Arterial stimulation and venous sampling for glucagonomas of the pancreas

Arterial stimulation and venous sampling (ASVS) is a catheter-based diagnostic technique used to identify the localization of an insulinoma or gastrinoma. The aim of this study was to clarify the clinical significance of ASVS for glucagonomas.

Eight patients with pancreatic hypervascular tumors and elevated serum glucagon levels in the peripheral blood were enrolled. Pancreatic angiography was performed and a bolus dose of calcium was injected into a suitable artery. Hepatic venous blood samples were then obtained to measure concentrations of glucagon and insulin. All patients underwent surgical resection, and the resected specimens were investigated immunohistochemically.

Compared to insulin, the glucagon levels stabilized after calcium stimulation in four patients, with a 1.2-fold increase or decrease. In the remaining four patients, there was a 1.6- to 5.8-fold increase in glucagon levels. The peak value of glucagon was observed at 90s or 120s which was slower than the insulin peak observed in patients with insulinoma. The patients with elevated glucagon levels during ASVS exhibited positive immunostaining of glucagon in resected specimens.

Increase in glucagon after calcium stimulation was observed in patients with glucagonomas. ASVS for glucagonomas may be useful in determining the most suitable surgical procedure.