Localization of insulinomas - Comparison of conventional arterial stimulation with venous sampling (ASVS) and superselective ASVS

Purpose: To examine the value of superselective arterial stimulation venous sampling (ASVS) to localize insulinomas. Material and Methods: Superselective ASVS (SS-ASVS) was performed in 9 pati ents with insulinoma. Injection of secretagogue (calcium gluconate: 0.01 mE q Ca++/kg) was performed into the gastroduodenal, splenic (proximal and dis tal), and superior mesenteric arteries in 9 patients and additionally into the dorsal pancreatic artery in 6 patients. Sampling from the hepatic vein was performed to measure serum insulin concentrations at 30, 60 and 120 s a fter each injection of secretagogue into these arteries. SS-ASVS results we re correlated with surgical findings, compared to those of conventional ASV S. Results: Insulinomas were correctly localized to the head, body or tail of the pancreas by SS-ASVS in 8 patients (89%). Conventional ASVS detected ins ulinomas in 7 patients (78%), although it could not distinguish whether the insulinoma was located in the pancreatic body or tail in 4 of the 7 patien ts. There were eight-fold or more increases in serum insulin levels in hepa tic venous samples related to the artery supplying the. tumor in 8 patients . Localization of the insulinomas was verified at surgery in all patients. Conclusion: SS-ASVS is a useful method for detailed evaluation of overprodu ction of insulin from pancreatic insulinomas and their localization. When t he pancreatic insulinoma is situated in the pancreatic body or tail, the lo calization is more accurately made by SS-ASVS than by conventional ASVS.