Changes in pancreatic function after pancreatoduodenectomy

Background: The objective of this study was to compare the alterations in pancreatic function after pancreatoduodenectomy between malignant and benign diseases. Methods: In 34 patients who underwent pancreatoduodenectomy for pariampullary cancer (malignant group; n = 18) and benign pancreatic disorders (benign group; n = 16), exocrine and endocrine functions were analyzed before surgery, at a short-term period (≤2 months), and at a long-term period (>12 months) after surgery. Assessment was based on the BT-PABA excretion test, fasting blood sugar level, and oral glucose tolerance test. Results: Compared with the preoperative level, urinary PABA excretion rate in the malignant group significantly decreased on short-term follow-up but recovered on long-term follow-up. However, that in the benign group increased on long-term follow-up without showing a short-term decline. Diabetes mellitus was present in 11 (61%) of the 18 patients in the malignant group and 6 (38%) of the 16 in the benign group before surgery. Glucose tolerance improved in 6 (55%) of the 11 patients in the malignant group but in only 1 (17%) of the 6 in the benign group shortly after surgery. In the benign group, 3 (30%) of 10 patients with normal preoperative glucose tolerance became diabetic after surgery, while no patient in the malignant group developed diabetes on short-term follow-up. Conclusions: Surgeons should pay attention to exocrine pancreatic function in patients with a periampullary cancer and to glucose metabolism in patients with benign disease over the short-term period after pancreatoduodenectomy.