Benign Biliary Strictures

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 through 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.

An exploration of radiological signs in post-intervention liver complications

The advent and progression of radiological techniques in the past few decades have revolutionized the diagnostic and therapeutic landscape for liver diseases. These minimally invasive interventions, ranging from biopsies to complex therapeutic procedures like transjugular intrahepatic portosystemic shunt placement and transarterial embolization, offer substantial benefits for the treatment of patients with liver diseases. They provide accurate tissue diagnosis, allow real-time visualization, and render targeted treatment for hepatic lesions with enhanced precision. Despite their advantages, these procedures are not without risks, with the potential for complications that can significantly impact patient outcomes. It is imperative for radiologists to recognize the signs of these complications promptly to mitigate further health deterioration. Ultrasound, CT, and MRI are widely utilized examinations for monitoring the complications. This article presents an overarching review of the most commonly encountered hepatobiliary complications post-radiological interventions, emphasizing their imaging characteristics to improve patient post-procedure management.

Off-label use of Lumen-apposing metal stents for treatment of short benign biliary strictures

BACKGROUND

Endoscopic stenting is the mainstay of treatment for benign biliary strictures. There is a not-negligible rate of recurrence and stent migration. Lumen-apposing metal stents (LAMS) have a unique design with short length, large diameter and wide flanges which make them less prone to migration.

AIMS

To describe the intraluminal use of LAMS to treat short benign biliary strictures.

METHODS

All consecutive patients who underwent bi-flanged LAMS placement for benign biliary strictures, in approximately 6 years, were retrospectively included. Primary outcomes were technical and clinical success; secondary outcomes were number of endoscopic procedures, adverse events evaluation and stricture recurrence during follow-up.

RESULTS

Seventy patients (35 male, mean age 67) were enrolled; bilio-enteric anastomotic stricture was the most common etiology. Technical and clinical success were 100 % and 85.7 %, respectively. Patients with post-surgical stricture had a higher success rate than patients with non-surgical stricture or with bilio-enteric anastomotic stricture (90.4 %, 86.3 % and 81.4 %, respectively). Adverse events were 12/70 (17.1 %): stent migration was the most frequent (8/70, 11.4 %). Stricture recurrence was found in 10/54 patients (18.5 %).

CONCLUSION

LAMS placement could be safe and effective treatment for short benign biliary strictures in patients in which a significant caliber disproportion between stricture and the duct above was revealed.

Diagnostic accuracy and interobserver agreement of cholangioscopy for indeterminate biliary strictures: A single-center experience

BACKGROUND AND STUDY AIMS

Characterization of indeterminate biliary strictures (IDBS) still represents a major challenge. Digital single-operator cholangioscopy (DSOC) could potentially overcome limits of conventional biopsy and brush sampling. The aim of this study was to compare diagnostic accuracy of visual evaluation and DSOC-guided biopsies to conventional trans-papillary sampling techniques and to evaluate the inter-observer agreement (IOA) on visual diagnosis.

PATIENTS AND METHODS

All consecutive patients undergoing DSOC-guided biopsy after conventional sampling techniques for IDBS during a six-year period were retrospectively evaluated. Final diagnosis was based on histological evaluation of the surgical specimen if available or a clinical follow-up of at least 6 months. For IOA, 20-second DSOC clips were retrospectively reviewed by 6 experts and 6 trainees and classified according to the Monaco Classification.

RESULTS

Thirty-five patients underwent DSOC for IDBS in the study period; 14 patients (F = 9) with a median age of 64 years (range 53-76) met the study aim. After DSOC, strictures location was changed in three patients (additional yield of 21.4 %). Intraductal DSOC-guided biopsy were technically successful in all cases, with an adequacy of 92.8 %. No adverse events were recorded. Final diagnosis was benign disease in five cases and cholangiocarcinoma in the others. For IOA, 29 videos were evaluated with almost perfect agreement for final diagnosis (kappa 0.871; agreement 93.1, p <0.001), although overall accuracy of DSOC visual finding was 73.6 % and 64.4 % for experts and trainees, respectively.

CONCLUSIONS

DSOC could improve diagnostic accuracy for IDBS, since it showed high sensitivity for visual finding and high specificity for DSOC guided-biopsy. Visual diagnosis seems reliable for diagnosis using the Monaco Classification.

