Extended Pancreatic Neck Transection Versus Conventional Pancreatic Neck Transection During Laparoscopic Pancreaticoduodenectomy( LPDEXCEPT)

Inclusion Criteria: 1. Patients with benign or resectable malignant tumors of the lower common bile duct, Vater ampulla, head or uncinate process of the pancreas. 2. 18 years old \< age \< 80 years old, no gender limit. 3. Patient is expected survival beyond 3 months. 4. No pregnancy or pregnancy plan within 3 months after surgery. 5. Nutrition risk score \<3 according to the Nutritional Risk Screening for Inpatients 2002 (NRS2002) standard score. 6. No contraindication to surgery for anesthetic evaluation. 7. The subjects voluntarily joined the study and signed an informed consent form, with good compliance and cooperation with follow-up. Exclusion Criteria: 1. Patients with borderline resectable and unresectable malignancies. 2. Patients undergoing neoadjuvant chemotherapy or radiotherapy. 3. Patients with tumors exceeding the level of the gastroduodenal artery as measured by preoperative radiography. 4. Intraoperative exploration reveals tumor adhesions with portal vein-superior mesenteric vein, requiring revascularization and reconstruction. 5. Operation transfers to open. 6. Operation transfers to other procedure. 7. The main pancreatic duct can not be found intraoperatively, the duct-to-mucosa pancreaticojejunostomy can not be operated.