Objective: To perform an unbiased assessment of first postoperative day (POD 1) drain amylase level and pancreatic fistula (PF) after pancreaticoduodenectomy (PD).
Background: Recent evidence demonstrated that drain abandonment in PD is unsafe. Early drain amylase levels have been proposed as predictors of PF after PD, allowing for selection of patients for early drain removal.
Methods: Daily drain amylase levels were correlated with the development of PF in 2 independent cohorts of patients undergoing PD: training cohort (n = 126; year 2008) and validation cohort (n = 369; years 2009-2012).
Results: POD 1 drain amylase level had the highest predictive ability (concordance index: 0.911) for PF in the training cohort. An amylase level of 612 U/L or higher showed the best accuracy (86%), sensitivity (93%), and specificity (79%). Thus, a cutoff value of 600 U/L was utilized. In the validation cohort, 229 (62.1%) patients had a POD 1 drain amylase level of lower than 600 U/L, and PF developed in only 2 (0.9%) cases; whereas in patients with POD 1 drain amylase level of 600 U/L or higher (n = 140) the PF rate was 31.4% (odds ratio [OR] = 52, P < 0.0001). On multivariate analysis, POD 1 drain amylase level of lower than 600 U/L (OR = 0.0192, P < 0.0001) was a stronger predictor of the absence of PF than pancreatic gland texture (OR = 0.193, P = 0.002) and duct diameter (OR = 0.861, P = 0.835).
Conclusions: After PD, the risk of PF is less than 1% if POD 1 drain amylase level is lower than 600 U/L. We propose that in this group, which comprise more than 60% of patients, drains should be removed on POD 1.