Percutaneous Transhepatic Sphincterotome-Guided Management of Post-Living Donor Liver Transplant Biliary Anastomotic Stricture: An Innovative Approach

Post-liver transplantation biliary complications remain a serious concern and are associated with reduced patient and graft survival. Among various biliary complications, anastomotic stricture (AS) is the most frequent and challenging one. The frequency of AS after living donor liver transplantation (LDLT) is higher as compared to deceased donor liver transplantation. The management involves endoscopic retrograde cholangiopancreatography and/or percutaneous transhepatic biliary drainage, but refractory cases necessitate surgical revision. We present a case of complex biliary AS in a 63-year-old man after LDLT. The conventional approaches including endoscopic retrograde cholangiopancreatography, percutaneous transhepatic cholangiography, and cholangioscope-guided interventions remained unsuccessful. An innovative approach using a wire-guided sphincterotome through percutaneous transhepatic route successfully managed the complex post-LDLT AS. This is perhaps the first reported case of novel utilization of sphincterotome through transhepatic route for the management of AS in LDLT, averting major surgical interventions with related morbidity and mortality.

Research on the Current Application Status of Magnesium Metal Stents in Human Luminal Cavities

The human body comprises various tubular structures that have essential functions in different bodily systems. These structures are responsible for transporting food, liquids, waste, and other substances throughout the body. However, factors such as inflammation, tumors, stones, infections, or the accumulation of substances can lead to the narrowing or blockage of these tubular structures, which can impair the normal function of the corresponding organs or tissues. To address luminal obstructions, stenting is a commonly used treatment. However, to minimize complications associated with the long-term implantation of permanent stents, there is an increasing demand for biodegradable stents (BDS). Magnesium (Mg) metal is an exceptional choice for creating BDS due to its degradability, good mechanical properties, and biocompatibility. Currently, the Magmaris® coronary stents and UNITY-BTM biliary stent have obtained Conformité Européene (CE) certification. Moreover, there are several other types of stents undergoing research and development as well as clinical trials. In this review, we discuss the required degradation cycle and the specific properties (anti-inflammatory effect, antibacterial effect, etc.) of BDS in different lumen areas based on the biocompatibility and degradability of currently available magnesium-based scaffolds. We also offer potential insights into the future development of BDS.

Post-ERCP pancreatitis occurs more frequently in self-expandable metallic stents than multiple plastic stents on benign biliary strictures: a meta-analysis

BACKGROUND

The occurrence of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) after using covered self-expandable metallic stents (CSEMS) and multiple plastic stents (MPS) in the therapy of benign biliary strictures (BBS) remains ambiguous, this analysis aimed to evaluate the outcomes.

CONCLUSIONS

Compared with MPS, CSEMS caused a significantly higher incidence of PEP but fewer ERCP procedures, while the rate of stricture resolution, recurrence, and overall adverse events were comparable. Prevention methods of PEP should be further evaluated in BBS when undergoing CSEMS placement.

METHODS

A systematic search of electronic databases (PubMed, Web of Science and Cochrane Library) was conducted for randomised controlled trials (RCTs), and the included studies were published between 2008 and 2021. The primary outcome was PEP, while the secondary outcomes were stricture resolution, recurrence, overall adverse events, costs, and ERCP sessions. Pooled effect sizes were calculated with the random-effects model or fixed-effects model depending on the heterogeneity.

RESULTS

Six RCTs contained 444 patients (221 with CSEMS, 223 with MPS) finally included in the meta-analysis. The present analysis shows that compared to MPS, PEP is more likely to occur in CSEMS (OR [odds ratio] = 3.34, 95% confidence intervals [CI]:1.44-7.77, p = .005). CSEMS needs fewer ERCP sessions (Mean Deviation [MD]: -1.56; 95%CI:-2.66, -0.46], p = .006). The difference in stricture resolution and recurrence was not significant between the two stent types (OR = 0.87, 95%CI: 0.49-1.56, p = .64; and OR = 2.3, 95%CI: 0.68-7.76, p = .18). The incidence of overall adverse events was comparable between CSEMS and the MPS group (OR = 1.49, 95% CI: 0.97-2.29, p = .07).

