Intra-biliary hydatid cyst rupture: A rare case report with superinfection

Key Clinical Message

Hydatid cysts, primarily found in the liver (70%), are caused by parasitic infections and can lead to severe complications such as cyst rupture. This case report describes a unique instance of a hydatid liver cyst occupying the right lobe with a communicating part with the biliary tree that ruptured showing a concurrent superinfection.

Abstract

Hydatid cysts are a clinical pathology resulting from parasitic infections. They may occur in different organs of the body. However, these are mostly found in the liver (70%). This can cause significant complications including cyst rupture. Several case reports have described various hydatid cyst ruptures; however, only a few have reported an intra-biliary hydatid cyst rupture. A 24-year-old male patient presented with right upper quadrant pain, jaundice, dark urine, and pale stool. Imaging studies, including Magnetic resonance cholangiopancreatography (MRCP) and computed tomography (CT), revealed a beavertail liver, cystobiliary communication and intrahepatic biliary tree-ruptured hydatid cysts. The cyst was in the right liver lobe, which is the most common site for hydatid cysts. Surgical intervention involving laparoscopic de-roofing and cyst removal resulted in a smooth recovery without complications. Several case reports have described various hydatid cyst ruptures; however, only a few have reported originally placed intra-biliary hydatid cyst ruptures. This case report describes a unique instance of a hydatid liver cyst occupying the right lobe with a communicating part with the biliary tree that ruptured showing a concurrent superinfection.

ASO silencing of a glycosyltransferase, Poglut1 , improves the liver phenotypes in mouse models of Alagille syndrome

BACKGROUND AND AIMS

Paucity of intrahepatic bile ducts (BDs) is caused by various etiologies and often leads to cholestatic liver disease. For example, in patients with Alagille syndrome (ALGS), which is a genetic disease primarily caused by mutations in jagged 1 ( JAG1) , BD paucity often results in severe cholestasis and liver damage. However, no mechanism-based therapy exists to restore the biliary system in ALGS or other diseases associated with BD paucity. Based on previous genetic observations, we investigated whether postnatal knockdown of the glycosyltransferase gene protein O -glucosyltransferase 1 ( Poglut1) can improve the ALGS liver phenotypes in several mouse models generated by removing one copy of Jag1 in the germline with or without reducing the gene dosage of sex-determining region Y-box 9 in the liver.

APPROACH AND RESULTS

Using an ASO established in this study, we show that reducing Poglut1 levels in postnatal livers of ALGS mouse models with moderate to profound biliary abnormalities can significantly improve BD development and biliary tree formation. Importantly, ASO injections prevent liver damage in these models without adverse effects. Furthermore, ASO-mediated Poglut1 knockdown improves biliary tree formation in a different mouse model with no Jag1 mutations. Cell-based signaling assays indicate that reducing POGLUT1 levels or mutating POGLUT1 modification sites on JAG1 increases JAG1 protein level and JAG1-mediated signaling, suggesting a likely mechanism for the observed in vivo rescue.

CONCLUSIONS

Our preclinical studies establish ASO-mediated POGLUT1 knockdown as a potential therapeutic strategy for ALGS liver disease and possibly other diseases associated with BD paucity.

Hepatobiliary-specific magnetic resonance contrast agents: role in biliary trauma

Non-iatrogenic traumatic bile duct injuries (NI-TBIs) are a rare complication after abdominal trauma, with an estimated prevalence of 2.8-7.4% in patients underwent blunt liver injuries. They may be overlooked in patients with extensive multi-organ trauma, particularly hepatic, splenic and duodenal injuries, which have a prevalence of 91%, 54% and 54%, respectively. Whole body contrast-enhanced computed tomography (CE-CT) represents the examination of choice in polytraumatized hemodynamically stable patients, as it allows a comprehensive evaluation of vascular, parenchymal, bone and soft tissues injuries, but the diagnosis of any biliary leaks is limited to the evaluation of nonspecific imaging findings and on findings evolution in the follow-up, such as the progressive growth of fluid collections. Furthermore, biliary complications, such as the occurrence of biloma or biliary peritonitis, may become manifest several days after the initial trauma, often with unspecific progressive signs and symptoms. Although CT and ultrasonography can suggest bile leaks based on several nonspecific imaging findings (e.g., fluid collections), magnetic resonance imaging (MRI) using hepatobiliary contrast agents helps to identify the site and entity of post-traumatic biliary disruption. Indeed, MRI allows to obtain cholangiographic sequences that may show post-traumatic active bile leakage and cysto-biliary communications by direct visualisation of contrast material extravasation into fluid collections, increasing the preoperative accuracy of NI-TBIs. Few data are available about MRI use in the follow-up of trauma with NI-TBI management. So, in the present mini review, its role is reviewed and our preliminary experience in this field is reported.

