Objectives: Cardiac surgery using cardiopulmonary bypass (CPB) initiates a systemic inflammatory response syndrome (SIRS) leading to potential organ dysfunction and increased mortality. Extracorporeal cytokine elimination is a novel promising technique to reduce postoperative inflammation and to improve postoperative recovery. In the past years, the release of neutrophil extracellular traps (NETs) has been studied thoroughly with first findings been reported in cardiac surgery patients. NETs correlate with neutrophil activation after surgery, being a predictor for inflammation on cell level. Therefore, we studied the release of cell-free (cf) DNA/NETs in patients undergoing cardiac surgery requiring CPB while using a CytoSorb cytokine adsorber.
Methods: Seventy-eight patients undergoing cardiac surgery were included in this prospective study. Patients were divided into 3 groups: on-pump with a CytoSorb adsorber (n = 25), on-pump (n = 35) as well as an off-pump (n = 18) control group. Blood samples were collected baseline, 1 hour (h), 6 hour, 24 hour and 5 days (d) postoperatively. Levels of cfDNA were quantified in patients' plasma using Pico Green staining. The fluorescence intensity was quantified in a multiplate reader.
Results: In both on-pump groups a significant 1.5-fold increase of cfDNA starting immediately after surgery was observed when compared with baseline (p < 0.001). In contrast, no significant differences were found in patients undergoing off-pump surgery. Compared with on-pump the CytoSorb group showed a significant earlier normalization of cfDNA levels (p < 0.001). In addition we observed a lower incidence in clinical events (e.g., infection, wound healing disturbances) not reaching statistical significance.
Conclusion: CfDNA and NETs elimination using a CytoSorb adsorber is feasible and safe. As an immediate effect, release of proinflammatory cytokines is reduced. The usage of a CytoSorb adsorber may reduce the trauma caused by CPB.