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022314864. Key messagesCSEMS and MPS placement remain a mainstay for patients with BBS, and severe complications after stent placement have not been compared.The incidence of PEP was higher after deployment of CSEMS compared to MPS.Prevention methods of PEP should be evaluated in BBS when undergoing CSEMS placement.

Endoscopic management of benign and malignant hilar stricture

Management of hilar strictures pose a significant challenge for endoscopists. Several strategies have been demonstrated in the last decade beyond decompression, however, there remains controversy and minimal consensus in the literature. This review seeks to summarize the current literature and discuss emerging therapies, such as photodynamic therapy and radiofrequency ablation.

Post-transplant biliary complications: advances in pathophysiology, diagnosis, and treatment

Liver transplantation (LT) is the only curative therapy in patients with end-stage liver disease. Long-term survival is excellent, yet LT recipients are at risk of significant complications. Biliary complications are an important source of morbidity after LT, with an estimated incidence of 5%-32%. Post-LT biliary complications include strictures (anastomotic and non-anastomotic), bile leaks, stones, and sphincter of Oddi dysfunction. Prompt recognition and management is critical as these complications are associated with mortality rates up to 20% and retransplantation rates up to 13%. This review aims to summarise our current understanding of risk factors, natural history, diagnostic testing, and treatment options for post-transplant biliary complications.

Post-Transplant Biliary Strictures: An Updated Review

Liver transplantation (LT) is the only curative therapy in patients with end-stage liver disease with excellent long-term survival; however, LT recipients are at risk of significant complications. Among these complications are biliary complications with an incidence ranging from 5 to 32% and associated with significant post-LT morbidity and mortality. Prompt recognition and management are critical as these complications have been associated with mortality rates up to 19% and retransplantation rates up to 13%. An important limitation of published studies is that a large proportion does not discriminate between anastomotic strictures and nonanastomotic strictures. This review aims to summarize our current understanding of risk factors and natural history, diagnostic testing, and treatment options for post-LT biliary strictures.

Significance of KRAS mutation testing in biliary brushing cytology specimens: A 10-year retrospective review

BACKGROUND

Biliary strictures can be caused by benign and malignant conditions. A biliary duct brushing diagnosis can be challenging because of low cellularity and overlapping morphology among different entities, leading to a variable reported sensitivity. This study aimed to assess the value of KRAS mutation testing in adding cytological diagnosis of biliary duct brushings.

METHODS

With institutional review board approval, biliary duct brushing cytology specimens were collected from 269 patients with extrahepatic biliary stenosis between August 2011 and July 2021. The results of cytology and KRAS mutational analyses were evaluated in view of corresponding cytology examination and histopathological/clinical follow-up.

RESULTS

KRAS mutations were identified in 50 of 269 biliary stricture brushing cases (19%). Among the cases with available follow-up, 72% (34 of 47) of biliary brushings had confirmed malignancy when there were KRAS mutations. The overall specificity and sensitivity of KRAS mutation testing was 92% and 36%, respectively. KRAS mutation was significantly more enriched in pancreatic duct adenocarcinoma than in cholangiocarcinoma (66% vs 5%, P < .001). The absolute risk of malignancy was 3%, 28%, and 71%, respectively, in negative, atypical, and suspicious cytological diagnostic categories and the risks increased to 14%, 68%, and 95% in corresponding categories with KRAS mutation.

CONCLUSIONS

Our results suggested that KRAS mutational analysis can be considered supplementary to cytology diagnosis of biliary duct brushing for patients with extrahepatic biliary stenosis in clinical practice.

Improving Diagnostic Yield in Indeterminate Biliary Strictures

Indeterminate biliary strictures are defined as a narrowing of the bile duct that cannot be differentiated as malignant or benign after performing cross-sectional imaging and an ERCP. Identifying the etiology of a bile duct stricture is the single most important step in determining whether a complex and potentially morbid surgical resection is warranted. Due to this diagnostic and therapeutic dilemma, new technologies, laboratory tests, and procedures are emerging to solve this problem.

A review on biodegradable biliary stents: materials and future trends

Biliary stricture is defined as the reduction and narrowing of the bile duct lumen, which can be caused by many factors such as cancer and inflammation. Biliary stent placement can effectively alleviate benign and malignant biliary strictures. However, the commonly used plastic or metallic biliary stents are far from ideal and do not satisfy all clinical requirements，although several types of biodegradable biliary stents have been developed and used clinically. In this review, we summarized current development status of biodegradable stents with the emphasis on the stent materials. We also presented the future development trends based on the published literature.

