DERMOFLUOROGRAPHY - CLINICAL POTENTIALS A ND LIMITS

Dermofluorography (DFG) is based upon intravenously injection of sodiu m-fluorescein and subsequent detection of the skin fluorescence. We de veloped an exitationlamp with high intensity and constant output, thus beeing able to observe the patients extremities continuously with a C CD-videocamera attached to a digital image processing unit. For the ev aluation a pseudocolor-coded summation image enables a direct estimati on of the arrival of the dye and the topographical distribution of the fluorescence. The average appearance time, the initial slope (the rat e of density increase during the first 30 s after appearance) and maxi mal fluorescence (the average of density at 10 min) are automatically computed for various regions of interest. We investigated 12 patients suffering from peripheral arterial occlusive disease (6 in stage II-II I and 6 in stage IV according to the Fontaine classification), 4 patie nts with chronic venous insufficiency and 2 patients after lumbal symp athetic block and compared the results with those of 11 healthy subjec ts. The patients with peripheral arterial occlusive disease showed an increased skin perfusion at rest. The method allows an evaluation of t he completeness of a lumbar block. Because of the existence of several factors with different influences on the skin fluorescense detected b y dermofluorography, it is difficult to interpret the findings with re gard to microvascular lesions in peripheral arterial occlusive disease and chronic venous insufficiency without combination with other techn iques studying skin perfusion.