Topographical relationship between the accessory hepatic duct and the hepatic artery system.

Hepatic biliary injury is one of the most common complications in cholecystectomy and is frequently accompanied by arterial injuries. Because there are several anatomical variations of the hepatic ducts, including the accessory hepatic ducts (AHDs), it is important to consider not only the anatomical position of the hepatic ducts but also those of the AHDs in cholecystectomy. However, the topographical relationships between the AHDs and the hepatic arteries are still poorly understood. In the present study we show that AHDs were observed in 7 out of 59 (11.9%) of the cadavers. There was a single AHD in the 6 out of the 7 cadavers and double AHDs in one. In these cases, the right AHDs emerged from the anterior medial segment of the liver piercing the parenchyma, while the left AHDs emerged directly from the anterior part of the caudate lobe. The right AHDs ran anterior to the right hepatic artery, while the left AHDs ran posterior to the hepatic arteries. The topographical relationship between the AHD and the hepatic artery system was thus reversed in the cases of the right and the left AHDs.

Hilar cholangiocarcinoma: Value of high-resolution enhanced magnetic resonance imaging for preoperative evaluation.

OBJECTIVES: The objective is to assess the accuracy of high-resolution (HR) enhanced magnetic resonance imaging (MRI) images in the preoperative evaluation of biliary and vascular invasion in hilar cholangiocarcinomas. METHODS: This retrospective study included 36 patients with hilar cholangiocarcinoma who underwent enhanced HR-MRI with an effective section thickness of 1.2 mm at 3.0 T before surgery. Combined HR-MRI and magnetic resonance cholangiopancreatography (MRCP) images were compared with MRCP in evaluating the extent of biliary infiltration according to the Bismuth-Corlette classification. To determine the suitable criterion for HR-MRI in predicting vessel invasion, Labeling 180 and 90 of circumferential contact of the tumor with the vessel were used to predict the invasion. The correlation between imaging findings and surgical and histopathological records was statistically analyzed. RESULTS: The accuracy in detecting biliary neoplastic invasion was higher for combined HR-MRI images (97.2%) than MRCP images (86.1%). HR-MRI images increased the accuracy in delineation of the tumor biliary extent (P < 0.05). The accuracy of Labeling 90 (98.6% in portal venous system and 98.0% in hepatic arterial system) was higher than that of Labeling 180 (96.5% in portal venous system and 94.6% in hepatic arterial system). However, there was no significant statistic difference between them (P > 0.05). Interobserver agreement was high with respect to biliary tract, portal venous, and hepatic arterial system involvement. CONCLUSIONS: Enhanced HR-MRI images showed excellent capability for assessing tumor extent and vascular invasion in hilar cholangiocarcinomas. More than 90° of circumferential contact of the tumor with the vessel on HR-MRI may be an appropriate criterion for predicting invasion.

Microvascularization of the canine hepatic ducts.

The angioarchitecture of the proximal and distal segments of the hepatic duct in the dog was investigated by means of vascular corrosion casts under a scanning electron microscope. The results of observations indicated a change of the pattern of vascularization of the hepatic duct along with the increasing distance of the hepatic duct from the liver and increasing diameter of the duct. In the proximal hepatic duct, the main blood vessels run along the duct as a pair of supplying arteriole and voluminous collecting venule, while in the distal segments of the hepatic duct on the opposite margin of the duct two vascular triads were observed, composed of two venules and one medial arteriole. On the surface of both segments of the hepatic duct, there are well-anastomosed outer venous plexuses. In the distal segments of the hepatic duct, the outer venous plexus accompanies a fine outer arterial rete. Observations of the intramural network indicate the presence of single terminal arterioles running to mucosa and supplying a subepithelial capillary network. Differences were observed in the blood drainage from the mucosa, as in the proximal segment of the hepatic duct single post-capillary venules are found, while in the distal segment in the mucosa a well-developed mucosal venous plexus is formed. In the well-developed venous system of the hepatic duct no valves were observed.

