What should we trust to define, predict and assess pancreatic fistula after pancreatectomy?

Abstract

Objective: The ISGPF postoperative pancreatic fistula (POPF) definition using amylase drain concentration is widely used. However, the interest of lipase drain concentration, daily drain output and absolute enzyme daily production (concentration x daily drain volume) have been poorly investigated.

Material and methods: These predictive on postoperative day (POD) 1, 3, 5 and 7 were analyzed in a development cohort, and subsequently tested in an independent validation cohort.

Results: Of the 227 patients of the development cohort, 17% developed a biochemical fistula and 34% a POPF (Grade B/C). Strong correlation was found between amylase/lipase drain concentration at all postoperative days (ρ = 0.90; p = 0.001). Amylase and lipase were both significantly higher in patients with a POPF (p < 0.001) presenting an equivalent under the ROC curve area (0.85 vs 0.84; p = 0.466). Combining POD1 and POD3 threefold enzyme cut-off value increased significantly POPF prediction sensibility (97.4% vs 77.8%) and NPV (97.1% vs 86.3%). These results were also confirmed in the validation cohort of 554 patients. Finally, absolute enzyme daily production and daily drain output were significantly higher in patients with a POPF (p < 0.001) but did not add clinical value when compared to drain enzyme concentration.

Conclusion: Lipase is as effective as amylase drain concentration to define POPF. Absolute enzyme daily production or daily drain output do not help to better predict clinically significant POPF occurrence and severity. Lipase and amylase should mainly be used for their negative predictive value to predict the absence of clinically significant POPF and could allow early drain removal and hospital discharge.

Keywords: Absolute enzyme daily production; Amylase; Lipase; Pancreatic fistula.