Fluorescein angiography and distal arterial pressure in patients with arterial disease of the legs

Self Cite

Video fluorescein imaging (VFI) is a new technique to continuously follow the development of fluorescence in the skin, i.e. blood inflow and perfusion, after intravenous injection of sodium fluorescein. The method is supplementary to other microcirculatory techniques for evaluation of peripheral arterial occlusive disease, particularly in critical ischaemia. In the present article we describe a totally computerized digital imaging processing system for evaluation and present results from a comparison between the evaluations of the appearance and development of the fluorescence in the sole of the foot using the computerized and the previously used manual techniques. With the computerized system the images are stored and correlated with the start of the injection. Regions of interest are then marked and a mean value of fluorescence intensity is calculated for each image. Using this computerized system the time required for evaluation has been shortened to about 10 min. The results of the comparison between the manual and computerized evaluations of appearance times showed that a significant correlation existed in all examined parts of the feet between the two techniques. The methods gave approximately the same results in regions with fluorescence appearance times between 20 and 50 s. With longer appearance times than approximately 50 s a systematic difference between the two techniques seemed to exist. In this interval shorter appearance times were measured with the computerized technique than with the manual technique. However, the clinical information with regard to prognosis would be relatively unchanged when the new computerized assessment technique and a new cut-off level for the appearance time are used. Also, regarding the development of fluorescence after the appearance time, expressed by the slope, a significant correlation was found between the manual and the computerized evaluation.

Section: Discussionsupporting

confidence: 94%

“…Slope values were expressed in units as the fluorescence intensity 10 s after the appearance of fluorescence in per cent of the maximum intensity (Wallin et al ., 1989).…”

Section: Methodsmentioning

confidence: 99%

Computerized analysis of video fluorescein imaging (VFI) of the skin

Lund¹,

Jogestrand²,

Kölegård³

2000

Self Cite

“…For limbs with arterial occlusions it has been demonstrated that in response to such a provocation manoeuvre macrocirculatory flow rates initially rise at the calf whereas they do not increase at the foot until proximal ones begin to return toward their control level (Bollinger et al , 1976). In contrast, when lowering the peripheral resistance by a metabolic stress the inverse relationship between both parameters again became obvious as recently reported for the state of peripheral vasodilation induced by elevating ambient temperatures (Scheffler & Rieger, 1988;Wallin et al, 1989). Under resting conditions no correlation between fluorescein appearance times (microcirculatory estimate of flow rates) and systolic ankle pressure indices (macrocirculatory estimate of perfusion pressure at rest) could be observed for the extremities included in this study as to be expected in case of a preserved dermal autoregulation of microvascular flow downstream from sufficiently compensated vascular obstructions (Henriksen & Paaske, 1980).…”

Section: Total Blood Flow During Reactive Hyperaemiasupporting

confidence: 74%

“…Recently, in a similar way, an increased heterogeneity of fluorescein delivery could be provoked in patients with arterial occlusive disease by an experimental reduction of perfusion pressures combined with high ambient temperatures (additional vasodilatation due to a suppression of sympathetic and myogenic activities; Wallin et al, 1989). A deterioration of acral skin perfusion patterns characterized by a development of steal effects also occurred after intra-arterial infusion of vasodilator drugs, e.g.…”

Section: Distribution Of Blood Flow During Reactive Hyperaemiamentioning

confidence: 99%

Skin perfusion patterns (fluorescein perfusography) during reactive hyperaemia in peripheral arterial occlusive disease

Scheffler¹,

Bold²,

Lienke³

et al. 1991

From the pathophysiological point of view the regional distribution of blood flow is of special importance in ischaemic tissues. Within this study foot sole skin perfusion was investigated by means of fluorescein perfusography at rest and during reactive hyperaemia in patients with peripheral arterial occlusive disease confined to one limb (Fontaine stage II). Ambient temperatures were maintained around 21 degrees C. Mean fluorescein appearance times on the one side and their standard deviations (SD) and coefficients of variation (CV) on the other side were taken as measures of overall blood supply and homogeneity of flow, respectively. At rest no differences in these parameters could be detected between diseased legs and controls. After a 3-min supra-systolic circulatory arrest at the thigh, a significant reduction of fluorescein appearance times was observed for both groups but was statistically more pronounced in the controls. Furthermore, during reactive hyperaemia standard deviations as well as coefficients of variation decreased significantly only in normal limbs whereas they either remained constant (SD) or even increased (CV) in those with arterial obstructions. All effects associated with reactive hyperaemia showed statistically significant correlations with systolic ankle pressure indices. From these results it is concluded that haemodynamically effective arterial obstructions are followed by not only a restriction of overall hyperaemic blood supply but also a failure to homogenize microcirculatory perfusion in the case of increased flow requirements.

“…However, such circumscribed measurements did not reflect possible topographical changes of cutaneous blood flow distribution. Fluorescein perfusography, in turn, is capable of recording two-dimensional stationary perfusion patterns of superficial skin layers (Lund, 1981;Perbeck et al, 1987;Wallin et al, 1989). Therefore, in the present study, this technique was applied to investigate postural effects on the cutaneous perfusion distribution between calf and foot in limbs with PAOD of varying severity.…”

Section: Introductionmentioning

confidence: 99%

Redistribution of skin blood flow during leg dependency in peripheral arterial occlusive disease

Scheffler¹,

Jendryssek²,

Rieger³

1992

A disturbed autoregulation of cutaneous blood flow in legs with peripheral arterial occlusive disease (PAOD) has previously been demonstrated for circumscribed skin areas. In the present study, posturally-induced changes of skin perfusion distribution along ischaemic limbs were investigated topographically in 35 PAOD patients by means of fluorescein perfusography. Among the 68 legs studied, 7 had patent arteries and 61 could be assigned to FONTAINE stages I to IV. Limbs with peripheral skin lesions (stage IV) were further differentiated according to either healing (stage IV+) or non-healing (stage IV-) on conservative treatment. Sitting-up always led to prolonged calf as well as foot fluorescein appearance times (AT) except for legs in stage III or IV- disease. In the latter two groups, decreased sitting as compared to supine AT foot-to-calf ratios indicated a relative shift of dye delivery from proximal towards distal skin regions during posture. In contrast, this measure of blood flow redistribution did not change in the other groups. The redirection of fluorescein influx was significantly correlated with the systolic arterial pressure ankle-to-arm ratios. In conclusion, besides small perfusion pressure increases or passive microvessel distension, a shift of the peripheral resistance ratios may contribute to the improved blood supply of ischaemic skin regions during leg dependency. An arteriolar vasoparalysis does not regularly exist in limbs with skin lesions not primarily originating from ischaemia (stage IV+).