Ischemia/reperfusion: A potential cause for tissue necrosis

There are many clinical conditions which are either caused or exacerbated by ischemia/reperfusion injury (IRI). While the wound care community has expanded its understanding of the cellular and molecular mechanisms surrounding the healing process, research involving the microcirculation and its impact on healing has been limited. Reasons for this include but are not limited to an emphasis on the diagnosis and treatment of macrovascular disorders, the absence of surgical options directed at the microcirculation, and a limited number of pharmacologic and/or modality–based therapeutic options. There are also few well–accepted methods for the diagnosis of adequate tissue perfusion, and those that are available have not been transferred well from the lab to the bedside. Clinicians are therefore left with their experience and macro–level observations as a primary means for gauging successful outcomes. Once macro–level changes are apparent, however, it is often too late to intervene therapeutically thus limiting the potential efficacy of treatment options. In this chapter, we will describe the basic anatomy and physiology of the microcirculation and then focus on the consequences, both positive and negative, of the restoration of flow to ischemic tissue. New potentially useful diagnostic methods for assessing tissue perfusion and microcirculation will be presented along with a clinical case that will bring these didactic concepts into a real–world clinical setting. Finally, new treatment options that may mitigate the effects of ischemic reperfusion injury will be discussed.