Bile Duct System Research Articles

Will we ever model PSC? – “It's hard to be a PSC model!”

Cholangiopathies such as primary sclerosing cholangitis (PSC) represent an important group of liver diseases of the intra- and extrahepatic bile ducts frequently causing end-stage liver disease with significant morbidity and mortality due to limited treatment options. The relatively low incidence of PSC and the difficult accessibility of the human bile duct system for longitudinal studies may represent some of the critical reasons for the lack of profound knowledge in regard to PSC pathophysiology. Therefore, there is an urgent need for reliable, well-defined and easily reproducible animal models to learn more about the pathophysiology of PSC and to test novel treatment modalities. In an ideal world, immunogenetically predisposed animals would develop fibrous-obliterative cholangitis of the intra- and extrahepatic bile ducts in association with inflammation of the gut (especially colitis) in a highly reproducible manner allowing to test new drugs. To date, however, no such animal model is available. We aimed to provide a systematic overview of current available rodent models for sclerosing cholangitis and biliary fibrosis and therefore critically analyzed the characteristics of models for chemically-induced cholangitis, knock-out mouse models with cholangitis, cholangitis induced by infectious agents, models of experimental biliary obstruction, models involving enteric bacterial cell-wall components or colitis, and models of primary biliary epithelial and endothelial cell injury.

Hepatopancreatic ganglioneuroma in a young dog: a case report

The clinical, pathological and immunohistochemical features of a hepatobiliary and pancreatic ganglioneuroma in a seven-month-old dog are described. The dog presented progressive weight loss, anorexia and abdominal pain. At laparoscopic examination numerous whitish nodules ranging from 0.5 to 1 cm in diameter were found in the peripancreatic tissues, the bile duct system and perihepatic tissues. Due to poor prognosis the dog was euthanized and necropsy was conducted. Tumour nodules were not noted in the other examined abdominal organs. Microscopically, the nodules were composed of large, well differentiated neurons embedded in an abundant stroma of nerve fibres and connective fibrous tissue. Through immunohistochemistry analysis, neurons were found to express neurofilaments and did not express S-100 protein. The histopathological and immunohistochemical features were consistent with a diagnosis of ganglioneuroma. This case is atypical as the majority of reported canine ganglioneuromas involve the gastrointestinal tract. The early age of the dog is also considered to be atypical for this tumour.

Ductal plates in hepatic ductular reactions. Hypothesis and implications. II. Ontogenic liver growth in childhood

This article discusses the processes of bile duct growth and new lobule formation in the liver during childhood in the light of the ductal plate (DP) hypothesis. Unlike in other organs in which tubular elongation and branching ends with the creation of the organ-specific terminal differentiation products, in the liver a steadily enlarging parenchymal mass needs to establish continuity of its canalicular network with the existing bile duct system. The hypothesis suggests that this occurs by DP formation, like in the embryonic liver, and further assumes that pathological ductular reactions (DRs) induced by cholestasis or hypoxia are amplified equivalents of similar mechanisms operating at low level during liver growth. The concept is confronted with data on porcine liver growth, since swine and non-swine liver growth is thought to be comparable. Relative bile acid load may be the driving force for establishment of new canaliculo-ductular connections, supported in zones of relative hypoxia by hypoxia-inducible factor 1 alpha secreted by hepatocytes. The latter mechanism is at the base for induction of appropriate vascular changes in selected sinusoids, resulting in the development of portal inlet venules and additional draining central veins. The process gives rise to the formation of new single lobules by formation of new portal tracts or to the transformation of single lobules in compound lobules by development of new vascular septa. The concept of postnatal DP formation is important in the elucidation of several unexplained findings in adult liver diseases.