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Summary of current development status of bioresorbable biliary stents with the emphasis on the stent materials.

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The future development trends based on the published literature.

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The advantages of bioresorbable biliary stents compared with metallic and plastic biliary stents.

A rare case report of obstructive jaundice caused by mucus-producing cholangiocarcinoma

RATIONALE

Cholangiocarcinoma is a common cause of obstructive jaundice but is mainly associated with solid mass and not semisolid secretion. In this report, the patient was admitted to the hospital with obstructive jaundice; however, no solid mass was found to lead to jaundice.

PATIENT CONCERNS

The patient developed symptoms of obstructive jaundice for 10 days, including fatigue and yellow skin staining.

DIAGNOSES

Postoperative pathological examination of the bile duct wall revealed cholangioadenocarcinoma, and the jelly like contents were inflammatory secretions.

INTERVENTIONS

The patient underwent laparotomy and was diagnosed with obstructive jaundice. An exploratory laparotomy revealed that the content in the biliary duct tree was a jelly like inflammatory secretion.

OUTCOMES

Follow-up data revealed that the levels of total bilirubin and aminotransferase were normal, and a computed tomography scan showed no tumor mass.

LESSONS

There are very few reports about obstructive jaundice caused by inflammatory secretion that almost filled up the biliary tree. Internal drainage of the cholestatic bile can be achieved through endoscopic retrograde cholangiopancreatograpy, or external drainage can be achieved through percutaneous transhepatic biliary drainage, which can relieve the symptoms of biliary obstruction and improve the patient's quality of life.

Klatskin-Mimicking Lesions

Altemeier-Klatskin tumor is a perihilar cholangiocarcinoma that occurs within 2 cm of the confluence of the right and left hepatic duct at the hepatic hilum and accounts for 50-70% of all cholangiocarcinomas cases. Although imaging techniques have come very far today, this entity can still be very challenging to diagnose as there are many lesions that can mimic Klatskin tumor. In this review, we will present the most common Klatskin-mimicking lesions.

Indian College of Radiology and Imaging Evidence-Based Guidelines for Percutaneous Image-Guided Biliary Procedures

Percutaneous biliary interventions are among the commonly performed nonvascular radiological interventions. Most common of these interventions is the percutaneous transhepatic biliary drainage for malignant biliary obstruction. Other biliary procedures performed include percutaneous cholecystostomy, biliary stenting, drainage for bile leaks, and various procedures like balloon dilatation, stenting, and large-bore catheter drainage for bilioenteric or post-transplant anastomotic strictures. Although these procedures are being performed for ages, no standard guidelines have been formulated. This article attempts at preparing guidelines for performing various percutaneous image-guided biliary procedures along with discussion on the published evidence in this field.

Biliary Strictures: A Surgeon's Perspective for Interventional Radiologists

Biliary strictures can be a challenging clinical problem to manage and often have unclear etiologies, including benign and malignant causes. Left untreated, these problems can lead to significant morbidity and mortality linked to their underlying diagnosis. The approach to adult patients with biliary strictures requires a multidisciplinary team involving surgeons, interventional endoscopists, and interventional radiologists for diagnosis, symptom relief, palliation, as well as potential curative management. From a surgeon's perspective, there are many ways to classify and approach these strictures. It is of paramount importance to start with an excellent understanding of the patient's prior surgical history. In approaching a patient with a new diagnosis of biliary stricture, it is also critical to understand its etiology relatively quickly, as 70% are malignant in the adult population. Concurrently, one must clearly define the location and extent of the stricture: intrahepatic, hilar, or distal extrahepatic bile duct, as well as whether it is a singular lesion or multifocal phenotypes. This information provides a path forward in clinical decision-making regarding durability and efficacy of therapy, which is typically aimed at decompression and/or surgical resection to prevent cholangitis, sepsis, and progressive hepatic insufficiency.

Percutaneous Biliary Endoscopy

Biliary endoscopy is underutilized by interventional radiologists and has the potential to become an effective adjunctive tool to help both diagnose and treat a variety of biliary pathology. This is particularly true in cases where endoscopic retrograde cholangiopancreatography fails or is not feasible due to surgically altered anatomy. Both preoperative clinical and technical procedural factors must be taken into consideration prior to intervention. In this article, clinical evaluation, perioperative management, and procedural techniques for percutaneous biliary endoscopy are reviewed.

