Laparoscopic Localization and Enucleation of Multiple Insulinomas Using a Combination of Indocyanine Green Fluorescence Imaging and Intraoperative Ultrasound

INTRODUCTION: Enucleating multiple insulinomas adjacent to the main pancreatic duct poses significant risks of parenchymal injury and postoperative complications. While indocyanine green (ICG) fluorescence aids in tumor localization, excessive background fluorescence and diminished intensity during prolonged procedures can obscure tumor margins. METHODS: A 38-year-old male presented with multiple insulinomas located in the pancreatic head, tail, and uncinate process. The head and tail lesions were within 1 mm of the main pancreatic duct. Laparoscopic enucleation was planned using combined ICG fluorescence and intraoperative ultrasound (IOUS). The patient received 25 mg of intravenous ICG 24 hours preoperatively. RESULTS: Intraoperative probing revealed no fluorescence from the preoperative ICG dose. Subsequently, a 12.5 mg intravenous ICG bolus was administered. Tumor enhancement was achieved in 15 seconds, and distinct tumor demarcation appeared at 30 minutes as background fluorescence dissipated. Guided by real-time ICG and IOUS, the tumors were safely enucleated using cold sharp dissection near the duct. Intraoperative portal vein blood sampling confirmed a significant decline in insulin and C-peptide levels. Blood loss was 50 mL, and operative time was 200 minutes. The patient was discharged on postoperative day 4 without pancreatic fistula. CONCLUSION: Integrating an intraoperative 12.5 mg ICG bolus with IOUS provides precise localization and enables safe, parenchyma-sparing enucleation of multiple insulinomas near the main pancreatic duct. Preoperative ICG administration 24 hours prior is not recommended.