Vesicant burns : is laser debridement ('lasablation') a viable method to accelerate wound healing?
The vesicant agents, Lewisite and sulphur mustard were initially deployed as chemical weapons in the First World War at Ypres in 1917. These agents cause immediate blistering followed by deep dermal to full thickness burns and can be fatal in 1-3% (NATO 1996). Dermabrasion can accelerate the healing of these types of burn injuries without the need for additional split skin grafting (Rice 1997 and Rice, Brown & Lam et al 1999). Current laser technology allows accurate laser debridement of burn wounds. The corollary of this is that it should be feasible to partially laser debride a vesicant burn to accelerate healing. This treatment should be more precise, encouraging rapid healing compared to dermabrasion. This thesis investigated the application of modem C02 and Erbium:YAG lasers for debriding Lewisite burns on a representative model. A large white pig model (n=6) was used to investigate the effectiveness of C02 and Erbium:YAG lasers in ablation of established Lewisite burns. Burns underwent treatment at four days post-exposure and were histologically assessed at one, two and three weeks thereafter for the rate of epithelial healing. The re-epithelialisation rates in the laser debrided groups were accelerated by a factor of four compared to untreated, historical controls by the first week. (Anova p = 0.006 for pulsed C02 and p = 0.012 for Erbium: YAG). Ablation of the burn eschar was thought to accelerate the rate of healing by causing partial debridement. This method has been termed 'lasablation' A concurrent study of C02 and Erbium: YAG laser debridement of normal skin resulted in a superficial resurfacing burn which healed within a week, regardless of the type of laser. The burn depth was in the order of 150 urn. The superficial nature of these burns allowed for rapid healing, consistent with previous findings. All work was carried out in accordance with the Animals (Scientific Procedures) Act 1986 with Home Office approval.