Biliary Vessels Research Articles

Imaging Features of Main Hepatic Resections: The Radiologist Challenging.

Liver resection is still the most effective treatment of primary liver malignancies, including hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), and of metastatic disease, such as colorectal liver metastases. The type of liver resection (anatomic versus non anatomic resection) depends on different features, mainly on the type of malignancy (primary liver neoplasm versus metastatic lesion), size of tumor, its relation with blood and biliary vessels, and the volume of future liver remnant (FLT). Imaging plays a critical role in postoperative assessment, offering the possibility to recognize normal postoperative findings and potential complications. Ultrasonography (US) is the first-line diagnostic tool to use in post-surgical phase. However, computed tomography (CT), due to its comprehensive assessment, allows for a more accurate evaluation and more normal findings than the possible postoperative complications. Magnetic resonance imaging (MRI) with cholangiopancreatography (MRCP) and/or hepatospecific contrast agents remains the best tool for bile duct injuries diagnosis and for ischemic cholangitis evaluation. Consequently, radiologists should be familiar with the surgical approaches for a better comprehension of normal postoperative findings and of postoperative complications.

A Reaction-Diffusion Algorithm for Segmentation of Three-Dimensional Sinusoidal Networks in Rats Fed a High-Fat and High-Cholesterol Diet: New Insights and Evaluation

Microstructures in the liver are primarily composed of hepatocytes, hepatic blood, and biliary vessels. Because each hepatocyte comes in contact with both vessels, these vessels form three-dimensional (3D) periodic network patterns. Confocal microscope images are useful for observing 3D structures; however, it is necessary to explicitly describe the vessel structures using 3D images of sinusoidal endothelial cells. For this purpose, we propose a new approach for image segmentation based on the Turing reaction-diffusion model, in which temporal and spatial patterns are self-organized. Turing conditions provided reliable tools for describing the 3D structures. Moreover, using the proposed method, the sinusoidal patterns of rats fed a high-fat/high-cholesterol diet were examined; these rats exhibited pathological features similar to those of human patients with nonalcoholic steatohepatitis related to metabolic syndrome. The findings showed that the parameter in diffusion terms differed significantly among the experimental groups. This observation provided a heuristic argument for parameter selection leading to pattern recognition problems in diseased rats.

A label-retaining but unipotent cell population resides in biliary compartment of mammalian liver

Cells with slow proliferation kinetics that retain the nuclear label over long time periods–the label-retaining cells (LRCs)–represent multipotent stem cells in a number of adult tissues. Since the identity of liver LRCs (LLRCs) had remained elusive we utilized a genetic approach to reveal LLRCs in normal non-injured livers and characterized their regenerative properties in vivo and in culture. We found that LLRCs were located in biliary vessels and participated in the regeneration of biliary but not hepatocyte injury. In culture experiments the sorted LLRCs displayed an enhanced self-renewal capacity but a unipotent biliary differentiation potential. Transcriptome analysis revealed a unique set of tumorigenesis- and nervous system-related genes upregulated in LLRCs when compared to non-LRC cholangiocytes. We conclude that the LLRCs established during the normal morphogenesis of the liver do not represent a multipotent primitive somatic stem cell population but act as unipotent biliary progenitor cells.

Endoscopic Treatment of Biliary Stenosis in Patients with Alveolar Echinococcosis--Report of 7 Consecutive Patients with Serial ERC Approach.

Background and AimsBiliary vessel pathology due to alveolar echicococcosis (AE) results in variable combinations of stenosis, necrosis and inflammation. Modern management strategies for patients with cholestasis are desperately needed. The aim is proof of principle of serial ERC (endoscopic retrograde cholangiography) balloon dilation for AE biliary pathology.MethodsRetrospective case series of seven consecutive patients with AE-associated biliary pathology and ERC treatment in an interdisciplinary endoscopy unit at a University Hospital which hosts a national echinococcosis treatment center. The AE patient cohort consists of 106 patients with AE of the liver of which 13 presented with cholestasis. 6/13 received bilio-digestive anastomosis and 7/13 patients were treated by ERC and are reported here. Biliary stricture balloon dilation was performed with 18-Fr balloons at the initial and with 24-Fr balloons at subsequent interventions. If indicated 10 Fr plastic stents were placed.ResultsSix patients were treated by repeated balloon dilation and stenting, one by stenting only. After an acute phase of 6 months with repeated balloon dilation, three patients showed “sustained clinical success” and four patients “assisted therapeutic success,” of which one has not yet reached the six month endpoint. In one patient, sustained success could not be achieved despite repeated insertion of plastic stents and balloon dilation, but with temporary insertion of a fully covered self-expanding metal stent (FCSEMS). There was no loss to follow up. No major complications were observed.ConclusionsSerial endoscopic dilation is a standard tool in the treatment of benign biliary strictures. Serial endoscopic intervention with balloon dilation combined with benzimidazole treatment can re-establish and maintain biliary duct patency in AE associated pathology and probably contributes to avoid or postpone bilio-digestive anastomosis. This approach is in accordance with current ERC guidelines and is minimally disruptive for patients.

