The artificial endocrine pancreas in the surgical treatment of insulinoma. Usefulness and limits

The usefulness and the limits of the artificial endocrine pancreas in the surgical management of insulinoma has been evaluated in three male patients who underwent pancreatic resection because of previously detected adenoma. In particular, blood glucose and contemporary levels of insulin and C-peptide were continuously monitored before, during and after surgery, to record the temporal relationship between the removal of insulinomas and the variations of these parameters. In the pre-resection phase, only two cases revealed hypoglycemia and required dextrose infusion to correct hypoglycemia and reach euglycemic levels, whereas all the patients showed elevated insulin and C-peptide levels. After anesthesia and surgical incision, the pancreas was observed and manipulated in search of adenoma. In all patients this manoeuvre caused an increase of insulin and C-peptide levels and in two cases a slight decrease of blood glucose levels. After adenoma resection, a prompt increase of glycemia was observed only in one patient, in the other two the time which elapsed before significant blood glucose changes was more prolonged (55 and 80 min. respectively). On the contrary, a rapid fall in insulin and C-peptide levels was observed in all cases. We conclude that artificial endocrine pancreas has the advantage of maintaining the normoglycemia before and during surgery, preventing the risk of dangerous hypoglycemia in basal conditions and following manipulation of pancreas while localizing adenoma. However, the prolonged interval elapsed before significant blood glucose variations limits the usefulness of the artificial endocrine pancreas in localizing intraoperatively previously undetected adenomas.