The aim of this study is to investigate a new pancreaticojejunal (PJ) anastomosis procedure named "One-layer duct-to-mucosa pancreaticojejunostomy" in pancreatoduodenectomy, which could provide a feasible option to pancreatic surgeons for patients with pancreaticoduodenectomy.

Pancreaticoduodenectomy is a standard surgical approach for resectable pancreatic tumors and periampullary tumors. It is considered a safe procedure resulting from the continuous improvement in surgical techniques over the years. Although postoperative mortality has obviously decreased, pancreatic fistula is still a major challenge in pancreatic surgery and remains the major cause of postoperative morbidity and mortality after pancreaticoduodenectomy(PD), ranging from 3% to 30%.

Many risks factors have been shown to cause pancreatic fistula(PF) after the operation, including advanced age, prolonged operation time, intraoperative hemorrhage, BMI, soft pancreas, size of the main pancreatic duct and texture of the remnant pancreas. Among them, soft pancreatic texture without a dilated main pancreatic duct is regarded as the most important risk factor in predicting pancreatic fistula.

The serious consequences of pancreatic fistula result from the pancreatic juice becoming activated by the bile and intestinal fluid, which will eventually corrupt the PJ anastomosis and the surrounding normal tissues. The corrosion of the vasculature will lead to lethal hemorrhage, which is the main cause of mortality after pancreaticoduodenectomy. Furthermore, pancreatin, together with the bacteria in the alimentary tract, will lead to intra-abdominal infection and abscess. To reduce the pancreatic fistula rate, several techniques have been described as alternatives to the conventional PJ anastomosis. Duct-to-mucosa sutures, binding pancreaticojejunostomy and end-to-side invaginated fashion are widely used in the current clinical setting. Some non-randomized studies showed that the one-layer duct-to-mucosa method was a relatively safe approach. However, the prospective clinical study found that in comparison with the conventional two-layer duct-to-mucosa did obviously decrease the incidence of pancreatic fistula as well as other operative complications. The postoperative pancreatic fistula (POPF), which determines postoperative mortality, length of hospital stay， is dependent of its definition, and is reported in up to 16% of patients. The purpose of this study is to determine whether the new anastomosis called " one-layer duct-to-mucosa " pancreaticojejunostomy can reduce the POPF rate and downgrade compared with the common accepted duct-to-mucosa pancreaticojejunostomy after pancreaticoduodenectomy. This single-centre, open, randomized controlled trail is conducted following International Study Group on Pancreatic Fistula (ISGPF) criteria for pancreatic fistula (PF). The primary endpoint is the POPF rate, and others include overall postoperative complication rate and their severity reoperation rate and hospital stay.

Inclusion Criteria:

• Both male and female, aged 18 to 80;
• Patients scheduled to undergo pancreaticoduodenectomy;
• Provided written informed consent;

Exclusion criteria:

• Patients with severe cardiopulmonary disorder that might prolong the postoperative hospital stay;
• Patients who had a previous pancreatic operation;
• Patients with an immunodeficiency;
• Patients who underwent an emergency operation;
• Pregnant patients.