In vivo ultrasonic parametric imaging of carotid atherosclerotic plaque by videodensitometric technique.

Extensive experimental and clinical data show that the ultrasonic image conveys information on the biochemical composition of the atherosclerotic plaque, ie, the relative content of lipids (hypoechoic), fibrous tissue (hyperechoic), and calcific deposits (very echogenic with shadowing). A more dishomogeneous echo structure of the plaque is also more often associated with clinically complicated carotid plaques. To date, however, the assessment of plaque density and homogeneity by transcutaneous B-mode imaging remains subjective and qualitative. The aim of this study was to assess whether plaque echodensity and homogeneity might be established on a more objective and quantitative basis by description of the spatial distribution of echo amplitude (referred to as tissue texture) applied to digitized images, obtained with commercially available B-mode transcutaneous imaging systems. A total of 47 B-mode images derived from echotomographic studies in 10 patients were digitized off line. For each region of interest, a set of first-order (mean gray level, standard deviation, skewness, kurtosis: mathematical descriptors of the shape of the frequency distribution of gray-level histogram) and of second-order (entropy, angular moment: mathematical descriptors of the spatial distribution of gray levels within the region of interest) textural parameters were evaluated. The visual, concordant reading by two independent, experienced observers assigned the plaques on the basis of qualitatively assessed echodensity to three groups: "soft" (n = 18), "fibrotic" (n = 20), "calcific" (n = 9). Regarding spatial gray-level distribution, 46 plaques would be separated into "homogenous" (n = 17) and "dishomogeneous" (n = 29). On digitized images, the normalized mean gray level was the most effective first-order textural parameter for distinguishing soft (24.2 +/- 12.4 arbitrary units in a zero to 255 scale) from fibrotic (64.5 +/- 16.4) and calcific plaques (125.3 +/- 24.5), P < 0.01 for all intergroup differences. "Homogeneous" plaques were separated from "heterogeneous" ones on the basis of entropy (5 +/- 1 vs 7.9 +/- 9.7; P < 0.01), whereas the values of angular second moment overlapped (1.542E-3 + 1.334E-3 vs 5.181E-4 +/- 2.5615E-4, P = ns). In conclusion, quantitative texture analysis of ultrasonic images derived from transcutaneous, high-resolution, commercially available B-scan systems is feasible in man and provides a quantitative operator-independent assessment of plaque echodensity and homogeneity.

Triflusal in the treatment of patients with chronic peripheral arteriopathy: multicentre double-blind clinical study vs placebo.

Many clinical trials have shown the effectiveness of platelet-antiaggregant drugs in the treatment of obliterative peripheral arteriopathy, both locally and in the system, by improving the claudication symptoms and by preventing major cardiovascular events. In this study we evaluated the effectiveness of a 24-week treatment with triflusal, a comparatively new inhibitor of platelet aggregation, in patients affected by chronic peripheral arteriopathy, comparing twice-daily oral doses of 300 mg triflusal with twice-daily placebo doses. The percentages of successes (defined as a 40% increase of total walking distance over the basal control) were 63.6% in the triflusal group (35/55 patients) and 22.5% in the placebo group (14/62 patients). Patients treated with triflusal showed a more important increase in total walking distance and in pain-free walking distance over the basal values than those treated with placebo, together with an improvement of the symptomatology correlated with claudication. Moreover, in the triflusal group there was an increase in the peak-flow recorded through strain-gauge plethysmography. In conclusion, triflusal significantly increased both the distance which could be walked and the clinical symptoms, presumably by improving microperfusion.

Long term prognosis of asymptomatic carotid artery occlusion.

Twenty six asymptomatic patients with internal carotid artery occlusion had ultrasound follow-up for a mean period of 34.3 months. During follow-up 3 patients (11.5%) reported transitory ischemic attacks (TIAs), one of these (3.8%) occurred in the vascular territory ipsilateral to the occlusion. There were not strokes. Annual TIA rate was 4% for all vascular territories, and 1.3% for the territory ipsilateral to the occlusion. Annual mortality was 9.4%. Our data on stroke risk in patients with asymptomatic carotid artery occlusion show a good prognosis in the long-term.

[Results of the use of the Strecker and Palmaz stents in the iliac artery region. Two years' experience]. / Risultati dell'impiego degli stent di Strecker e di Palmaz nel distretto arterioso iliaco. Esperienza di due anni.

Our personal experience is reported with the use of vascular endoprostheses (Strecker and Palmaz stents) in the non-surgical treatment of iliacofemoral steno-occlusive arteriopathy. Over a 15-month period, 56 PTAs were performed in 40 patients; 20 vascular endoprostheses were positioned--17 Strecker and 3 Palmaz stents--in 16 patients, to correct such PTA complications as dissections or to improve the results of a suboptimal PTA maneuver. Venous DSA follow-up was performed at 30 days, and serial color-Doppler US studies were performed every fourth month. Immediate and satisfying clinical results were observed in 15/16 patients (93.7%): only one case of acute thrombosis following the procedure was observed, which could not be treated with intraarterial fibrinolytic therapy and was therefore operated on. Overall long-term patency rate is 100%, mean follow-up is 13.8 months. Finally, the indications for the use of such devices in iliacofemoral arteriopathies are critically discussed, together with the criteria of choice of a type of stent over another one, the immediate and long-term results and the best follow-up protocols.