Primary sclerosing cholangitis complicated by amyloid A amyloidosis: complete regression of the nephrotic syndrome by liver transplantation

Secondary amyloidosis may complicate chronic inflammatory conditions and mostly presents as a renal disease with nephrotic syndrome or renal insufficiency. Its prognosis is largely affected by control of the underlying disease. We report a patient with primary sclerosing cholangitis, who developed cirrhosis over a 4-year period. Therapy with steroids and azathioprine was necessary for symptom control. Despite this treatment, she developed secondary amyloidosis with nephrotic syndrome 4 years after the initial presentation. The inflammatory process in the bile ducts was considered the cause of amyloid A amyloidosis. To control the nephrotic syndrome, liver transplantation was performed with the removal of the diseased liver and bile duct system. Liver transplantation was followed by a progressive and complete disappearance of the nephrotic syndrome. This is the first report describing the occurrence of amyloid A amyloidosis in primary sclerosing cholangitis, and the reversal of a secondary amyloidosis-induced nephrotic syndrome as a result of liver transplantation.

Double Cystic Duct in a Patient with Sinus Inversus Totalis

Purpose: Double cystic duct is a rare congenital anomaly. Here we describe a patient with situs inversus and biliary pancreatitis who had a double cystic duct complicating laparoscopic cholecystectomy. A 49-year-old male with sinus inversus totalis was referred to our institution for an ERCP. The patient had a history of multiple episodes of left upper quadrant pain. Following the resolution of the first episode, he underwent open cholecystectomy in which a double cystic duct was found. An IOC showed a delayed passage of contrast into the duodenum, raising suspicion of choledocholithiasis. He was referred to our institution for endotherapy. A tube cholangiogram delineated the opacified the cystic duct bearing the biliary tube drain that joined the common bile duct (CBD) (Figure 1). An ERCP was performed under general anesthesia with the patient in the conventional left lateral semiprone position. Attempted cannulation was extremely difficult and biliary access was possible only after a needle-knife sphincterotomy. Retrograde cholangiography confirmed a CBD stone, but could not be retrieved. A 10F biliary stent was deployed ensuring free flow of bile. He was observed overnight and discharged the following morning without any complications. Variations in cystic duct anatomy are common. However, very few cases of a double cystic duct draining into a single gallbladder have been reported. When any of these variations are suspected, a cholangiography or ERCP is recommended to define the anatomy, and then a cholecystectomy can be completed safely. If the anatomy is not defined, there is a high chance of surgical complications from injury to the bile duct system. Complicating the clinical picture was the sinus inversus totalis anomaly of his biliary tract. The most challenging aspect of performing an ERCP is the mirror image anatomy. In a patient with sinus inversus, many people have recommended performing a right-sided approach, in conjunction with the anomalous anatomy. In summary, a double cystic duct is a rare congenital anomaly that becomes further complicated when the patient has sinus inversus and develops choledocholithiasis. An intraoperative cholangiogram could help defining the anatomy and help to minimize the risk of complications.Figure

Percutaneous Biliary Drainage in Patients With Nondilated Intrahepatic Bile Ducts Compared With Patients With Dilated Intrahepatic Bile Ducts

The purpose of this article is to compare the technical success and guidance of percutaneous transhepatic biliary drainage (PTBD) in patients with nondilated and dilated bile duct systems using different techniques to supplement the conventional approach. Between 2006 and 2008, 71 patients (mean age, 66.6 years) underwent PTBD with 97 interventions. According to sonographic evaluation of bile duct morphology, patients were divided into two groups: 50 patients with dilated and 21 patients with nondilated bile ducts. In a retrospective analysis, both groups were compared for technical success, fluoroscopy time, complications, and medical indications. The use of interventional guidance (deviations from the standard protocol) in patients with nondilated bile ducts was recorded. The technical success rate was 90% in patients with dilated bile ducts versus 81% in patients with nondilated ducts, with no significant difference (p = 0.36). The greater complexity of the intervention in patients with nondilated bile ducts resulted in longer fluoroscopy times (p = 0.04). Complication rates were not different between the two groups. The main indication for PTBD was relief of a compressed biliary system in patients with dilated ducts and postoperative management of complications or prevention of tumor-associated bile duct obstruction in patients with nondilated ducts. T-drainage, additional CT-guided puncture, and temporary gallbladder drainage were performed in 16 of 21 interventions for patients with nondilated bile ducts, resulting in a 100% success rate, versus a success rate of 60% in the five PTBDs of nondilated ducts performed in the conventional manner. T-drainage, additional CT-guided puncture, and temporary gallbladder drainage improve the technical success of PTBD when used in patients with nondilated bile ducts. With these measures, technical success and complication rates in patients with nondilated ducts are comparable to those for PTBD of dilated bile ducts.

