Objectives: Subsequent to total gastrectomy, many patients develop maldigestion and weight loss. The mechanisms that underlie these changes are not known. Therefore, in a prospective study, we have analyzed endocrine and exocrine pancreatic function in patients before and 3 months after total gastrectomy.
Methods: In 15 patients (12 male, three female, median age 62.4 yr) undergoing total gastrectomy due to gastric cancer, a direct exocrine pancreatic function test (secretin-cerulein test) was performed. In addition, a standard test meal was given to all patients to study endocrine pancreatic function and the pattern of hormones that influence exocrine pancreatic secretion. In nine patients, both function tests were repeated 3 months after total gastrectomy. Before and at 11 points after the application of the test meal, blood samples were taken for the measurement of glucose, insulin, glucagon, gastrin, pancreatic polypeptide, and cholecystokinin. In addition, a secretin-cerulein test was performed to analyze trypsin, chymotrypsin, amylase, bicarbonate, and the juice volume in the duodenal aspirates.
Results: Three months after total gastrectomy, all patients exhibited severe primary exocrine pancreatic insufficiency. Secretin-cerulein tests revealed that pancreatic juice secretion, trypsin, chymotrypsin, and amylase were significantly reduced by 76%, 89%, 91%, and 72%, respectively, 3 months after total gastrectomy and secretin and cerulein stimulation. Post-operatively, the patients had a pathological glucose tolerance with increased postprandial insulin and glucagon secretion. The baseline and postprandial gastrin and pancreatic polypeptide secretion were significantly decreased after total gastrectomy. In contrast, early postprandial cholecystokinin secretion was significantly increased postoperatively.
Conclusions: After total gastrectomy, patients develop severe primary exocrine pancreatic insufficiency with decreased gastrin, decreased late postprandial pancreatic polypeptide, and increased cholecystokinin levels. These findings may explain why many patients with total gastrectomy have maldigestion and weight loss postoperatively. Therefore, gastrectomized patients should be given pancreatic enzymes to avoid these symptoms.