Immediate burn excision fails to reduce injury progression

The contact thermal injury model in the pig was used to determine whether immediate burn excision could alter the extent of injury progression. It was hypothesized that immediate excision of burns would prevent or reduce tissue necrosis in the uninjured interspaces. Four comb burns were created on the back of each animal, using a brass comb preheated in hot water (100 °C) for 5 minutes. This brass comb produced four distinctive burns sites separated by three "interspaces" of unburned skin, which were to undergo progressive injury. Immediately after burn creation, half of the full-thickness burns were excised leaving the unburned interspaces intact. Two full-thickness excisional wounds per pig with the dimensions identical to the comb burns were included as controls. Burn injury progression was microscopically assessed and reported as the percentage of unburned interspaces that progressed to full-thickness necrosis 7 days after injury. Scar formation was grossly evaluated on day 28 after injury and reported as the total surface area (in square centimeters) of the scar. A total of 24 combs with 72 interspaces were evenly distributed among the three groups. The unburned interspaces of both comb burns and excised comb burns had undergone progressive injury and were 100% dead (24/24; i.e., necrotic and/or apoptotic) 7 days postinjury (95% confidence interval, 86-100%) for both. However, interspaces of the control excisional wounds maintained complete viability, that is, no necrosis or apoptosis (0/24 [0%]; 95% confidence interval, 0-14%; P < .001). There was no significant difference in both surface area and depth of scar resulting from excised and nonexcised comb burns. Immediate burn excision neither prevented nor limited burn injury progression.