Development of an experimental heterogeneous burn wound model

Jamie Neelon; Marc A Thompson; Sergio A Garcia; Addison Hicken; Logan Leatherman; Randolph Stone Ii; Kristo Nuutila

doi:10.1016/j.burns.2024.107303

Development of an experimental heterogeneous burn wound model

Burns. 2024 Oct 28;51(1):107303. doi: 10.1016/j.burns.2024.107303. Online ahead of print.

Authors

Jamie Neelon¹, Marc A Thompson², Sergio A Garcia², Addison Hicken², Logan Leatherman², Randolph Stone Ii², Kristo Nuutila³

Affiliations

¹ Department of Surgery, Brooke Army Medical Center, Fort Sam Houston, TX, USA; United States Army Institute of Surgical Research, Fort Sam Houston, TX, USA.
² United States Army Institute of Surgical Research, Fort Sam Houston, TX, USA.
³ United States Army Institute of Surgical Research, Fort Sam Houston, TX, USA. Electronic address: kristo.j.nuutila.ctr@health.mil.

PMID: 39579581
DOI: 10.1016/j.burns.2024.107303

Abstract

Background: Many research-based burn models rely on creating homogenous burns that are subsequently studied and treated. However, the majority of burn wounds sustained - and in particular those that are combat-related - are heterogeneous in nature, with varying degrees of severity intermixed throughout the entire wound, creating a complex debridement and overall treatment plan. The purpose of this study was to develop a clinically relevant heterogeneous porcine burn wound model.

Materials and methods: This study consisted of 3 anesthetized pigs with up to 6 heterogeneous 10 cm x 10 cm burn wounds. The burns were created using a thermocouple device with a square plate (5 cm x 5 cm) heated to 100 °C applied to the skin at constant pressure. The device was applied for a duration between 2-20 s for each burn segment to create burns of varying severity (superficial, partial-thickness, and full-thickness). Each heterogeneous burn wound consisted of 4 separate 5 cm x 5 cm burns, each with different and randomized burn times. Macroscopic images of the burns were obtained on days 0, 1, and 3. A punch biopsy was collected from each burn segment (1 of each depth) to determine the burn depth on day 0. On day 3, after euthanasia, all of the burns were harvested to give a cross-sectional view of the burn.

Results: Histology demonstrated that heterogeneous burns were created and burn progression was evident during the 3-day follow-up time. The depth of the burn wound significantly correlated with the burn time. By day 3, the 20-second burn wound had the deepest depth at 1003 ± 67 µm while the 2-second burn wound had the shallowest depth of burn at 258 ± 19 µm. Burn heterogeneity was also demonstrated with laser speckle image analysis. By day 3, the superficial blood flow for 20, 15, 12, 9, and 6 s burn times was below 85 AU. The 2 s burn mean flux (138 ± 48 AU) was noticeably different from other groups and well above the intact skin values (102 ± 4 AU). It was also shown that on day 3, at least 1 burn for each burn time resulted in identifiable infection via macroscopic imaging.

Conclusions: The heterogeneity of burn wounds creates a clinical challenge. This model will help to create burns that are more similar to the heterogeneous burn wounds that are seen in clinical practice and will help further research efforts in treating burns.

Keywords: Burn research; Burns; Experimental model; Heterogeneous burns; Porcine model.