Intraarterial calcium stimulation (ASVS) for pancreatic insulinoma: comparison of preoperative localization procedures

Evaluation of clinical relevance of the arterial stimulation procedure with venous sampling (ASVS) in the preoperative localization of insulinoma. Thirteen patients with endogenous hyperinsulinism underwent preoperative transabdominal ultrasound (US), helical CT (CT), MRI, endoscopic ultrasound (EUS), and angiography (DSA) in conjunction with the ASVS-test for the detection of insulinoma. The results were compared with intraoperative findings, intraoperative ultrasound (IOUS) and histology. Sensitivity was as follows: US 8%, MRI 27%, CT 46%, EUS 50%,DSA 69%,and ASVS 92%.Intraoperative palpation and IOUS yielded a sensitivity of 77%. In 3 patients the tumors were neither palpable nor detectable by IOUS, the mode of resection was based on preoperative diagnostics.The ASVS procedure as a functional test was superior to all other modalities for the preoperative tumor detection. The ASVS was the most sensitive diagnostic modality. It should especially be considered in terms of health economical aspects when CT or MRI do not yield conclusive results. (orig.)