Dynamic Assessment of Drain Fluid Amylase Estimates the Risk of Clinically Relevant Postoperative Pancreatic Fistula Following Pancreatoduodenectomy.

Abstract

To evaluate whether drain fluid amylase levels on day 1 [drain fluid amylase on postoperative day 1 (DFA1)] and day 3 [drain fluid amylase on postoperative day 3 (DFA3)] can reliably estimate the risk of clinically relevant postoperative pancreatic fistula (CR-POPF) after pancreatoduodenectomy (PD) compared with either value alone or in combination with clinicopathologic variables. CR-POPF is a major source of morbidity and mortality after PD. Current drain management algorithms are variable and are mostly dependent on DFA1, whereas DFA3 is seldom utilized to guide clinical decision-making. Between 2015 and 2020, patients who underwent PD at 2 high-volume pancreas centers and had intraoperative drain placement with measurement of DFA1 and DFA3 were retrospectively reviewed. Models to predict CR-POPF were constructed using DFA1, DFA3, fistula risk score, and other patient or treatment-related parameters. The fittest and more parsimonious model was used to construct a CR-POPF risk calculator. Nine hundred twenty-three patients were included in the analysis. The fistula risk score was high in 100 (10.9%), intermediate in 524 (57.3%), low in 211 (23.1%), and negligible in 79 (8.6%) patients. The overall rate of CR-POPF was 9.2%. Five logistic regression models were constructed using variables known to be implicated in CR-POPF. A model based solely on DFA1 and DFA3 with a cross-validated area under the curve of 0.846 was selected. A calculator using DFA1 and DFA3 was created based on this model to estimate the risk of CR-POPF. The risk of CR-POPF after PD can be accurately estimated based on the measurement of DFA1 and DFA3. Our CR-POPF kinetics calculator can facilitate postoperative risk stratification and guide drain management algorithms.