Percutaneous Management of Benign Biliary Strictures

Benign biliary strictures are often due to a variety of etiologies, most of which are iatrogenic. Clinical presentation can vary from asymptomatic disease with elevated liver enzymes to obstructive jaundice and recurrent cholangitis. Diagnostic imaging methods, such as ultrasound, multidetector computed tomography, and magnetic resonance imaging (cholangiopancreatography), are used to identify stricture location, extent, and possible source of biliary obstruction. The management of benign biliary strictures requires a multidisciplinary team approach and include endoscopic, percutaneous, and surgical interventions. Percutaneous biliary interventions provide an alternative diagnostic and therapeutic approach, especially in patients who are not amenable to endoscopic evaluation. This review provides an overview of benign biliary strictures and percutaneous management by interventional radiologists. Diagnostic evaluation with percutaneous transhepatic cholangiography and treatment options, including biliary drainage, balloon dilation, retrievable/biodegradable stents, and other innovative minimally invasive options, are discussed.

Oriental Cholangiohepatitis in a Caucasian male

Recurrent pyogenic cholangitis (RPC) is a condition found almost exclusively in individuals who lived in Southeast Asia. We report a case of a Caucasian veteran diagnosed with RPC after presenting with a 5-year history of recurrent fevers and abdominal pain 20 years after serving in Japan, South Korea, and Guam. Extensive evaluation led to the diagnosis of RPC with improvement after biliary decompression and antibiotics. Although rare, RPC should be considered in individuals who present with recurrent bouts of abdominal pain and fevers regardless of race.

Determining the Indeterminate Biliary Stricture: Cholangioscopy and Beyond

PURPOSE OF REVIEW

Indeterminate biliary strictures (IDBS) continue to be an area of frustration for clinicians. Standard endoscopic retrograde cholangiopancreatography (ERCP) with conventional brush cytology and/or forceps biopsy has a low sensitivity for distinguishing benign from malignant biliary strictures. A delay in diagnosis of malignancy has consequences for subsequent therapy or surgery. In this article, we review current and emerging technologies that may aid in this diagnostic dilemma.

RECENT FINDINGS

Several technologies have been utilized in IDBS to establish a diagnosis which include peroral cholangioscopy, confocal laser endomicroscopy, endoscopic ultrasound with fine needle aspiration, intraductal ultrasound, optical coherence tomography, fluorescence in situ hybridization, next generation sequencing, integrated molecular pathology, and DNA-image cytometry. While cholangioscopy and confocal laser endomicroscopy have become standards of care in expert centers for the evaluation of patients with IDBS, there are several endoscopic and molecular modalities that may also aid in establishing a diagnosis. Further head-to-head prospective diagnostic studies as well as cost-efficacy studies are needed.

Use of bacterial cellulose film for repair of bile duct injury in pigs

BACKGROUND/OBJECTIVE

The aim was to evaluate the use of bacterial cellulose film and bile duct autograft in repairing critical common bile duct injury in pigs.

METHODS

A prospective experimental analytical study was carried out on 20 Sus Domesticus, Piau suidae swine, divided into a control group (n = 10) and an experimental group (n = 10) divided into two subgroups: bacterial cellulose film E1 and bacterial cellulose film E2 to which bacterial cellulose film was randomly allocated. The control group underwent two complete critical common bile duct sections 10 mm apart, while the experimental group with a single critical common bile duct defect underwent a 10 mm section of the longitudinal shaft with edge resection. The defects in the control group were treated with end-to-end conventional anastomosis using polyglycolic 6-0 surgical thread and the experimental group with bacterial cellulose film by continuous suture using the same material. The animals were clinically evaluated throughout the experiment on days D150 (bacterial cellulose film E1), D225 (control group), and D330 (bacterial cellulose film E2) and by intraoperative ultrasound examination related to histopathological and biochemical findings.

RESULTS

The intraoperative ultrasonography detected the changes resulting from the common bile duct anastomosis in the control group that produced a considerable incidence of ductal narrowing and obstruction to the biliary flow. In the bacterial cellulose film E2 group, there was an increase in inflammation intensity, granulomatous reaction, fibrosis, and vessels density, without producing bile duct dilation in the ultrasonography assessment. Biochemical analysis of liver enzymes yielded results in the normal range confirming preservation of liver function at the different post-surgery time points.

