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Aims: Small common bile duct stones are known to occasionally clear spontaneously. This study aimed to prospectively assess the role of biliary stent placement in promoting the spontaneous clearance of small common bile duct stones. Methods and Results: We analyzed patients presenting with common bile duct stones of ≤5 mm diameter between June 2020 and May 2022. The exclusion criteria included asymptomatic patients, biliary pancreatitis, altered gastrointestinal anatomy, bile duct strictures (malignant or benign), and a history of EST. The biliary stents were inserted without stone removal. Stone clearance was assessed using endoscopic ultrasonography or endoscopic retrograde cholangiopancreatography after 3 months. Our primary endpoint was the clearance rate of common bile duct stones over 6 months, targeting a lower limit for the 95% confidence interval (CI) exceeding 25%. Of the 32 enrolled patients, 18 (56.3%; 95% CI: 37.7–73.6%) exhibited stone clearance. Early complications occurred in 11 patients (34.4%), totaling 12 incidents: acute cholecystitis in four, acute pancreatitis in three, biliary pain in three, and cholangitis in two patients. No severe complications occurred. Six (18.8%) patients experienced asymptomatic stent migration. Following stone clearance, four (12.5%) patients experienced stone recurrence, with an average duration of 256 ± 164 days. Conclusion: Biliary stenting appeared to effectively promote the clearance of small common bile duct stones in approximately half of the patients. However, the potential complications and risks of stone recurrence warrant close monitoring. This trial was registered in the Japan Registry of Clinical Trials (jRCT1042200020). [ABSTRACT FROM AUTHOR]

The β phase spinodal decomposition during continuous cooling in Ti‒Nb‒O alloys is investigated by the phase-field method. Addition of only a few at.%O to Ti‒23Nb (at.%) alloy remarkably increases the driving force of the β phase spinodal decomposition. During isothermal heat treatment at 1000 K and 1100 K in Ti‒23Nb‒3O (at.%) alloy, the β phase separates into β1 phase denoted as (Ti)1(O, Va)3 and β2 phase denoted as (Ti, Nb)1(Va)3, resulting in the formation of nanoscale concentration modulation. The phase decomposition progresses in 0.3‒20 ms. In Ti‒23Nb‒XO alloys (X = 1.0, 1.2, 2.0), the spinodal decomposition occurs during continuous cooling with the rate of 500 K s‒1, indicating that the spinodal decomposition occurs during water quenching in the alloys. It is assumed that there is a threshold value of oxygen composition for inducing the spinodal decomposition because it does not occur during continuous cooling in Ti‒23Nb‒0.6O (at.%) alloy. The concentration modulation introduced by the β phase decomposition has significant effect on the β→α” martensitic transformation. Hence, it seems that for controlling microstructure and mechanical properties of Ti‒Nb‒O alloys, careful control of heat treatment temperature and cooling rate condition is required.

Objectives: Endoscopic lithotripsy and elective cholecystectomy, followed by endoscopic retrograde cholangiopancreatography, are the first-line treatments for patients with common bile duct (CBD) stones (CBDS) and gallstones. However, this approach entails acute cholecystitis and recurrent cholangitis risk while patients await surgery. We aimed to identify acute cholecystitis and cholangitis risk factors during the waiting time for elective cholecystectomy., Methods: This study comprised 151 patients with CBDS combined with gallstones who underwent cholecystectomy within 90 days of the first endoscopic retrograde cholangiopancreatography at two tertiary care centers between January 2019 and October 2021., Results: The incidence of biliary tract events (acute cholecystitis, acute cholangitis, or any complications requiring unplanned cholangiopancreatography) was 28% (43 cases). In univariate and multivariate analyses, plastic stent placement as a bridge to surgery for the first treatment of CBDS was an independent risk factor for biliary tract events during the waiting time for surgery (odds ratio 4.25, p = 0.002). A subgroup analysis among those with plastic stent placement revealed a CBD diameter of ≤ 10 mm as an independent risk factor for acute cholecystitis (odds ratio 4.32; p = 0.027); a CBD diameter ≥ 11 mm was an independent risk factor for acute cholangitis and unplanned re-endoscopic retrograde cholangiopancreatography (odds ratio 5.66; p = 0.01)., Conclusions: Plastic stent placement for CBDS before elective cholecystectomy increases the risk of acute cholecystitis or acute cholangitis during the waiting time for elective cholecystectomy., Competing Interests: None., (© 2024 The Authors. DEN Open published by John Wiley & Sons Australia, Ltd on behalf of Japan Gastroenterological Endoscopy Society.)