In Vivo Evaluation of Wound Bed Reaction and Graft Performance After Cold Skin Graft Storage: New Targets for Skin Tissue Engineering

Platelet-Rich Plasma for Skin Graft Storage: An Experimental Study Using Rabbit Ears

BACKGROUND

Storage of surplus grafts for later use is one of the standard procedures used in plastic surgery. For the delayed use of skin grafts, various methods and media have been investigated for short-term storage. This study aimed to investigate the effect of platelet-rich plasma (PRP) skin graft storage on the survival of skin grafts obtained from rabbit ears.

MATERIALS AND METHODS

Twelve rabbits were used in this study. A total of 12 skin grafts measuring 1 × 1 cm were obtained from the inner surfaces of the rabbits' ears. The grafts were stored at +4°C in saline, Hartmann's, and PRP media. On days 3, 7, 10, and 14, the grafts were implanted into the ears in areas measuring 1 × 1 cm where the skin, cartilage, and perichondria were excised. After the implantation of the grafts, the survival rates were evaluated by measuring the graft areas on day 0, day 10, and day 30.

RESULTS

The graft survival rate decreased as the storage period increased in all 3 of the media. The decrease in survival rate was higher in the grafts that were stored in the Hartmann's media in comparison with the saline and PRP media, and the difference was statistically significant. The decrease in graft survival was similar between the storage in saline and PRP media; however, the differences were statistically insignificant.

CONCLUSIONS

Although in vitro criteria are important for evaluating graft survival, in vivo studies showing the graft take rate in the recipient area are required. When the in vivo criteria are evaluated, the use of PRP is not superior to the use of saline for graft storage. However, additional studies are required to evaluate the effects of PRP media on graft quality.

Skin graft storage in platelet rich plasma (PRP)

Storage of skin grafts for later use is one of the standard applications in surgery. It is the most preferred method to maintain at +4°C in refrigeration after wrapping the surplus grafts into sterile gauze pad moistened with saline. Although there are many studies on the storage of skin grafts, less is known about storing skin grafts with PRP. Twenty-five pieces of 1 × 1 cm² partial thickness skin graft were harvested from 12 patients during the reduction mammoplasty operation. Twenty-four grafts were divided into 4 groups, and each group consisted of 6 grafts, 1 graft was analyzed as Day 0. Grafts in Group 1, 2, and 3 were wrapped by sterile gauze pad moistened by either saline (Group 1) or Hartman (Group 2) or PRP (Group 3). Grafts were analyzed macroscopically and microscopically. There were no significant differences between media for the first 10 days. Decrease in viability was less in saline and PRP wrapped grafts at 20 day, viability decreased significantly in all environments after 20 days. Although there was no significant difference in saline or PRP storage, it was observed macroscopically that the grafts stored in the PRP appeared better.

Induced Granulation Tissue but not Artificial Dermis Enhances Early Host-Graft Interactions in Full-Thickness Burn Wounds

BACKGROUND

Cellular grafts used for skin repair require rapid integration with the host tissue to remain viable and especially to nourish the epidermal cells. Here, we evaluated the responses in the split-thickness skin grafts (STSGs) grafted on three differently treated wound beds: directly on excised wound bed (EX), on an artificial dermal template (DT) and on granulation tissue (GT) induced by cellulose sponge.

METHODS

In ten burn patients, after excision, a test area was divided into three sections: One transplanted with STSG instantaneously and two sections had a pre-treatment for 2 weeks with either DT or a cellulose sponge inducing granulation tissue formation and thereafter grafted with STSGs.

RESULTS

One week after grafting, the STSGs on GT demonstrated most endothelial CD31⁺ staining, largest average vessel diameters as well as most CD163⁺ staining of M2-like macrophages and most MIB1⁺ proliferating epidermal cells, suggesting an active regenerative environment. STSGs on DT had smallest vessel diameters and the least CD163⁺ macrophages. STSGs on EX had the least CD31⁺ cells and the least MIB1⁺ proliferating cells. After 3 months, this reactivity in STSGs had subsided, except increased dermal cell proliferation was observed in STSGs on EX.

CONCLUSIONS

Results show that pre-treatment of wound bed and induction of granulation tissue formation can accelerate host-graft interaction by stimulating graft vasculature and inducing cell proliferation.

The Use of Platelet-Rich Plasma for Storage of Surplus Harvested Skin Grafts

BACKGROUND

There is a need for improved methods and storage media to sustain the tissue viability of autologous skin grafts.

OBJECTIVE

To compare histological changes in human skin grafts stored in platelet-rich plasma (PRP) with those of grafts stored in saline.

METHODS

Eight circular, 3-mm full-thickness skin graft samples were harvested from the abdominal skin of each of 5 patients scheduled to undergo an abdominoplasty procedure. Four of these graft samples were stored in saline, and the other 4 were stored in saline mixed with PRP prepared from the patient's own venous blood. Histological assessment of the microscopic appearance of the samples was performed on days 5, 8, 11, and 14. The integrity of the epidermal-dermal junction, number of keratinocytes with perinuclear halos, collagen organization, and number of fibroblasts per field were assessed. The cellular apoptosis rate was also measured on these same days.

RESULTS

On day 5, significant differences were observed microscopically between the PRP- and saline-stored grafts (P < .05). The grafts preserved in saline exhibited early marked cellular and nuclear swelling with pleomorphism, as well as early nuclear halo formation. The cell viability rate of the PRP group was significantly higher than that of the saline-stored group on day 8 (P < .05).

CONCLUSION

Platelet-rich plasma and its inherent growth factors supported longer graft survival; however, its effect lasted only until day 8. Platelet-rich plasma may be beneficial if grafts need to be stored for delayed application(s).