New rabbit model for benign biliary stricture formation with repeatable administration

BACKGROUND The treatment of benign biliary strictures(BBS)is a challenging clinical problem.At present,there is a lack of ideal models for the study of BBS treatment.AIM To develop a novel animal model of BBS to simulate studies on the processes and mechanisms in the human condition.METHODS A rabbit model of benign bile duct stricture was established by surgical injury of the bile duct.After removal of the gallbladder,a drainage tube was placed th-rough the cystic duct at the stump,and a BBS model was induced by surgical injury at the lower end of the common bile duct.RESULTS Compared with the control group,the model rabbits showed gross jaundice,increased serum bilirubin,and decreased liver function.Cholangiography showed segmental bile duct stenosis in the model rabbits.Pathological staining showed inflammatory cell infiltration and fibrosis in the biliary tract of rabbits in the model group.This was consistent with the clinical manifestations of BBS.This model provided serology,imaging,pathology,and other aspects of BBS.CONCLUSION We have successfully established an animal model of benign stricture of the lower bile duct with repeatable administration,which is consistent with the clinical manifestations of BBS.

Endoscopic management of benign biliary strictures:Looking for the best stent to place

Benign biliary strictures(BBS)might occur due to different pancreaticobiliary conditions.The etiology and location of biliary strictures are responsible of a wide array of clinical manifestations.The endoscopic approach endoscopic retrograde cholangiopancreatography represents the first-line treatment for BBS,considering interventional radiology and surgery when endoscopic treatment fails or it is not suitable.The purpose of this review is to provide an overview of possible endoscopic treatments for the optimal management of this subset of patients.

Mechanism of benign biliary stricture: A morphological and immunohistochemical study

AIM: To explore the mechanism of benign biliary stricture. METHODS: A model of trauma of bile duct was established in 28 dogs. The anastomosed tissues were resected and examined by light and electron microscopes on day 3, in wk 1, 3 and mo 3, 6 after operation. CD68, TGF-β1 and α-SMA were examined by immunohistochemical staining, respectively. RESULTS: The mucosal epithelium of the bile duct was slowly recovered, chronic inflammation lasted for a long time, fibroblasts proliferated actively, extracellular matrix was over-deposited. Myofibroblasts functioned actively and lasted through the whole process. The expression of macrophages in lamina propria under mucosa, TGF-β1 in granulation tissue, fibroblasts and endothelial cells of blood vessels, oc-SMA in myofiroblasts were rather strong from the 1st wk to the 6th mo after operation. CONCLUSION: The type of healing occurring in bile duct belongs to overhealing. Myofibroblasts are the main cause for scar contracture and stricture of bile duct. High expressions of CD68, TGF-β1 and a-SMA are closely related to the active proliferation of fibroblasts, extracellular matrix over-deposition and scar contracture of bile duct.

Still elusive: Developments in the accurate diagnosis of indeterminate biliary strictures

Indeterminate biliary strictures pose a significant diagnostic dilemma for gastroenterologists.Despite advances in endoscopic techniques and instruments,it is difficult to differentiate between benign and malignant pathology.A positive histological diagnosis is always preferred prior to high risk hepatobiliary surgery,or to inform other types of therapy.Endoscopic retrograde cholangiopancreato-graphy with brushings has low sensitivity and despite significant improvements in instruments there is still an unacceptably high false negative rate.Other methods such as endoscopic ultrasound and cholangioscopy have improved diagnostic quality.In this review we explore the techniques available to aid accurate diagnosis of indeterminate biliary strictures and obtain accurate histology to facilitate clinical management.

Use of fully covered self-expanding metal stents in benign biliary diseases

Biliary fully covered self-expanding metal stents (FCSEMS) are now being used to treat several benign biliary conditions. Advantages include small predeployment and large postexpansion diameters in addition to an easy insertion technique. Lack of imbedding of the metal into the bile duct wall enables removability. In benign biliary strictures that usually require multiple procedures, despite the substantially higher cost of FCSEMS compared with plastic stents, the use of FCSEMS is offset by the reduced number of endoscopic retrograde cholangiopancreatography interventions required to achieve stricture resolution. In the same way, FCSEMS have also been employed to treat complex bile leaks, perforation and bleeding after endoscopic biliary sphincterotomy and as an aid to maintain permanent drainage tracts obtained by means of Endoscopic Ultrasound-guided biliary drainage. Good success rates have been achieved in all these conditions with an acceptable number of complications. FCSEMS were successfully removed in all patients. Comparative studies of FCSEMS and plastic stents are needed to demonstrate efficacy and cost-effectiveness