Preoperative and intraoperative topographic diagnosis of insulinomas

Altogether 120 patients with organic hyperinsulinism underwent clinical examination and treatment (38 male, 82 female, mean age 44.2 +/- 4.6 years). The cause of hyperinsulinism was benign insulinomas in 96 (80.0%), malignant tumors in 9 (7.5%), and hyperplasia of beta cells in 6 (5.0%). In 9 (7.5%) patients the origin of hyperinsulinism was not diagnosed. The tumor was localized in the head, body, and tail of the pancreas in 31.8%, 36.4%, and 31.8% of cases, respectively. Intraoperative ultrasonography (IOUS) was undertaken in 37 patients, and in 83 cases only intraoperative palpation was done. Arterial stimulated venous sampling (ASVS) was performed in 17 patients (blood was sampled from the right hepatic vein for determination of the insulin level after arterial stimulation by calcium gluconate in different parts of the pancreas). The sensitivity of ultrasonography (US) was 29.5%, computed tomography (CT) 24.2%, angiography 55.9%, superselective angiography (branches of the celiac trunk) 72.2%, and intraoperative palpation 90.0%. ASVS showed an accuracy of 90.0%. Combining angiography with ASVS gave an exact diagnosis of hyperinsulinism in 100% of cases, and IOUS revealed tumors in 100% of cases. Hyperplasia of beta-cells was diagnosed only by means of ASVS. A total of 117 patients underwent surgery, including distal resection of pancreas (n = 39), enucleation of tumor (n = 70), and laparotomy (n = 8). The postoperative mortality associated with insulinomas was 7.7%. The frequency of postoperative complications was 43.6%. Benign insulinomas recurred at a rate of 5.4%. Patients with malignant insulinomas had a 5-year survival of 66.0%. The diagnosis of insulinomas was achieved by a combination of selective angiography, ASVS, and IOUS.