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Expansion of the Multi-Link Frontier™ coronary bifurcation stent: micro-computed tomographic assessment in human autopsy and porcine heart samples.

Kralev S, Haag B, Spannenberger J, Lang S, Brockmann MA, Bartling S, Marx A, Haase KK, Borggrefe M, Süselbeck T - PLoS ONE (2011)

Bottom Line: PD and PA were significantly smaller in human autopsy heart samples than in porcine heart samples (3.54±0.47 mm vs. 4.04±0.22 mm, p = 0.048; 10.00±2.42 mm(2) vs. 12.84±1.38 mm(2), p = 0.034, respectively) and than those given by the manufacturer (3.54±0.47 mm vs. 4.03 mm, p = 0.014).L was smaller in human autopsy heart samples than in porcine heart samples, although data did not reach significance (16.66±1.30 mm vs. 17.30±0.51 mm, p = 0.32), and significantly smaller than that given by the manufacturer (16.66±1.30 mm vs. 18 mm, p = 0.015).Special consideration should be given to the stent deployment procedure (and to the follow-up) of dedicated stent systems, considering final intravascular ultrasound or optical coherence tomography to visualize (and if necessary optimize) stent expansion.

View Article: PubMed Central - PubMed

Affiliation: I. Department of Medicine, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany. stefan.kralev@umm.de

ABSTRACT

Background: Treatment of coronary bifurcation lesions remains challenging, beyond the introduction of drug eluting stents. Dedicated stent systems are available to improve the technical approach to the treatment of these lesions. However dedicated stent systems have so far not reduced the incidence of stent restenosis. The aim of this study was to assess the expansion of the Multi-Link (ML) Frontier™ stent in human and porcine coronary arteries to provide the cardiologist with useful in-vitro information for stent implantation and selection.

Methodology/principal findings: Nine ML Frontier™ stents were implanted in seven human autopsy heart samples with known coronary artery disease and five ML Frontier™ stents were implanted in five porcine hearts. Proximal, distal and side branch diameters (PD, DD, SBD, respectively), corresponding opening areas (PA, DA, SBA) and the mean stent length (L) were assessed by micro-computed tomography (micro-CT). PD and PA were significantly smaller in human autopsy heart samples than in porcine heart samples (3.54±0.47 mm vs. 4.04±0.22 mm, p = 0.048; 10.00±2.42 mm(2) vs. 12.84±1.38 mm(2), p = 0.034, respectively) and than those given by the manufacturer (3.54±0.47 mm vs. 4.03 mm, p = 0.014). L was smaller in human autopsy heart samples than in porcine heart samples, although data did not reach significance (16.66±1.30 mm vs. 17.30±0.51 mm, p = 0.32), and significantly smaller than that given by the manufacturer (16.66±1.30 mm vs. 18 mm, p = 0.015).

Conclusions/significance: Micro-CT is a feasible tool for exact surveying of dedicated stent systems and could make a contribution to the development of these devices. The proximal diameter and proximal area of the stent system were considerably smaller in human autopsy heart samples than in porcine heart samples and than those given by the manufacturer. Special consideration should be given to the stent deployment procedure (and to the follow-up) of dedicated stent systems, considering final intravascular ultrasound or optical coherence tomography to visualize (and if necessary optimize) stent expansion.

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Assessment of the stent opening diameters and areas.Diameters were measured by aligning the z-axis with the centreline of the stent looking exactly perpendicular into the stent lumen (panel A, panel B). Panel C depicts the measurement of the side branch opening area (SBA). Measurements were performed in multiplanar reformation (MPR) mode.
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pone-0021778-g003: Assessment of the stent opening diameters and areas.Diameters were measured by aligning the z-axis with the centreline of the stent looking exactly perpendicular into the stent lumen (panel A, panel B). Panel C depicts the measurement of the side branch opening area (SBA). Measurements were performed in multiplanar reformation (MPR) mode.

