Biocompatibility and bioabsorption of microfibrillar collagen hemostat in experimental animals

The effects of Microfibrillar Collagen Hemostat (MCH) and Gelfoam after surgical implantation into incision sites of the liver, kidney, and brain were studied in beagle dogs, rabbits, and beagle dogs, respectively. The results of these experimental animal studies suggest that MCH is comparable to Gelfoam with respect to biocompatibility, rate of bioassimilation, and a lack for adverse systemic effects. The brain, liver, and kidney tissues responded comparably to MCH and Gelfoam with a mild to moderate infiltration of macrophages and mononuclear cells. Most of the hemostatic compound had disappeared from the incision sites by Day 28 and completely disappeared by Day 84. The tissue degree response was interpreted as a factor in the process of bioassimilation of the two hemostatic materials. Both hemostatic compounds contributed to adhesion formation in the experimental models. The incidence of adhesions was somewhat lower for MCH than for Gelfoam, but both produced more adhesions than were found at the control sites. The adhesions were only to the adjacent structures and always localized to the surgical site. When MCH or Gelfoam is used under conditions similar to those in the present experimental study, where tissue approximation is impaired, and where growth of granulation tissue is stimulated by the physical presence of the hemostatic compound, there is the possibility for increased incidence of adhesion formation. However, when an intraperitoneal absorbable hemostatic compound is desired, the present studies in experimental animals suggest that MCH will be safe by exhibiting minimal tissue reaction.