A Multi-center Study to Evaluate the Efficacy and Safety of Pancreatic Duct Stents Placement Before the Enucleation of Insulinoma Located in the Head and Neck of the Pancreas Near the Main Pancreatic Duct

Inclusion Criteria: * The clinical qualitative diagnosis of insulinoma was clear; * The localization diagnosis was clear, and it was determined that the tumor was single, located in the head and neck; * The distance between the tumor and the main pancreatic duct was determined to be ≤ 2mm by preoperative imaging (enhanced CT, MRI, etc.); * Truly informed and voluntarily participate in this study. Exclusion Criteria: * Maximum diameter of the tumor \>2cm proved pathologically * Severe cardiopulmonary complications before operation * Combined with other known tumor diseases * Insulinoma is invasive or has suspicious metastatic lesions * Previous upper abdominal surgery history * Refusal or inability to cooperate in the study