Cellular coating of the left ventricular assist device textured polyurethane membrane reduces adhesion of Staphylococcus aureus
Received 14 June 2006; received in revised form 7 October 2006; accepted 25 October 2006.
Objective
Infections are among the most common and serious complications of ventricular assist device implantation. These infections generally occur within the first 2 months after surgery. The basis for this high incidence of infection is not well established, so a murine intravascular infection model was developed with aortic implantation of the textured polyurethane patch material currently used in HeartMate ventricular assist devices (Thoratec Corporation Pleasanton, Calif).
Methods
Polyurethane patch material was placed in the wall of the mouse descending aorta. Mice were then infected with Staphylococcus aureus 1 or 14 days after implantation. In vitro adhesion studies were conducted with polyurethane membranes coated with endothelial cells and membranes coated with fibrinogen.
Results
Mice were susceptible to infection in both dose- and time-dependent fashions. The patch material was significantly more susceptible to infection at day 1 than day 14. Immunohistologic and morphologic studies demonstrated that the CD31+ cells deposited on the membrane surface phenotypically appeared to be endothelial cells. In vitro adhesion studies of polyurethane membranes coated with endothelial cells showed them to be less susceptible to S aureus binding than were membranes coated with fibrinogen.
Conclusion
Textured polyurethane membranes are less susceptible to infection as cellular deposition occurs. The time frame within which these membranes become populated with cellular material is consistent with the time-dependent clinical incidence of infection. Cellular coating of polyurethane may provide a strategy for reducing the risk of infection.
aDepartment of Surgery, New York Presbyterian Hospital, College of Physicians & Surgeons, Columbia University, New York, NY
bDepartment of Medicine, New York Presbyterian Hospital, College of Physicians & Surgeons, Columbia University, New York, NY
cDepartment of Pathology, New York Presbyterian Hospital, College of Physicians & Surgeons, Columbia University, New York, NY.
Address for reprints: Mario C. Deng, MD, FACC, FESC, Director of Cardiac Transplantation Research, Department of Medicine, Columbia University College of Physicians & Surgeons, New York, NY 10032.
Supported by the National Heart, Lung, and Blood institute (NHLBI) Specialized Center for Clinically Oriented Research (SCCOR) grant HL 077096-01, named “The Biology of Human Long-Term Mechanical Circulatory Support,” and by The Health Research Board program grant PRO 09/2002.
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