Use of fibrinolytic agents to coat wire implants to decrease infection. An animal model.
OBJECTIVE
Infection is a serious complication of metallic prosthesis implantation and may necessitate removal of the prosthesis. This study uses an animal model to evaluate the effects of coating stainless steel wire implants with fibrinolytic agents to prevent infection after bacterial contamination.


METHODS
Three types of steel wire implants were used: plain stainless steel, heparin-coated steel, and urokinase-heparin-coated steel. Wire implants were incubated in a known concentration of Staphylococcus epidermidis and placed into the subcutaneous tissues of three groups of anesthetized hamsters. The implants and surrounding tissues were excised after 1 week and submitted for quantitative cultures.


RESULTS
Using 100 organisms as the upper allowable limit to categorize abscesses as noninfected, the following rates of noninfectivity were observed: group 1 (control), 0% noninfected; group 2 (heparin-coated wire), 40% noninfected; and group 3 (urokinase-heparin-coated wire), 50% noninfected. The noninfectivity rates of groups 2 and 3 were significantly higher than the rate of group 1 (P < 0.001). There was no significant difference between groups 2 and 3 (P = 0.19).


CONCLUSIONS
Both the heparin-coated and urokinase-heparin-coated wire exhibited significantly decreased infection rates compared with uncoated wire; the heparin coating may inhibit bacterial adherence. The urokinase coating of the heparin-coated wire appears to further decrease the infection rate, but not to a statistically significant degree.
D000038:Abscess / Q000382:microbiology / Q000517:prevention & control; D000818:Animals; D001422:Bacterial Adhesion / Q000187:drug effects; D001864:Bone Wires; D015169:Colony Count, Microbial; D003238:Connective Tissue / Q000601:surgery; D006224:Cricetinae; D062109:Dermatologic Surgical Procedures; D004195:Disease Models, Animal; D004866:Equipment Contamination; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D006493:Heparin / Q000008:administration & dosage / Q000627:therapeutic use*; D010960:Plasminogen Activators / Q000008:administration & dosage / Q000627:therapeutic use*; D019736:Prostheses and Implants; D016459:Prosthesis-Related Infections / Q000517:prevention & control*; D013193:Stainless Steel; D013203:Staphylococcal Infections / Q000517:prevention & control*; D013212:Staphylococcus epidermidis / Q000302:isolation & purification; D013499:Surface Properties; D014568:Urokinase-Type Plasminogen Activator / Q000008:administration & dosage / Q000627:therapeutic use*
D005343:Fibrinolytic Agents; D013193:Stainless Steel; D006493:Heparin; D010960:Plasminogen Activators; D014568:Urokinase-Type Plasminogen Activator