Management of Biliary Cysts in Adults: A Single-Center 10-Year Experience

BACKGROUND

A choledochal cyst is a cystic dilatation of the biliary tree, also termed a biliary cyst, including an intrahepatic cyst as well. Magnetic resonance cholangiopancreatography (MRCP) is the gold standard investigation of choice for this pathology. Todani classification is most commonly used to classify choledochal cysts.

MATERIALS AND METHODS

A total of 30 adult patients with choledochal cysts presenting at our center from December 1, 2009, to October 31, 2019, were studied retrospectively.

RESULTS

The mean age was 35.13 years ranging from 18 to 62 years with a male-to-female ratio of 1:3.29. Of the patients, 86.6% presented with abdominal pain. Total serum bilirubin was raised in six patients with a mean of 1.84 mg/dL. MRCP was done in all patients, which had almost 100% sensitivity. Two cases had anomalous pancreaticobiliary duct union. In our study, we found only type I and type IVA cysts according to the Todani classification (type IA = 56.3%, IB = 11%, 1C = 16%, and IVA = 17%). The mean size of the cyst was 2.37 cm. Complete cyst excision with Roux-en-Y hepaticojejunostomy was performed in all patients. Four patients had surgical site infections and two had bile leaks. One patient developed hepatic artery thrombosis. All complications were eventually managed conservatively. Mortality was nil in our study with the mean postoperative stay being 7.97 days.

CONCLUSION

Adult presentation of biliary cysts is not an uncommon entity in the Indian population and should be considered as a differential diagnosis of biliary pathology in adult patients. Complete excision of cysts with bilioenteric anastomosis is the current treatment of choice.

Statins associate with lower risk of biliary tract cancers: A systematic review and meta-analysis

BACKGROUND

Biliary tract cancers (BTCs), encompassing cholangiocarcinoma (CCA), gallbladder (GBC), and ampulla of Vater cancers (AVC), are common hepatobiliary cancer after hepatocellular carcinoma with a high mortality rate. As there is no effective chemopreventive agent to prevent BTCs, this study aimed to explore the role of statins on the risk of BTCs.

METHODS

PubMed, Embase, and Cochrane Library from inception until 24 April 2020 were searched according to the Meta-Analyses of Observational Studies in Epidemiology (MOOSE) guidelines. The adjusted risk ratios (aRRs) of BTCs and individual cancer were pooled using a random-effects model.

RESULTS

Eight observational studies (3 cohort and 5 case-control studies) were included with 10,485,231 patients. The median age was 68.0 years (IQR: 67.0-71.5) and 48.3% were male. Statins were associated with a lower risk of all BTCs (aRR: 0.67; 95% CI: 0.51-0.87). The pooled aRR for CCA was 0.60 (95% CI: 0.38-0.94) and GBC was 0.78 (95% CI: 0.68-0.90). There was only one study on AVC with aRR of 0.96 (95% CI: 0.66-1.41). The pooled aRR for lipophilic and hydrophilic statins was 0.78 (95% CI: 0.69-0.88) and 0.70 (95% CI: 0.61-0.80), respectively. The effects were attenuated in studies that adjusted for aspirin and/or non-steroidal anti-inflammatory drugs (aRR: 0.80, 95% CI: 0.72-0.89) and metformin (aRR: 0.80, 95% CI: 0.72-0.90).

CONCLUSIONS

Statins, both lipophilic and hydrophobic, were associated with a lower risk of BTCs, particularly CCA and GBC.

Corrosion Cast and 3D Reconstruction of the Murine Biliary Tree After Biliary Obstruction: Quantitative Assessment and Comparison With 2D Histology

Background

Obstructive cholestasis can lead to significant alterations of the biliary tree depending on the extent and duration of the biliary occlusion. Current experimental studies reported about advanced techniques for corrosion cast and 3D reconstruction (3D-reco) visualizing delicate microvascular structures in animals. We compared these two different techniques for visualization and quantitative assessment of the obstructed murine biliary tree with classical 2D histology.

