Effect of ice water injection toward the duodenal papilla for preventing post-ERCP pancreatitis: study protocol for a multicenter, single-blinded, randomized controlled trial (EUTOPIA study)

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is an essential procedure in the diagnosis and treatment of biliopancreatic diseases. The most common adverse event of ERCP is post-ERCP pancreatitis (PEP), which can sometimes be severe. Our previous study suggested that injecting ice water at the end of ERCP suppressed PEP, and we decided to investigate this effect in a multicenter randomized controlled trial. METHODS: This study is being conducted at eight hospitals in Japan starting in April 2022. Patients undergoing ERCP will be randomized to ice water group and control group. In the ice water group, 250 ml of ice water is injected toward the papilla at the end of ERCP. The next morning, a physical examination and blood tests are performed to evaluate for the development of pancreatitis. The goal is to have 440 cases in each group. DISCUSSION: The main cause of PEP is thought to be papilla edema. Cooling the papilla, as everyone naturally does at the time of a burn, is expected to prevent its inflammation and edema. Various methods to suppress PEP have been reported, but so far none of them are reliable. The method we have devised is very simple, easy, and safe. We hope that our study will change the world's ERCP common practice. Trial registration:UMIN000047528. Registered 20 April 2022, https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000053209