Background: Approximately 10% of all insulinomas--the most common neuroendocrine pancreatic tumor--occur in multiple sites of the pancreas (e.g., multiple endocrine neoplasia type I) and rarely as islet cell hyperplasia. Malignant insulinomas appear in 10% to 15% of cases. For these special groups and for patients with a reoperation preoperative localization of the tumour is advisable. With current imaging technology, including computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography, and somatostatin receptor scintigraphy (SRS), localization of insulinomas is often inadequate.
Methods: In this study we report our results using intra-arterial calcium-stimulated venous blood sampling (ASVS) to localize and guide the management of insulinomas for patients with a reoperation because of recurrent insulinomas or persistent hyperinsulinism, for patients with malignant neoplasm and for patients with a previous abdominal operation.
Results: For all three cases the insulinomas were correctly localized by the ASVS in contrast to the preoperative imaging studies.
Conclusions: Our experience and a review of the current literature demonstrate that ASVS is a highly accurate (sensitivity > 90%) and a safe method for preoperative localization of insulinomas. For patients with a reoperation ASVS is recommended and the extensive use of other costly preoperative methods should be avoided.