Development of noninvasive and quantitative methodologies for the assessment of chronic ulcers and scars in humans

Chronic ulcers are a significant and common cause of morbidity and mortalit y worldwide. They disrupt the epidermis and dermis, resulting in a loss of barrier function. Keloids and hypertrophic scars (benign cutaneous tumors) represent an abnormal healing response. These fibroproliferative disorders are characterized by an overabundance of collagen and accumulation of extra cellular matrix due to an imbalance between synthesis and degradation. culm inating in excessive scarring. The objectives of this study were to evaluat e and compare noninvasive biophysical methods for the measurement of outsta nding quantitative parameters of scars and chronic ulcers, and to establish correlations between the parameters measured and the results of convention al subjective clinical evaluations. The development of new technologies, ba sed on ultrasonography and laser Doppler, makes possible new dermatological evaluation methods. Fifteen patients (6 females and 9 males) with 15 chron ic ulcers (4 diabetic ulcers, 10 venous ulcers and 1 pressure ulcer) and 30 patients (19 females and 11 males) with 30 scars (25 hypertrophic and 5 ke loids) were included in this study. Clinical evaluation was performed by a dermatologist, an aesthetic surgeon and an endocrinologist. Biophysical mea surements were used to assess local blood flow by laser Doppler flowmetry ( Moor DRT4), thickness and echogeniciiy by high frequency ultrasonography (2 0 MHz, Dermascan C) and ulcer linear dimensions by image analysis. Our resu lts show that blood flow within the ulcers and scars was higher than within normal skin. Also, skin thickness of chronic ulcers was decreased when com pared to normal skin; the thickness of hypertrophic scars, but not of keloi ds, was increased in comparison to normal skin, and presented the possibili ty of measuring wound and scar surfaces with precision. In summary, this pi lot study established the feasibility of measuring various biophysical para meters and adapted their potential utility to research on wounds.