Consensus definition of sludge and microlithiasis as a possible cause of pancreatitis.

OBJECTIVE: In up to 20% of patients, the aetiology of acute pancreatitis (AP) remains elusive and is thus called idiopathic. On more detailed review these cases can often be explained through biliary disease and are amenable to treatment. Findings range from biliary sludge to microlithiasis but their definitions remain fluid and controversial. DESIGN: A systematic literature review (1682 reports, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines) analysed definitions of biliary sludge and microlithiasis, followed by an online international expert survey (30 endoscopic ultrasound/hepatobiliary and pancreatic experts; 36 items) which led to definitions of both. These were consented by Delphi voting and clinically evaluated in a retrospective cohort of patients with presumed biliary pancreatitis. RESULTS: In 13% of original articles and 19.2% of reviews, microlithiasis and biliary sludge were used synonymously. In the survey, 41.7% of experts described the term 'sludge' and 'microlithiasis' as identical findings. As a consequence, three definitions were proposed, agreed on and confirmed by voting to distinctly discriminate between biliary sludge (hyperechoic material without acoustic shadowing) and microlithiasis (echorich calculi of ≤5 mm with acoustic shadowing) as opposed to larger biliary stones, both for location in gallbladder and bile ducts. In an initial attempt to investigate the clinical relevance in a retrospective analysis in 177 confirmed cases in our hospital, there was no difference in severity of AP if caused by sludge, microlithiasis or stones. CONCLUSION: We propose a consensus definition for the localisation, ultrasound morphology and diameter of biliary sludge and microlithiasis as distinct entities. Interestingly, severity of biliary AP was not dependent on the size of concrements warranting prospective randomised studies which treatment options are adequate to prevent recurrence.

Severity of gallstone, sludge or microlithiasis induced pancreatitis - all of the same?

BACKGROUND/AIM: Severity of microlithiasis and sludge-induced pancreatitis in comparison to gallstone-induced pancreatitis has never been studied for a lack of definition. In order to understand whether bile duct obstruction or other mechanisms contribute to biliary pancreatitis severity we performed a monocentric, retrospective cohort study. METHODS: In this retrospective cohort study 263 patients with acute biliary pancreatitis treated at a tertiary care center from 2005 to 2021 were stratified according to the recent consensus definition for microlithiasis and sludge. The gallstone-pancreatitis cohort was compared to microlithiasis, sludge and suspected stone passage pancreatitis cohorts in terms of pancreatitis outcome, liver function and EUS/ERCP results using one-way ANOVA and Chi2 test. Multinomial logistic regression analysis was performed to correct for bias. RESULTS: Microlithiasis and sludge-induced pancreatitis classified according to the revised Atlanta classification, did not present with a milder course than gallstone-induced pancreatitis (p = 0.62). Microlithiasis and sludge showed an increase in bilirubin on the day of admission to hospital, which was not significantly different from gallstone-induced pancreatitis (p = 0.36). The likelihood of detecting biliary disease on EUS resulting in bile duct clearance was highest on the day of admission and day 1, respectively. CONCLUSION: Microlithiasis and sludge induce gallstone-equivalent impaired liver function tests and induce pancreatitis with similar severity compared with gallstone-induced acute biliary pancreatitis.