Implantation of any foreign device or material through the means of surgery results in at least some degree of tissue trauma. Therefore, especially when removing a native heart valve either partially or completely, the tissue trauma will trigger a cascade of inflammatory responses and elicit acute inflammation. During the initial phase of acute inflammation, vasodilation occurs to increase blood flow to the wound site along with the release of growth factors, cytokines, and other immune cells. Furthermore, cells release reactive oxygen species and cytokines, which cause secondary damage to surrounding tissue.  These chemical factors then proceed to promote the recruitment of other immune responsive cells such as monocytes or white blood cells, which help foster the formation of a blood clot and protein-rich matrix.