Right/left symmetry of the intrahepatic distribution and terminology of the hepatic artery proper and the intrahepatic bile duct system: proposals to revise the Terminologia Anatomica

Anatomical terminology is the foundation of medical terminology and it is important that doctors and scientists throughout the world use the same name for each structure. It is also important that the anatomical terms for a specific anatomical structure are presented in a logical order. To eliminate confusion, it is crucial that the same name is not attributed to two or more anatomical elements. However, the term artery of caudate lobe is used for two distinct anatomic elements with different origins (right/left branch of hepatic proper artery). Also, I draw attention to the incorrect positioning of right/left duct of caudate lobe in the description of terms homologated for the intrahepatic bile duct system. These proposals to amend the terminology in the liver anatomy are a necessary step in the evolution of the Terminologia Anatomica.

Extrahepatic bile duct duplication with choledocholithiasis in an accessory left bile duct draining into the antrum of the stomach: A case report

We present the case of a 60-year-old woman admitted to hospital with acute abdominal pain on a background history of vague dyspeptic symptoms managed as an outpatient. Serial imaging investigation with a barium contrast meal, oesophagogastroduodenoscopy, ultrasonography, computed tomography, endoscopic retrograde cholangiopancreatography and magnetic resonance cholangiopancreatography (MRCP) established a very rare diagnosis. Our patient had extrahepatic bile duct duplication with an accessory bile duct draining the left lobe of the liver into the antrum of the stomach without intrahepatic communication of the left and right bile duct systems, complicated by choledocholithiasis of the accessory duct. Diagnosis of this variant was finally made with MRCP at 2 months follow-up to the initial admission, which also demonstrated spontaneous passage of the accessory duct stone. A differential diagnosis list for cystic structures in the lesser omentum is considered. We believe that this is the first such case to be demonstrated with all 6 forms of imaging described, which were performed, undoubtedly, because of its rarity. Retaining awareness of such rare anomalies in our clinical practice should lead to appropriate imaging being initiated early and avoid delay in diagnosis, especially because of associations with potentially serious complications.

Image Quality and Bile Duct Volumetry in MR Cholangiopancreatography Augmented With Low-Dose Morphine

Opioids are applied to augment visualization of the biliary system in MR cholangiopancreatography (MRCP) to take advantage of a side effect, the constriction of the sphincter of Oddi. This prospective study was performed to determine the effect of IV low-dose morphine on image quality and bile duct delineation in MRCP. Fifteen healthy volunteers and 15 consecutive patients underwent MRCP on a 1.5-T MRI scanner. Strongly T2-weighted 3D single-shot fast spin-echo (SSFSE) sequences were acquired before and 10 minutes after IV administration of morphine (0.04 mg/kg of body weight; mean +/- SD, 2.9 +/- 0.5 mg). Maximum intensity projections were reconstructed from the SSFSE sequence data. Image quality was rated by two independent radiologists using a 4-point scale (1 = excellent, 4 = not diagnostic). Delineation of segmental and subsegmental intrahepatic bile duct orders before and after morphine administration was compared. Volumetry of the common bile duct (CBD) was performed using electronic measurements (AngioTux software, ECCET image processing system). IV morphine did not significantly improve subjective image quality of the extra- and intrahepatic bile ducts (mean image quality score before vs after morphine administration, 2.3 vs 2.0) or delineation of the intrahepatic bile duct orders. The volume of the CBD remained constant after morphine administration (mean CBD volume before vs after morphine administration, 14.1 vs 13.6 mL). Notable side effects of morphine were seen in two young healthy female volunteers. IV-administered low-dose morphine seems to have no essential influence on image quality or delineation of the bile duct system in MRCP. Therefore, the general advice to perform morphine-augmented MRCP should be discussed critically.

