Three-Dimensional Intravascular UItrasound Assessment of Coronary Lumen and Atherosclerotic Plaque Dimensions

Since the introduction of coronary balloon angioplasty in the clinical arena, percutaneous catheter- based interventions are perfornled with coronary angiographic guidance, depicting the lumen of an entire coronary artery in certain angiographicviews. Subsequently, quantitative coronary angiography was developed as an instnullent for off-line quantitative analysis of the acute and long-tenn effects of catheter-based and phanl1acological approaches on atherosclerotic lesions and on lesion recurrence following angioplasty. Despite some inherent limitations, tills analysis method became generally accepted for on-line guidance of balloon angioplasty and alternative catheterbased techniques. Thereafter, intravascular ultrasound (IVUS) was introduced as a new imaging method that provided deeper insights into the pathology of coronary artery disease by defining vessel wall geometry and the major components of the atherosclerotic plaque. Although invasive, IVUS is safe and allows in vivo a more comprehensive assessment of the plaque than the 'luminal silhouette' furnished by coro

Volumetric intracoronary ultrasound: a new maximum confidence approach for the quantitative assessment of progression-regression of atherosclerosis?

Quantitative assessment of atherosclerosis during its natural history and following therapeutic interventions is important, as cardiovascular disease remains the most significant cause of morbidity and mortality in industrial societies. While coronary angiography delineates the vessel lumen, permitting only the indirect determination of atherosclerotic wall changes encroaching upon the lumen, intracoronary ultrasound permits direct plaque assessment and quantification. The angiographic percent diameter stenosis, previously suggested as measure of a maximum confidence approach, is still commonly used to quantify stenosis severity, but the reference segments which are required for angiographic interpolation of the normal vessel dimensions are frequently involved in the general process of atherosclerosis, including progression or regression. Considering also the variability of vascular remodeling during the evolution of atherosclerosis, including compensatory enlargement and paradoxical arterial shrinkage, intracoronary ultrasound appears currently to be the only reliable technique to measure plaque burden and progression or regression of atherosclerosis. However, correct matching of the site of measurement at follow-up with the site of the initial ultrasound study is often difficult to achieve, but is significantly facilitated by the use of volumetric intracoronary ultrasound. This approach permits not only area measurement, but also measurement of plaque volume, which appears to be the ideal measure for quantifying the atherosclerotic plaque, as it is highly reproducible and directly reflects the changes of an entire arterial segment

Usefulness of three-dimensional reconstruction for interpretation and quantitative analysis of intracoronary ultrasound during stent deployment.

In conclusion, on-line 3-D ICUS is feasible during stent implantation, more sensitive than 2-D ICUS in the assessment of optimal stent expansion, and requires a shorter time for analysis

Angiographic, ultrasonic, and angioscopic assessment of the coronary artery wall and lumen area configuration after directional atherectomy: the mechanism revisited.

The purpose of the present study was to use the complementary information of angiography, intravascular ultrasound, and intracoronary angioscopy before and after directional atherectomy to characterize the postatherectomy appearance of vessel wall contours and the mechanism of lumen enlargement. Directional coronary atherectomy aims at debulking rather than dilating a coronary artery lesion. The selective removal of the plaque may potentially minimize the vessel wall damage and lead to subsequent better late outcome. Whether plaque removal is the main mechanism of action has only to be assessed indirectly by angiography and warrants further investigation with detailed analysis of luminal changes and vessel wall damage by ultrasound and direct visualization with angioscopy. Twenty-six patients have been investigated by quantitative angiography, intravascular ultrasound, and intracoronary angioscopy (n = 19) before and after atherectomy. In addition, all retrieved specimens were microscopically examined. Ultrasound imaging showed an increase in lumen area from 1.95 ± 0.70 mm2 to 7.86 ± 2.16 mm2 at atherectomy. The achieved gain mainly resulted from plaque removal because plaque plus media area decreased from 18.16 ± 4.47 mm2 to 13.13 ± 3.10 mm2. Vessel wall stretching (i.e., change in external elastic lamina area) accounted for only 15% of lumen area gain. Luminal gain was higher in noncalcified (6.52 ± 2.12 mm2) lesions than in lesions containing deeply located calcium (5.19 ± 0.99 mm2) and lowest in superficially calcified lesions (5.41 ± 2.41 mm2). Ultrasound imaging identified an atherectomy byte in 85% of the cases, whereas angioscopy revealed such a crevice in 74%. The complementary use of the three techniques revealed an underestimation of the presence of dissection/tear and new thrombus by angiography (10% and 4%) and ultrasound imaging (12% and 0%) compared with angioscopy (26% and 21%). The combined use of angiography, ultrasound, and angioscopy reveals that the postatherectomy luminal lining is not as regular and smooth as that seen by angiography. Luminal enlargement with atherectomy is achieved by plaque excision rather than arterial expansion