[Efficacy and safety analysis of an improved overlength biliary stent in the treatment of biliary stricture].

Objective: To evaluate the efficacy and safety of an improved overlength biliary stent in the treatment of bile duct stricture. Methods: Prospective randomized controlled study. Patients with bile duct stricture in Peking University International Hospital from February 2016 to June 2021 were randomly divided into the conventional plastic biliary stents (CPBS) group and the improved overlength biliary stents (IOBS) group by envelope random method. CPBS or IOBS were placed after endoscopic retrograde cholangiopancreatography (ERCP) breast catheterization was successfully conducted and the stenosis length was determined by angiography. The incidence of postoperative complications, median patency time of postoperative stent and reoperation rate within 6 months were compared between the two groups, Kaplan-Meier method was used to draw the survival curve, and log-rank test was conducted to evaluate the safety and efficacy of IOBS in the treatment of bile duct stricture. Results: A total of 90 patients were included. There were 45 patients in IOBS group, including 28 males and 17 females, aged (67.2±11.7) years. There were 45 patients in CPBS group, including 26 males and 19 females, aged (64.6±14.4) years. The patients in the both groups were balanced and comparable. There were no significant differences in success rate of operation, operation time, hospitalization time, operation cost and prospective complication rate between the two groups (all P>0.05). There were no significant differences in the changes of liver function index before and 72 hours after operation between the two groups (both P>0.05). The median patency time of stents in IOBS group was longer than that in CPBS group [M(Q1, Q3), 201(155,246) vs 109(55,167) d, P=0.002].The IOBS group had lower reoperation rate than the CPBS group within 6 months [46.2% (18/39) vs 78.9%(30/38), P=0.003]. Conclusion: IOBS has good safety in the treatment of bile duct stricture and the clinical efficacy is superior to CPBS.

1079.5- and 1341.4-nm: larger energy from a dual-wavelength Nd:YAIO(3) pulsed laser.

On the basis of oscillation conditions of simultaneous multiple-wavelength lasing that we have established, a larger-energy (1079.5 and 1341.4 nm) dual-wavelength Nd:YAlO(3) pulsed laser has been developed. Output energies of 3.71 and 1.39 J with efficiencies of 1.29% and 0.48% for the 1341.4-and 1079.5-nm wavelengths, respectively, have been achieved. To our knowledge, this is the best result among simultaneous dual-wavelength solid-state lasers to date. The temporal and spatial distributions of these beams obtained from a free-running dual-wavelength Nd:YAlO3 pulsed laser have also been measured. Experimental results show that the temporal and spatial overlap of the two beams is quite good for this type of laser.