Multipotent stem cells in the biliary tree.

The biliary tree system consists of two divisions: intrahepatic bile ducts and extrahepatic bile ducts. The development of the biliary tree, and secondarily the liver, shares a common origin with ventral pancreas. A common progenitor for liver, biliary duct system, and ventral pancreas exists at early stages of development, when the anterior definitive endoderm is forming the foregut. Several studies indicate that the biliary tree contains stem cell compartments for liver, pancreas and the bile duct system and persisting into adulthood. These stem cell compartments are present in the peribiliary glands and possibly give rise to committed progenitors in gallbladder that does not have peribiliary glands. The biliary tree stem/progenitors represent a new source of cells that can be used as tools for regenerative medicine of liver, bile duct and pancreas.

Application of a Visible Simulation Surgery Technique in Preoperation Planning for Intrahepatic Calculi

The aim of this study was to evaluate a visible simulation surgery technique for choosing the best surgical plan in patients with intrahepatic calculi. A medical image processing system was used to process computed tomography (CT) scanning data collected from four cases of intrahepatic calculi. Models of liver and bile ducts in standard template library format were processed by a free-form modeling system and reconstructed three-dimensionally. Accurate digital information about the bile duct system, lesions, calculi distribution, and adjacent organs from all directions, multiple angles, and multi-strata were used to choose the best surgical plan. Then, visible simulation surgery was performed with simulation operation software. Three-dimensionally reconstructed models provide clarity with strong relief perception and a user-friendly interface. Visible simulation surgery performed based on three-dimensionally reconstructed models led to optimal operation planning. Visible simulation surgery is more objective and complete than routine preoperative examinations to choose the best operation plan for intrahepatic calculi.

Ultrasensitive Detection of KRAS2 Mutations in Bile and Serum from Patients with Biliary Tract Carcinoma Using LigAmp Technology

Patients with biliary tract carcinoma have a poor prognosis. Early detection efforts are urgently needed to ameliorate the dismal prognosis for these patients. Mutations of the KRAS2 gene are one of the most common genetic aberrations in this cancer. In this study, we used LigAmp, an ultrasensitive technology for detecting point mutations, to analyze KRAS2 mutations in patients with a variety of neoplastic and non-neoplastic pancreatobiliary diseases. DNA was isolated from 64 samples, including 44 bile samples and 20 serum samples. Oligonucleotides specific for KRAS2 G35A (GAT, G12D), G35T (GTT, G12V), and G34A (AGT, G12S) mutations were used. KRAS2 mutations were detected in 14 of 16 (87.5%) neoplastic bile samples and in 9 of 28 (32.1%) non-neoplastic bile samples. However, the mutation levels were significantly lower in the non-neoplastic bile (median = 0.4%) compared with those in the neoplastic bile (median = 5.1%). KRAS2 mutations were also detected in 9 of 11 (81.8%) serum samples from patients with biliary tract carcinoma, which was further confirmed by cloning BstN1-refractory PCR products and DNA sequencing. However, KRAS2 mutations were not present in the sera from eight patients with benign pancreatobiliary diseases. These data demonstrate that KRAS2 mutations are detectable in both bile and serum using LigAmp. This technology has the potential for early biliary tract carcinoma detection and possibly for residual disease monitoring post-therapy.

Diagnose und Differenzialdiagnose von Gallenwegserkrankungen

Erkrankungen der Gallenblase und der Gallenwege (Cholepathien) lassen sich grundsätzlich in angeborene Erkrankungen und erworbene Erkrankungen einteilen. Unter den anlagebedingten Erkrankungen sind insbesondere die Gallengangsatresie und die Choledochuszysten zu nennen. Erworbene Cholepathien beinhalten Gallensteinerkrankungen, entzündliche Veränderungen und Neoplasien.

