Hemostatic agents: brain tissue reaction and effectiveness. A comparative animal study using collagen fleece and oxidized cellulose.

In a series of 26 young rabbits, three cortical lesions were made in each hemisphere. Two of these holes were filled with collagen fleece (CF) and oxidized cellulose (OC), respectively, while the third was left empty as a control. The bleeding time was measured. Hemostasis with CF was statistically significantly faster than with OC, which in turn was statistically significantly faster than with no hemostatic agent. The animals were killed successively on Days 7, 14, 28, 42, and 241 after operation. Histopathological investigation showed that CF did not induce more tissue reaction that the control lesion and that CF was resorbed faster than OC. The removal of OC occurred from the borders of the material, moving gradually inward. With CF, there was an immediate ingrowth of reactive cells throughout the material. In contrast to OC, CF did not induce the formation of polynucleated giant cells. From these results, it can be concluded that CF is a fast, safe, and absorbable topical hemostatic agent suitable for use in neurosurgical procedures.