Burn wound assessment in porcine skin using indocyanine green fluorescence

Background: An accurate assessment of deep dermal burns within the first week after burn is still an unresolved clinical problem. Infrared-excited fluorescence of indocyanine green was examined as a method of early determination of burn depth. Methods: Burns of varying depths were placed on the paraspinal region, flank, and abdomen of swine using a heated brass block. Fluorescence images of the burns were recorded 1, 24, 48, and 72 hours later. Results: The ratio of fluorescence in 64 burn wounds relative to adjacent normal tissue identified wounds that healed and did not heal within 21 days with an accuracy of 100%, after accounting for the age of the burn. Higher fluorescence ratios were observed in newly placed burns relative to older burns having comparable depths. Conclusion: Deep partial-thickness burns were differentiated from deep dermal full-thickness burns in a porcine skin burn model independent of body location. Diagnosis was possible between 1 and 72 hours after injury.