Carbon dioxide laser ablation with immediate autografting in a full- thickness porcine burn model

Objective: To compare the long-term clinical and histologic outcome of immediate autografting of full-thickness burn wounds ablated with a high- power continuous-wave CO₂ laser to sharply debrided wounds in a porcine model. Summary Background Data: Continuous-wave CO₂ lasers have performed poorly as tools for burn excision because the large amount of thermal damage to viable subeschar tissues precluded successful autografting. However, a new technique, in which a high-power laser is rapidly scanned over the eschar, results in eschar vaporization without significant damage to underlying viable tissues, allowing successful immediate autografting. Methods: Full- thickness paravertebral burn wounds measuring 36 cm² were created on 11 farm swine. Wounds were ablated to adipose tissue 48 hours later using either a surgical blade or a 150-Watt continuous-wave CO₂ laser deflected by an x-y galvanometric scanner that translated the beam over the tissue surface, removing 200 μm of tissue per scan. Both sites were immediately autografted and serially evaluated clinically and histologically for 180 days. Results: The laser-treated sites were nearly bloodless. The mean residual thermal damage was 0.18 ± 0.05 mm. The mean graft take was 96 ± 11% in manual sites and 93 ± 8% in laser sites. On postoperative day 7, the thickness of granulation tissue at the graft-wound bed interface was greater in laser- debrided sites. By postoperative day 180, the manual and laser sites were histologically identical. Vancouver scar assessment revealed no differences in scarring at postoperative day 180. Conclusions: Long-term scarring, based on Vancouver scar assessments and histologic evaluation, was equivalent at 6 months in laser-ablated and sharply excised sites. Should this technology become practical, the potential clinical implications include a reduction in surgical blood loss without sacrifice of immediate engraftment rates or long- term outcome.