Advancing early diagnosis of colorectal anastomotic leakage using drain fluid biochemical analysis

Anastomotic leakage is a common and very serious complication in colorectal surgery. While minor leaks can often be managed conservatively, advanced leaks with peritonitis require surgical reintervention. Leakage is frequently diagnosed late, which we attribute to the absence of an effective screening method and a standardized postoperative protocol. The current classification of leaks is predominantly retrospective and descriptive, offering limited clinical utility. Our goal is to develop a functional postoperative protocol, and a new clinical classification of leaks. In this initial study, we focused on advancing early diagnosis of leakage, by incorporating biochemical analysis of drain fluids. As early markers we chose Calprotectin, Neopterin and D-Lactate. We included 96 patients into this study. We analyzed the drainage fluids during the first postoperative days and compared concentrations of markers between groups with and without leakage. We proved a statistically significant difference in concentrations and its dynamics in the first postoperative days in calprotectin in the leakage group. We further report a statistically significant difference in concentration of calprotectin on the 5th postoperative day, and of Neopterin on the 4th and 5th postoperative days in the leakage group. Taken together, these results suggest promise for calprotectin and neopterin as diagnostic biomarkers.