CorMatrix tubular grafts implanted as interposition conduits in ovine carotid artery - a quantitative histological study 360 days after implantation
Abstract
Two types of CorMatrix (CMX) tubular grafts, namely CorMatrix 4 (CMX4) and CorMatrix 6 (CMX6), were used and implanted as interposition grafts into ovine carotid arteries. After 360 days, the samples were explanted and underwent stereological analysis of microscopic composition.
The CMX material before implantation was thinner than the native carotid artery. The CMX before implantation contained a smaller fraction of smooth muscle cells and less elastin than native carotid artery.
On the contrary, native carotid artery had less total collagen, less type I and type III collagens than the CMX before implantation. The CMX material contained a considerable density of residual nuclear fragments.
After 360 days, the wall thickness of the free grafts considerably expanded, exceeding their pre-implantation thickness as well as the wall thickness of adjacent native carotids. The in vivo expansion of the graft decreased the density its collagen, but the fraction of collagen in the graft still exceeded the collagen fraction in adjacent native carotids.
After 360 days in vivo, the free graft still contained less actin and less elastin than native carotid arteries. The free graft was invaded by vasa vasorum that reached a greater density than the vasa vasorum of adjacent native carotids.