Pancreatic Chymotrypsin Activity Rather Than Amylase Level Better Predicts Postoperative Pancreatic Fistula.

ABSTRACT

OBJECTIVE: To assess the predictive value of chymotrypsin activity in pancreatic juice on clinically relevant postoperative pancreatic fistula (CR-POPF) after pancreatic resection, since pancreatic peptidases rather than glycolytic enzymes play a pivotal role in causing tissue damage due to pancreatic leakage. BACKGROUND: The risk of CR-POPF has been estimated based on amylase level in abdominal drainage fluid. METHODS: Eighty-one consecutive patients underwent pancreatoduodenectomy, and postoperative pancreatic juice and drainage fluids were collected for 14 days. The chymotrypsin activity and fluid amylase level in these fluids were measured, and their susceptibility to the elapsed postoperative time and circadian rhythm were evaluated. The predictive value for the development of CR-POPF was compared between assessment of pancreatic chymotrypsin activity versus fluid amylase level. RESULTS: No significant differences in the daily pancreatic chymotrypsin activity were observed, whereas the amylase level in pancreatic juice was susceptible to the postoperative interval and circadian rhythm. CR-POPF developed in 19 patients (23%). Assessment of pancreatic chymotrypsin activity on the first postoperative day predicted CR-POPF with a sensitivity/specificity of 84/87% (area under the curve, 0.855; cut-off value, 0.5 arbitrary units), which was better than measurement of fluid amylase level. Independent predictors of CR-POPF were the day-1 pancreatic chymotrypsin activity (≥0.5 arbitrary units, P < 0.001) and the main pancreatic duct index (<0.25, P = 0.039). CONCLUSIONS: Assessment of pancreatic chymotrypsin activity may allow for more rapid and accurate prediction of CR-POPF than use of conventional diagnostic criteria based on fluid amylase level, enabling individualized surgical procedures and postoperative drain management.