Assessment of Tissue Oxygenation Using Multispectral Imaging

In Canada, the age-standardized prevalence of diabetes is on the rise (increasing from 3.3% in 1998/99 to 5.6% in 2008/2009 Public Health Agency of Canada (July 2011)) and is almost 1 in 10 globally. One of the most devastating complications of diabetes is the loss of a limb, (also known as lower extremity amputation, or LEA) due to complications resulting from a diabetic foot ulcer (DFU). Diabetics have a lifetime risk of 15-25% of developing a DFU1, which can lead to significant decreases in the quality of life, limitations in mobility, function and independence, and increased chance of depression and anxiety. In addition, diabetics post-LEA have high rates of mortality, with 30% dying in the first year post LEA and 70% at 5 years (more than the lifetime risk of dying from cancers). What differentiates a DFU that heals and one that progresses to LEA is often the vascularity of the limb; the diabetic lower extremity often becomes ischemic due to the vascular sequelae that are a common complication of diabetes, which hampers wound closure and immune clearance of wound-associated infections. Understanding limb oxygenation can direct treatment of a DFU, which may require limb revascularization to heal.