Combined Blunt-Clamp Dissection and LigaSure Ligation for Hepatic Parenchyma Dissection: Postcoagulation Technique

Blunt-clamp dissection allows for visualization of intrahepatic vessels and individual ligation of major blood or bile vessels. Recently, many instruments have been developed for "precoagulation" of liver parenchyma before sharp transection, but suffer from the possibility of injuring major blood and biliary vessels that are not well-visualized, along with high cost. In this article, we describe a "postcoagulation" technique combining clamp dissection and sealing of vessels under direct vision using a tissue-sealing device. Clinical evaluation of 400 patients from 2 centers subjected to liver resection using this technique. There were no cases complicated by hemorrhage. There was an incidence of 1.8% for bile leaks. This low incidence of biloma formation was seen even with the high incidence (49%) of abnormal parenchyma encountered in this cohort. Combining the clamp-crushing method with use of the LigaSure device (Valleylab) allows identification of intraparenchymal vessels followed by sealing. This method of parenchymal transaction optimizes ease of use with confidence in vessel ligation.

Interaction of Positional Isomers of Quercetin Glucuronides with the Transporter ABCC2 (cMOAT, MRP2)

The exporter ABCC2 (cMOAT, MRP2) is a membrane-bound protein on the apical side of enterocytes and hepatic biliary vessels that transports leukotriene C(4), glutathione, some conjugated bile salts, drugs, xenobiotics, and phytonutrients. The latter class includes quercetin, a bioactive flavonoid found in foods such as onions, apples, tea, and wine. There is no available three-dimensional (3D) structure of ABCC2. We have predicted the 3D structure by in silico modeling, showing that 3-[[3-[2-(7-chloroquinolin-2-yl)vinyl]phenyl]-(2-dimethylcarbamoylethylsulfanyl)methylsulfanyl] propionic acid (MK571) binds most tightly to the putative binding site, and then tested the computational prediction experimentally by measuring interaction with all quercetin monoglucuronides occurring in vivo (quercetin substituted with glucuronic acid at the 3-, 3'-, 4'-, and 7-hydroxyl groups). The 4'-O-beta-D-glucuronide is predicted in silico to interact most strongly and the 3-O-beta-D-glucuronide most weakly, and this prediction is supported experimentally using binding and competition assays on ABCC2-overexpressing baculovirus-infected Sf9 cells. To test the transport in situ, we examined the effect of two ABCC2 inhibitors, MK571 and cyclosporin A, on the transport into the media of quercetin glucuronides produced intracellularly by Caco2 cells. The inhibitors reduced the amount of all quercetin glucuronides in the media. The results show that the molecular model of ABCC2 agrees well with experimentally determined ABCC2-ligand interactions and, importantly, that the interaction of ABCC2 with quercetin glucuronides is dependent on the position and nature of substitution.

Cloning and expression pattern of connexin39, a new member of the gap junction gene family isolated from the neural tube of chicken embryos.

In this study, a new gap junction (GJ) connexin (Cx) gene was isolated from the neural tube of chicken (c) embryos (HH21) and cloned by degenerate reverse transcription-polymerase chain reaction (RT-PCR). The open reading frame of the gene encodes for a protein of 343 amino acid residues with strong similarity to highly conserved connexin sequences. On the basis of the predicted molecular mass of 39144 kDa, we denominated it as cCx39. Sequence analysis allocated the cCx39 to the alpha-group of connexin gene family. The mRNA expression of cCx39 was detected by RT-PCR and Northern blot in several tissues of chicken, including different parts of central nervous system, heart, liver, kidney, aorta and ovary. In situ hybridisation analysis of chicken brain showed strong expression in neurons of granular layers of cerebellum, optic tectum and ectostriatum. The in situ hybridisation of extracererebral tissues revealed strong expression of cCx39 in the atrium of the heart, the external layer of the aorta and endothelium of biliary vessels; moderate expression was found in the endothelium of the aorta.

