Adhesion of thrombotic components to the surface of a clinically used oxygenator is not affected by Trillium coating

Adsorption of Blood Components to Extracorporeal Membrane Oxygenation (ECMO) Surfaces in Humans: A Systematic Review

The accumulation of blood proteins and cells on extracorporeal membrane oxygenation (ECMO) circuits has been proposed as a contributing factor to the coagulopathic state of many patients. This systematic review aims to summarize and discuss the existing knowledge of blood components binding to the ECMO circuits in human patients. A systematic review was conducted using the Medline, PubMed and Embase databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Seven studies were included in this review. Three studies identified a leukocyte adhesion, three studies observed von Willebrand factor accumulation and four studies identified bound platelets on the surface of the circuits. Other identified components included fibrin, albumin, hemoglobin, erythrocytes, progenitor cells, fibronectin and IgG. This systematic review demonstrates the limited state of knowledge when it comes to adsorption to the ECMO circuits in humans. Most of the studies lacked insight or detail into the mechanisms of binding and the interactions between different components bound to the ECMO circuits. Further research is required to comprehensively characterize surface adsorption to ECMO circuits in humans and to define the specific mechanisms of binding, enabling improvements that increase biocompatibility between the blood-circuit interface in this important clinical setting.

Insulin binding to the cardiopulmonary bypass biomaterials

Hyperglycemia associated with cardiopulmonary bypass (CPB) is an independent predictor of morbidity and mortality. One suggested cause of hyperglycemia during CPB is a decline of serum insulin concentrations. Since plasma C-proteins are not reduced during CPB — suggesting that pancreatic insulin secretion is not affected — the reduction of insulin concentrations is hypothesized to be due to the binding of the insulin protein to the CPB biomaterials. The hypothesis of this study is that insulin binds to the CPB polyvinyl chloride (PVC) tubing and that selected bio-coatings inhibit this process. Human insulin was diluted to a physiologic concentration of 30 μU/mL in saline and exposed to four types of sterile PVC tubing, namely: uncoated, Terumo X-coated, Medtronic Carmeda, and Cobe SMARxT for 30 minutes at 37°C. Insulin concentrations were determined with ELISA. The recovered insulin concentrations were found to be 9.3 ± 0.6 μU/mL in the uncoated (control), 17.7 ± 1.9 μU/mL in the X-coating, 17.9 ± 1.1 μU/mL in the Carmeda, and 14.28 ± 0.17 μU/mL in the SMARxT coated tubing. These data support the hypothesis that the insulin binding to the PVC tubing can be reduced by 48% and up to 35% with X-coating and Carmeda, and SMARxT coating, respectively. Therefore, the use of coated CPB systems is justified to reduce CPB-associated hyperglycemia. Perfusion (2007) 22, 207—210.