2.02] Confocal endomicroscopy (CFE) in gastroenterology: Ready for prime time?

Objective Confocal laser endomicroscopy (CFE), when implemented during endoscopy, enables in vivo microscopy of the mucosal layer of any tissue in the gastrointestinal tract with subcellular resolution. Endomicroscopy opens the door to immediate tissue and vessel analysis. Different types of diseases can be diagnosed with optical surface and subsurface analysis. Discrimination between normal and malignant cells is possible. Analysis of the in vivo microarchitecture can be used for targeting biopsies to relevant areas, and subsurface imaging can unmask microscopic diseases. The aim of our study was to validate this new technique further. Material and methods For CFE we used a Cellvizio® miniprobe, which is compatible for all endoscopes with an operating channel of 2.6 mm. Placed in contact with the mucosa, the miniprobe delivers real-time video sequences of the tissue microarchitecture at 12 images per second and a depth resolution of about 50 μm. We used CFE to perform “optical biopsies” in patients with known Barrett's esophagus, one with a known high-grade intraepithelial neoplasia, in the follow-up of a patient after small bowel transplantation, and in a patient with invasive cholangiocellular carcinoma of the bile duct. Additionally, we performed CFE in a newly established pig model of benign bile duct stenosis. The benign stenosis were induced by endoscopic retrograde cholangiography (ERC) with introduction of a 10 Fr-heater probe and application of HF energy (400 J) approximately 3 cm proximal of the papillae. Results Confocal imaging of the normal squamous epithelium of the esophagus demonstrated squamous cells at high resolution, showing capillaries (filled with red blood cells) within single papillae. The typical shape of Barrett's epithelium was villous, differing from the cardiac epithelium. High-grade intraepithelial neoplasias can be recognized by a distinct cell type in endomicroscopy. Nevertheless, this technique appears to require experience and is not an “easy-to-use-method” in the esophagus. In contrast, CFE appears to be safe and useful for monitoring patients for transplant rejection after small bowel transplantation. In bile duct cancer, CFE showed a deranged vascular architecture in contrast to the regular pattern obtained within the normal epithelium of this patient. In our pig model we were able to establish a reproducible benign bile duct stenosis. These fibrotic structures were characterized by virtually no CFE signal. This is in direct contrast to the normal bile duct epithelium of animals and to the bile duct cancer mentioned above. Conclusion CFE is feasible in a wide variety of gastrointestinal tissues using regular endoscopes and a thin miniprobe. Although real-time “optical biopsies” are achievable, the exact diagnosis still has to be made by the pathologist. CFE is helpful for discrimination between normal tissue and dysplasia or even carcinoma. The application in the bile duct system probably requires an additional cholangioscope for placing the miniprobe specifically in the suspected area. Further studies are necessary to evaluate this promising technique in bile-duct disorders in humans.

3D Imaging of Intrahepatic Strictures During Endoscopic Retrograde Cholangiography (ERC): First Clinical Data