Methods

Male mice (n = 36) were allocated to 3 different experiments. In experiments 1 and 2, we injected two different media (Microfil© for 3D-reco, MV; Batson's No.17 for corrosion cast, CC) into the extrahepatic bile duct. In experiment 3 we sampled liver tissue for 2D histology (HE, BrdU). Time points of interest were days 1, 3, 5, 7, 14, and 28 after biliary occlusion. We used different types of software for quantification of the different samples: IMALYTICS Preclinical for 3D scans (MV); NDP.view2 for the digital photography of CC; HistoKat software for 2D histology.

Results

We achieved samples in 75% of the animals suitable for evaluation (MV and CC, each with 9/12). Contrasting of terminal bile ducts (4th order of branches) was achieved with either technique. MV permitted a fast 3D-reco of the hierarchy of the biliary tree, including the 3rd and 4th order of branches in almost all samples (8/9 and 6/9). CC enabled focused evaluation of the hierarchy of the biliary tree, including the 4th to 5th order of branches in almost all samples (9/9 and 8/9). In addition, we detected dense meshes of the smallest bile ducts in almost all CC samples (8/9). MV and CC allowed a quantitative assessment of anatomical details of the 3rd and 4th order branches of almost every sample. The 2D histology identified different kinetics and areas of proliferation of hepatocytes and cholangiocytes. Complementary usage of 3D-reco, corrosion casting and 2D histology matched dense meshes of small bile ducts with areas of intensive proliferative activity of cholangiocytes as periportal proliferative areas of 4th and 5th order branches (∼terminal bile ducts and bile ductules) matched with its morphological information the matching assessment of areas with increased proliferative activity (BrdU) and a partial quantification of the characteristics of the 4th order branches of the biliary tree.

Conclusion

The 3D-reco and corrosion casting of the murine biliary tree are feasible and provide a straightforward, robust, and reliable (and more economical) procedure for the visualization and quantitative assessment of architectural alterations, in comparative usage with the 2D histology.

Spontaneous Bile Leak in a Patient Without Recent Abdominal Surgery or Trauma

Bile leaks are a rare occurrence most often seen as a complication of cholecystectomy. Other less common etiologies include endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiography (PTC), liver surgery, percutaneous drainage of liver abscesses, living donor hepatectomy, and non-iatrogenic abdominal trauma. In this case study, we present a 67-year-old female with morbid obesity who presented with abdominal pain and was diagnosed with a spontaneous bile leak. She had no history of recent surgery or abdominal trauma. CT revealed that the patient's gallbladder was located in the right lower quadrant, most likely due to mass effect from a large ventral hernia, and possible fluid collection extending from the gallbladder along the surface of the anterior inferior right hepatic lobe. Hepatobiliary iminodiacetic acid (HIDA) was performed due to a concern for cholecystitis. HIDA demonstrated a bile leak in the right upper abdomen of unknown etiology. Initially, there was a concern for gallbladder obstruction. Gastroenterology recommended magnetic resonance cholangiopancreatography (MRCP), however, MRCP was not possible due to the patient's body habitus. The patient had normal liver function tests, was tolerating oral intake, and her abdominal pain resolved, therefore, we became less suspicious of gallbladder obstruction. This case suggests that bile leak should be included in the differential diagnosis for abdominal pain even in patients who have not had recent abdominal surgery or procedures. This case also highlights the unique anatomical finding of a right lower quadrant gallbladder secondary to mass effect from a large ventral hernia.

Spatial architecture of biliary tree in mammals: Fractal and Euclidean geometric features

The study of the fractal architecture of various organs and structures expanded the possibilities for determining the ranges of their functioning and structural arrangement, which, as a result, was reflected in the development of new approaches to diagnostics and therapeutic impacts. The architecture of the excretory duct systems, similar to the hemo- and lymph- circulatory beds and the bronchial tree, is considered fractal. At the same time, information about hitherto unknown structures of the biliary tree continues to appear in the literature. We aimed to study the features of the spatial geometry of the biliary tree and assess the significance of both its fractal and Euclidean characteristics for the development of approaches that facilitate comprehensive description of intrahepatic biliary tract architecture. We investigated the architecture of the biliary trees of six men, seven male canines, and seven male Wistar rats using the corrosion casting method. Corrosion casts were prepared by injecting solidifying latexes into the bile ducts. The preparations were studied using a light stereomicroscope and a scanning electron microscope. Biliary tree branching is of various types. In addition, the correlation between variations in the caliber and length of the bile ducts and their order is not significant. Therefore, the biliary tree should not be considered as a classical fractal and it consists of the main modules, represented by the network of the bile canaliculi (first nonfractal module) and a biliary tree with a fractal branching (second module) that drains the bile canaliculi mesh and the additional modules represented by the mucosal biliary glands (in mammals with the gallbladder) or the periportal biliary plexus (in mammals without a gallbladder) and the aberrant biliary ducts. Such a configuration of the biliary bed should optimally ensure the smooth implementation of the physiological function of the liver, as well as its adaptation to different pathologies accompanied by biliary hypertension. It also might be considered in the diagnosis and assessment of ductular reaction, biliary regeneration, and/or carcinogenesis.

