Arterial calcium stimulation with hepatic venous sampling for insulinoma

Intraarterial injection of calcium, an insulin secretagogue in patients with insulinoma but not in healthy individuals, and changes in hepatic venous serum insulin concentrations in a patient with suspected insulinoma. The hepatic venous serum insulin concentration increased 10-fold after superior mesenteric artery injection, 1.4-fold after the gastroduodenal artery injection, and did not change after the splenic artery injection. An insulinoma was removed from the uncinate process.