Most often, patients with critical limb ischemia, undergo multiple debridements in the operating room as well as vascular procedures, prior to reaching a viable level of amputation. This increases the patients' co-morbidities from repetitive exposure to anesthesia. Each debridement may be removing viable tissue and decreasing the length of the eventual amputation. Additionally, intraoperatively, the viability of the skin edges is a subjective assessment based on the surgeon's experience. That judgement can be inaccurate in 10-20% of cases and lad to reoperation. With the use of the SPY imaging system, a better assessment of not only macrovascularity, but also microvascularity of the tissues is able to be evaluated objectively. This helps identify the tissues that are underperfused.