Combining the selective arterial calcium injection test and intraoperative blood glucose monitoring for multiple insulinomas: report of two cases.

To date, no precise methods of preoperatively localizing multiple insulinomas or intraoperatively confirming their complete removal have been established. We describe herein the effectiveness of combining the selective arterial calcium injection (SACI) test to locate tumors preoperatively, with intraoperative continuous blood glucose monitoring (IOBGM) to confirm their complete removal. During the 8-year period from 1990 to 1997, we experienced two patients with multiple insulinomas. The first patient required resection of a residual tumor in the remnant pancreas for persistent hyperinsulinemia after a distal pancreatectomy performed under conventional diagnostic procedures. In the second patient, a SACI test was performed in addition to other diagnostic imaging procedures, and while computed tomography scan, endoscopic ultrasonography, and arteriography demonstrated multiple tumors in the body and tail of pancreas, the SACI test suggested that there were also tumors in the head of pancreas. Intraoperative ultrasonography showed a tumor measuring 5 mm in diameter on the surface of the head of the pancreas, apart from the multiple tumors in the body and tail of the pancreas. Complete removal of all tumors was assessed by the hyperglycemic rebound after resection of the tumors, determined by IOBGM. Based upon our experience, we believe that the SACI test and IOBGM are helpful for establishing precise localization and achieving complete removal of multiple insulinomas.