CONCLUSION

Bacterial cellulose film, when used as a graft for bile duct repair, proved to be a biocompatible material that produced a complete healing process and biliary flow continuity.

Biliary Endoscopy for Benign and Malignant Biliary Strictures

Percutaneous endoscopy operated by interventional radiologists has the potential to become an effective tool to both help diagnose and treat benign and malignant biliary strictures. This is particularly true in cases where endoscopic retrograde cholangiopancreatography fails or is not feasible due to surgically-altered anatomy. Both preoperative clinical and technical procedural factors must be taken into consideration when pursuing percutaneous endoscopy. In this article, clinical evaluation, perioperative management, and procedural techniques for biliary endoscopy for benign and malignant strictures are reviewed.

Management of Biliary Strictures: State-of-the-Art Review

Biliary strictures can be broadly classified as benign or malignant. Benign biliary strictures are most commonly iatrogenic in nature and are a consequence of hepatobiliary surgery. Cholangiocarcinoma and adenocarcinoma of the pancreas are the most common causes of malignant biliary obstruction. This article reviews state-of-the-art minimally invasive techniques used to manage these strictures. In addition, the roles of (a) recently introduced biodegradable biliary stents in the management of benign biliary strictures and (b) intraprocedural imaging and navigation tools, such as cone-beam CT, in percutaneous reconstruction of the biliary-enteric anastomosis are discussed.

A Novel Rabbit Model for Benign Biliary Stricture Formation and the Effects of Medication Infusions on Stricture Formation

BACKGROUND

Benign biliary stricture (BBS) is highly refractory. Currently, there is no effective strategy for prevention of BBS recurrence. The aim of this study is to establish a novel BBS rabbit model and to investigate the efficacy of biliary infusion with anti-proliferative medications for treating BBS.

METHOD

A BBS model was established via surgical injury and biliary infection. The biliary infusion tube was inserted into the common bile duct via the stump of cystic duct after cholecystectomy. Biliary infusions with Rapamycin, Pirfenidone and Fasudil were performed daily during the 4 weeks following the surgery. The wall thickness and luminal area of the bile duct were assessed.

RESULTS

All rabbits formed BBS after surgery. The mortality rate was 13% (8/60) and tube withdrawal rate was 4% (2/48). The thickness of the bile duct wall was significantly reduced; whereas the luminal area of the bile duct was dramatically enlarged in the Rapamycin or the Pirfenidone treated group, compared to the saline treated group. Furthermore, the local treatment significantly decreased the levels of proliferation makers, including PCNA, Collagen I and fibrogenic mediators, including ACTA2 and TGF-beta.

CONCLUSION

We have established a novel animal model for BBS formation. We have further demonstrated that biliary infusion with Rapamycin or Pirfenidone limits the biliary strictures through inhibiting the proliferation of the bile duct wall in this model. This may represent a new avenue for preventing biliary restenosis.

Indeterminate biliary strictures: a simplified approach

Pre-operative evaluation of biliary strictures remains challenging. The dilemma that exists is how to balance the risk of failing to detect malignancy and the potential morbidity caused by unnecessary surgery in patients with benign etiologies. With emerging novel diagnostic modalities, this study aims to assess the efficacy of diagnostic techniques and facilitate a clinical approach to indeterminate biliary strictures. Areas covered: Conventional imaging modalities are crucial in identifying the location of a stricture and are helpful for choosing further diagnostic modalities. Utilization of endoscopic techniques, including endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS), is key in establishing a diagnosis. The emergence of novel diagnostic modalities, such as fluorescence in-situ hybridization (FISH), peroral cholangioscopy (POC), intraductal endoscopic ultrasound (IDUS) and confocal laser endomicroscopy (CLE), enhance the diagnostic yield in the evaluation of indeterminate biliary strictures. Expert commentary: More reliable and validated visual criteria for differentiating malignancy from benign biliary conditions, utilizing advanced imaging modalities such as POC and CLE, need to be established. It is of significance to further evaluate these novel diagnostic modalities through ongoing trials and to develop a diagnostic algorithm that reconciles cost-effectiveness with diagnostic accuracy.