Drain amylase on the first postoperative day of whipple surgery: What value is the best predictor for early drain removal?

Abstract

Background: The value of drain amylase on the first postoperative day after pancreatic resections has been described as an efficient predictor of pancreatic fistula. In spite of this, the cut-off point below which the drains can be removed early remains controversial. Aim: Validate the use of the amylase on the 1st postoperative day in the correlation with pancreatic fistula and define the value at which early drain removal is safe. Method: Were included patients undergoing Whipple surgery in the period of 2007 to 2016. Group 1 enrolled the ones who did not develop fistula and those who developed biochemical fistula for less than seven days postoperatively and group 2 included patients who developed persistent biochemical fistula between seven and 21 days and those with grade B and C fistula. Results: Sixty-one patients were included, 41 comprised group 1 and 20 group 2. The incidence of abdominal collections, need for reoperation and time of hospitalization were for group 1 and 2, respectively: 17.1%, 17.1% and 9.5 days, and 65%, 40% and 21.1 days. The median of the amylase from the drain at 1st postoperative day was in group 1 and 2, respectively: 175 U/l and 3172.5 U/l (p=0.001). Using a cut-off of 180 to predict the group to which the patient would belong there was obtained sensitivity, specificity, positive predictive value and negative predictive value of 100%, 48.8%, 50% and 100% respectively. Conclusion: It was validated the cut-off value of 180 U/l as appropriate to early drain removal.