Comparing Laparoscopic and Open Pancreaticoduodenectomy for Nonpancreatic Periampullary Adenocarcinomas

Inclusion Criteria: 1. Age between 18 years and 75 years. 2. Histologically confirmed NPPC or clinically diagnosed NPPC by an MDT without histopathologic evidence. 3. Patients feasible to undergo both LPD and OPD ac- cording to MDT evaluations. 4. Patients understanding and willing to comply with this trial. 5. Provision of written informed consent before patient registration. 6. Patients meeting the curative treatment intent in ac- cordance with clinical guidelines. Exclusion Criteria: 1. Patients with distant metastases, including peritone- al, liver, distant lymph node metastases and involve- ment of other organs. 2. Patients requiring left, central or total pancreatecto- my or other palliative surgery. 3. Preoperative American Society of Anaesthesiologists (ASA) score ≥4. 4. History of other malignant disease 5. Pregnant or breastfeeding women. 6. Patients with serious mental disorders 7. Patients treated with neoadjuvant therapy. 8. Patients with vascular invasion and requiring vascular resection as evaluated by the MDT team according to abdominal imaging data. 9. Body mass index \>35 kg/m 2 . 10. Patients participating in any other clinical trials with- in 3 months.