Clinical Study On Percutaneous Covered Metal Stent-assisted Minimally Invasive Drainage For Infected Pancreatic Necrosis

Infected pancreatic necrosis(IPN)is a mid-to-late local complication of severe acute pancreatitis,which greatly affects the prognosis of patients.Compared with traditional open pancreatic necrosectomy,the step-up minimally invasive drainage significantly improves the prognosis of patients with IPN and has become the standard treatment for IPN.The "four-step"step-up minimally invasive drainage adopted by our center has some problems in clinical practice,such as the difficulty of indwelling the double cannula,patients experiencing severe pain,and longer waiting time for percutaneous endoscopic debridement to increase patients’length of hospital stay.The covered self-expanding metal stent has a large inner diameter,which allows self-made double cannula and endoscopes to pass through its cavity into the pus cavity.However,whether it can solve the problems encountered in our clinical practice,which is lack of related reports and research.Therefore,the following two parts are used to study the role of covered metal stent in the establishment of sinus tract for percutaneous continuous negative pressure drainage and the effect of its application in patients with IPN through the following two parts:PART1The Before and After Controlled Study on the Efficacy and Efficiency of Covered Metal Stent-assisted Percutaneous Endoscopic Necrosectomy Background and Aim:Stent-assisted percutaneous endoscopic necrosectomy(SAPEN)is an alternative option for surgical necrosectomy,but the theoretical advantages to this procedure remain unproven.The aim of this study is to explore the efficacy and efficiency of SAPEN in patients with IPN.Methods:This is a retrospective,before-and-after controlled cohort study.All IPN patients admitted to our cente from Jan 2015 to Dec 2018 were screened for eligibility.Patients were divided into the before group(without a percutaneous metal stent)and the after group(with a percutaneous metal stent)based on whether a percutaneous metal stent was placed.Demographic characteristics,clinical outcomes and endoscopic management endpoints of the two groups were analyzed.The primary endpoint was a composite of major complications and/or death.Other outcomes include individual components of the primary endpoint,new-onset sepsis,length of hospital stay,pancreatic fistula,the frequency and waiting time of endoscopic debridement,etc.Results:There were 73 patients who underwent standard surgical step-up approach(Before group)and 37 patients who had SAPEN(After group)included for analysis.The introduction of the SAPEN procedure failed to reduce the incidence of the primary endpoint(35%versus 52%,p=0.095).However,significant shorter length of hospital stays(38 versus 48 days,p=0.035)and lower incidence of new-onset sepsis were observed in the After group(35%versus 56%,p=0.037).There was no significant difference in the number of endoscopic debridement and the success rate of clinical treatment between the two groups,and the waiting time for endoscopic debridement in After group was significantly shortened(median:3 days versus 8 days,p<0.0001).Conclusions:In conclusion,Although the application of FCSEMS in percutaneous endoscopic necrosectomy procedure for patients with IPN could not reduce the mortality and the incidence of major complications,could shorten length of hospital stay,decrease new-onset sepsis,and allow earlier percutaneous endoscopic debridement.PART2Effects of covered metal stent on pain experience and post-operative inflammatory response in patients with infected pancreatic necrosis in the establishment of sinus tract for percutaneous continuous negative pressure drainage:a pilot studyBackground and Aim:In the clinical application of percutaneous minimally invasive step-up approach,there are still some problems,such as double cannula is difficult or fail to place,and patients experience severe pain during the operation.Therefore,the purpose of this study was to investigate whether fully covered self-expanding metal stent(FCSEMS)could increase the success rate of the placement of double cannula,relieve patients’ pain and the postoperative inflammatory response.Methods:During the 2-months study period,clinical data of patients who met the inclusion/exclusion criteria were collected prospectively and continuously.Patients are divided into a covered metal stent group and a non-covered metal stent group according to whether the application of covered metal stent or not Analyze the demographic and clinical baseline characteristics of the two groups of patients,compare the success rate of the placement of double cannula the Numerical Rating Scale(NRS)score and Behavioral Pain Scale(BPS)score during the placement of the covered metal stent or double cannula,the time of operation,the interruption times of operation,changes in SOFA score and inflammatory response indicators(SIRS score,PCT,CRP)on one day before and after operation and complications associated with indwelling of covered metal stents or double cannula.Results:At the end of the 2-month study period,7 patients were collected in each group.There were no differences in clinical baseline data between the two groups of patients.Seven patients in the covered metal stent group successfully placed double cannula,while three patients in the non-covered metal stent group failed to place double cannula for the first time.During the placement of the covered metal stent or double cannula,patients with the covered metal stent had lower NRS scores(median,4 Vs 7,P=0.002)and fewer the interruption times of operation(median,1 Vs 3,P=0.048),the time of operation is shortened(median,170 seconds Vs 236 seconds,P=0.026).Only 1 patient in the covered metal stent group had postoperative CRP elevation,and no patient had PCT elevation after operation,while 6 patients in the non-covered metal stent group had postoperative CRP elevation and 3 patients had PCT elevation after operation.Conclusion:The introduction of covered metal stent during the establishment of sinus tract for continuous negative pressure drainage in IPN patients can alleviate the patients’ painful experience during operation and the post-operative inflammatory response.The application of covered metal stent can assist the placement of double cannula and facilitate the process of operation.