The Duct of Luschka: An Anatomical Variant of the Biliary Tree - Two Case Reports and a Review of the Literature

Anatomical variations occurring in the bile ducts, including the duct of Luschka, are very common. It is essential for radiologists and surgeons to understand these anomalies so they can diagnose them before and during the surgery to prevent postoperative complications. In this report, we present the case of two patients who were admitted to the emergency department for abdominal pain and fever following cholecystectomy. Postoperative imaging led to the diagnosis of injury to the duct of Luschka.

Intraductal Papillary Neoplasm of Bile Duct: Updated Clinicopathological Characteristics and Molecular and Genetic Alterations

Intraductal papillary neoplasm of the bile duct (IPNB), a pre-invasive neoplasm of the bile duct, is being established pathologically as a precursor lesion of invasive cholangiocarcinoma (CCA), and at the time of surgical resection, approximately half of IPNBs show stromal invasion (IPNB associated with invasive carcinoma). IPNB can involve any part of the biliary tree. IPNB shows grossly visible, exophytic growth in a dilated bile duct lumen, with histologically villous/papillary neoplastic epithelia with tubular components covering fine fibrovascular stalks. Interestingly, IPNB can be classified into four subtypes (intestinal, gastric, pancreatobiliary and oncocytic), similar to intraductal papillary mucinous neoplasm of the pancreas (IPMN). IPNBs are classified into low-grade and high-grade based on lining epithelial features. The new subclassification of IPNB into types 1 (low-grade dysplasia and high-grade dysplasia with regular architecture) and 2 (high-grade dysplasia with irregular architecture) proposed by the Japan–Korea pathologist group may be useful in the clinical field. The outcome of post-operative IPNBs is more favorable in type 1 than type 2. Recent genetic studies using next-generation sequencing have demonstrated the existence of several groups of mutations of genes: (i) IPNB showing mutations in KRAS, GNAS and RNF43 belonged to type 1, particularly the intestinal subtype, similar to the mutation patterns of IPMN; (ii) IPNB showing mutations in CTNNB1 and lacking mutations in KRAS, GNAS and RNF43 belonged to the pancreatobiliary subtype but differed from IPMN. IPNB showing mutation of TP53, SMAD4 and PIK3CA might reflect complicated and other features characterizing type 2. The recent recognition of IPNBs may facilitate further clinical and basic studies of CCA with respect to the pre-invasive and early invasive stages.

Spontaneous bronchobiliary fistula: Case report

Bronchobiliary fistula (BBF) is a rare condition that results from the communication between the bile ducts and the bronchial tree. It is characterized by the presence of bile in the sputum as pathognomonic symptom, and it is often associated with suspicious pneumonia. The most common causes include infections (e.g. echinococcosis), hepatobiliary surgery, blunt torso traumas, tumors and percutaneous transhepatic procedures. Opinions about BBF treatment are still controversial as it can be treated by both conservative and surgical procedures, while pharmacological treatments are only rarely used. This case report presents a patient who had been diagnosed with chronic BBF of unknown cause, underwent several ineffective conservative procedures and was at last surgically treated.

Distinct EpCAM-Positive Stem Cell Niches Are Engaged in Chronic and Neoplastic Liver Diseases

In normal human livers, EpCAM^pos cells are mostly restricted in two distinct niches, which are (i) the bile ductules and (ii) the mucous glands present inside the wall of large intrahepatic bile ducts (the so-called peribiliary glands). These EpCAM^pos cell niches have been proven to harbor stem/progenitor cells with great importance in liver and biliary tree regeneration and in the pathophysiology of human diseases. The EpCAM^pos progenitor cells within bile ductules are engaged in driving regenerative processes in chronic diseases affecting hepatocytes or interlobular bile ducts. The EpCAM^pos population within peribiliary glands is activated when regenerative needs are finalized to repair large intra- or extra-hepatic bile ducts affected by chronic pathologies, including primary sclerosing cholangitis and ischemia-induced cholangiopathies after orthotopic liver transplantation. Finally, the presence of distinct EpCAM^pos cell populations may explain the histological and molecular heterogeneity characterizing cholangiocarcinoma, based on the concept of multiple candidate cells of origin. This review aimed to describe the precise anatomical distribution of EpCAM^pos populations within the liver and the biliary tree and to discuss their contribution in the pathophysiology of human liver diseases, as well as their potential role in regenerative medicine of the liver.

