Cholecystectomy 7 days vs 4 weeks after mild biliary pancreatitis; looking a decrease the incidence of persistent choledocholithiasis and ERCP: A multicentric randomized clinical trial.

BACKGROUND: Mild acute biliary pancreatitis (MABP) requires definitive treatment of the cholelithiasis to avoid recurrent biliary events. Recent publications recommend performing early surgery to prevent readmissions. However, an exceedingly early cholecystectomy could imply missing the presence of persistent choledocholithiasis or requiring a significant number of preoperative endoscopic retrograde cholangiopancreatographies (ERCP). This multicentre randomized clinical trial compares early surgery performed a week after MABP with delayed surgery (at 4 weeks), to compare readmission rates for recurrent biliary events and the incidence of residual choledocholithiasis between the two groups. MATERIALS AND METHODS: A total of 198 patients with a first episode of MABP defined by the Atlanta 2012 criteria were enrolled. Randomization was done by a central study coordinator: 98 to early surgery and 100 to delayed surgery. All of them had preoperative or intraoperative imaging to exclude persistent choledocholithiasis. Laparoscopic cholecystectomy was performed by dedicated teams of experienced surgeons. RESULTS: Early surgery reduced the rate of readmissions for biliary events before cholecystectomy by half (7.2% vs 15.8%, p = 0,058). There were no differences in the type of surgery, postoperative stay, or complications compared with delayed surgery. Choledocholithiasis was observed in 9.0% of patients in the early group and 7.7% in the delayed group (p 0,719). The preoperative or intraoperative imaging study avoided unnecessary ERCP, which was performed in only 6 (3%) patients. CONCLUSIONS: Early cholecystectomy performed seven days after resolution of MABP had a low incidence of recurrent biliary events and complications, and was not associated with an increase in residual choledocholithiasis or need for unnecessary ERCP.

Effect of Pr in CO2 Methanation Ru/CeO2 Catalysts.

CO2 methanation has been studied with Pr-doped Ru/CeO2 catalysts, and a dual effect of Pr has been observed. For low Pr content (i.e., 3 wt %) a positive effect in oxygen mobility prevails, while for high Pr doping (i.e., 25 wt %) a negative effect in the Ru-CeO2 interaction is more relevant. Isotopic experiments evidenced that Pr hinders the dissociation of CO2, which takes place at the Ru-CeO2 interface. However, once the temperature is high enough (200 °C), Pr improves the oxygen mobility in the CeO2 support, and this enhances CO2 dissociation because the oxygen atoms left are delivered faster to the support sink and the dissociation sites at the interface are cleaned up faster. In situ Raman spectroscopy experiments confirmed that Pr improves the creation of oxygen vacancies on the ceria lattice but hinders their reoxidation by CO2, and both opposite effects reach an optimum balance for 3 wt % Pr doping. In addition, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments showed that Pr doping, regardless of the amount, decreases the population of surface carbon species created on the catalysts surface upon CO2 chemisorption under methanation reaction conditions, affecting both productive reaction intermediates (formates and carbonyls) and unproductive carbonates.