Exocrine pancreatic function in the early period after pancreatoduodenectomy and effects of preoperative pancreatic duct obstruction

Exocrine pancreatic function in the early period after pancreatoduodenectomy was investigated. The effects of preoperative pancreatic duct obstruction on exocrine pancreatic function were also investigated. The volume of pancreatic juice and its amylase activity were investigated in 39 patients who underwent pancreatoduodenectomy (including pylorus-preserving pancreatoduodenectomy). The N-benzoyl-L-tyrosyl-p-aminobenzoic acid (BT-PABA) test was performed on 23 of 39 patients about 40 days after pancreatoduodenectomy. The exocrine pancreatic function was inhibited three to eight days after pancreatoduodenectomy (amylase activity: 23,700 +/- 4300 IU/day), and recovered on days 9-15 (48,000 +/- 8400 IU/day) in patients with a normal main pancreatic duct. In patients with pancreatic duct obstruction, the exocrine pancreatic function was almost eliminated (amylase activity: 440 +/- 260 IU/day) and BT-PABA test results were low (45 +/- 17%). In patients with narrowed pancreatic duct, amylase secretion was significantly inhibited even in patients with a normal number of acinar cells. There was a good positive correlation (Spearman's rank correlation coefficient, rs = 0.715, P0.01) between amylase secretion and BT-PABA test. Amylase secretion more than 10,000 IU/day is essential for a normal BT-PABA test and normal digestive function. The inhibited digestive function in patients with pancreatic duct obstruction may be due to the decreased number of acinar cells and the inhibition of exocrine pancreatic function.