Feline abdominal ultrasonography: what's normal? what's abnormal? The biliary tree

PRACTICAL RELEVANCE

Abdominal ultrasound plays a vital role in the diagnostic work-up of many cats presenting to general and specialist practitioners. The biliary tree encompasses the liver, gall bladder and bile ducts, although only diseases affecting the latter two are discussed here. Diseases of the bile ducts and gall bladder are more common than those of the liver parenchyma and ultrasound plays an important role in their diagnosis.

CLINICAL CHALLENGES

Despite ultrasonography being a commonly used modality, many practitioners are not comfortable performing an ultrasound examination or interpreting the resulting images. Even differentiating between normal variation and pathological changes can be challenging for all but the most experienced. In addition, a lack of pathological change does not necessarily rule out disease; for example, absence of gall bladder and/or extrahepatic biliary distension is not sufficient to exclude the possibility of biliary obstruction, and in many cases of cholangitis the liver and biliary tree are unremarkable on ultrasound examination.

EQUIPMENT

Ultrasound facilities are readily available to most practitioners, although use of ultrasonography as a diagnostic tool is highly dependent on operator experience.

AIM

This review, part of an occasional series on feline abdominal ultrasonography, discusses the appearance of the normal and diseased biliary system. It is aimed at general practitioners who wish to improve their knowledge and confidence in feline abdominal ultrasound and is accompanied by high-resolution images. Percutaneous ultrasound-guided cholecystocentesis is also covered. Ultrasound examination of the liver was discussed in an article published in January 2019 and an upcoming article will cover hepatic vascular anomalies.

EVIDENCE BASE

Information provided in this article is drawn from the published literature and the author's own clinical experience.

Sox9 Is a Modifier of the Liver Disease Severity in a Mouse Model of Alagille Syndrome

BACKGROUND AND AIMS

Alagille syndrome (ALGS) is a multisystem developmental disorder characterized by bile duct (BD) paucity, caused primarily by haploinsufficiency of the Notch ligand jagged1. The course of the liver disease is highly variable in ALGS. However, the genetic basis for ALGS phenotypic variability is unknown. Previous studies have reported decreased expression of the transcription factor SOX9 (sex determining region Y-box 9) in late embryonic and neonatal livers of Jag1-deficient mice. Here, we investigated the effects of altering the Sox9 gene dosage on the severity of liver disease in an ALGS mouse model.

APPROACH AND RESULTS

Conditional removal of one copy of Sox9 in Jag1+/- livers impairs the biliary commitment of cholangiocytes and enhances the inflammatory reaction and liver fibrosis. Loss of both copies of Sox9 in Jag1+/- livers further worsens the phenotypes and results in partial lethality. Ink injection experiments reveal impaired biliary tree formation in the periphery of P30 Jag1+/- livers, which is improved by 5 months of age. Sox9 heterozygosity worsens the P30 biliary tree phenotype and impairs the partial recovery in 5-month-old animals. Notably, Sox9 overexpression improves BD paucity and liver phenotypes in Jag1+/- mice without ectopic hepatocyte-to-cholangiocyte transdifferentiation or long-term liver abnormalities. Notch2 expression in the liver is increased following Sox9 overexpression, and SOX9 binds the Notch2 regulatory region in the liver. Histological analysis shows a correlation between the level and pattern of SOX9 expression in the liver and outcome of the liver disease in patients with ALGS.

CONCLUSIONS

Our results establish Sox9 as a dosage-sensitive modifier of Jag1+/- liver phenotypes with a permissive role in biliary development. Our data further suggest that liver-specific increase in SOX9 levels is a potential therapeutic approach for BD paucity in ALGS.

