Portal and pancreatic vein catheterization with radioimmunologic determination of insulin.

Percutaneous transhepatic catheterization of the portal vein along with the catheterization of the aorta and the vena cava was performed in six patients, one of whom had hypoglycemic attacks due to Whipple's triad. Blood samples from different branches in the different vessel systems were withdrawn for radioimmunologic determination of insulin. By this method, preoperative localization of the insulin producing pancreatic islet cell tumor was su-cessfully performed. Multiple tumors as well as liver metastases were preoperatively excluded. Recatheterization and blood sampling for radioimmunologic determination of insulin was performed postoperatively to verify the radicality of the operation. Insulin concentrations from the hypoglycemic patients were compared with those of the patients without insulinoma and found to be significantly higher. The procedure is proposed as a useful method for localizing all types of gastrointestinal hormone producing primary or secondary tumors in which a method for hormone determination is available. The postoperative investigation is useful as a check of the operation performed and as a follow-up examination for the early diagnosis of recurrence.