Anatomy of the hepatic hilar area: the plate system

To surgically manage hilar bile duct carcinoma successfully, it is important to be familiar with the principal anatomical variations of the biliary and vascular components of the plate system in the hepatic hilar area, because all the variations in the bile ducts and vessels occur in the plate system. The plate system consists of bile ducts and blood vessels surrounded by a sheath. There are three plates in the hilar area: the hilar plate, the cystic plate, and the umbilical plate. The bile duct and blood vessel branches penetrate the plate system and form Glisson's capsule in all segments of the liver, except for the medial segment. The right hepatic duct is usually (in 53%–72% of individuals) formed by the union of the anterior segmental duct and the posterior segmental duct in the hilar area. However, three other variations have been found in which these segmental ducts do not form the right hepatic duct. Few anatomical variations have been identified in the left hepatic duct, but confusion arises because of the variations in the medial segment ducts (B4) which join the left hepatic duct at different sites. In 35.5% of individuals they join the hepatic duct in the vicinity of the hilar confluence (type I B4 anatomy), and in 64.5% of individuals they join the left hepatic duct some distance away from the confluence (type II B4 anatomy). Because B4 is very close to the hilar confluence in type I, hilar bile duct carcinoma can easily invade B4 and, for that reason, for curative resection of hilar bile duct carcinoma, resection of S4a (the inferior part of the medial segment) should be considered along with the resection of extrahepatic bile duct and caudate lobe. Variations in the portal vein and hepatic artery are found in 16%–26% and 31%–33% of individuals, respectively. Because a considerable number of anatomical variations in the bile ducts and vessels persist in the hilar area, and the reported proportions of the different variations vary, it is necessary to have a good knowledge of the plate system and the variations in the bile ducts and blood vessels in the hilar area to perform safe and curative surgery for hilar bile duct carcinoma.     

Preoperative cholangiography of the caudate lobe: Surgical anatomy and staging for biliary carcinoma

The biliary branches of the caudate lobe (B1) join the right hepatic duct, the left hepatic duct, the confluence of these ducts, and/or the right posterior segmental bile duct. Therefore, in the preoperative staging of biliary tract carcinoma it is important to delineate the anatomy of B1 and the extent of cancer spread into B1. Tube cholangiography through percutaneous transhepatic biliary drainage or selective cholangiography by percutaneous transhepatic cholangioscopy enables us to obtain fine images of B1. We have developed cholangiography in the cephalad anterior oblique position to visualize B1 more clearly and distinctly. Four separate types of biliary branches are identified in the caudate lobe: (1) A duct running from the cranial portion of the right caudate lobe along the inferior vena cava to the hepatic hilus (B1r); (2) a duct from the cranial portion of the left caudate lobe to the hepatic hilus (B1ls); (3) a duct from the left lateral part of the left caudate lobe to the hepatic hilus (B1li); and (4) a duct from the caudate process to the hepatic hilus (B1c). The findings of the root of B1 in resected patients with biliary tract carcinoma were classified into four groups: not stenotic, short segmental stenosis, long segmental stenosis, and poorly imaged. A study of 64 branches of B1 in 42 resected patients with biliary tract cancer revealed carcinoma invasion in or near the root of B1 in all patients with poorly imaged or long segmental stenosis of B1, and in 33% of those with short segmental stenosis of B1.     

Distributing pattern of the bile duct of the caudate lobe on computed tomography with drip infusion cholangiography and its surgical significance

