Survival and Wound Contraction of Full-Thickness Skin Grafts are Associated With the Degree of Tissue Edema of the Graft Bed in Immediate Excision and Early Wound Excision and Grafting in a Rabbit Model

Abstract

The objective of this study was to evaluate the survival of skin grafts on graft beds of immediate excision and early wound excision at various time periods after burns and to establish the appropriate timing of burn excision and grafting in a rabbit model. Eight groups of male Japanese white rabbits (n = 5 per group) were established. Animals of all groups were given a 5 x 10-cm full-thickness burn on their shaved back and received the autografting 3, 6, 12, 18, 24, 48, and 72 hours and 5 days after receiving burns, respectively. Weekly skin-graft evaluation was performed for 5 weeks after grafting by measurement of the secondary skin graft contracture (in size) and the survival area of grafts, with use of computerized planimetry. In addition, relative quantitative analysis of exudation on the burned wound was evaluated. Our results indicated that the exudate-related graft loss and graft contracture varied according to the timing of wound excision. The wound contractures of the grafts were maximal in both the 18-hour and 24-hour groups at 2, 3, 4, and 5 weeks after grafting. The 18-hour and 24-hour groups exhibited significantly greater graft loss than the 72-hour and 5-day groups (P < .05). An apparent increase in the amount of exudation on the graft bed was shown in the 18- and 24-hour groups vs the other groups (P < .05). A reverse correlation was detected between the survival area of the skin graft and the degree of exudation of the graft bed. In conclusion, the survival area and secondary contraction of skin grafts are associated with the degree of tissue edema of the graft bed in immediate excision and early excision in the rabbit model. The adverse affect of edema leakage on the graft bed for skin graft survival was shown. We believe that immediate excision or early wound excision and grafting performed within 12 hours after burn or 48 hours later should be considered in the rabbit model.

Primary contraction of skin grafts: a porcine preliminary study

“…[1] Keratinocytes may also play a distinct role at the early stages of contraction, since studies have shown that keratinocytes are capable of inducing collagen gel contraction in vitro. [12][13][14][15] The actinfilament organization within keratinocytes at the wound margin appears to be responsible for the epidermal "purse-string phenomenon". [14] In addition, cytokines and growth factors such as ransforming growth factor-β1, insulin-like growth factor and fibroblast growth factors have also been found to play a major role in secondary contraction.…”

“…[14] In addition, cytokines and growth factors such as ransforming growth factor-β1, insulin-like growth factor and fibroblast growth factors have also been found to play a major role in secondary contraction. [15] Unlike secondary contracture, which is the result of a prolonged biological process, primary skin graft contraction is mainly an immediate physical change in graft dimensions mediated by the tough fibrous layer of the dermis, which is primarily composed of collagens, glycosaminoglycans and elastins.…”

Prolonged survival of GalT‐KO swine skin on baboons

“…A treatment option that has helped to decrease mortality over the past 10 yrs has been the immediate excision of burned skin with replacement by grafted skin [2–4]. The ideal material for grafting is autologous skin, taken from a non‐burned region of the patient’s own skin.…”

Lack of Cross-Sensitization Between α-1,3-Galactosyltransferase Knockout Porcine and Allogeneic Skin Grafts Permits Serial Grafting

“…The current standard of care for burns requiring operative treatment is early burn excision and split-thickness skin grafting (3, 4). Autologous skin, harvested from nonburned regions of the patient’s own body, is preferred; however, in large burns, sufficient donor sites may not be available to achieve the necessary coverage even when meshed grafts are utilized (5, 6).…”