The 7th Joint Session between JDDW-KDDW-TDDW3(JDDW)
Thu. November 2nd   9:00 - 12:00   Room 10: Portopia Hotel Waraku
JKT3-2
 Development and Clinical Application of a Novel Stent for EUS-Guided Transmural Drainage
Sang Hyub Lee
Department of Internal Medicine and Liver Research Institute, Seoul National University Hospital, Seoul National University College of Medicine
Endoscopic ultrasonography-guided transmural drainage in the pancreaticobiliary field is currently widely used for acute cholecystitis in peripancreatic fluid retention, and has shown great progress in recent years. In the past, a dedicated stent for this procedure was not developed, so a plastic stent inserted into the biliary tract or a tubular metal stent (tubular SEMS) was used. However, tubular SEMS has the disadvantage of low patency and technical difficulty in insertion, and tubular SEMS has the disadvantage of high risk of deviation and possible leakage. Recently, LAMS (Lumen Apposing Metal Stent) was developed as a stent for endoscopic ultrasound-guided transmural drainage to improve these disadvantages. LAMS is a barbell-shaped stent with a very large diameter and short length, and has the advantage of lowering the risk of stent detachment or leakage by bringing the two structures into close contact. It is considered to be superior to conventional stents in pancreatic fluid retention with solid debris as it is advantageous for endoscopic debridement. (1,2) However, for endoscopy beginners with insufficient experience, LAMS procedures are technically difficult, and when stents are placed for a long period of time, there is a risk of adverse reactions such as bleeding or buried LAMS syndrome (3). In the 2018 European Society of Gastrointestinal Endoscopy (ESGE) guidelines, when LAMS is inserted in pancreatic duct break syndrome, it is recommended to remove it within 4 weeks to prevent adverse reactions (4). Tornado stent was developed to overcome these disadvantages.
The Tornado stent ® is a self-expanding, self-expanding, self-expanding metal stent with a double pigtail structure, and is composed of a silicon coating with a metal thread of nitinol (5). The characteristic pig tail structure on both ends is in the form of a flexible spiral, which is designed to minimize the risk of proximal or distal stent detachment. The diameter of the stent is 8 mm, and the length is 22 cm when inside the delivering catheter, 14 cm when the outer sheath is removed during deployment, and 6 cm after the stent is fully deployed and has a spiral shape. Through this design, it is expected that the disadvantages of existing stents can be supplemented. Compared to plastic stents, it has a wider diameter, enabling effective drainage. Compared to tubular SEMS, the flexible spiral pigtail structure reduces the risk of stent detachment. Compared to LAMS, the stent is more flexible, making it easier to remove the stent after fistula formation and the risk of serious adverse events such as buried LAMS syndrome or hemorrhage is expected to be low. Recently, an animal experiment was conducted to evaluate the feasibility and safety of ultrasound-guided transmural drainage using a tornado stent. Eight mini pigs (Sus Scrofa) underwent gastro-cholecystectomy using Tornado stent under ultrasound endoscopic guidance, and were followed up for 28-49 days. Technical success was confirmed in all 8 test animals, and patency of the stent was confirmed in all 8 animals in follow-up endoscopy after 28-49 days, and the stent could be easily removed using a snare. There were no adverse reactions such as stent detachment, and a microscopic endoscope was inserted through the fistula to enter the gallbladder. Recently, the use of the Tornado stent has begun in clinical practice, and in the near future, it is expected that the range of use will be expanded to clinical studies to prove its role as a stent in lowering the risk of complications in ultrasound-guided transmural drainage.
References
1. Shah RJ, Shah JN, Waxman I, Kowalski TE, Sanchez-Yague A, Nieto J, et al. Safety and efficacy of endoscopic ultrasound-guided drainage of pancreatic fluid collections with lumen-apposing covered self-expanding metal stents. Clin Gastroenterol Hepatol. 2015;13(4):747-52.
2. Siddiqui AA, Kowalski TE, Loren DE, Khalid A, Soomro A, Mazhar SM, et al. Fully covered self-expanding metal stents versus lumen-apposing fully covered self-expanding metal stent versus plastic stents for endoscopic drainage of pancreatic walled-off necrosis: clinical outcomes and success. Gastrointest Endosc. 2017;85(4):758-65.
3. Bang JY, Hasan M, Navaneethan U, Hawes R, Varadarajulu S. Lumen-apposing metal stents (LAMS) for pancreatic fluid collection (PFC) drainage: may not be business as usual. Gut. 2017;66(12):2054-6.
4. Arvanitakis M, Dumonceau JM, Albert J, Badaoui A, Bali MA, Barthet M, et al. Endoscopic management of acute necrotizing pancreatitis: European Society of Gastrointestinal Endoscopy (ESGE) evidence-based multidisciplinary guidelines. Endoscopy. 2018;50(5):524-46.
5. Huh G, Choi JH, Lee SH, Paik WH, Ryu JK, Kim YT, et al. Innovation of EUS-guided transmural gallbladder drainage using a novel self-expanding metal stent. Sci Rep. 2020;10(1):11159.
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