Assessment of coronary stent by optical coherence tomography, methodology and definitions

Abstract

Optical coherence tomography has emerged as a powerful tool for stent assessment, and in a short time, has become the modality of choice for studying stent and vascular interactions in vivo. In this review, we discuss qualitative and quantitative parameters used for stent assessment by OCT. Various qualitative/quantitative variables of stent assessment are discussed in the perspective of the clinical and research values of each of them.

First Results of the DEB-AMI (Drug Eluting Balloon in Acute ST-Segment Elevation Myocardial Infarction) Trial

“…Images were acquired with automated pullback at a rate of 2, 3, or 20 mm/s (according to the type of OCT system). All cross-sectional images (frames) were initially screened for quality assessment and excluded if any portion of the stent was out of the screen, images were not analyzable due to side branches, or images had poor quality caused by residual blood, artifacts, or reverberation (17).…”

Optical coherence tomography assessment of in-stent restenosis after percutaneous coronary intervention with two-stent technique in unprotected left main

“…1 Struts covered by tissue had positive SIT values, whereas uncovered or malapposed struts had negative SIT values. Strut malapposition was defined when the negative value of SIT was higher than the sum of strut thickness plus abluminal polymer thickness, according to stent manufacturer specifications, plus a compensation factor of 20μm to correct for strut blooming (13,14). Tissue protrusion was defined as a tissue prolapse between stent struts that directly correlates with the underlying plaque, without abrupt transition and different optical properties …”

Evolução temporal da proliferação neointimal após implante de dois tipos de stent farmacológico com polímeros biodegradáveis em modelo porcino: avaliação qualitativa por tomografia de coerência óptica sequencial

“…Since the blooming artefact was systematically included in the measurements, to determine strut apposition it was necessary to take into account its total thickness (thickness of the metal strut + thickness of the polymer + drug) plus a correction factor of 20 µm, which corrects for the actual location of the strut surface by discounting half of the blooming. 18,19 The distance between the luminal surface of blooming produced by the struts and the contour of the vascular lumen was analysed indivi dually for each strut. For the stents in this study, if the distance was greater than the sum of the thicknesses of the struts (Biomatrix ® , 112 µm; Inspiron ® , 75 µm) plus the thicknesses of the polymers (Biomatrix ® , 10 µm; Inspiron ® , 5 µm) plus 20 µm (correction factor), the strut would be considered malpositioned.…”

“…Compared to histology, OCT allows for the evaluation of the vascular healing process in vivo at different stages, providing qualitative and quantitative information along the full length of the stent. [17][18][19][20] By enabling analysis at multiple time points, it is possible to compare the same intrastent region at different times and thereby assess temporal neointima maturation, as well as to evaluate each intrastent millimetre strut by strut.…”