Effects of burn location and investigator on burn depth in a porcine model.
BACKGROUND
In order to be useful, animal models should be reproducible and consistent regardless of sampling bias, investigator creating burn, and burn location. We determined the variability in burn depth based on biopsy location, burn location and investigator in a porcine model of partial thickness burns.


METHODS
24 partial thickness burns (2.5 cm by 2.5 cm each) were created on the backs of 2 anesthetized pigs by 2 investigators (one experienced, one inexperienced) using a previously validated model. In one of the pigs, the necrotic epidermis covering each burn was removed. Five full thickness 4mm punch biopsies were obtained 1h after injury from the four corners and center of the burns and stained with Hematoxylin and Eosin and Masson's trichrome for determination of burn depth by a board certified dermatopathologist blinded to burn location and investigator. Comparisons of burn depth by biopsy location, burn location and investigator were performed with t-tests and ANOVA as appropriate.


RESULTS
The mean (SD) depth of injury to blood vessels (the main determinant of burn progression) in debrided and non-debrided pigs pooled together was 1.8 (0.3)mm, which included 75% of the dermal depth. Non-debrided burns were 0.24 mm deeper than debrided burns (P<0.001). Burn depth increased marginally from cephalic to caudal in non-debrided burns, but showed no statistical differences for these locations, in debrided burns. Additionally, there were also no statistical differences in burn depths from midline to lateral in either of these burn types. Burn depth was similar for both investigators and among biopsy locations.


CONCLUSIONS
Burn depth was greater for caudal locations in non-debrided burns and overall non-debrided burns were deeper than debrided burns. However, burn depth did not differ based on investigator, biopsy site, and medial-lateral location.
Department of Emergency Medicine, Stony Brook University, Stony Brook, NY, USA. Electronic address: adam.singer@stonybrook.edu.
Adam J
AJ
Singer
Department of Emergency Medicine, Stony Brook University, Stony Brook, NY, USA.
Jimmy
J
Toussaint
Department of Emergency Medicine, Stony Brook University, Stony Brook, NY, USA.
Won Taek
WT
Chung
Department of Emergency Medicine, Stony Brook University, Stony Brook, NY, USA.
Henry C
HC
Thode
Department of Emergency Medicine, Stony Brook University, Stony Brook, NY, USA.
Steve
S
McClain
Research & Development Center, 7100 Euclid Avenue, Cleveland, OH 44103, USA.
Vivek
V
Raut
D000818:Animals; D005260:Female; D001706:Biopsy; D002056:Burns / Q000473:pathology / Q000601:surgery; D003646:Debridement; D020405:Dermis / Q000473:pathology / Q000601:surgery; D004195:Disease Models, Animal; D015203:Reproducibility of Results; D012108:Research Personnel; D034421:Sus scrofa; D013552:Swine; D006801:Humans
Biopsy location; Burn depth; Burn location; Investigator burn experience; Porcine burn model; Skin