137 Maximal Harvest Density of Full-Thickness Skin Columns in Skin Replacement Therapy

Abstract

Abstract Introduction Split-thickness skin grafts (STSGs) are the mainstay of skin replacement therapy but fail to adequately reproduce basic skin functions and subject patients to new, open wounds that can cause significant pain and scarring. Full-thickness skin grafts (FTSGs) have improved cosmetic outcomes and better recapitulate skin functions, but few sites can serve as donors and requirement for “take” is greater. Prior research has shown that full-thickness skin column (FTSC) harvest results in improved healing of the injured site and decreased morbidity of the donor site at 10% harvest density. This study aims to determine the maximal harvest density of FTSC donor sites. Methods Ten donor sites were created on the dorsum of anesthetized swine (Sus scrofa domestica). STSG donor sites were harvested with a dermatome (12/1000 inch) and compared to FTSC donor sites with the highest possible harvest ratio of sixteen 1.5mm-diameter skin columns/1cm2 (28% harvest density). Donor site morbidity was assessed via re-epithelialization, contraction, pigmentation, number of hair follicles, and scar thickness on post-burn day (PBD) 7, 14, 21, 28, 60, and 90. Results There were no significant differences in re-epithelialization or contraction between FTSC and STSG donor sites. STSG donor site pigmentation was significantly decreased as compared to control on all assessment days (p=0.0161, 0.0003, 0.0031, 0.0095, 0.0244, respectively), and remained significantly hypopigmented as compared to FTSC starting at PBD 14 (p< 0.0001). Pigmentation was decreased for FTSC donor sites at PBD 14 (p=0.0204) but significance was lost by PBD 21. Both FTSC and STSG donor sites showed significantly fewer hair follicles as compared to control at PBD 7 (p=0.0011, 0.0003, respectively). On PBD 21, STSG had significantly less hair follicles as compared to FTSC donor sites (p=0.0010). This resolved by PBD 28. FTSC scars were significantly thicker than both control and STSG at PBD 28 (p=0.0348, 0.0038, respectively) and PBD 60 (p=0.0174, 0.0329, respectively). This significance was lost by PBD 90. Conclusions No statistically significant differences were seen in re-epithelialization and contraction between FTSC and STSG donor sites. STSG were hypopigmented as compared to FTSC donor sites and had significantly less hair follicles at day 21. FTSC donor site scars were significantly thicker than STSG. Although decreased donor site morbidity has been observed at lower harvest densities (10%), these results were not seen at 28%, which likely exceeds the optimal harvest density.