Effects of oxidized cellulose and microfibrillar collagen on infection

Topical hemostatic agents may be used to control bleeding from a variety of surgical sites. Oxidized cellulose (Surgicel), gelatin sponge (Gelfoam), and microfibrillar collagen (Avitene) are the hemostatic agents in widest use. Oxidized cellulose has previously been shown to be superior to gelatin sponge with respect to infection. Microfibrillar collagen has not been studied in this regard. Contamination of experimental wounds with an inoculum of 3.2 to 3.6 X 10(4) colony-forming units of Staphylococcus aureus did not produce any infection. The addition of 20 mg of oxidized cellulose to wounds that received the same level of bacterial contamination resulted in nine infected wounds of 20 (45%). When the wounds were treated with 20 mg of microfibrillar collagen prior to contamination, 18 of 20 (90%) developed infection. The observed difference between the two hemostatic agents was significant (P less than 0.008). When 5 and 10 mg of oxidized cellulose was added to experimentally contaminated wounds, infection did not ensue. The incidence of infection increased strikingly when the amount of oxidized cellulose employed was increased to 20 and 30 mg. No such dose effect was observed for microfibrillar collagen. Infection developed even when very small quantities of the agent were used. Both oxidized cellulose and microfibrillar collagen may promote infection. The present study, in which a subcutaneous wound model was used, suggests an advantage of oxidized cellulose as compared with microfibrillar collagen from the standpoint of infection. Further studies with these agents in other body sites seem warranted.