Clinical Evaluation of Enteral-extended Anti-reflux Stents for Pancreatic Pseudocyst

At present, endoscopic therapy is the preferred method to solve biliary or pancreatic diseases. And EUS-guided stent implantation and drainage of pancreatic pseudocyst is the main method in Endoscopic treatment of pancreatic pseudocyst. However, blockage of stent is a problem that has puzzled endoscopists for a long time. The mechanism of stent blockage is related to the reflux of gastrointestinal contents into the stent. Although plastic stents are widely used in patients who needed drainage. However, the average free time for stent is only 77 to 126 days, leading to the need for stent replacement in most patients within 3 months. As one end of the double pigtail stent used for drainage of pancreatic pseudocyst may be located in the stomach, it may cause the stent to be blocked by the contents of the stomach. Therefore, multiple stents or additional stents or drainage tube are often needed to further strengthen the drainage. It seems that the mechanism of stent blockage are associated with gastrointestinal contents reflux. And stents required be replaced again by endoscopic approach when jamming. However, EUS and ERCP are difficult, costly, and may be with complications. Additional operations will increase the risks and costs. Therefore, a stent that can effectively prevent reflux, solve clinical problems, and effectively prolong stent patency time is urgently needed.

At present, endoscopic therapy is the preferred method to solve biliary or pancreatic diseases. And EUS-guided stent implantation and drainage of pancreatic pseudocyst is the main method in Endoscopic treatment of pancreatic pseudocyst. However, blockage of stent is a problem that has puzzled endoscopists for a long time. The mechanism of stent blockage is related to the reflux of gastrointestinal contents into the stent. Although plastic stents are widely used in patients who needed drainage. However, the average free time for stent is only 77 to 126 days, leading to the need for stent replacement in most patients within 3 months. As one end of the double pigtail stent used for drainage of pancreatic pseudocyst may be located in the stomach, it may cause the stent to be blocked by the contents of the stomach. Therefore, multiple stents or additional stents or drainage tube are often needed to further strengthen the drainage. It seems that the mechanism of stent blockage are associated with gastrointestinal contents reflux. And stents required be replaced again by endoscopic approach when jamming. However, EUS and ERCP are difficult, costly, and may be with complications. Additional operations will increase the risks and costs. Therefore, a stent that can effectively prevent reflux, solve clinical problems, and effectively prolong stent patency time is urgently needed. The extended enteral anti-reflux stent developed by our research team has potential advantages in prolonging the patency period of the stent and preventing secondary infection of pseudocysts. In this study, we aim to evaluate the effect of the stent on the drainage of pancreatic pseudocyst.

Inclusion Criteria: Pancreatic pseudocyst by a variety of causes, including acute pancreatitis, chronic pancreatitis, drug-induced pancreatitis Pseudocyst compressed gastrointestinal or bile duct and causes obstruction symptoms or causes other symptoms Diameter of pseudocyst >6 cm with no compression symptoms, but progressively increases and is failed to conservatively treat Exclusion Criteria: Wall-off necrosis with liquidation mimics pseudocyst Pseudocyst formation ≤8 weeks, cyst wall is immature Cannot puncture by EUS-guided approach for any reason Patients with serious cardiovascular or cerebrovascular diseases or other diseases which are not fitted to anaesthetize Severe coagulopathy or thrombocytopenia

Reddy DN, Banerjee R, Choung OW. Antireflux biliary stents: are they the solution to stent occlusions? Curr Gastroenterol Rep. 2006 Apr;8(2):156-60. doi: 10.1007/s11894-006-0012-x.

Pedersen FM, Lassen AT, Schaffalitzky de Muckadell OB. Randomized trial of stent placed above and across the sphincter of Oddi in malignant bile duct obstruction. Gastrointest Endosc. 1998 Dec;48(6):574-9. doi: 10.1016/s0016-5107(98)70038-0.

van Berkel AM, Boland C, Redekop WK, Bergman JJ, Groen AK, Tytgat GN, Huibregtse K. A prospective randomized trial of Teflon versus polyethylene stents for distal malignant biliary obstruction. Endoscopy. 1998 Oct;30(8):681-6. doi: 10.1055/s-2007-1001388.

Walter D, Will U, Sanchez-Yague A, Brenke D, Hampe J, Wollny H, Lopez-Jamar JM, Jechart G, Vilmann P, Gornals JB, Ullrich S, Fahndrich M, de Tejada AH, Junquera F, Gonzalez-Huix F, Siersema PD, Vleggaar FP. A novel lumen-apposing metal stent for endoscopic ultrasound-guided drainage of pancreatic fluid collections: a prospective cohort study. Endoscopy. 2015 Jan;47(1):63-7. doi: 10.1055/s-0034-1378113. Epub 2014 Sep 30.

Aburajab M, Smith Z, Khan A, Dua K. Safety and efficacy of lumen-apposing metal stents with and without simultaneous double-pigtail plastic stents for draining pancreatic pseudocyst. Gastrointest Endosc. 2018 May;87(5):1248-1255. doi: 10.1016/j.gie.2017.11.033. Epub 2017 Dec 9.

Brimhall B, Han S, Tatman PD, Clark TJ, Wani S, Brauer B, Edmundowicz S, Wagh MS, Attwell A, Hammad H, Shah RJ. Increased Incidence of Pseudoaneurysm Bleeding With Lumen-Apposing Metal Stents Compared to Double-Pigtail Plastic Stents in Patients With Peripancreatic Fluid Collections. Clin Gastroenterol Hepatol. 2018 Sep;16(9):1521-1528. doi: 10.1016/j.cgh.2018.02.021. Epub 2018 Feb 21.