Objective: Our aim was to determine whether the glucagon provocative test could be used in place of secretin test in patients with gastrinoma.
Methods: Three patients with gastrinoma underwent the following examinations: (1) preoperative intravenous glucagon test to enable a definitive diagnosis, (2) intra-arterial glucagon injection test to localize the tumor, and (3) intraoperative and postoperative intravenous glucagon test to confirm the completeness of the resection.
Results: Serum gastrin levels increased in response to intravenous glucagon in all three patients preoperatively. Computed tomography scans revealed a tumor in the lesser omentum, pancreatic head, and the pancreatic uncinate in cases 1, 2, and 3, respectively. Intra-arterial glucagon test revealed that the feeding artery for the tumor was the left gastric artery in case 1 and the superior mesenteric artery in case 3. Resection of the remnant stomach with tumor, pancreaticoduodenectomy with portal vein resection, and enucleation of the tumor were performed in cases 1, 2, and 3, respectively. Serum gastrin levels did not increase in response to intravenous glucagon intraoperatively and postoperatively in cases 1 and 3. Although intravenous glucagon caused a slight increase in serum gastrin in case 2, no recurrent tumors were evident.
Conclusion: These results indicate that the glucagon provocative test is a suitable alternative to testing with secretin, which is not commercially available in Japan.