The blood supply of the biliary ductal system and its relevance to vasculobiliary injuries following cholecystectomy.

BACKGROUND: Cholecystectomy remains the only satisfactory treatment for symptomatic gall bladder stones. Unfortunately, in some cases the operation is complicated by vasculobiliary injury. The present study was undertaken to investigate the blood supply of the normal biliary system, to simulate vasculobiliary injuries described after cholecystectomy, and to determine the possible effects of the vascular injury on biliary reconstruction. METHODS: The blood supply of the biliary system in nine normal livers was investigated by injection of the coeliac axis and superior mesenteric arteries with coloured gelatin. The specimens were dissected under magnification and drawings prepared. Injection dissection studies were also carried out in eight specimens in which various vasculobiliary injuries encountered after cholecystectomy were simulated. RESULTS: The bile ducts possess an arterial plexus on their surface which is supplied from below by ascending marginal vessels derived from the postero-superior pancreaticoduodenal artery. These marginal vessels end above in the right hepatic artery or its branches. The right and left hepatic ductal systems are supplied by the right and left hepatic arteries and their sectoral or segmental branches. The right and left hepatic arteries communicate freely via the hilar plate arterial plexus. This collateral system allows the blood supply to the right hepatic duct to be maintained after ligation of the right hepatic artery and interruption of the common hepatic duct or excision of the confluence. CONCLUSION: A knowledge of the blood supply of the normal biliary system and the collateral hilar plate arterial plexus forms the anatomical foundation for successful reconstructive surgery, not only in vasculobiliary injuries following cholecystectomy, but also for a wide range of hepatobiliary procedures.

Arterial ring encircling the bile duct with coexisting anomalous liver irrigation.

Analysis of the arterial system of the liver in a 64-year-old male cadaver revealed an anomaly of the branching of the proper hepatic artery. The right branch of the hepatic artery was missing, replaced by two segmental arteries, so that a 'trifurcation' occurred, consisting of two segmental arteries, anterior segmental and posterior segmental, and the left branch of the hepatic artery. These segmental arteries formed an arterial ring around the common hepatic duct, completely encircling it. A single cystic artery unusually originated from the posterior segmental artery. An extremely rare anatomical variation of the dorsal liver segment irrigation proves the fact that anatomical anomalies are usually multiple. The arterial blood supply for the dorsal liver segment is through four separate vessels ('quadruple type'), two originating from the left branch of the hepatic artery and two from the posterior segmental artery. These four arteries presented numerous anastomotic bridges among themselves.

Limitations of percutaneous transhepatic cholangioscopy for the diagnosis of the intramural extension of bile duct carcinoma.

