Role of intraoperative ultrasonography in the surgical management of insulinomas

The findings in 35 surgically treated patients with insulinoma and 43 tumors of these patients were analyzed to confirm the efficacy of diagnostic modalities and surgical interventions. The rate of accurate preoperative tumor localization was 72% by angiography, 53% by computed tomographic scan, 55% by ultrasonography, and 83% by percutaneous transhepatic portal vein sampling. Extensive operative exposure and palpation detected 81% of the tumors and intraoperative ultrasonography demonstrated 96% of the tumors. Intraoperative ultrasonography was significantly better than any other diagnostic procedure and was able to demonstrate the anatomical relationship of the insulinoma to the essential structures of the pancreas. Intraoperative ultrasonography also helped determine the safest route for enucleating the insulinomas. Five patients (14%) in our series had metastatic diseases; 2 of these patients with metastases beyond the lymph nodes died due to the growth of tumors. The other 33 patients were free of insulinoma syndrome after the removal of the insulinomas. Streptozotocin was used in 1 patient with recurrent malignant insulinoma, with encouraging results.