Gastrinomas: localization by means of selective intraarterial injection of secretin

Small doses (30 U) of secretin were injected directly into the splenic, gastroduodenal, hepatic, and superior mesenteric arteries of 13 patients with Zollinger-Ellison syndrome who were undergoing angiography to localize gastrin-secreting tumors of the islet cells. Blood samples from the right hepatic vein and a peripheral vein were drawn before and 30, 60, 120, and 210 seconds after each intraarterial secretin (IAS) injection. A 50% rise in gastrin level in the 30-second sample from the hepatic vein localized the gastrinoma to the head, body, or tail of the pancreas, depending on the artery into which secretion was injected. IAS results were positive in seven of 13 patients (54%); selective angiography was positive in five of 13 (38%); and the combined study, selective angiography with IAS injection, was positive in 10 of 13 (77%). Portal venous sampling was positive in six of 13 (46%). Selective IAS injection, combined with angiography, is the most sensitive study for localizing gastrinomas and avoids percutaneous transhepatic catheterization for portal venous sampling.