Factors influencing insulin secretion after pancreatoduodenectomy

Preoperative patients with periampullary cancer had a higher mean Σ IRI value than that of normal controls, and also had a delayed pattern of insulin response and a lower insulinogenic index during oral-GTT. Σ IRI levels after pancreatoduodenectomy were similar to those of normal controls when the pancreatic remnants were histologically intact at the time of surgery. Postoperative Σ IRI levels could not be predicted based on the extent of histological fibrosis of the distal pancreas at the time of surgery. Patency of pancreatojejunostomy was obtained with the modified Warren's method in 39 out of 40 patients, and Σ IRI levels were maintained up to 5 years postoperatively. No significant difference was found in Σ IRI levels between pancreatoduodenectomised patients with the conventional Roux-en-Y procedure and those with the inverted Roux-en-Y with jejunal interposition. The mean insulin peak value and Σ IRI level were higher in pancreatoduodenectomised patients than in normal controls, and higher in gastrectomised patients than in pancreatoduodenectomised patients. Pancreatoduodenectomy with superior mesenteric arterial dissection resulted in remarkably low Σ IRI levels.