Presence and density of common bile duct microlithiasis in acute biliary pancreatitis

AIM: Common bile duct microlithiasis (CBDM) is found in majority of patients with acute biliary pancreatitis (ABP) and no CBD stones in fluoroscopy during urgent ERCP. It is unclear, however, weather CBDM is a cause or the result of the disease. This prospective study was done to investigate the presence and density of CBDM in patients with ABP, when endoscopic retrograde cholangiopancreatography (ERCP) was done in different periods from the onset of the disease. METHODS: One hundred fifty one consecutive patients with ABP and no CBDS on ERCP, performed as an urgent (< 24 h of admission) procedure, (101 - with gallbladder stones, 50 post-cholecystectomy patients), treated during last 4 years were prospectively included to the study. The presence and density of CBDM (cholesterol monohydrate crystals-CMCs and calcium bilirubinate granules-CBGs) in bile collected directly from common bile duct during ERCP was prospectively calculated according to Juniper and Burson criteria. High density of crystals was considered, when we found > 10 CMCs; and/or > 25 clusters of CBGs on 1 slide. RESULTS: CBD microlithiasis was present in given number of patients: on d 1-30/34 (88.2 %), on d 2 41/49 (83.7 %), on d 3-23/33 (69.6 %), on d 4-7-24/35 (68.6 %) [ P for trend = 0. 018 ]. In patients with CBD microlithiasis the high density of crystals was observed in given number of patients: on d 1-27/30 (90 %), on d 2-34/41 (82.9 %), on d 3-18/23 (78.3 %), on d 4-7-16/24 (66.7 %) [ P for trend= 0. 039]. CONCLUSION: In patients with ABP and no CBDS on ERCP, CBD microlithiasis is observed in the majority of patients, especially during the first day of the disease. Density of,CBD microlithiasis is the highest in the first day of the disease, This suggests that CBD microlithiasis can be the cause and not the result of ABP.