Biliary strictures complicating living donor liver transplantation:Problems,novel insights and solutions

Biliary stricture complicating living donor liver transplantation(LDLT) is a relatively common complication, occurring in most transplant centres across the world. Cases of biliary strictures are more common in LDLT than in deceased donor liver transplantation. Endoscopic management is the mainstay for biliary strictures complicating LDLT and includes endoscopic retrograde cholangiography, sphincterotomy and stent placement(with or without balloon dilatation). The efficacy and safety profiles as well as outcomes of endoscopic management of biliary strictures complicating LDLT is an area that needs to be viewed in isolation, owing to its unique set of problems and attending complications; as such, it merits a tailored approach, which is yet to be well established. The diagnostic criteria applied to these strictures are not uniform and are over-reliant on imaging studies showing an anastomotic narrowing. It has to be kept in mind that in the setting of LDLT, a subjective anastomotic narrowing is present in most cases due to a mismatch in ductal diameters. However, whether this narrowing results in a functionally significant narrowing is a question that needs further study. In addition, wide variation in the endotherapy protocols practised in most centres makes it difficult to interpret the results and hampers our understanding of this topic. The outcome definition for endotherapy is also heterogenous and needs to be standardised to allow for comparison of data in this regard and establish a clinical practice guideline. There have been multiple studies in this area in the last 2 years, with novel findings that have provided solutions to some of these issues. This review endeavours to incorporate these new findings into the wider understanding of endotherapy for biliary strictures complicating LDLT, with specific emphasis on diagnosis of strictures in the LDLT setting, endotherapy protocols and outcome definitions. An attempt is made to present the best management options currently available as well as directions for future research in the area.

Endoscopic therapy for biliary strictures complicating living donor liver transplantation: Factors predicting better outcome

AIM To identify factors predicting outcome of endoscopic therapy in bile duct strictures(BDS) post living donor liver transplantation(LDLT).METHODS Patients referred with BDS post LDLT, were retrospectively studied. Patient demographics, symptoms(Pruritus, Jaundice, cholangitis), intra-op variables(cold ischemia time, blood transfusions, number of ducts used, etc.), peri-op complications [hepatic artery thrombosis(HAT), bile leak, infections], stricture morphology(length, donor and recipient duct diameters) and relevant laboratory data both pre-and post-endotherapy were studied. Favourable response to endotherapy was defined as symptomatic relief with > 80% reduction in total bilirubin/serum gamma glutamyl transferase. Statistical analysis was performed using SPSS 20.0.RESULTS Forty-one patients were included(age: 8-63 years). All had right lobe LDLT with duct-to-duct anastomosis. Twenty patients(48.7%) had favourable response to endotherapy. Patients with single duct anastomosis, aggressive stent therapy(multiple endoscopic retrogradecholagiography, upsizing of stents, dilatation and longer duration of stents) and an initial favourable response to endotherapy were independent predictors of good outcome(P < 0.05). Older donor age, HAT, multiple ductal anastomosis and persistent bile leak(> 4 wk post LT) were found to be significant predictors of poor response on multivariate analysis(P < 0.05). CONCLUSION Endoscopic therapy with aggressive stent therapy especially in patients with single duct-to-duct anastomosis was associated with a better outcome. Multiple ductal anastomosis, older donor age, shorter duration of stent therapy, early bile leak and HAT were predictors of poor outcome with endotherapy in these patients.

Artificial intelligence in endoscopy: More than what meets the eye in screening colonoscopy and endosonographic evaluation of pancreatic lesions

Artificial intelligence(AI)-based tools have ushered in a new era of innovation in the field of gastrointestinal(GI)endoscopy.Despite vast improvements in endoscopic techniques and equipment,diagnostic endoscopy remains heavily operator-dependent,in particular,colonoscopy and endoscopic ultrasound(EUS).Recent reports have shown that as much as 25%of colonic adenomas may be missed at colonoscopy.This can result in an increased incidence of interval colon cancer.Similarly,EUS has been shown to have high inter-observer variability,overlap in diagnoses with a relatively low specificity for pancreatic lesions.Our understanding of Machine-learning(ML)techniques in AI have evolved over the last decade and its application in AI–based tools for endoscopic detection and diagnosis is being actively investigated at several centers.ML is an aspect of AI that is based on neural networks,and is widely used for image classification,object detection,and semantic segmentation which are key functional aspects of AI-related computer aided diagnostic systems.In this review,current status and limitations of ML,specifically for adenoma detection and endosonographic diagnosis of pancreatic lesions,will be summarized from existing literature.This will help to better understand its role as viewed through the prism of real world application in the field of GI endoscopy.

Role of endoscopic ultrasound guided fine needle aspiration/biopsy in the evaluation of intra-abdominal lymphadenopathy due to tuberculosis

BACKGROUND Intra-abdominal lymphadenopathy due to tuberculosis(TB)poses a diagnostic challenge due to difficulty in tissue acquisition.Although endoscopic ultrasound guided fine needle aspiration/biopsy(EUS-FNA/B)has shown promise in the evaluation of mediastinal lymph nodes,its role in the evaluation of intra-abdominal lymphadenopathy is not clear.AIM To assess the role of EUS-FNA/B in the evaluation of intra-abdominal lymphadenopathy due to TB.METHODS This was a retrospective study where patients with intra-abdominal lymphadenopathy who underwent evaluation with EUS-FNA/B were included.TB was diagnosed if the patient had any one of the following:(1)Positive acid fast bacilli(AFB)stain/TB GeneXpert/TB-polymerase chain reaction/AFB culture of tissue sample;and(2)Positive Mantoux test and response to anti-tubercular therapy.EUS-FNA reports,clinical reports and imaging characteristics of patients were recorded for a detailed analysis of patients with TB.RESULTS A total of 149 patients underwent an EUS-FNA/B from lymph nodes(mean age 51±17 years,M:F=1.2).Benign inflammatory reactive changes were seen in 45 patients(30.2%),while 54 patients(36.2%)showed granulomatous inflammation with/without caseation.Among these,51 patients(94.4%)were confirmed to have TB as per pre-defined criteria.Patients with TB were more likely to have hypoechoic and matted nodes[40 patients(67.7%)].EUS-FNA/B was found to have a sensitivity and specificity of 86%and 93%respectively,with a diagnostic accuracy of 88%in the evaluation of intra-abdominal lymphadenopathy due to TB.CONCLUSION EUS-FNA/B has a high diagnostic yield with a good sensitivity and specificity in the evaluation of intra-abdominal lymphadenopathy due to TB.However,the validity of these findings in populations with low prevalence of TB needs further evaluation.