Mentions: The stented segments were each prepared in a conical 50 ml polypropylene tube (BD Falcon™ Tube, Becton Dickinson, Franklin Lakes). Micro-CT was performed using an industrial micro-CT system (Yxlon Y.Fox, Yxlon International GmbH, Hamburg, Germany). A total of 1200 projections were acquired within 40 s of scan time (2×2 binning of the detector; 944×704 pixel; 360° rotation; 90 µA; 160 kV). Proprietary scanner control software was used to monitor the scanning process, and to save projection data. Standard cone-beam CT reconstruction was performed using a filtered back-projection algorithm (Reconstruction Studio Version 1.2, Comet GmbH, Garbsen, Germany) with Shepp-Logan filter applied. The reconstructed volumes (512 Matrix) were reviewed in multiplanar reformation (MPR) as well as in a 3D volume rendering mode using OsiriX-software (v3.5.1). Data sets were reviewed in MPR (OsiriX) and 3D volume rendering using standard radiological equipment (I-View 3D 1.0.2.3, TeraRecon Inc., San Mateo, USA). After that, devices were surveyed and proximal and distal stent diameters (PD, DD), side branch diameters (SBD), mean stent length (L), as well as the corresponding opening areas (PA, DA, SBA) were measured. The measurements were carried out in MPR-mode. The stent length (Figure 2, panel A), stent diameters and sidebranch diameters (Figure 3, panel A and B) were measured aligning the z-axis with the centreline of the stent looking exactly perpendicular into the stent lumen. In the real world stent opening is not always exactly circular, consequently the stent expansion cannot always be assessed by measuring a diameter, and two orthogonal angiographic views or IVUS (intravascular ultrasound, visualizing vessel lumen and stent opening area) are recommended for evaluation of stent expansion. As with IVUS, micro-CT also offers the possibility of visualizing the stent opening area. Therefore, in this study, in all cases both the diameters and the opening areas were measured and compared with the data given by the manufacturer. The compliance chart of the manufacturer contains the diameters of the stent, so the corresponding opening areas were calculated by applying the circle area formula Area = πr2 with r describing the radius of the circle, conforming to 1/2 the diameter. All opening areas were first manually traced by the observer and then determined by the software (Figure 3, panel C, sidebranch opening area).


Expansion of the Multi-Link Frontier™ coronary bifurcation stent: micro-computed tomographic assessment in human autopsy and porcine heart samples.

Kralev S, Haag B, Spannenberger J, Lang S, Brockmann MA, Bartling S, Marx A, Haase KK, Borggrefe M, Süselbeck T - PLoS ONE (2011)

Assessment of the stent opening diameters and areas.Diameters were measured by aligning the z-axis with the centreline of the stent looking exactly perpendicular into the stent lumen (panel A, panel B). Panel C depicts the measurement of the side branch opening area (SBA). Measurements were performed in multiplanar reformation (MPR) mode.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3140974&req=5

pone-0021778-g003: Assessment of the stent opening diameters and areas.Diameters were measured by aligning the z-axis with the centreline of the stent looking exactly perpendicular into the stent lumen (panel A, panel B). Panel C depicts the measurement of the side branch opening area (SBA). Measurements were performed in multiplanar reformation (MPR) mode.
Mentions: The stented segments were each prepared in a conical 50 ml polypropylene tube (BD Falcon™ Tube, Becton Dickinson, Franklin Lakes). Micro-CT was performed using an industrial micro-CT system (Yxlon Y.Fox, Yxlon International GmbH, Hamburg, Germany). A total of 1200 projections were acquired within 40 s of scan time (2×2 binning of the detector; 944×704 pixel; 360° rotation; 90 µA; 160 kV). Proprietary scanner control software was used to monitor the scanning process, and to save projection data. Standard cone-beam CT reconstruction was performed using a filtered back-projection algorithm (Reconstruction Studio Version 1.2, Comet GmbH, Garbsen, Germany) with Shepp-Logan filter applied. The reconstructed volumes (512 Matrix) were reviewed in multiplanar reformation (MPR) as well as in a 3D volume rendering mode using OsiriX-software (v3.5.1). Data sets were reviewed in MPR (OsiriX) and 3D volume rendering using standard radiological equipment (I-View 3D 1.0.2.3, TeraRecon Inc., San Mateo, USA). After that, devices were surveyed and proximal and distal stent diameters (PD, DD), side branch diameters (SBD), mean stent length (L), as well as the corresponding opening areas (PA, DA, SBA) were measured. The measurements were carried out in MPR-mode. The stent length (Figure 2, panel A), stent diameters and sidebranch diameters (Figure 3, panel A and B) were measured aligning the z-axis with the centreline of the stent looking exactly perpendicular into the stent lumen. In the real world stent opening is not always exactly circular, consequently the stent expansion cannot always be assessed by measuring a diameter, and two orthogonal angiographic views or IVUS (intravascular ultrasound, visualizing vessel lumen and stent opening area) are recommended for evaluation of stent expansion. As with IVUS, micro-CT also offers the possibility of visualizing the stent opening area. Therefore, in this study, in all cases both the diameters and the opening areas were measured and compared with the data given by the manufacturer. The compliance chart of the manufacturer contains the diameters of the stent, so the corresponding opening areas were calculated by applying the circle area formula Area = πr2 with r describing the radius of the circle, conforming to 1/2 the diameter. All opening areas were first manually traced by the observer and then determined by the software (Figure 3, panel C, sidebranch opening area).

