Inflammatory potential of cotton‐based surgically invasive devices: Implications for cardiac surgery

Abstract

Cotton-based surgical invasive devices with their desired hemostyptic properties have been used for decades in the surgical field. However, in cardiac surgery using the heartlung machine with direct retransfusion of suction blood, activated blood may re-enter the circulation without filtration and may trigger a cascade reaction leading to systemic inflammation and thrombosis. We therefore set out to evaluate the inflammatory potential of untreated and pyrogen-impregnated cotton-based surgical invasive medical devices. After incubation of the swabs with whole blood or PBMC, the cell-free supernatant was investigated for IL1β and IL6. While the reaction of human whole blood toward cotton swabs could not be influenced by any sterilization technique, dry heat and gammairradiation were able to diminish the inflammatory reaction of PBMC toward the material and the used pyrogens. In conclusion, using PBMC in direct contact to cotton we are the first to establish a suitable test method for quantification of the pyrogenic/inflammatory activity of this material. The unaltered reaction of whole blood, however, suggests a crosstalk of cells and plasma proteins in the inflammation activation that is not prevented by sterilization of the swabs. This new in vitro testing methodology may help to better display the clinical situation during development of new materials.

Synthetic Material Abdominal Swabs Reduce Activation of Platelets and Leukocytes Compared to Cotton Materials

“…In a preliminary in vitro test, the inflammatory activation of blood by synthetic and cotton abdominal swabs was investigated using the monocyte activation test (MAT). As observed previously [15], cotton abdominal swabs themselves induced relatively strong secretion of the inflammatory cytokine IL1β, whereas blood incubated with the synthetic material showed no measurable IL1β secretion, actually the same response as blood without LPS or materials (Figure 1). The significantly different responses between swab types (p < 0.0001) indicate that the synthetic material does not activate the blood monocytes and thus shows different material properties than cotton, which induced a similar IL1β secretion in blood as the middle of the LPS standard curve (0.1 EU/mL) (Figure 1).…”

“…The significantly higher IL6 secretion in blood wrung from cotton swabs likely reflects a material-induced inflammatory activation of monocytes [15], whereas the significant increase at the end of HLM in the cotton compared to the synthetic group for both inflammatory cytokines (IL1β and IL6) can be induced by activated monocytes, platelets, or endothelial cells [54,55]. The SDF-1α expression can be upregulated by inflammatory mediators such as IL1β or TNFα [56,57].…”

“…The MAT was performed with human whole blood as described before [15]. Briefly, the cotton or synthetic swabs (untreated or pyrogen-impregnated) were placed in sterile 2 mL DNA LoBind Eppendorf reaction tubes, and 1.5 mL of 1:10 diluted pooled human whole blood was added and incubated for 18 h at 37 • C. Increasing 2-fold concentrations from 0.0125 to 0.5 EU/mL LPS (concentrations correspond to the volume in the incubation to enable a comparison to a solid swab material) were added to the diluted blood to detect the immune activation potential of the pooled blood to pyrogens (standard dilution row).…”

“…Hypercoagulant swabs reduced the ACT and the concentration of free heparin [3]. Further studies showed that even sterilized abdominal swabs were able to activate inflammatory processes in human blood [15], which indicates that the material itself has a certain inflammation activation potential. The retransfusion of sucked blood, which came in contact with the cotton abdominal swabs, without purification might lead to a higher risk of postoperative complications, such as thromboembolic or inflammatory events.…”