梁侧生根型多管支架的计算与分析

合理地设计支吊架,对于化工和医药管道安装具有重要意义。针对工程常用的梁侧生根型多管支架的结构型式进行描述,并详细介绍了单层多管支架和多层多管支架的计算方法,可作为该类型管架设计的理论参考。

Endoscopic management of occluded biliary uncovered metal stents:A multicenter experience

AIM:To compare diverse endoscopic interventions in the management of occluded uncovered self-expanding metal stents(SEMSs) that had been placed for palliative treatment of unresectable malignant biliary obstruction.METHODS:A retrospective review was undertaken in 4 tertiary endoscopic centers to determine optimal management of different types of occluded SEMSs.The technical success of performed treatment in occluded SEMSs,the patency of the stent,the need for re-intervention and the financial costs of each treatment were analyzed.RESULTS:Fifty four patients were included in the analysis;21 received Hanaro,19 Wallstent and 14 Flexus.For the relief of obstruction,a plastic stent was inserted in 24 patients,a second SEMS in 25 and mechanical cleaning was performed in 5 patients.The overall median second patency rates between second SEMSs and plastic stents did not differ(133 d for SEMSs vs 106 d for plastic stents;P = 0.856).Similarly,no difference was found between the overall survival of SEMS and plastic stent groups,and no procedure-related complications occurred.Incremental cost analysis showed that successive plastic stenting was a cost-saving strategy at least in Greece.CONCLUSION:Insertion of uncovered SEMSs or plastic stents is a safe and effective treatment for occluded uncovered SEMSs;insertion of plastic stents appears to be the most cost-effective strategy.

Repair of bile duct defect with degradable stent and autologous tissue in a porcine model

AIM： To introduce and evaluate a new method to re- pair bile duct defect with a degradable stent and au- tologous tissues. METHODS： Eight Ba-Ma mini-pigs were used in this study, Experimental models with common bile duct （CBD） defect （0,5-1,0 cm segment of CBD resected） were established and then CBD was reconstructed by duct to duct anastomosis with a novel degradable stent made of poly [sebacic acid-co-（1,3-propanediol）-co- （1,2-propanediol）]. In addition, a vascularized greater omentum was placed around the stent and both ends of CBD. Cholangiography via gall bladder was per- formed for each pig at postoperative months 1 and 3 to rule out stent translocation and bile duct stricture. Complete blood count was examined pre- and post- operatively to estimate the inflammatory reaction. Liver enzymes and serum bilirubin were examined pre- and post-operatively to evaluate the liver function. Five pigs were sacrificed at month 3 to evaluate the healing of anastomosis. The other three pigs were raised for one year for long-term observation. RESULTS： All the animals underwent surgery success- fully. There was no intraoperative mortality and no bile leakage during the observation period, The white blood cell counts were only slightly increased on day 14 and month 3 postoperatively compared with that before operation, the difference was not statistically significant （P = 0.652）. The plasma level of alanine aminotrans- ferase on day 14 and month 3 postoperatively was also not significantly elevated compared with that before operation （P = 0.810）. Nevertheless, the plasma level of y-glutamyl transferase was increased after opera- tion in both groups （P = 0.004）, especially 2 wk after operation. The level of serum total bilirubin after opera- tion was not significantly elevated compared with that before operation （P = 0.227）, so did the serum direct bilirubin （P = 0.759）. By cholangiography yia gall blad- der, we found that the stent maintained its integrity of shape and was stillin situ at month 1, and it disap- peared completely at month 3. No severe CBD dilation and stricture were observed at both months 1 and 3. No pig died during the 3-too postoperative observation period. No sign of necrosis, bile duct stricture, bile leak- age or abdominal abscess was found at reoperation at month 3 postoperatively. Pigs had neither fragments of stent nor stones formed in the CBD. Collagen deposit was observed in the anastomosis by hematoxylin and eosin （HE） and Masson＇s trichrome stains. No severe cholestasis was observed in liver parenchyma by HE staining. Intestinal obstruction was found in a pig 4 mo after operation, and no bile leakage, bile duct stricture or biliary obstruction were observed in laparotomy. No sign of bile duct stricture or bile leakage was observed in the other two pigs. CONCLUSION： The novel method for repairing bile duct defect yielded a good short-term effect without postoperative bile duct stricture. However, the long- term effect should be further studied.

INTRAVASCULAR ULTRASOUND EVALUATING CORONARY STENTS FOR PATIENTS WITH CORONARY ARTERY DISEASE：COMPARED OLD WITH NEW MULTILINK STENTS

Objective.It was suggested that coronary stent design and coating may affect stent performance and hence induce varying degrees of thrombogenesis and neointimal hyperplasia.T he purpose of this study is to compare the6-month follow-up results between o ld and new Multilink stents with the method of intravascular ultrasound(IVUS)imaging.Methods.We have performed old(n =40)and new(n =35)Multilink stent implantations on 75patients with coronary artery disease.Coron ary angiography was performed before,immediately after,and 6months after the in-stent procedure respectively.Six-month follow-up IVUS imaging was performed and analyzed off-line.Results.Minimal lumen cross sectional area(CSA)of new Multilink stents was signific antly larger than that of old Multilink stents(P=0.0053).Mean stent lumen area of new Multili nk stents was significantly larger than that of old Multilink stents(P=0.040).Similarly,minimal lumen diameter(MLD)of new Multilink stents was larger than that of old Mul tilink stents(P=0.011).Old Multilink stents had a higher percentage of plaque area than new Multilink stent s.Conclusion.The new Multilink stent is obviously superior to old Multilink stents,in particular,in the stent MLD and lumen CSA---major determinants of the restenosis.