Abstracts
1997 Digestive Disease Week

Surgical treatment of insulinoma. Study of 59 cases.

MCC Machado, JE Monteiro da Cunha, J Jukemura, T Bacchella, E Abdo, A Montagnini, P Herman, MAC Machado, HW Pinotti. Department of Gastroenterology, Surgical Division, Sao Paulo University Medical School - Sao Paulo, Brazil.

One of the major problems associated with the management of insulinomas is their preoperative localization after the diagnosis has been made. The purpose of this study was to analyze the efficacy of preoperative localization of these tumors and the immediate and late results of their surgical treatment.

Fifty-nine patients with hyperinsulinism were studied and the results of the diagnostic tools for tumor preoperative localization were compared with findings at surgical intervention. The influence of the type of surgical procedure on the immediate and late postoperative courses was studied.

Fifty-five of the 59 cases were benign lesions. Preoperative diagnosis was possible by US in 28.1 % of the cases; by CT imaging in 25%; by combined selective celiac and mesenteric angiography in 54.1%; by EUS in 27.2% and by assay of portal plasma insulin levels in 94.4%. In 54/55 cases (98.2%) the tumors could be identified intraoperatively by palpation. By the addition of intraoperative US all lesions were identified. Twenty-nine enucleations and 32 resections were performed in the 55 patients with benign tumors. The five patients with malignant lesions were submitted to pancreatic resections. There was no mortality in this series. External pancreatic fistulas were the most frequent complications and all healed spontaneously. Late diabetes developed in three cases after distal pancreatic resection. Long term results were excellent in 98.1% of the benign cases. Only one of the patients with malignant tumors survived more than 5 years.

It is concluded that preoperative localization of insulinomas is not absolutely necessary and by combining peroperative palpation with intraoperative US, mainly at reoperations, most of the cases can be adequately dealt with. Tumor enucleation is the best choice for treatment of the benign lesions except those associated with type I multiple endocrine neoplasia.