A scanning electron microscopy study of CO₂ laser-albumin soldering in the rabbit model

Objective: We sought to assess the rabbit as an experimental animal in the investigation of laser skin soldering. We studied, using the scanning electron microscope (SEM), the surface appearances of experimental incisions made on the rabbit back skin and soldered by CO₂ laser. Background Data: Laser soldering of incisions in various tissues is a modality of wound healing of a very promising clinical value. At present, more component studies on animals directed at paving the way towards clinical protocols are needed. Methods: Surgical incisions on rabbits back skin were bonded using either albumin-assisted CO₂ laser soldering (experimental) or thread suturing (reference). The incisions closed were excised 2, 3, 4, and 5 days postoperatively, and skin surfaces were studied in the SEM. Results: Naked eye inspection and SEM analysis showed that full-length sealing of soldered and sutured incisions was discernible as early as day 2. In the SEM, all incisions were found confluently coated by epidermal cells along the former cut streak. Soldering subserved to bond incisions efficiently, with surface smooth and close to normal skin. On the other hand, the surface of sutured incisions appeared convoluted and its aesthetic quality inferior to that of the former. Some of the days two and three soldered incisions suffered dehiscence on excision, which suggests an incomplete regeneration of tensile strength at this early phase of healing. Sutured incisions tolerated excision, very probably due to the microthread still present in the skin tissue rather than because of breaking strength regained during wound healing. Also, hair stumps re-grown on the skin by day 5 postoperative might impair satisfactory microscopy of bonded incisions. Conclusions: CO₂ laser soldering of incisions on the rabbit back skin effected rapid wound sealing and resulted in smooth scars indistinguishable from normal skin. The rabbit is well suited for this kind of studies, provided that excision of experimental cuts takes place not later than 5 days post-incision so that hair stumps may not grow large enough to jeopardize the quality of scanning electron microscopy.