Most reliable indicator for predicting postoperative pancreatic fistula after distal pancreatectomy: A retrospective study

Abstract

Abstract Background: Postoperative pancreatic fistula (POPF) is a major complication of pancreatic surgery. Drain fluid amylase concentration (DAC) is considered a predictive indicator of POPF. However, other indicators related to postoperative drain fluid amylase status exist, and the most reliable indicator for predicting POPF remains unclear. Thus, this study compared the accuracy of these indicators in predicting POPF development after distal pancreatectomy (DP). Methods: This single-institution retrospective study included 122 patients who underwent DP. The study was conducted between 2010 and 2022 at Gifu University Hospital. We statistically analyzed DAC, drain fluid amylase amount (DAA) calculated by multiplying DAC and daily drainage volume, and drain and serum amylase concentration ratio (DSACR) to assess the correlation with POPF. Results: Based on the definition and grading of the International Study Group of Pancreatic Fistula, 24.6 (%) of the 122 patients had Grades B and C POPF. The cutoff value of DAC on postoperative day [POD] 1 was 7,238 (U/L) (area under the curve [AUC] 0.65, sensitivity 56.7%, specificity 80.2%, and accuracy 74.4%). The cutoff value of DAC on POD3 was 737 (U/L) (AUC 0.73, sensitivity 73.3%, specificity 65.9%, and accuracy 67.8%). The cutoff value of DAA on POD1 was 103 (U/day) (AUC 0.64, sensitivity 80.0%, specificity 46.2%, and accuracy 54.5%). The cutoff value of DAA on POD3 was 31 (U/day) (AUC 0.72, sensitivity 70.0%, specificity 73.6%, and accuracy 72.7%). The cutoff value of DSACR on POD1 was 17 (AUC 0.69, sensitivity 80.0%, specificity 58.2%, and accuracy 63.6%). The cutoff value of DSACR on POD3 was 22 (AUC 0.77, sensitivity 77.7%, specificity 73.3%, and accuracy 73.6%). Overall, DSACR on POD3 had the highest AUC value. Furthermore, a multivariate logistic regression analysis revealed that pancreatic texture (soft; odds ratio [OR] 5.06; 95% confidence interval [CI] 1.57–19.95; p = 0.006) and DSACR on POD3 (>22; OR 15.57; 95% CI 2.41–307.76; p = 0.003) were independently associated with POPF after DP. Conclusions: DSACR on POD3 is the most reliable indicator of drain fluid amylase status for predicting POPF after DP.