BACKGROUND AND STUDY AIMS: Vascular dilatation seen on percutaneous transhepatic cholangioscopy (PTCS) is diagnostic of intramural invasive carcinoma of the bile duct, but the limitations of the technique, including biopsy, for the diagnosis of intramural extension of bile duct carcinoma have not to our knowledge been investigated before. The aims of the present study were to estimate the thickness of the specimens of bile duct wall taken by biopsy, to assess the sensitivity of PTCS for detecting intramural invasive carcinoma, and to identify the characteristics of the intramural extension of bile duct carcinoma associated with vascular dilatation. PATIENTS AND METHODS: A total of 135 biopsy, and 16 surgical specimens obtained from 25 bile duct carcinomas were examined for: the thickness of the biopsy specimens and of the mucosa and combined mucosal-fibromuscular layers in the resected common bile ducts and common hepatic ducts; the presence of muscular and neural bundles in the biopsy specimens; the number of invasive carcinomas in the biopsy specimens that had been taken from stenosed regions; and the relation between intramural extension of invasive carcinoma and vascular dilatation. RESULTS: The mean thickness of the biopsy specimens did not differ from the mean thickness of the mucosa in the resected specimens, but was significantly lower than that of the combined mucosa and fibromuscular layer. Muscular bundles were included in only 13 (14%) of the biopsy specimens, and there were no neural bundles. Carcinomas and invasive carcinomas were diagnosed histologically from the biopsy specimen in 96% and 91% of the cases, respectively. The sensitivity of a single biopsy for diagnosis for invasive carcinoma in stenosed regions was 62%, almost the same as the sensitivity in non-stenosed regions with vascular dilatation (68%). On histologic examination of 16 resected specimens, the sensitivity and specificity of vascular dilatation as a marker of the intramural extension of an invasive carcinoma were 39% and 100%, respectively, and this was significantly more common in invasive carcinomas that were invading the mucosa beyond the adventitia than in those limited to the adventitia. CONCLUSION: Histologic examinations of specimens obtained by PTCS-guided biopsy can detect invasive carcinoma in only the superficial layers of the bile duct, such as the mucosa and the shallowest fibromuscular layer. Multiple specimens are needed for the diagnosis of invasive carcinoma because the sensitivity of examination of a single specimen for detecting invasive carcinoma is low. Vascular dilatation is characteristic of carcinoma that is invading the mucosa beyond the adventitia, so the diagnosis of intramural extension of bile duct carcinoma limited to the adventitia, particularly if it has spread to the deeper fibromuscular layer and the adventitia, is difficult to make by PTCS.

Blood supply of the right and left hepatic ducts.

BACKGROUND: Increasing precision of liver resection and use of reduced liver grafts stimulated this study of the blood supply of the intrahepatic bile ducts. METHOD: Corrosion casts of human liver were dissected to study the blood supply of the right and left hepatic ducts. RESULTS: The dissected casts showed that the ducts are surrounded by a vascular plexus supplied from the main right and left hepatic arteries, segmental arteries, gastroduodenal artery and accessory hepatic arteries. This plexus is closely associated with the arteries supplying the caudate lobe. They arise from both right and left in two general patterns. This plexus links the arterial supplies of the right and left livers. Segment i.v. and the central portion of the left hepatic duct are often supplied by the right arterial system. CONCLUSION: This study provides further insights into bile duct blood supply. The caudate lobe and biliary plexus provide collateral connections between the right and left livers.

Bile duct varices.

The diagnosis of biliary duct varices and portal vein occlusion should be considered when nodular or notched defects in the wall of the biliary duct system are shown by cholangiography or when pedunculated vascular structures in the bile ducts are seen at surgery. We present two cases of common hepatic and common bile duct varices due to portal vein occlusion.

[Arterial circulation of the extrahepatic bile ducts]. / Die arterielle Blutversorgung der extrahepatischen Gallenwege.

The blood supply of the extrahepatic bile ducts was investigated in 15 human specimens. Human embryology explains the origin of the main blood supply in this area by the a. pancreaticoduodenalis posterior superior, the a. cystica and the a. hepatic propria. Other arteries are inconsistent and functionally unimportant. 2 or 3 marginal arteries are predominant in the arterial system surrounding the common bile duct. Surgery of the extrahepatic bile ducts should be performed with respect to this particular arterial network.

[Surgical importance of the topography of the vessels and bile ducts in the hepatic portal in case of their atypical branching and formation]. / Khirurgicheskoe znachenie topografii sosudov i zhelchnykh protokov v vorotakh pecheni pri ikh atipichnom delenii i formirovanii

The portal triad was studied on 100 specimens of porta hepatis, using the methods of preparation, roentgenography and corrosion. An unusual origin of hepatic arteries was observed in 36%, atypical formation of bile ducts--in 33%, and a specific branching of the portal vein--in 15%. Different variants of vessels and bile ducts related with their specific development can be intercombined. Due to it, during surgical procedures in the region of porta hepatis it is necessary to bear in mind not only an atypical structure of each element of the Glisson system, but also the possibility of frequent combination of their different variants.