Postoperative fistula is the major complications of distal pancreatectomies which prohibit patients' recovery. Previous studies have reported controversial results regarding the efficacy of pancreatic stump reinforcement methods. Prior research has commonly included minimally invasive and open cases together. Moreover, stapler and suture were combined in most studies making interpretation difficult. Data has shown that staple line plus reinforcement might potentially decrease the CR-POPF rate of patients who underwent distal pancreatectomies, but well-designed high-quality evidence is lacking. Thus, the investigators design the present study to the question that whether routine staple line plus reinforcement would bring benefit for participants.

Distal pancreatectomy (DP)is the standard surgical method for benign or malignant pancreatic tumors locating at body and tail [1]. Clinically relevant postoperative pancreatic fistula (CR-POPF) is the major complication after pancreatectomy. In literature, reported CR-POPF rate after distal pancreatectomy varied between 5% and 64% from different centers. It's still a challenge to prevent CR-POPF via effective pancreatic remnant closure and no consensus on the optimal surgical technique has been established. Reported surgical strategies to prevent CR-POPF included stapler transection, staple line reinforcement, stump coverage with autologous tissue or fibrin glue, mesh reinforcement, and prophylactic administration of octreotide. However, none had convincing outcome [2-4].

Data has shown that staple line plus suture reinforcement might potentially decrease the CR-POPF rate of patients who underwent distal pancreatectomies, but well-designed high-quality evidence is lacking. Meanwhile, prior researches have commonly included minimally invasive and open cases together. Moreover, stapler and suture were combined in most studies making interpretation difficult [5-8].

Thus, the investigators design a single-centered, parallel, randomized controlled trial to compare the efficacy of routine staple line plus reinforcement versus staple only on the CR-POPF rate of participants who underwent minimally invasive distal pancreatectomies.

Inclusion Criteria:

• Those who will receive distal pancreatectomy via minimally invasive approaches, no matter benign or malignant;
• Aged from 18 - 80 years;
• Preoperative diagnosis of serous or mucinous cystic adenoma;
• Preoperative diagnosis of solid pseudopapillary tumor (SPT);
• Preoperative diagnosis of neuroendocrine tumor;
• Preoperative diagnosis of intraductal papillary mucinous neoplasm (IPMN);
• Preoperative diagnosis of or pseudocyst;
• Preoperative diagnosis of distal pancreatic malignancies;
• Patients willing to provide informed consent.

Exclusion Criteria:

• History of upper abdominal surgical history such as splenectomy, gastrectomy, liver resection, duodenal or pancreatic resection (not including laparoscopic cystectomy);
• Pancreatic trauma;
• With pneumoperitoneum contraindications;
• With severe heart or pulmonary diseases which is not fit for surgeries.

It will be single blinded. Operator, first assistant and data collector could not be blinded. Whereas patients, nurses, data analyzer, and those who have the access to the primary predictor will be blinded.