The risk of developing postoperative complications following pancreatic resection depends mainly on how difficult it is to perform a proper pancreaticointestinal anastomosis. We have evaluated the serum pancreolauryl test, a rapid tubeless pancreatic function test, as a simple preoperative predictor of the degree of pancreatic fibrosis. Degree of fibrosis in turn provides an indirect parameter for the difficulties of performing a proper and safe pancreaticointestinal anastomosis. In 35 patients (21 chronic pancreatitis, 14 pancreatic tumors) undergoing major pancreatic resection, we found a negative correlation (r = -0.75, p < 0.001) between the degree of fibrosis at the resection margin and the serum pancreolauryl test results. Patients with chronic pancreatitis had a significantly higher degree of fibrosis at the resection margin (59 +/- 22 vs. 34 +/- 25%; X +/- SD; p < 0.01) and lower fluorescein serum concentrations (2.6 +/- 1.9 vs. 4.3 +/- 2.1 micrograms/ml; X +/- SD; p < 0.01) in comparison with patients with pancreatic tumors. These findings indicate that the degree of pancreatic fibrosis, the difficulties of performing a proper pancreaticointestinal anastomosis, and subsequently the potential risk of postoperative complications can easily be predicted preoperatively.