In contrast to other imaging techniques ERC combines diagnostic and therapeutic options. In case of Klatskin tumors, strictures can be visualized, diagnosed by biopsy specimen or brush cytology and treated e.g. by stent placement at the same procedure. With regard to surgical resection techniques an exact estimation of the extention of the tumor into the hepatic ducts is mandatory but still difficult. In a pilot trial patients with intrahepatic bile duct strictures underwent diagnostic ERC with three-dimensional (3D) angiographic reconstruction of the bile duct system in volume rendering technique. The aim of this trial was to compare both imaging modalities with regard to the potential of imaging the stricture morphology. Patients/Methods: Consecutive patients with known bile duct strictures underwent ERC in prone position with intravenously administered midazolam and propofol with constant monitoring of oxygen saturation and heart rate as well as blood pressure in intervals. In a first step the contrast filled bile ducts are viewed from different positions using the rotational capabilities of the C-arm. In a second step a 3D volume rendering technique is undertaken: 99 projection images are recorded during the 5 second rotation of the C-arm and this dataset is automatically reconstructed and displayed on a different screen. A special software provides virtual 3D rotation of the bile duct system, enabling the examiner to look at the strictures from different positions. Results: Five consecutive patients were presented for intrahepatic strictures (Klatskin type IV n=2, intrahepatic stenosis of the left hepatic duct n=2 and of the right hepatic duct n=1). ERC with three dimensional reconstruction was successful in all examinations. All of the known strictures were visualized in 3D imaging. Analysis of length and number as well as degree of strictures was facilitated by 3D imaging. Due to the evaluation of the bile duct system from different virtual positions with 3D reconstruction analysis of length, number and degree of strictures was facilitated. In one patient 3D analysis showed an only slight stricture without need for treatment that had been estimated differently in conventional two-dimensional ERC imaging. Conclusion: Online three dimensional imaging of intrahepatic strictures during ERC is feasible. 3D ERC has the advantage of imaging intrahepatic strictures from different virtual positions thus may improve analysis of duct morphology and tumor staging and may have implications on therapeutic interventions. This hypothesis has to be confirmed in larger trials.

Cellular organization of normal mouse liver: a histological, quantitative immunocytochemical, and fine structural analysis.

The cellular organization of normal mouse liver was studied using light and electron microscopy and quantitative immunocytochemical techniques. The general histological organization of the mouse liver is similar to livers of other mammalian species, with a lobular organization based on the distributions of portal areas and central venules. The parenchymal hepatocytes were detected with immunocytochemical techniques to recognize albumin or biotin containing cells. The macrophage Kupffer cells were identified with F4-80 immunocytochemistry, Ito stellate cells were identified with GFAP immunocytochemistry, and endothelial cells were labeled with the CD-34 antibody. Kupffer cells were labeled with intravascularly administered fluorescently labeled latex microspheres of both large (0.5 mum) and small (0.03 mum) diameters, while endothelial cells were labeled only with small diameter microspheres. Neither hepatocytes nor Ito stellate cells were labeled by intravascularly administered latex microspheres. The principal fine structural features of hepatocytes and non-parenchymal cells of mouse liver are similar to those reported for rat. Counts of immunocytochemically labeled cells with stained nuclei indicated that hepatocytes constituted approximately 52% of all labeled cells, Kupffer cells about 18%, Ito cells about 8%, and endothelial cells about 22% of all labeled cells. Approximately, 35% of the hepatocytes contained two nuclei; none of the Kupffer or Ito cells were double nucleated. The presence of canaliculi and a bile duct system appear similar to that reported for other species. The cellular organization of the mouse liver is quite similar to that of other mammalian species, confirming that the mouse presents a useful animal model for studies of liver structure and function.

A New Systematic Classification of Peripheral Anatomy of the Right Hepatic Duct: Experience From Adult Live Liver Donor Transplantation

Objective The peripheral intrahepatic biliary anatomy, especially at the sectorial level on the right side, has not been adequately described. The purpose of our study was to systematically describe this complex anatomy in clinically applicable fashion. Patients and Methods We analyzed three-dimensional computed tomography (CT) imaging reconstructions of 139 potential living liver donors evaluated at our institution between January 2003 and June 2007. Results Eighty-nine (64%) donors had a normal right bile duct sectorial anatomy. In the other 50/139 (36%) cases, we observed abnormal sectorial branching patterns, with 45/50 abnormalities as trifurcations, whereas the remaining ones were quadrifurcations. In 22/50 (44%) abnormalities, a linear branching pattern (types B1/C1) and an early segmental origin off the right hepatic duct (types B3/C3) were present, a finding of particular danger when performing a right graft hepatectomy. In 2 cases, we noted a mixed type (B6/C6) of a rare complex anatomy. Conclusions Our proposed classification of the right sectorial bile duct system clearly displays the “area at risk” encountered when performing right graft adult live donor liver transplantation and tumor resections involving the right lobe of the liver.

