Discordance between histologic and visual assessment of tissue viability in excised burn wound tissue

Abstract

The regenerative capacity of burn wounds, and the need for surgical intervention, depends on wound depth. Clinical visual assessment is considered the gold standard for burn depth assessment but it remains a subjective and inaccurate method for tissue evaluation. The purpose of this study was to compare visual assessment with microscopic and molecular techniques for human burn depth determination, and illustrate differences in the evaluation of tissue for potential regenerative capacity. Using intraoperative visual assessment, patients were identified as having deep partial thickness or full thickness burn wounds. Tangential excisions of burn tissue were processed with hematoxylin and eosin to visualize tissue morphology, lactate dehydrogenase assay to ascertain cellular viability, and Keratin‐15 and Ki67 to identify epidermal progenitor cells and proliferative capacity, respectively. RNA from deep partial and full thickness burn tissue as well as normal tissue controls were submitted for RNA sequencing. Lactate dehydrogenase, Keratin‐15, and Ki67 were found throughout the excised burn wound tissue in both deep partial thickness burn tissues and in the second tangential excision of full thickness burn tissues. RNA sequencing demonstrated regenerative capacity in both deep partial and full thickness burn tissue, however a greater capacity for regeneration was present in deep partial thickness compared with full thickness burn tissues. In this study, we highlight the discordance that exists between the intraoperative clinical identification of burn injury depth, and microscopic and molecular determination of viability and regenerative capacity. Current methods utilizing visual assessment for depth of injury are imprecise, and can lead to removal of viable tissue. Additionally, hematoxylin and eosin microscopic analysis should not be used as the sole method in research or clinical determination of depth, as there are no differences in staining between viable and nonviable tissue.

Indeterminate-Depth Burn Injury—Exploring the Uncertainty

“…Complicating this assessment is the use of tourniquets and infiltration of vasoconstrictor agents (e.g., epinephrine) that are often employed to decrease the amount of blood loss during excision. 20 There is a fine balance between inadvertently removing viable tissue and leaving necrotic tissue in the wound bed; the latter risks autograft loss, as necrotic tissue increases inflammation and hinders wound healing. Therefore, surgeons tend to overexcise the wound, as evidenced by studies showing viable cells present in excised burn tissue.…”

Modelling early thermal injury using anex vivohuman skin model of contact burns

“…The mechanisms of burn progression early after injury, and the minimum regenerative capacity that is necessary for healing without surgery in deep partial thickness burns, are fundamental questions that remain unknown [2,3,21]. The lack of a clinically relevant, reproducible human skin burn model is a major barrier to addressing these mechanistic and clinically important questions.…”

Optimization of interstrand interactions enables burn detection with a collagen-mimetic peptide

“…49 Current methods to diagnose burns face challenges, such as the disparity between the clinical identification of burn depth and the histopathologic determination of cellular and ECM damage. 50 Further, only 70% of visual assessments of fullthickness burn injuries are accurate. 51 Our approach could enable the reliable detection of thermally damaged collagen in a clinical setting.…”