Optimal Timing of Endoscopic Intervention in the Treatment of Chronic Pancreatitis.

Chronic pancreatitis（CP）is a chronic progressive fibro-inflammatory disease of the pancreas induced by a wide range of factors including genetic and environmental elements, with recurrent abdominal pain and pancreatic secretion insufficiency as its major clinical signs. Chronic pancreatitis is not only a tough disease of the gastrointestinal system but also a worldwide medical problem. At present, the MESS (medicine-extracorporeal shock wave lithotripsy-endoscopic retrograde cholangiopancreatography-surgery）formed by changhai hospital in CP diagnosis and treatment is gradually becoming mature, and the clinical effect of this system is obvious. However, there are still some difficulties and knowledge gaps in the clinical treatment of CP. Currently, it is recommended by both domestic and foreign guidelines that ERCP combined with ESWL as the first-line treatment pattern for patients with chronic pancreatitis associate pain. It has previously been observed that ERCP performed less than 2 days after ESWL may be more likely to fail, possibly owing to ESWL-induced edema. However, there is no high-quality research to demonstrate how to choose the most optimal timing of ERCP after ESWL for patients with indications for endoscopic treatment. This prospective, randomized controlled research has therefore aimed to determine the most optimal timing of ERCP after ESWL. Patients with painful chronic pancreatitis and pancreatic stones larger than 5 mm in diameter will be randomly and equally assigned to two groups, which are divided according to the time interval between ESWL and ERCP, including the same day (< 12 hours) subgroup and the next day ( ≥12 hours) subgroup. The cannulation success rate and stone clearance rate of the pancreatic duct will be assessed in each group to explore the most appropriate timing of ERCP, and then provide an important reference basis for the clinical treatment of chronic pancreatitis.

Inclusion criteria

• symptomatic adult patients diagnosed with chronic pancreatitis and main pancreatic duct positive stones（>5mm in diameter）
• no ERCP and ESWL history before the admission
• provides informed consent

Exclusion criteria

• suspected to have malignant tumors;
• history of pancreatic surgery or gastrojejunostomy (Billroth II);
• with end-stage disease;
• with contraindications to ESWL or ERCP, such as pregnancy, abdominal aortic aneurysm, etc.
• acute pancreatitis within 3 days
• pancreatic ascites