Analysis Of Curative Effect And Complications Of Different Metal Stents In The Treatment Of Unresectable Distal Malignant Biliary Obstruction

Objective:To compare the efficacy and complications of fully covered self-expanding metal stent(FCSEMS)and uncovered self-expanding metal stent(USEMS)in the treatment of unresectable distal malignant biliary obstruction(DMBO).Methods:A total of 310 patients who received endoscopic biliary metal stent treatment in the General Hospital of the Northern Theater were included in this study.All patients were definitely diagnosed as malignant biliary obstruction with obstructive jaundice and could not be treated surgically.According to the type of stent,it was divided into FCSEMS group(235 cases)and USEMS group(75 cases).Inclusion criteria:over 18years old;pathological or imaging diagnosis of distal malignant biliary obstruction.The blood biochemical indexes,stent patency time,patient survival time and complication rate of FCSEMS group and USEMS group were compared by using statistical software.Single factor and multiple factor analysis were used to determine the relevant factors of stent patency.Results:A total of 310 patients with DMBO underwent placement of biliary metal stent under endoscopic retrograde cholangiopancreatography(ERCP).The blood biochemical indexes of USEMS group and FCSEMS group decreased significantly after operation compared with that before operation(P<0.05).The median stent patency time was 445days(95%CI,329-560 days)in the FCSEMS group and 348 days(95%CI,102-594days)in the USEMS group.The stent patency time in the FCSEMS group was significantly longer than that in the USEMS group(P=0.020).There was no significant difference in survival time between the USEMS group and the FCSEMS group(P=0.566),respectively.There was no significant difference in the incidence of complications such as acute pancreatitis,cholecystitis,cholangitis,postoperative hemorrhage,stent obstruction and stent migration between the two groups(P>0.05).We also further analyzed the factors affecting stent patency.Multivariate analysis of the COX risk proportional model showed that EST(HR 1.259,95%CI[1.679-1.358],P<0.001),USEMS(HR 2.277,95%CI[1.750-2.963],P<0.001),stent length>70mm(HR 1.804,95%CI[1.662-1.959],P<0.001),and pre-operative biliary stent(HR 1.166,95%CI[1.070-1.271],P<0.001),non-pancreatic cancer(HR 1.404,95%CI[1.299-1.516],P<0.001)were independent risk factors affecting stent patency.BMI>24kg/m~2(HR 0.600,95%CI[0.548-0.657],P<0.001)was a protective factor affecting stent patency.Conclusion:Our study found that in the treatment of distal malignant biliary obstruction,the blood biochemical indexes of FCSEMS group and USEMS group were significantly improved after stent implantation.There was no statistically significant difference in total survival time between the two groups of patients,but the patency time of FCSEMS stents was significantly better than that of USEMS.Further regression analysis showed that EST,USEMS,stent length>70mm,Pre-operative biliary stent and non-pancreatic cancer were independent risk factors affecting stent patency,while BMI>24 kg/m~2was a protective factor.There was no statistical difference between the two groups in the incidence of complications including pancreatitis,cholecystitis,cholangitis,postoperative hemorrhage,stent obstruction and stent migration.