Animal models in pressure ulcer research

Background/Objective: Research targeting the pathophysiology, prevention, and treatment of pressure ulcers (PrUs) continue to be a significant priority for clinical and basic science research. Spinal cord injury patients particularly benefit from PrU research, because the prevalence of chronic wounds in this category is increasing despite standardized medical care. Because of practical, ethical, and safety considerations, PrUs in the human environment are limited to studies involving patients with pre-existing ulcers. Therefore, we are limited in our basic knowledge pertaining to the development, progression, and healing environment in this devastating disease. Methods: This review provides a synopsis of literature and a discussion of techniques used to induce PrUs in animal models. The question of what animal model best mimics the human PrU environment has been a subject of debate by investigators, peer review panels, and editors. The similarities in wound development and healing in mammalian tissue make murine models a relevant model for understanding the causal factors as well as the wound healing elements. Although we are beginning to understand some of the mechanisms of PrU development, a key dilemma of what makes an apparently healthy tissue develop a PrU waits to be solved. Results and Conclusions: No single method of induction and exploring PrUs in animals can address all the aspects of the pathology of chronic wounds. Each model has its particular strengths and weaknesses. Certain types of models can selectively identify specific aspects of wound development, quantify the extent of lesions, and assess outcomes from interventions. The appropriate interpretation of these methods is significant for proper study design, an understanding of the results, and extrapolation to clinical relevance.