Preoperative diagnosis of well-differentiated neuroendocrine tumor in common hepatic duct by brush cytology: A case report

The biological behavior of neuroendocrine tumors (NETs) is heterogeneous and differs from that of cholangiocarcinoma, which is the most common malignant tumor of the biliary tree. However, the preoperative diagnosis of NET in the biliary tree is extremely difficult and to our knowledge, diagnosis by brush cytology has not previously been reported. Herein, we first reported a case of biliary NET preoperatively diagnosed by brush cytology in a 33-year-old female patient. Imaging study revealed a 2.6-cm mass in the common hepatic duct. The brush cytology was characterized by loosely cohesive plasmacytoid tumor cells and scattered clusters of thin vascular septa. The tumor cells showed abundant cytoplasm and severe nuclear size variation but mitosis was not observed. Immunohistochemical staining of the cell block (CB) showed strong positivity for both synaptophysin and chromogranin A and a Ki-67 labeling index of 3.5%. The surgically resected bile duct mass was pathologically confirmed as NET, G2 with lymphovascular and perineural invasion of the tumor cells. The patient showed no evidence of tumor recurrence 10 months after operation without adjuvant chemotherapy. Suspicion of this rare tumor and immunohistochemical staining of the CB are important for the preoperative diagnosis of NET in the biliary tree.

Targeted Therapies in Cholangiocarcinoma: Emerging Evidence from Clinical Trials

Cholangiocarcinoma (CCA) is a highly-aggressive malignancy arising from the biliary tree, characterized by a steady increase in incidence globally and a high mortality rate. Most CCAs are diagnosed in the advanced and metastatic phases of the disease, due to the paucity of signs and symptoms in the early stages. This fact, along with the poor results of the local and systemic therapies currently employed, is responsible for the poor outcome of CCA patients and strongly supports the need for novel therapeutic agents and strategies. In recent years, the introduction of next-generation sequencing technologies has opened new horizons for a better understanding of the genetic pathophysiology of CCA and, consequently, for the identification and evaluation of new treatments tailored to the molecular features or alterations progressively elucidated. In this review article, we describe the potential targets under investigation and the current molecular therapies employed in biliary tract cancers. In addition, we summarize the main drugs against CCA under evaluation in ongoing trials and describe the preliminary data coming from these pioneering studies.

Calcium Signaling in Cholangiocytes: Methods, Mechanisms, and Effects

Calcium (Ca²⁺) is a versatile second messenger that regulates a number of cellular processes in virtually every type of cell. The inositol 1,4,5-trisphosphate receptor (ITPR) is the only intracellular Ca²⁺ release channel in cholangiocytes, and is therefore responsible for Ca²⁺-mediated processes in these cells. This review will discuss the machinery responsible for Ca²⁺ signals in these cells, as well as experimental models used to investigate cholangiocyte Ca²⁺ signaling. We will also discuss the role of Ca²⁺ in the normal and abnormal regulation of secretion and apoptosis in cholangiocytes, two of the best characterized processes mediated by Ca²⁺ in this cell type.

One duct, two orifices, no names! the anatomy of the biliary cystic duct

The biliary cystic duct (CD) connects the gallbladder to the extra-hepatic bile duct, and the point at which it does this delineates the division between the common hepatic duct and the common bile duct. Its clinical relevance in disease, and importance during interventions relating to the gallbladder mean that its normal and variant anatomy has been described extensively in literature. However, an aspect not yet fully described includes naming of its two orifices on either end. This is highly relevant for surgical, endoscopic, and percutaneous procedures. We describe these as encountered in normal CD and biliary tree anatomy. We believe this is crucial for interventions relating to the gallbladder and the biliary tree, including prevention of iatrogenic injury. Clin. Anat. 31:422-423, 2018. © 2018 Wiley Periodicals, Inc.

Adult Mouse Liver Contains Two Distinct Populations of Cholangiocytes

The biliary system plays an important role in several acquired and genetic disorders of the liver. We have previously shown that biliary duct epithelium contains cells giving rise to proliferative Lgr5⁺ organoids in vitro. However, it remained unknown whether all biliary cells or only a specific subset had this clonogenic activity. The cell surface protease ST14 was identified as a positive marker for the clonogenic subset of cholangiocytes and was used to separate clonogenic and non-clonogenic duct cells by fluorescence-activated cell sorting. Only ST14^hi duct cells had the ability to generate organoids that could be serially passaged. The gene expression profiles of clonogenic and non-clonogenic duct cells were similar, but several hundred genes were differentially expressed. RNA fluorescence in situ hybridization showed that clonogenic duct cells are interspersed among regular biliary epithelium at a ∼1:3 ratio. We conclude that adult murine cholangiocytes can be subdivided into two populations differing in their proliferative capacity.

