Angiogenesis in pathological and surgical scars

We identified immunohistochemically vessels within cutaneous scars to test the hypothesis that they are qualitatively and quantitatively different in pathological and normally healing scars. The vascular density within and adjacent to 58 cutaneous scars was measured on histological sections stained for factor VIII-related antigen. Four scar types were studied; surgical scars (n = 25), hypertrophic scars (n = 10), keloid (n = 12), and periocular scars (n = 11). Statistical analyses were performed to test the hypothesis that vessel numbers were different in the varying types of scar. Results were also compared with mast cell counts previously derived from the same tissues. A significant reduction was found in the vascular density in keloids compared with surgical and hypertrophic scars (P < .05). No correlation was found between the vascular density and the number of mast cells in the lesions. We have shown quantitatively that keloids have a reduced vascular component compared with hypertrophic scars and normally healing surgical scars at periocular and systemic sites. The formation of keloid scars may be related to their reduced level of vascularization mediated through tissue hypoxia.