BACKGROUND/AIMS: It is important to recognize the distribution of the bile ducts in the caudate lobe of the liver for the hepato-biliary surgery. To map the spatial relationship between the bile ducts and the liver parenchyma under physiological conditions, we performed an anatomical analysis of them using computed tomography combined with drip infusion cholangiography (DIC-CT). METHODOLOGY: We identified the bile ducts in the caudate lobe, which was divided into the Spiegel lobe, paracaval portion, and caudate process, with DIC-CT. We then investigated their number and confluence pattern in 132 patients without any abnormality in the hilar bile ducts. RESULTS: The mean number of the bile ducts in the caudate lobe was 2.68 per liver. In the Spiegel lobe, the branches drained into the left hepatic duct system in about 83%. The confluence of the paracaval branch was the left hepatic duct, right hepatic duct, and posterior segmental branch, all with the same frequency of approximately 30%. Almost all of the caudate process branches (92.4%) drained into the posterior segmental branch. CONCLUSIONS: DIC-CT is a useful method for the anatomical analysis of the intrahepatic bile ducts under physiological conditions, and we obtained novel and important findings for surgery.     

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.     

Resection of an icteric type hepatoma with tumor thrombi filling the right posterior bile duct

A 67-year-old male with jaundice was found to have hepatocellular carcinoma in the right hepatic lobe and tumor thrombi in the common hepatic duct. Physicians initially considered the tumor unresectable, and treated the patient with transcatheter arterial infusion chemotherapy and biliary endoprosthesis. The patient developed a liver abscess after the second transcatheter arterial infusion, and the physicians consulted our department for another form of therapy. Percutaneous transhepatic biliary drainage was performed to relieve revived obstructive jaundice. Cholangiography revealed tumor thrombi extending through the right posterior segmental bile duct into the common hepatic duct. Most biliary branches of the caudate lobe joined with the left lateral posterior segmental branch. Arterial and portal venous branches of the caudate lobe were not involved. Right hepatic lobectomy and extrahepatic bile duct resection were performed 1 year after initial diagnosis. On histologic examination, the epithelium of the right posterior segmental bile duct, which was filled with the tumor thrombi, was not detected. The patient is alive without recurrence 24 months after surgery. Careful investigation of biliary branches of the caudate lobe on cholangiography is essential to determine the necessity of caudate lobectomy in patients with hepatocellular carcinoma and tumor thrombi filling the right posterior segmental bile duct.     

Anomalous connection of the right hepatic duct into the cystic duct: utility of magnetic resonance cholangiopancreatography

A 41-year-old female was admitted to our hospital for treatment of uterus carcinoma. Abdominal ultrasound showed gallbladder stones. Although magnetic resonance cholangiopancreatography revealed the right intrahepatic bile ducts, left hepatic duct and the common bile duct, the confluence of the right and left hepatic ducts was not visualized. At surgery, intra-operative cholangiography showed a biliary anomaly of the right hepatic duct entering the cystic duct. Subsequently cholecystectomy was accomplished without any injury to the bile duct. Our case may be the eighth such case of this rare biliary anomaly. When magnetic resonance cholangiopancreatography does not show the confluence of the right and left hepatic ducts, biliary anomaly of the right hepatic duct should be suspected and careful dissection should be performed from the Hartman's pouch, followed by intraoperative cholangiography, in order to avoid unnecessary injury to the bile duct.     

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.     

Biliary cystadenocarcinoma with superficial spread to the extrahepatic bile duct.

We report a case of biliary cystadenocarcinoma of the liver with superficial spread to the extrahepatic bile duct. Preoperative endoscopic retrograde cholangiography revealed communication between a 4.5-cm cyst in segment 4 of the liver and the bile duct. From the findings obtained by peroral cholangioscopy and intraoperative cholangioscopy, the granular mucosa in the bile duct was diagnosed as superficially spreading cancer. The right posterior segmental bile duct and the right anterior segmental bile duct were resected at the point where the spread of cancer was no longer traceable and left lobectomy plus caudate lobectomy was carried out. This achieved radical resection, leaving the resected margin of the bile duct free from cancer. Histopathologically, well-differentiated papillary adenocarcinoma was found on the inner surface of the cyst, and the cancer had superficially spread from the cyst to the extrahepatic bile duct via the 2.5-mm diameter communication between the cyst and bile duct. The cancer was limited only to the mucosal layer all over the lesion. When performing radical surgery for biliary cystadenocarcinoma, it is recommended that cholangioscopy be performed to examine whether the cancer has superficial spread to the extrahepatic bile duct or not. Bile duct resection should be carried out, depending on the extent of the superficial spread, so that the resected margin of the bile duct is free from cancer.     

