Cardiovascular Revascularization Medicine xxx (2014) xxx–xxx
Contents lists available at ScienceDirect
Cardiovascular Revascularization Medicine
Strategy for optimal side-branch positioning of bioresorbable vascular scaffolds in dedicated 2-stent techniques: Insights from optical coherence tomography Tadashi Miyazaki a, b, 1, Charis Costopoulos a, b, 1, Katsumasa Sato a, b, Toru Naganuma a, b, Vasileios F. Panoulas a, b, c, Filippo Figini a, b, Azeem Latib a, b, Antonio Colombo a, b,⁎ a b c
Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy Imperial College London, National Heart and Lung Institute, London, UK
a r t i c l e
i n f o
Article history: Received 30 December 2013 Received in revised form 28 January 2014 Accepted 31 January 2014 Available online xxxx
a b s t r a c t We present a case of a left anterior descending artery/diagonal branch bifurcation successfully treated with a dedicated 2-stent technique utilizing bioresorbable vascular scaffolds, where the bifurcation angle did not strictly allow a T-stenting approach. We also propose a strategy to avoid or reduce scaffold overlap in the main branch, especially important in view of the bulkier size of these novel devices. © 2014 Elsevier Inc. All rights reserved.
Keywords: Bioresorbable vascular scaffolds Bifurcation lesion T-stenting
1. Introduction
2. Case report
Bioresorbable vascular scaffolds (BVS) are an exciting novel treatment for coronary artery disease (CAD) as their eventual resorption renders the artery free from a permanent metallic cage. Studies to date have been promising with regards to their clinical efficacy and safety [1]. However their use in this context has been largely limited to simple lesions. Over the last two years and since the CE Mark approval of ABSORB (Abbott Vascular, Santa Clara, CA, USA), an increasing number of ‘real-world’ patients has been treated with these devices including those with heavily calcified lesions, long diffuse disease and lesions at bifurcations sites. With this increasing experience however concerns have also been raised with regards to the use of BVS in dedicated 2-stent techniques. This has been especially the case for the culotte and ‘mini-crush’ techniques as in the case of culotte 300 μm of scaffold (strut thickness 150 μm) covers the lumen of the vessel proximal to the bifurcation site and in the case of ‘mini-crush’ approximately 450 μm on one side, albeit for a short distance. Although an approach that utilizes BVS in the main-branch (MB) and a metallic drug-eluting stent in the side branch can reduce total strut thickness, as conventional DES are much thinner, it would be ideal if the whole lesion could be treated with BVS given the theoretical advantages of these devices.
Here we describe a case of left anterior descending artery (LAD)/ diagonal branch (Dg) bifurcation lesion (Medina classification: 1, 1, 1) where the bifurcation angle did not strictly allow a T-stenting approach and propose a strategy results to avoid or reduce scaffold overlap in the MB as much as possible. In the case presented (Fig. 1), predilatation was performed in the MB and side branch (SB) with 3.5 mm and 2.5 mm non-compliant (NC) balloons, respectively. Following this a 2.5/28 mm BVS was positioned in the SB. To help with accurate placement, a balloon was advanced in the MB as indicated by Fig. 1 (on maximum magnification), to help overcome the limitations of angiography and more specifically foreshortening. Following implantation of the SB scaffold, the scaffold balloon was reinflated at the same time as a NC balloon (3.5 mm) in the MB (kissing balloon inflation) to ensure that enough space is available for the MB scaffold to be delivered. The side balloon was the last to be deflated. We then proceeded with implantation of the MB BVS (3.5/28 mm) over the ostium of the SB, and as this did not cause SB flow deterioration, we did not postdilate the MB cells towards the SB. The final OCT images from the LAD demonstrate complete coverage of the ostium with no evidence of double scaffold layers in the MB and an adequate MB scaffold area (8.93 mm 2) (Fig. 2). 3. Discussion
⁎ Corresponding author at: EMO-GVM Centro Cuore Columbus, 48 Via M. Buonarroti, 20145 Milan, Italy. Tel.: +39 024812920; fax: +39 0248193433. E-mail address: [email protected] (A. Colombo). 1 Dr Miyazaki and Dr Costopoulos are co-joint first authors for this article.
