segment III cholangiojejunostomy with analysis of 13 cases

BACKGROUND

The majority of patients who require palliation for jaundice and pruritus resulting from malignant hilar obstruction are treated by stenting. Stenting is usually achieved from below after performing an endoscopic retrograde cholangiopancreatography. In some cases the rendezvous technique is employed, negotiating the passage through a malignant stricture from above and stenting from below. A minority of cases, such as those who had a previous polyagastrectomy and those in whom attempts at stenting have failed, are considered to be suitable for a Segment III cholangiojejunostomy. We have investigated the anatomical basis for Segment III duct bypass and have critically analysed the results in 13 patients. Ten patients were treated by Segment III duct bypass alone, and three patients had a Segment III duct bypass combined with stenting of the right liver.

METHODS

The anatomy of the biliary tree was investigated by dissection of 54 normal livers removed at autopsy. Clinical details of the 13 patients who had Section III cholangiojejunostomy were obtained from hospital records and by contacting treating practitioners.

RESULTS

In 64.8% of the anatomical dissections, the findings were favourable for a Section III cholangiojejunostomy. In these specimens the Segment III duct bypass would have drained Segments II, III and IV. In 35.2% of the specimens the anatomical disposition was potentially unfavourable, mainly due to the Segment II or IV ducts joining close to the confluence and therefore liable to obstruction by the tumour. In nine of the 54 specimens the true left hepatic duct was less than 6 mm in length, making it unsuitable for a bypass procedure to drain the left hemi liver. Of the 10 patients who were subjected to a palliative Section III cholangiojejunostomy only, there was one postoperative death. Of the nine patients who survived, six obtained excellent palliation of jaundice and pruritus.

CONCLUSIONS

In carefully selected cases, Section III cholangiojejunostomy achieves excellent palliation in patients with unresectable hilar malignancies that have been unable to be stented pre-operatively or who have unresectable tumours at the time of laparotomy.