Anatomic variations in intrahepatic bile ducts in a north Indian population

Background and Aim:  In the present study, we described the anatomical variations in the branching patterns of intrahepatic bile ducts (IHD) and determined the frequency of each variation in north Indian patients. There are no data from India.
Methods:  The study group consisted of 253 consecutive patients (131 women) undergoing endoscopic retrograde cholangiograms for different indications. Anatomical variations in IHD were classified according to the branching pattern of the right anterior segmental duct (RASD) and the right posterior segmental duct (RPSD), presence or absence of first-order branch of left hepatic duct (LHD) and of an accessory hepatic duct.
Results:  Anatomy of the IHD was typical in 52.9% of cases ( n  = 134), showing triple confluence in 11.46% ( n  = 29), anomalous drainage of the RPSD into the LHD in 18.2% ( n  = 46), anomalous drainage of the RPSD into the common hepatic duct (CHD) in 7.1% ( n  = 18), drainage of the right hepatic duct (RHD) into the cystic duct 0.4% ( n  = 1), presence of an accessory duct leading to the CHD or RHD in 4.7% ( n  = 12), individual drainage of the LHD into the RHD or CHD in 2.4% ( n  = 6), and unclassified or complex variations in 2.7% ( n  = 7). None had anomalous drainage of RPSD into the cystic duct
Conclusion:  The branching pattern of IHD was atypical in 47% patients. The two most common variations were drainage of the RPSD into the LHD (18.2%) and triple confluence of the RASD, RPSD, and LHD (11.5%).     

Study of biliary anatomy in living related liver transplantation

BACKGROUND: Anatomic variations of the biliary tree are frequent and increase complications after liver transplantation. AIM: To describe the anatomy of the bile ducts of donors and recipients of living related liver transplantation. METHODS: From March 1998 to September 2002, the study was retrospective (23 transplantations). From October 2002 to August 2003, the study was prospective (17 transplantations). We studied the hepatic anatomy of 80 consecutive patients (40 donors and 40 recipients) of the living-related liver transplantation program of the "Hospital de Clínicas da Universidade Federal do Paraná" and the "Hospital Nossa Senhora das Gra?as", Curitiba, PR, Brazil; 51 were male (27 recipients 24 donors) and 29 female (13 recipients and 16 donors). The median age among the donors was 32.6 years and among the recipients was 36.3 years. Thirty-two recipients were adults and 8 recipients were under 15 years old. The bile duct anatomy was studied by magnetic resonance cholangiography in 33 patients, and anomalies were seen in 3 of them (9.1%). RESULTS: The most prevalent variation of bile ducts was the fusion of the right posterior duct with the left duct (6.06%; n=2). In the 40 harvesting operations, the right bile duct was single in 25 patients (87.5%), among the 32 right-lobe donors, double in 2 (6.25%) and triple in 2 (6.25%). All of the eight left livers procured had single bile ducts. Among the 40 recipients, the common bile duct was bifurcated in 2 of them (5%). CONCLUSION: The prevalence of biliary anomalies is high in patients subjected to living liver transplantation and some anomalies are not diagnosed with preoperative imaging exams.     

Left hepatic trisegmentectomy for intraductal papillary cholangiocarcinoma: report of a case

We present a rare case of intraductal papillary cholangiocarcinoma in a 69 year-old man which was treated with left hepatic trisegmentectomy. The hepatic bile ducts were dilated by intraductal masses, which had extended into the intrahepatic bile ducts without involvement of the posterior inferior segmental duct (B6). The patient underwent left hepatic trisegmentectomy with hilar duct resection. The tumors in the posterior superior segmental duct (B7) were resected and biliary reconstruction was performed with a jejunal loop. Post-operative recovery was good, and the patient survived for 7 months after surgery.     