The permanent presence of a metallic segment that remains beyond its intended function of preventing recoil and providing sufficient radial support following implantation can be associated
1553-8389/$ – see front matter © 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.carrev.2014.01.015
Please cite this article as: Miyazaki T, et al, Strategy for optimal side-branch positioning of bioresorbable vascular scaffolds in dedicated 2stent techniques: Insights from op..., Cardiovasc Revasc Med (2014), http://dx.doi.org/10.1016/j.carrev.2014.01.015
2
T. Miyazaki et al. / Cardiovascular Revascularization Medicine xxx (2014) xxx–xxx
Fig. 1. Angiographic and schematic images demonstrating technique for side-branch scaffold positioning. A. Initial angiographic image demonstrating significant disease in the mainand side-branch on a LAD/Dg bifurcation (arrow and arrowhead). B. Angiographic and schematic images demonstrating side-branch scaffold and main-branch balloon positions prior to scaffold deployment. B1) demonstrates inaccurate positioning of the scaffold (yellow arrow pointing to the balloon marker being too distal). B2) demonstrates accurate positioning ensuring ostial coverage and no protrusion of side branch scaffold. The main branch balloon is positioned so that the side branch ostium corresponds to its mid length. The side-branch scaffold balloon marker is positioned within the area of an imaginary triangle (green dotted line) as shown in the diagram taking into consideration the effect the bifurcation angle has on the position of the side-branch scaffold (an angle that approaches 90o requires less protrusion into the triangle as compared to a bifurcation with more shallow angle).
with a number of drawbacks. More specifically, it prevents lumen expansion due to positive remodelling and can interfere with vessel geometry and endothelial function. It can also be a source of inflammation predisposing to neoatherosclerosis and thus in-stent
restenosis and late or very late stent thrombosis (ST) [2]. BVS can theoretically address a number of these issues, something that may particularly important in complex lesions such as those at bifurcation sites requiring a dedicated 2-stent strategy. Here, we propose a 2-
Fig. 2. Final angiographic and optical coherence tomography (OCT) images demonstrating good ostial coverage with no evidence of protrusion. A. Final angiographic image. Numerals are corresponding to figure C. B. Cross sectional OCT image of at the bifurcation site prior to implantation of BVS in main- branch demonstrates SB scaffolds (arrowheads). C. Cross sectional OCT image following BVS implantation in main-branch (arrows) with no evidence of double scaffold layers in the distal and proximal edges of the diagonal ostium. D. Longitudinal OCT image of bifurcation site demonstrating that the side-branch ostium is completely covered by the side-branch scaffold with no obvious evidence of protrusion or crushed.
Please cite this article as: Miyazaki T, et al, Strategy for optimal side-branch positioning of bioresorbable vascular scaffolds in dedicated 2stent techniques: Insights from op..., Cardiovasc Revasc Med (2014), http://dx.doi.org/10.1016/j.carrev.2014.01.015
T. Miyazaki et al. / Cardiovascular Revascularization Medicine xxx (2014) xxx–xxx
stent strategy with BVS that although may not 100% guarantee the absence of protrusion it can help to reduce this, whilst ensuring that the SB ostium is covered. This can help avoid other 2-stent techniques, which can result in excessive scaffold overlap. This may be particularly important with BVS as these devices have thicker struts (150 μm) as compared to conventional stents. A double strut layer in the case of a ‘culotte’ technique leads to approximately a 160 μm circumferential strut layer in the case of currently utilized stents and to 300 μm in the case of BVS. With regards to the ‘mini-crush’ technique, this leads to a triple strut layer on one side of the vessel which would correspond to a strut layer of approximately 240 μm in the case of conventional stents and to 450 μm in the case of BVS. Although BVS inherently are more biocompatible that current stents it is still important to minimize overlap as this may increase the risk of adverse events as experience with conventional stents dictates (although no data is available with regards to this in the case of BVS). This is also paramount in the smaller vessels (b 2.5 mm) where multiple BVS layers can lead to lumen compromise. Furthermore, assuming that SB flow following MB stenting is acceptable, the eventual scaffold resorption allows the use of this strategy without additional post-dilatation of the MB scaffold cell towards the SB or kissing inflation [3]. Finally it is important to note that in especially challenging cases where angiography or intravascular ultrasound is
3
not sufficient to delineate the anatomy of the bifurcation intended to treat, 3D OCT can provide important information regarding the carina shape and angle as well as the orientation of the SB relative to the MB allowing thus more accurate procedural planning.
4. Conclusion BVS offer the potential of revolutionizing the treatment of coronary artery disease. Through this case we propose a strategy for the treatment of bifurcations that require a 2-stent approach that can help reduce scaffold overlap, particularly important in view of the thick struts of these devices.