Bottom Line: PD and PA were significantly smaller in human autopsy heart samples than in porcine heart samples (3.54±0.47 mm vs. 4.04±0.22 mm, p = 0.048; 10.00±2.42 mm(2) vs. 12.84±1.38 mm(2), p = 0.034, respectively) and than those given by the manufacturer (3.54±0.47 mm vs. 4.03 mm, p = 0.014).L was smaller in human autopsy heart samples than in porcine heart samples, although data did not reach significance (16.66±1.30 mm vs. 17.30±0.51 mm, p = 0.32), and significantly smaller than that given by the manufacturer (16.66±1.30 mm vs. 18 mm, p = 0.015).Special consideration should be given to the stent deployment procedure (and to the follow-up) of dedicated stent systems, considering final intravascular ultrasound or optical coherence tomography to visualize (and if necessary optimize) stent expansion.

View Article: PubMed Central - PubMed

Affiliation: I. Department of Medicine, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany. stefan.kralev@umm.de

ABSTRACT

Background: Treatment of coronary bifurcation lesions remains challenging, beyond the introduction of drug eluting stents. Dedicated stent systems are available to improve the technical approach to the treatment of these lesions. However dedicated stent systems have so far not reduced the incidence of stent restenosis. The aim of this study was to assess the expansion of the Multi-Link (ML) Frontier™ stent in human and porcine coronary arteries to provide the cardiologist with useful in-vitro information for stent implantation and selection.

Methodology/principal findings: Nine ML Frontier™ stents were implanted in seven human autopsy heart samples with known coronary artery disease and five ML Frontier™ stents were implanted in five porcine hearts. Proximal, distal and side branch diameters (PD, DD, SBD, respectively), corresponding opening areas (PA, DA, SBA) and the mean stent length (L) were assessed by micro-computed tomography (micro-CT). PD and PA were significantly smaller in human autopsy heart samples than in porcine heart samples (3.54±0.47 mm vs. 4.04±0.22 mm, p = 0.048; 10.00±2.42 mm(2) vs. 12.84±1.38 mm(2), p = 0.034, respectively) and than those given by the manufacturer (3.54±0.47 mm vs. 4.03 mm, p = 0.014). L was smaller in human autopsy heart samples than in porcine heart samples, although data did not reach significance (16.66±1.30 mm vs. 17.30±0.51 mm, p = 0.32), and significantly smaller than that given by the manufacturer (16.66±1.30 mm vs. 18 mm, p = 0.015).

Conclusions/significance: Micro-CT is a feasible tool for exact surveying of dedicated stent systems and could make a contribution to the development of these devices. The proximal diameter and proximal area of the stent system were considerably smaller in human autopsy heart samples than in porcine heart samples and than those given by the manufacturer. Special consideration should be given to the stent deployment procedure (and to the follow-up) of dedicated stent systems, considering final intravascular ultrasound or optical coherence tomography to visualize (and if necessary optimize) stent expansion.

Show MeSH
Related in: MedlinePlus