Left hepatectomy or left trisectionectomy with resection of the caudate lobe and extrahepatic bile duct for hilar cholangiocarcinoma (with video)

Purpose

Although left-sided hepatectomy, such as a left hepatectomy or left trisectionectomy with resection of the caudate lobe and extrahepatic bile duct, is used to treat hilar cholangiocarcinoma predominantly involving the left side of the hepatic hilum, it is associated with several difficult technical points. The important points during left-sided hepatectomy are described here.

Techniques

There are anatomical variations of the sectional artery and bile duct. It is essential to understand the individual intrahepatic and hilar anatomy preoperatively. Surgical procedures consist of lymph node clearance, dissection of the distal bile duct, skeletonization resection of the hepatoduodenal ligament, mobilization of the liver and liver resection, dissection of the intrahepatic bile ducts, and biliary reconstruction. During lymph node dissection and skeletonization resection of the hepatoduodenal ligament, the nerve plexus around the hepatic artery is dissected, and its adventitia is exposed with great care to avoid injuring the hepatic artery. Mobilization of the caudate lobe is performed only from the left side. There is no clear landmark between the caudate lobe and the right posterior section during liver resection. In the final step of liver resection, it progresses toward the right edge of the inferior vena cava. When dividing intrahepatic bile ducts, extreme care should be used to avoid injury to the corresponding hepatic arteries, especially the anomalous supraportal posterior sectional artery.

Conclusions

Left-sided hepatectomy for hilar cholangiocarcinoma should be considered a more complicated and technically demanding procedure than right-sided hepatectomy. Surgeons need to pay close attention to anatomical variations in order to perform a left-sided hepatectomy safely and successfully.     

Ultrasonography in the diagnosis of obstructive jaundice

Forty-seven patients with cholestatic jaundice were evaluated for extrahepatic biliary obstruction by ultrasonic cholangiography and the results verified by contrast cholangiography, celiotomy, or autopsy. Sonograms were evaluated both with ("official" reading) and without ("blind" reading) clinical information. By showing dilated bile ducts, sonography correctly diagnosed extrahepatic obstruction in 26 of 30 patients on "official" reading and 23 of 30 on "blind" reading. In all 17 patients without extrahepatic obstruction, sonography revealed the absence of dilated bile ducts. Among patients with extrahepatic obstruction, those with larger bile ducts had higher bilirubin concentrations, longer duration of jaundice, and were more reliably detected by sonography. In these patients, 94% with total bilirubin concentration greater than 10 mg/dl were detected by sonography, while 47% with total bilirubin concentration less than 10 mg/dl were detected. Although we recognize the limited sensitivity of sonography in early extrahepatic obstruction, we find it to be a valuable screening test in cholestatic jaundice.     

Biliary tract reconstruction with autologous rectus sheath graft--an experimental study

BACKGROUND/AIMS: Common bile duct injuries which cause significant morbidity and mortality are one of the most serious complications of cholecystectomies. They can be repaired by various approaches. METHODOLOGY: We used an autologous graft obtained from the posterior sheath of the rectus muscle in biliary tract reconstruction for common bile duct defect. This experimental study was carried out on six dogs. A tissue fragment was excised from the posterior sheath of the rectus muscle together with the fascia transversalis and peritoneum. A channel from the fascial graft was formed around a T-tube. The autologous rectus sheath graft was sutured to the common bile duct as a segmental conduit graft. Afterwards, blood biochemistry values and liver histopathology were investigated. Dogs were studied by T-tube cholangiography 4 months postoperatively just prior to removing the T-tube and again 2 months later at relaparotomy. The hepatic parenchyma, intra- and extrahepatic bile ducts were detected by ultrasonography during the last 2 months, one time in fifteen days. RESULTS: There was no anastomotic insufficiency. The fascial graft gained an appearance similar to bile duct in dogs. Postoperatively, no change in blood biochemical parameters was observed, and in the preoperative and postoperative periods no histopathological change in the liver was found. CONCLUSIONS: These findings indicate that the use of an autologous fascial graft to repair common bile duct injuries as a conduit graft for segmental bile duct loss may be a feasible and alternative method of treatment.     

