Chronic leg ulcers are frequent and debilitating complications of sickle cell anemia. Inadequate blood supply has been postulated to be an important factor in their occurrence and delayed healing. Little is known about their microcirculatory and histopathological changes. We evaluated the microcirculation of lower extremity ulcers with laser speckle contrast imaging and infrared thermography, and obtained clinical and laboratory characteristics in 18 adults with sickle cell anemia and chronic leg ulcers. Skin biopsies were obtained in four subjects. Subjects had markers of severe disease, anemia, and high degree of hemolysis, inflammation and thrombophilia. Higher blood flow was present in the ulcer bed, lesser in the immediate periwound area, compared to an unaffected control skin area. Microscopic examination showed evidence of venostasis, inflammation, and vasculopathy. Blood vessels were increased in number, had activated endothelium and evidence of thrombosis/recanalization. High blood flow may be due to chronic inflammation, cutaneous vasodilatation, and involvement of arterio-venous anastomosis. These changes in skin microcirculation are similar to chronic venous ulcers in the non-SCD population, thus suggesting that leg ulcers may be another end-organ complication with endothelial dysfunction that appears in patients with SCD at a younger age and with higher frequency than in the general population. Analysis of vascular tone on ulcer periphery was performed and will be reported in 2015. The skin temperature circadian rhythms of the patients are in the process of being analyzed.

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4
Fiscal Year
2014
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Biomedical Imaging & Bioengineering
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