Debridement of porcine burns with a highly purified, ananain-based cysteine protease preparation.

A novel enzymatic debriding agent was evaluated on experimental full-thickness porcine contact burns. This agent consists of a highly purified, ananain-based, cysteine protease preparation formulated in a hydrophilic cream vehicle. Debridement of full-thickness burns was found to be dependent on several factors including the concentration of enzyme in the vehicle, the duration of treatment, and the hydration status of the burn wound before treatment. With an optimized debridement regimen, burns were consistently debrided of all gelatinized tissue with two 5-hour treatments. Histologic evaluation of the debrided wounds revealed an acellular deeper dermis that was debrided of necrotic cellular debris; however, the collagen matrix of the deeper dermis remained intact. This observation was consistent with a demonstrated in vitro specificity of the ananain-based protease for gelatin over collagen. A direct comparison of debridement efficacy with sutilains ointment, showed the ananain-based, debriding enzyme preparation to provide more rapid debridement of gelatinized tissue. Enzymatically debrided wounds exhibited graft take only after surgical excision of approximately 1 mm of the remaining acellular, avascular dermis. This highly purified enzyme preparation offers the potential for rapid nonsurgical debridement of gelatinized burn tissue, but required additional surgical debridement for graft take in this porcine model.