Practice Innovations
Autologous split-thickness skin grafting (STSG) is generally considered the “gold standard” for the treatment of acute and chronic wounds.1 However, STSG is limited by donor site tissue availability and donor site morbidity including scarring, increased pain and/or infection.2 Full-thickness autologous microcolumns (FTAM) of tissue have been shown to reduce donor site morbidity.3 We evaluated a novel automated skin harvesting device designed to collect 316 FTAM at 0.5mm diameter and depth of 3.25mm for the treatment of wounds in a porcine model.
Eighteen animals were included in a six-week wound healing study. All animals received 12 cm2 full-thickness excisional wounds that were treated with either FTAM, STSG or Untreated (without graft). Percent wound site coverage with donor site tissue was 5x greater for STSG recipient wounds compared to FTAM recipient wounds (50% and 10%, respectively). The healing trajectories for donor and treatment sites were monitored by clinical observation and wounds were collected for histologic analyses at terminal timepoints (Weeks 1, 3, and 6 (n=6 per group)). Stained tissues were scored in a blinded fashion by a pathologist.
Based on clinical observation, significantly faster FTAM donor site re-epithelization occurred at Day 4, compared to STSG donor sites. Histological analyses demonstrated that a higher percentage of FTAM donor sites expressed collagen compared to STSG donor sites throughout the study. The FTAM donor sites showed reduced exudate, less necrosis, more adnexal structures, and increased rete ridge restoration compared to the STSG donor sites. The time to recipient wound closure was 3.3 weeks, 2.4 weeks, and 4.1 weeks, for FTAM, STSG, and Untreated wounds, respectively (p< 0.05). Importantly, by Week 5, the FTAM recipient wound sites were completely re-epithelized largely attributed to “epithelial islands” and gap closure in contrast to wound site contracture observed in the Untreated wound sites.
We conclude that a novel automated skin harvesting device can be used to collect and dispense FTAM resulting in faster donor site healing and reduced donor site morbidity compared to STSG. The FTAM and STSG recipient wounds had comparable wound healing rates yet 5x less donor site tissue was harvested for FTAM treatments.