Classification, Diagnosis, and Management of Patients with Biliary Sludge and Early-Stage Cholelithiasis (Literature Review and Expert Council Resolution)

Background. On May 20, 2025, a Council of Experts was held in Moscow. The aim of the meeting was to discuss current understanding of the pathogenesis and clinical significance of biliary sludge.

Key points. The following definition of biliary sludge has been established: echogenic fluid within the gallbladder cavity without a clear acoustic shadow, which shifts with changes in body position without fragmentation into fine particles. The absence of an acoustic shadow distinguishes sludge from gallstones. The International Consensus of Experts in Pancreatobiliary Diseases (2023) proposed distinguishing between biliary sludge, microlithiasis (echogenic stones ≤ 5 mm with acoustic shadowing), and larger gallstones in the gallbladder and/or ducts. When managing a patient with biliary sludge, it is important to identify the underlying disease or condition predisposing to the development of sludge. The most important factors are genetic and demographic ones, dietary habits, conditions associated with rapid weight loss, and medications that affect bile composition or gallbladder function. Biliary sludge can be asymptomatic, with dyspeptic symptoms, or lead to complications typical of gallstones. Some data suggest that sludge is associated with idiopathic pancreatitis. The primary diagnostic method for sludge is transabdominal ultrasound. If clinical manifestations characteristic of cholelithiasis complications develop, the common bile duct becomes dilated, or stones are detected in the common bile duct, additional diagnostic testing using magnetic resonance cholangiopancreatography and/or endoscopic ultrasound is recommended. Clinical observations also suggest the potential for sludge to transform into gallstones. However, the view that biliary sludge is the first stage of gallstone disease was not shared by all Council members due to the high incidence of reversible sludge. At this stage, it is proposed to consider biliary sludge more as a risk factor or a specific form of gallstone disease. The only medication shown to dissolve biliary sludge is ursodeoxycholic acid.

Conclusion. The Expert Council adopted a resolution, the provisions of which emphasize the need for accurate diagnosis, individual assessment of risk factors for the development of biliary sludge, the feasibility of developing a scoring system for assessing biliary sludge, determining the location of ursodeoxycholic acid therapy for sludge, and the need to supplement the Clinical Guidelines of the Russian Ministry of Health for the diagnosis and treatment of cholelithiasis with sections devoted to the diagnosis and treatment of biliary sludge.

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