Tumor localization studies and surgical treatment in patients with insulinoma

In the present study, we retrospectively reviewed thirteen consecutive patients with insulinomas including 2 reoperations at our department for insulinomas, from the viewpoint of preoperative localization studies, surgery and long term follow-up. The results of the preoperative localization studies proved to be percutaneous transhepatic portal venous sampling (PTPVS) 6/7, angiography 8/15, ultrasonography (US) 6/11, endoscopic ultrasonography (EUS) 4/4, computed tomography (CT) 3/10, and magnetic resonance imaging (MRI) 2/2. The tumor was visualized by intraoperative ultrasonography (IUS) in 6 of 6 patients (100%). Six patients underwent enucleation, 6 patients underwent distal pancreatectomy, 2 patients underwent subtotal (80%) distal pancreatectomy, and one patient a pylorus preserving pancreaticoduodenectomy (PPPD). Two patients, one of whom belonged to the MEN-I group, underwent reoperations because they had multiple adenomas. The development of iatrogenic diabetes occurred in the case of 3 patients. These results suggest that the use of selected preoperative localization studies (PTPVS and probably EUS) may be very helpful for detecting insulinoma, and that IUS is an essential part of the operative exploration for insulinoma. Our data may further indicate the need for an aggressive surgical procedure in the case of multiple adenoma or insulinoma in MEN-I.