The Predictive Effect of "Real Amylase Value": A More Accurate Predictor for Postoperative Pancreatic Fistula

Postoperative pancreatic fistula (POPF) is a common and serious complication following pancreatic surgery. While several studies have attempted to predict the development of POPF using drain amylase concentration, predictive values vary widely due to factors like abdominal irrigation and chylous drainage, which can dilute the amylase levels. This study aims to evaluate whether the "Real Amylase Value" (RAV), calculated as the product of drain amylase concentration and drainage volume, provides a more reliable prediction of POPF compared to conventional amylase concentration. Better prediction of pancreatic fistula development could lead to closer clinical monitoring of these patients, reassessment of hospital stay duration, and more careful management of drains over an extended period. Additionally, carefully managing the timing of drain removal may improve patient recovery and discharge process.

Data from 198 patients who underwent pancreaticoduodenectomy (PD) and distal pancreatectomy (DP) were retrospectively analyzed. Drain amylase concentrations and drainage volumes were measured on postoperative days (POD) 1 and 3, and the RAV (U) was calculated. Real Amylase Value (RAV) (U) was calculated using the formula: RAV (U) = Drain Amylase Concentration (U/L) × Drainage Amount (L). Predictive values for POPF were evaluated using receiver operating characteristic (ROC) curve analysis, comparing conventional amylase concentration (U/L) and RAV (U).

On POD1, the RAV (U) demonstrated greater predictive value for POPF compared to the conventional drain amylase concentration (U/L) with an area under the ROC curve (AUROC) of 0.85 versus 0.79, respectively. Similarly, on POD3, RAV showed superior predictive accuracy (AUROC 0.89) compared to amylase concentration (AUROC 0.79).

The RAV (U) offers a more accurate and reliable prediction of POPF than traditional drain amylase concentration (U/L), with improved sensitivity and specificity. This method could refine clinical management, particularly in the timing of drain removal and early intervention strategies for patients at high risk of developing pancreatic fistulas.