Re-intervention Study Of Uncovered Self-expandable Metal Stent Dysfunction In Patients With Malignant Distal Biliary Stricture

Objective To compare the clinical efficacy and safety of plastic stent（PS）,uncovered self-expandable metal stent（USEMS）and covered self-expandable metal stent（CSEMS）in the re-intervention treatment of USEMS stent dysfunction in patients with malignant distal biliary stricture.Methods The clinical data of patients with USEMS stent dysfunction in malignant distal biliary stricture in the Department of Gastroenterology of Hangzhou first people’s Hospital from January 2016 to June 2021 were analyzed retrospectively.After USEMS dysfunction,another plastic or metal stent was placed in the original dysfunctional USEMS.A total of 57 patients met the inclusion criteria.According to the type of the secondary stent,the patients were divided into PS group,USEMS group and CSEMS group.The blood biochemical indexes,secondary stents patency time,secondary stents patency rate and complication rate in the three groups were compared by statistical software to evaluate their efficacy and safety.Results A total of 57 patients were included in the study,including PS group（32 cases）,USEMS group（17 cases）and CSEMS group（8 cases）.There was no significant difference in baseline data among the three groups（P>0.05）.After endoscopic re-intervention,the blood biochemical indexes were significantly decrease compared with before re-intervention（P<0.05）,except for the decrease of ALT and AST.In addition,except for alkaline phosphatase,there was no significant difference in blood biochemical indexes among the three groups before and after operation（P>0.05）.The secondary stents patency time and patency rate in CSEMS group were significantly better than those in PS group（P=0.005）.The secondary stents patency time and patency rate in USEMS group was significantly higher than that in PS group（P=0.033）.But there was no significant difference between CSEMS group and USEMS group（P=0.114）.Multivariate COX risk analysis showed that the risk of stent obstruction in CSEMS group was 0.184 times higher than that in PS group（P=0.003）.There was no significant difference in the risk ratio between USEMS group and PS group（P>0.05）.The incidence of hyperamylasemia in CSEMS group was significantly higher than that in other groups（P=0.04）.There was no significant difference in the incidence of cholangitis,postoperative pancreatitis,bleeding,perforation and death among the three groups（P>0.05）.Conclusion Endoscopic placement of PS,USEMS or CSEMS in the original stent is a safe and effective minimally invasive therapy for USEMS dysfunction in patients with malignant distal biliary stricture,and those short-term effects are similar.In the selection of secondary stents,CSEMS has a better long-term effect,and has obvious advantages over PS and USEMS in patency time and long-term patency rate.For patients with long expected survival,CSEMS can be used as the suprior choice for secondary stent placement.