A new preparation process was studied which should allow the implantation of collagen type I in its native structure in reconstructive surgery, in this special case for closure of incisional hernias. As experimental animals we used 30 female Lewis rats. A defect of the anterior abdominal wall measuring 3 cm X 4 cm was closed with our collagen substitute. Biopsies taken after 4, 6 and 8 weeks were examined morphologically. As criteria for revitalization and revascularization we used the type of infiltrating cells, the depth and density of infiltration and the formation of new blood vessels. After 4 weeks the implants were infiltrated by fibroblasts that decreased in density towards the centre. Good revascularization could be seen on the muscle-implant interface. After 6 weeks the density of infiltrating cells had increased markedly even to the centre of the collagen implant. Sporadically small vessels could be seen. Eight weeks after implantation the density of infiltrated cells was at the same high level, and capillary bundles could be seen within the whole implant. We believe that this collagen implant is suitable for the closure of hernias as shown by its physical and morphological properties. In particular it appears to guarantee and earlier and tighter closure of hernias than other materials.
Animals Biocompatible Materials