•

Adult cholangiocytes consist of two distinct subsets

•

ST14 is heterogeneously expressed in adult biliary epithelium

•

ST14^hi cells are the clonogenic duct subset interspersed in normal bile ducts

•

Gene expression differs between ST14^hi and ST14^lo duct cells

Regenerative Medicine and the Biliary Tree

Despite decades of basic research, biliary diseases remain prevalent, highly morbid, and notoriously difficult to treat. We have, however, dramatically increased our understanding of biliary developmental biology, cholangiocyte pathophysiology, and the endogenous mechanisms of biliary regeneration and repair. All of this complex and rapidly evolving knowledge coincides with an explosion of new technological advances in the area of regenerative medicine. New breakthroughs such as induced pluripotent stem cells and organoid culture are increasingly being applied to the biliary system; it is only a matter of time until new regenerative therapeutics for the cholangiopathies are unveiled. In this review, the authors integrate what is known about biliary development, regeneration, and repair, and link these conceptual advances to the technological breakthroughs that are collectively driving the emergence of a new global field in biliary regenerative medicine.

Ischemia reperfusion of the hepatic artery induces the functional damage of large bile ducts by changes in the expression of angiogenic factors

Liver transplantation and cholangiocarcinoma induce biliary dysfunction following ischemia reperfusion (IR). The function of the intrahepatic biliary tree is regulated by both autocrine and paracrine factors. The aim of the study was to demonstrate that IR-induced damage of cholangiocytes is associated with altered expression of biliary angiogenic factors. Normal and bile duct ligation rats underwent 24-h sham or hepatic reperfusion after 30 min of transient occlusion of the hepatic artery (HAIR) or portal vein (PVIR) before collecting liver blocks and cholangiocyte RNA or protein. We evaluated liver histology, biliary apoptosis, proliferation and expression of VEGF-A/C, VEGFR-2/3, Ang-1/2, and Tie-1/2 in liver sections and isolated small and large cholangiocytes. Normal rat intrahepatic cholangiocyte cultures (NRICC) were maintained under standard conditions in normoxic or under a hypoxic atmosphere for 4 h and then transferred to normal conditions for selected times. Subsequently, we measured changes in biliary proliferation and apoptosis and the expression of VEGF-A/C and VEGFR-2/3. In vivo, HAIR (but not PVIR) induced damage of large bile ducts and decreased proliferation and secretin-stimulated cAMP levels. HAIR-induced damage of large bile ducts was associated with increased expression of VEGF-A/C, VEGFR-2/3, Ang-1/2, and Tie-1/2. In vitro, under hypoxic conditions, there was increased apoptosis and reduced proliferation of NRICC concomitant with enhanced expression of VEGF-A/C and VEGFR-2/3. The functional damage of large bile ducts by HAIR and hypoxia is associated with increased expression of angiogenic factors in small cholangiocytes, presumably due to a compensatory mechanism in response to biliary damage.

Cannulation of the biliary tree under endoscopic control with an echoendoscope, without fluoroscopy: report of a case series

INTRODUCTION

Endoscopic ultrasonography (EUS) is a validated technique allowing precise diagnosis and staging of pancreatic, biliary and ampullary disease. Developments in instruments and accessories have led to a more extensive use of this technology to perform operations. The use of EUS as an operative technique, alone or in conjunction with other endoscopic procedures, has already been described in the literature in several reports. However, despite the use of EUS, fluoroscopy has always been required to perform these operations. There are no data in the literature describing the feasibility, safety and efficacy of operative EUS in the treatment of common bile duct (CBD) obstruction, following a malignant or benign disease, performed completely under EUS guidance without fluoroscopic assistance.

METHODS

In this series we describe three cases of EUS treatment of CBD diseases performed without fluoroscopic assistance.

RESULTS

All the cases were treated by EUS without fluoroscopic assistance and no complications were encountered.

CONCLUSION

Operative EUS without fluoroscopy appears to be a feasible technique. Its major advantages could be to shorten the examination time and to enable biliary or pancreatic operative endoscopy in patients in whom fluoroscopy could be dangerous, such as pregnant women. The endoscopist should have a good training both in EUS and endoscopic retrograde cholangiopancreatography. Prospective, larger studies are needed to confirm our preliminary data.

Dyskerin expression in human fetal, adult and neoplastic intrahepatic bile ducts: correlations with cholangiocarcinoma aggressiveness

AIMS

To investigate the immunohistochemical expression of dyskerin, a biomarker involved in ribosome production and telomere maintenance, in human fetal, adult and neoplastic bile ducts, and possible correlations with cholangiocarcinoma aggressiveness.

