Value of the calcium intraarterial stimulation test in preoperative localization of insulinoma

Objective: To evaluate the efficacy of the intraarterial calcium test in preoperative localization of insulinomas. Methods: Sixteen patients with suspected insulinoma underwent ASVS method, which meant injecting calcium stimulant into pancreatic arteries and then taking blood specimens from hepatic vein to gauge the insulin levels. Six samples, each 2 ml, were taken before and 30, 60, 90, 120, 150 seconds after the injection. Results: Twelve solitary insulinomas and one hyperplasia were diagnosed after surgery. Except one insulinoma, ASVS allowed accurate localization of the tumor. For the other three cases, which were excluded the diagnosis of insulinoma by surgical exploration or follow-up, ASVS were negative. Thus the sensitivity, specificity, and overall accuracy of ASVS were 92.3%(12/13), 100%(3/3), and 93.7%(15/16), respectively. Conclusion: ASVS is an accurate and safe technique to localize insulinomas, especially for those undetectable at preoperative morphologic studies