Gross Anatomical Studies on the Portal Vein, Hepatic Artery and Bile Duct in the Liver of the Pig

Nowadays, pig has been chosen as the potential source of organs and cells for human to overcome a sever shortage of human material for clinical transplantation especially in the last 10 years by use of genetically modified swine. Consequently, the present study was conducted to give detailed information about the distribution of the blood vessels and bile ducts and their topographic relations, which may give a useful base for the hepatic segmentation in this animal aiming to provide a correct base for surgical procedures and liver transplantation. � The present study was conducted on 33 livers of pigs. Dissection, casting and radio-opaque techniques have been applied to show the different ramifications of the portal vein, hepatic artery and bile duct systems as well as their topographic relations with proposals of hepatic segmentation. The results revealed that, the caudate, right lateral and right medial lobes were supplied by R. dorsalis dexter and R. ventralis dexter of the portal vein in addition to R. dexter of the hepatic artery and right hepatic duct. The quadrate, left medial and left lateral lobes were supplied by the R. sinister of the portal vein and hepatic artery and left hepatic duct. � The liver of the pig could be divided into two independent segments; right and left. These two segments were separated by a segmental plane passed from the esophageal notch dorsally to the fossa of the gall bladder ventrally.

Ultrasonographic Imaging of Bile Duct Lesions in Autoimmune Pancreatitis

Patients with autoimmune pancreatitis (AIP) commonly have lesions in the bile duct itself and show stenosis of the bile duct system; however, no detailed study has evaluated the ultrasonographic findings of bile duct lesions in AIP. In this study, we monitored the clinical course and imaging findings, mainly ultrasonographic, of bile duct lesions in AIP. We retrospectively analyzed the incidence of bile duct lesions, imaging findings, and clinical course in 37 patients with AIP. Characteristic bile duct and gallbladder wall thickening was recognized on ultrasound in 37.8% (14/37) of AIP patients. We divided the patients into 2 types according to the ultrasonographic findings of bile duct wall thickening: (1) 3-layer type (64.3%) and (2) parenchymal-echo type (35.7%). All 14 cases were treated with prednisolone, with immediate resolution of the bile duct lesions. Sclerosing cholangitis is one of the extrapancreatic lesions that are commonly detected in AIP patients; it is detected on ultrasonographic imaging as characteristic wall thickening. Our ultrasonographic findings reflect the fact that bile duct wall thickening in AIP is an inflammatory process that responds to prednisolone therapy. Ultrasonography is a useful tool in detecting biliary tract lesions in AIP.

Distribution of the interstitial Cajal-like cells in the gallbladder and extrahepatic biliary duct of the guinea-pig

It has been suggested that interstitial Cajal-like cells (ICLC) may be involved in the spontaneous rhythmic electrical activities of the extrahepatic bile duct system. The present study investigated the distribution and characteristics of ICLC, which are immunopositive for CD117/ Kit receptor tyrosine kinase, using immunohistochemistry employing a monoclonal antibody raised against CD117/Kit on whole-mount preparations. The Kit-positive ICLC were examined using confocal laser scanning microscopy or fluorescence microscopy. ICLC, immunoreactive for Kit, were pleiomorphic and/or spindle-shaped cells with a few bipolar processes and distributed in the smooth muscle layers of the gallbladder and bile duct system. They were scattered in the hepatic duct, cystic duct and gallbladder as well as in the upper part of the common bile duct. The ICLC gradually increased in number and formed a completed cellular network in the lower part of the common bile duct and ampulla. The numbers of ICLC in the ampulla were similar to that of the duodenum and significantly much greater in number than in the gallbladder and bile ducts. The density of the ICLC in the common bile duct was significantly higher than that of other bile ducts. Our results suggested that the ICLC might contribute to the regulation of the spontaneous rhythmic contraction and development of motility disorders of the bile duct system.