METHODS AND RESULTS

Sixty consecutive intrahepatic cholangiocarcinomas were collected and used for tissue microarray construction (total: 176 cores); clinical data and follow-up were also collected. Five fetal and 10 normal adult livers were included as controls. Automated immunohistochemistry for dyskerin, p53, and Ki67, and nucleolar silver staining, were performed. In normal livers, dyskerin expression was negative in smaller bile ducts (mean 44.8 μm) and positive in bile ducts of larger diameter (mean 116.1 μm; P < 0.001). Expression was positive in 56.7% of cholangiocarcinomas, and correlated with p53 mutation (P = 0.008) and a higher proliferative (Ki67) index (P = 0.003), which were included as markers of tumour aggressiveness. Finally, dyskerin-positive cholangiocarcinomas showed a negative trend in disease-free survival (P = 0.078) on univariate analysis.

CONCLUSIONS

The non-neoplastic biliary tree seems to progressively lose dyskerin expression from the major branches to the peripheral portal bile ducts. Similarly, intrahepatic cholangiocarcinomas showed two patterns of dyskerin expression, and the dyskerin-positive phenotype seemed to characterize more aggressive cholangiocarcinomas.

Duct of Luschka diagnosed by sonography in a patient with bile duct carcinoma and intrahepatic bile duct dilatation

The bile duct of Luschka (BDL) is an anatomic anomaly that is an important cause of bile leakage after bile duct surgery. We report a case of bile duct carcinoma with dilated BDL that was diagnosed by ultrasonography (US). An 83-year-old man presented with an obstructive jaundice. US on admission revealed the presence of a solid hypoechoic mass in the bile duct at the hepatic duct confluence and a branch of the bile duct, about 2-4 mm in diameter, distinct from the dilated right anterior hepatic duct slightly upstream of the tumor. This branch had a spiral structure, extended along the gallbladder bed on the surface of segment 5 (S5) of the liver, and emanated small branches that entered the hepatic parenchyma. There has been no previous report of delineation of BDL by preoperative US.

Percutaneous ultrasound-guided drainage of the biliary tree in palliative treatment of mechanical jaundice: 17 years of experience

INTRODUCTION

Advanced malignant tumours involving the head of the pancreas, gallbladder or extrahepatic bile ducts usually lead to the development of cholestasis. In such cases improvement of the quality of life of patients can be achieved with the decompression of jaundice. Endoscopic implantation of self-expanding or (seldom) rigid plastic stents into the biliary tree constitutes the most common technique allowing for restoration of bile duct patency. In some patients however the use of such a procedure is technically impossible. In this particular group percutaneous drainage of the biliary tree can constitute the only method of management.

AIM

Presentation of our experience with the use of percutaneous ultrasound-guided drainage of the biliary tree in patients with mechanical jaundice resulting from malignant tumours.

MATERIAL AND METHODS

There were 852 patients with mechanical jaundice resulting from malignant neoplasms treated in the 2(nd) Chair of Surgery of Jagiellonian University Medical College from January 1994 to December 2010. In 199 of them jaundice was decompressed by means of open - radical or palliative - surgical operations. In 539 patients endoscopic treatment was implemented while in 114 of them percutaneous ultrasound-guided drainage was performed.

RESULTS

In 5 patients percutaneous drainage was introduced to prepare them for radical surgical treatment, while in the remaining 109 it constituted the definitive way of management. The average hospitalization time for women was 6.5 days (range: 1-22 days) and proved to be twice as short as in men - 12.2 days (range: 1-38 days). The duration of percutaneous drainage prior to surgical treatment averaged 7.2 days (range: 6-10 days). Mean volume of the bile drained during the first day was 370 ml (range: 10-1300 ml), increased to 450 ml (range: 100-1150 ml) during the second day and reached 780 ml (range: 80-1600 ml) during the third day. Mean bilirubin level before the drainage was 320-23 µmol/l (range: 658-130.7 µmol/l) and decreased by half before discharge or before the operation, reaching on average 181.87 µmol/l (range: 14.5-343 µmol/l).

CONCLUSIONS

Complications of the percutaneous ultrasound-guided technique were found sporadically and resulted from leakage of the bile into the peritoneum.

New approach in diagnosis of bile duct disease with ultrasound and magnetic resonance imaging

Advances in technology have made possible the clinical application of magnetic resonance cholangiography, endoscopic, intra-operative and laparoscopic ultrasound in the study of the biliary tree, in addition to conventional magnetic resonance imaging and transabdominal ultrasound. The role of the conventional, as well as the newer techniques, in the diagnosis of bile duct disease and the limitations and pros and cons of each technique, will be the subject of the present discussion.