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 débrided 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 microm 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.

Burn depth estimation by use of indocyanine green fluorescence: initial human trial.

Indocyanine green dye (ICG) fluoresces when illuminated by infrared light. After successful trials in a porcine model and with approval of the Massachusetts General Hospital's human studies committee, 10 adult patients with burn injuries were given 0.2 mg/kg ICG intravenously, and 825 nm fluorescence images were obtained with 780 nm excitation at 5 minutes after injection in the initial five patients and at 1, 2, 3, 4, 5, and 10 minutes in the subsequent five patients. Fluorescence intensities at burned and unburned sites were determined and images were correlated with burn depth as determined by healing or intraoperative assessment. In the latter five patients, seven sites were imaged (six that were of partial thickness and one that was of full thickness). The burn/normal skin fluorescence ratio was greater than 1 for superficial burns and less than 1 for deep burns. Imaging within 5 minutes of injection resulted in optimal contrast between injured and uninjured tissue. In this initial pilot trial it is apparent that ICG fluorescence has potential value as an aid in the early estimation of burn depth. In subsequent trials we will attempt to refine our ability to correlate ICG fluorescence images with burn depth.