A new method of preventing bile duct injury in laparoscopic cholecystectomy

AIM: Of all the complications of laparoscopic cholectecystomy, bile duct injury (BDI) is the most serious complication. The prevention of injury to the common bile duct (CBD) remains a significant concern in laparoscopic cholecystectomy (LC). Different kinds of methods have been advanced to avoid this injury but no single method has gained wide acceptance. Because of various limitations of current methodologies we began a study using cold light illumination of the extrahepatic biliary system (light cholangiography LCP) to better visualize this area and thereby reduce the risk of bile duct injury. METHODS: Thirty-six patients with cholelithiasis were divided into two groups. Group I (16 cases) received LCP and group II (20 cases) received methelenum coeruleum cholangiography (MCCP). In group I cold light was used to illuminate the common bile duct by leading an optical fiber into the common duct with a duodenoscope at the time of LC. The light coming from the fiber in the CBD could clearly illuminate the location of CBD and hepatic duct establishing its location relative to the cystic duct. This method was compared with the dye injection technique using methelenum coeruleum. RESULTS: In group I thirteen cases were successfully illuminated and three failed. The cause of three failed cases was due to the difficulty in inserting the fiber into the ampulla of Vater. No complications occurred in the thirteen successful cases. In each of these successful cases the location of the common and hepatic ducts was clearly seen differentiating the ductal system from surrounding anatomy. In ten cases both the left and right hepatic ducts could be seen and in three only the right hepatic ducts were seen. In four of the thirteen cases, cystic ducts were also seen. In group II, eighteen of the twenty cases were successful. The location of extrahepatic ducts became blue differentiating the ductal system from surrounding anatomy. Two cases failed due to a stone obstructing the cystic duct, and extravisation of the dye turned the entire area blue. LCP showed the common and hepatic ducts more clearly than MCCP. CONCLUSION: LCP is the only technique that can clearly and directly show the location of the extrahepatic biliary system and may be useful in selecting cases of uncertain anatomy in the prevention of bile duct injury.     

Evaluation of a new sequence of magnetic resonance cholangio-pancreatography in thick cut and one shot acquisition

OBJECTIVES: To assess the accuracy and reproducibility of a new magnetic resonance cholangiopancreatography sequence (MRCP), using long echo time and "single shot" acquisition (providing high-contrast thick slices: 20 mm or more), in the morphological analysis of the biliary tree and pancreatic ducts. METHODS: Fifty four patients with biliary and/or pancreatic disease were investigated with MRCP "single shot" thick slices. Biliary ducts were explored with MRCP "single shot", coronal and oblique coronal 20 mm thick slices on a 256 x 256 matrix. Natives pictures were reviewed by three independent radiologists, from three different institutions. MRCP results were compared with reference examinations in 54 cases (direct biligraphy methods: 54, CT scan: 11, endoscopic ultrasonography: 6, surgery: 6). RESULTS: For detection of bile duct dilatation, the agreement of MRCP "single shot" thick slices was more than 96% (Kappa > 0.92) and the inter-observer agreement was excellent (Kappa=0.92). For detection of biliary tree and/or pancreatic duct obstruction, MRCP "single shot" thick slice sensitivity was above 89% and specificity was 75%. The malignant nature of the lesions was determined with a sensitivity of 100% and a specificity of 92%. MRCP "single shot" thick slices could not differentiate pancreatic carcinomas from distal main bile duct cholangiocarcinomas. MRCP "single shot" thick slices did not detect small stones ( 3 mm) of the common bile duct. CONCLUSION: The excellent sensitivity, specificity and inter-observer agreement of MRCP "single shot" thick slices can be used to limit invasive imaging methods in the diagnosis of extrahepatic cholestasis.     

