Two-point measurement of amylase in drainage fluid predicts severe postoperative pancreatic fistula after gastric cancer surgery.

Background: Early identification of patients at risk of postoperative pancreatic fistula (POPF) allows appropriate management after gastrectomy. Although some reports have suggested a correlation between POPF and the concentration of amylase in drained abdominal fluid (D-AMY), this has not been proven to impact sufficiently on clinical decision-making. A sustained high level of D-AMY is often assumed to be due to unsatisfactory drainage or excessive pancreatic leakage. We assessed the clinical utility of measuring D-AMY on postoperative day (POD) 1 and POD3 for prediction of POPF.

Methods: Starting in April 2014, 801 patients who underwent radical gastrectomy with prophylactic drain placement were consecutively enrolled. We routinely measured D-AMY on POD1 and POD3, and compared the incidence of problematic POPF and clinical factors including D-AMY. We also attempted to clarify whether such two-point D-AMY measurement was clinically useful for patient management after gastrectomy.

Results: Fifty-one of the patients (6.4%) developed Clavien-Dindo grade III or worse POPF. Using D-AMY cutoffs of 2218 IU/L on POD1 and 555 IU/L on POD3, the patients were successfully classified. The highest risk group, in which D-AMY was higher than the cut-off value on both POD1 and POD3, showed a significantly high rate of occurrence (33/105, 31.4%) and high positive likelihood ratio (6.74). Multivariate analysis showed that classification into this highest risk group was an independent risk factor for development of severe POPF (odds ratio 15.2, 95% CI 7.92-29.0).

Conclusion: Two-point measurement of D-AMY may be an efficient tool for achieving individualized management of POPF following radical gastrectomy.