Selective intraarterial methylene blue for pancreatic and duodenal endocrine tumors

Pancreatic and duodenal endocrine tumors can be difficult to localize intraoperatively. Three patients are described in whom selective intraarterial injection of methylene blue was used to correctly identify the position of an endocrine tumor. These patients had a duodenal gastrinoma, a pancreatic polypeptide-producing pancreatic islet cell tumor, and a duodenal somatostatinoma, respectively. Selective arterial secretin injection with hepatic vein gastrin measurement and selective arterial calcium injection with hepatic vein pancreatic polypeptide measurement were used to preoperatively identify the feeding artery. The duodenal somatostatinoma was identified by endoscopy. A catheter placed in the feeding artery just prior to surgery was used for injection of the methylene blue. The combination of selective arterial stimulation and selective arterial methylene blue injection is a promising method for helping surgeons localize elusive endocrine tumors in the duodenum and pancreas.