INTRABILIARY OBSTRUCTION DUE TO RUPTURED HEPATIC HYDATID CYST: EVALUATION WITH COMPUTED TOMOGRAPHY AND MAGNETIC RESONANCE IMAGING

Background: One of the most common and very serious complications of a hepatic echinococcal cyst is the intrabiliary rupture of the cyst and, in some cases, the obstruction of the biliary system. The effectiveness of computed tomography (CT) and magnetic resonance imaging (MRI) was evaluated for the preoperative diagnosis of hydatid cyst into the biliary tree.Methods: The techniques of CT, MRI and magnetic resonance (MR) cholangiography were used to examine nine cases of intrabiliary rupture of the hepatic hydatid cyst. The confirmation of the diagnosis was made at surgery in four cases and with endoscopic retrograde cholangiopancreatography in five cases.Results: By using CT and MRI, the intrabiliary rupture of an echinococcal cyst was diagnosed readily and accurately in all cases. In eight cases, we found a dilated intrahepatic biliary vessel near the ruptured echinococcal cyst, without any evidence of communication between the cyst and the biliary system. Also in six cases there was an abnormal configuration of the terminal part of the biliary radicle.Conclusion: This study suggests that a dilated biliary radicle with conical configuration of its end‐part and in close proximity with hydatid cyst is strong evidence of previous or active rupture of hydatid cyst into the biliary system. A combined study of CT or MRI and MR cholangiography is mandatory for proper preoperative evaluation of the intrabiliary rupture of hepatic hydatid cyst.

Carcinoid Heart Disease.

Carcinoid syndrome originates from metastatic carcinoid tumors localized in the gastrointestinal system, pancreas, biliary vessels, bronchi, ovaries, and testes; it is characterized by flushing, telangiectasias, diarrhea, bronchoconstriction, and fibrous endocardial plaques in the heart. Cardiac involvement is detected by echocardiography in over 50% of patients with this syndrome. Right-sided valvular heart disease occurs frequently in patients with carcinoid syndrome, involving most commonly the tricuspid and pulmonary valves. Involvement of the left-sided valves rarely occurs. Medical therapy for carcinoid heart disease includes digitalis and diuretics for congestive heart failure symptoms; the effects of carcinoid syndrome can be treated with the use of somatostatin analogues. Conventional chemotherapy has been of little beneficial value, with response rates of only 10% to 30%. The use of octreotide, a long-acting and potent somatostatin analogue, is a major advance in the management of carcinoid tumors. In addition to providing effective symptom relief in malignant carcinoid syndrome, octreotide can also be used for diagnostic purposes. Despite its expense, octreotide is the current agent of choice for the treatment of this condition. Analogues with different receptor specificities and pharmacokinetics hold promise for the future. Valve surgery is the only definitive treatment for intractable right-sided heart failure. Although cardiac surgery carries high perioperative mortality, marked symptomatic improvement occurs in survivors. Surgical intervention therefore should be considered in the appropriate patients when cardiac symptoms become severe. Balloon valvulotomy in patients with severe pulmonary artery stenosis often results in palliation of symptoms; however, surgery still is required often in these patients.

Diagnostic Accuracy of Gray Scale Ultrasonography for the Jaundiced Patient

This study of cholestatic jaundice suggests that gray scale ultrasonography should precede invasive techniques or surgery. The failure of ultrasound to demonstrate dilated ducts suggests intrahepatic cholestasis. Display of liver parenchyma by ultrasound provided the correct diagnosis of diffuse liver disease in 61% of the cases. Observation of a dilated biliary tree allowed differentiation between intrahepatic and extrahepatic obstruction, with an accuracy of 96.4%. One false positive (0.7%) occurred, and most false negatives were due to gallstones producing intermittent obstruction owing to a ball-valve effect. Observations of normal biliary canaliculi suggest that physiological distention of intrahepatic biliary vessels does not occur. Long-standing obstruction of biliary tree may result in permanent distention despite surgical relief, predisposing the patient to recurrent ascending cholangitis. This stresses the need for early diagnosis and prompt relief of extrahepatic biliary obstruction.

CLINICAL ASPECTS OF JAUNDICE

When a patient with jaundice presents himself, the clinician is confronted with the necessity of speedy diagnosis, and he will remember that operation on jaundiced patients carries the extra hazard of increased liability to hemorrhage. The need for prompt relief of obstruction in the extrabiliary passages has been illustrated by the work of Counseller and Mclndoe, who have shown in necropsy specimens the enormous dilatation of the intrahepatic biliary vessels which occurs in obstructive jaundice. When obstruction occurs rapidly, as in pancreatic carcinoma, this dilatation may quickly induce pressure atrophy of the parenchymal and vascular tissues of the liver. When obstruction occurs more slowly, dilatation of the bile passages is in part opposed by concomitant thickening of the walls of the ducts and proliferation of the interstitial or supporting tissue of the liver, a compensatory mechanism which may express itself later as biliary cirrhosis. But while surgical intervention should be