Primary sclerosing cholangitis successfully treated by resection of the confluence of the hepatic duct

Primary sclerosing cholangitis (PSC) is a cholestatic disease characterized by chronic inflammatory fibrosis of the extra- and intrahepatic bile ducts. Although the prognosis of patients with PSC was believed to be poor, some patients have not experienced the expected rapid clinical progression. A 51-year-old man with PSC was initially hospitalized for jaundice. Laboratory data showed low levels of the complement components C3, C4, and CH50. Percutaneous transhepatic biliary drainage was performed. Cholangiography revealed complete obstruction of the common bile duct below the confluence of the cystic duct. The confluence of the hepatic duct was resected and it was reconstructed by hepaticojejunostomy for palliation of the obstructive jaundice. Increased thickness of the walls of the common bile duct, right hepatic bile duct, and gallbladder was observed. Histopathological examination of the resected specimen revealed periductal fibrosis, with an onion-skin-like appearance. The patient is currently doing well, approximately 7 years after the surgery, without any signs of PSC recurrence. In this extraordinary patient, the laboratory data for C3, C4, and CH50 showed a complete return to normal levels. The positive results in this patient suggest that resection of the confluence of the hepatic duct may be an effective surgical treatment for noncirrhotic PSC patients who have dominant extrahepatic strictures.     

Electron microscopic observation of destruction of biliary epithelium in primary biliary cirrhosis

ABSTRACT— Electron microscopic studies of the intrahepatic biliary tree in 16 patients with primary biliary cirrhosis (PBC) disclosed four types of biliary epithelial injury suggesting cell death in the ducts: 1) coagulative and 2) lytic necrosis without detachment of affected cells from the biliary epithelial layer, and 3) apoptosis and 4) detachment of several adjoining biliary cells from the basement membrane and neighboring biliary cells. Lesions 1), 2) and 3) were also found in livers with extrahepatic cholestasis without bile duct loss, and 1) and 2) were found in PBC livers irrespective of the degree of bile duct loss. 3) was rare and mostly confined to bile ductules, when present. By contrast, 4) was only observed in PBC, especially in livers with a moderate degree of bile duct loss in which extensive bile duct destruction appeared to be progressing. Detached biliary cells in lesion 4) were occasionally in contact with and/or surrounded by migrating lymphocytes with pseudopod formation, suggesting lymphocyte-target cell interactions. It therefore seems possible that epithelial detachment is an important ultrastructural lesion associated with extensive bile duct destruction in PBC livers.     

Precancerous lesions of the biliary tree

The neoplasms of the biliary tree include the carcinomas of the intra- and extrahepatic bile ducts, the gallbladder and the ampulla. Two types of precancerous lesions precede these adenocarcinomas: the flat and non-tumour forming type that is called biliary intraepithelial neoplasia, and the papillary and tumour-forming type that has been named intraductal papillary neoplasm of the bile duct. Rarely also biliary mucinous cystic neoplasm can give rise to invasive biliary adenocarcinomas. This review discusses the pathological, molecular, epidemiological, clinical and prognostic features of the precancerous biliary lesions, separated according to their origin in the bile ducts, the ampulla and the gall bladder.     

Cholangiocarcinoma:principles and current trends

BACKGROUND:Cholangiocarcinoma(CCA)is a lethal cancer of the biliary epithelium,originating from the liver(intrahepatic),at the confluence of the right and left hepatic ducts(hilar)or in the extrahepatic bile ducts.It is a rare malignancy associated with poor prognosis.DATA SOURCES:We searched the PubMed/MEDLINE database for relevant articles published from 1989 to 2008.The search terms used were related to cholangiocarcinoma and its treatment.Although no language restrictions were imposed initially,for the...