References [1] Gogas BD, Farooq V, Onuma Y, Serruys PW. The ABSORB bioresorbable vascular scaffold: an evolution or revolution in interventional cardiology? Hellenic J Cardiol 2012;53(4):301–9. [2] Latib A, Costopoulos C, Naganuma T, Colombo A. Which patients could benefit the most from bioresorbable vascular scaffold implant: from clinical trials to clinical practice. Minerva Cardioangiol 2013;61(3):255–62. [3] Okamura T, Serruys PW, Regar E. Cardiovascular flashlight. The fate of bioresorbable struts located at a side branch ostium: serial three-dimensional optical coherence tomography assessment. Eur Heart J 2010;31(17):2179.
Please cite this article as: Miyazaki T, et al, Strategy for optimal side-branch positioning of bioresorbable vascular scaffolds in dedicated 2stent techniques: Insights from op..., Cardiovasc Revasc Med (2014), http://dx.doi.org/10.1016/j.carrev.2014.01.015
Contents lists available at ScienceDirect
Cardiovascular Revascularization Medicine
Strategy for optimal side-branch positioning of bioresorbable vascular scaffolds in dedicated 2-stent techniques: Insights from optical coherence tomography Tadashi Miyazaki a, b, 1, Charis Costopoulos a, b, 1, Katsumasa Sato a, b, Toru Naganuma a, b, Vasileios F. Panoulas a, b, c, Filippo Figini a, b, Azeem Latib a, b, Antonio Colombo a, b,⁎ a b c
Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy Imperial College London, National Heart and Lung Institute, London, UK
a r t i c l e
i n f o
Article history: Received 30 December 2013 Received in revised form 28 January 2014 Accepted 31 January 2014 Available online xxxx
a b s t r a c t We present a case of a left anterior descending artery/diagonal branch bifurcation successfully treated with a dedicated 2-stent technique utilizing bioresorbable vascular scaffolds, where the bifurcation angle did not strictly allow a T-stenting approach. We also propose a strategy to avoid or reduce scaffold overlap in the main branch, especially important in view of the bulkier size of these novel devices. © 2014 Elsevier Inc. All rights reserved.
Keywords: Bioresorbable vascular scaffolds Bifurcation lesion T-stenting
1. Introduction
2. Case report
Bioresorbable vascular scaffolds (BVS) are an exciting novel treatment for coronary artery disease (CAD) as their eventual resorption renders the artery free from a permanent metallic cage. Studies to date have been promising with regards to their clinical efficacy and safety [1]. However their use in this context has been largely limited to simple lesions. Over the last two years and since the CE Mark approval of ABSORB (Abbott Vascular, Santa Clara, CA, USA), an increasing number of ‘real-world’ patients has been treated with these devices including those with heavily calcified lesions, long diffuse disease and lesions at bifurcations sites. With this increasing experience however concerns have also been raised with regards to the use of BVS in dedicated 2-stent techniques. This has been especially the case for the culotte and ‘mini-crush’ techniques as in the case of culotte 300 μm of scaffold (strut thickness 150 μm) covers the lumen of the vessel proximal to the bifurcation site and in the case of ‘mini-crush’ approximately 450 μm on one side, albeit for a short distance. Although an approach that utilizes BVS in the main-branch (MB) and a metallic drug-eluting stent in the side branch can reduce total strut thickness, as conventional DES are much thinner, it would be ideal if the whole lesion could be treated with BVS given the theoretical advantages of these devices.
Here we describe a case of left anterior descending artery (LAD)/ diagonal branch (Dg) bifurcation lesion (Medina classification: 1, 1, 1) where the bifurcation angle did not strictly allow a T-stenting approach and propose a strategy results to avoid or reduce scaffold overlap in the MB as much as possible. In the case presented (Fig. 1), predilatation was performed in the MB and side branch (SB) with 3.5 mm and 2.5 mm non-compliant (NC) balloons, respectively. Following this a 2.5/28 mm BVS was positioned in the SB. To help with accurate placement, a balloon was advanced in the MB as indicated by Fig. 1 (on maximum magnification), to help overcome the limitations of angiography and more specifically foreshortening. Following implantation of the SB scaffold, the scaffold balloon was reinflated at the same time as a NC balloon (3.5 mm) in the MB (kissing balloon inflation) to ensure that enough space is available for the MB scaffold to be delivered. The side balloon was the last to be deflated. We then proceeded with implantation of the MB BVS (3.5/28 mm) over the ostium of the SB, and as this did not cause SB flow deterioration, we did not postdilate the MB cells towards the SB. The final OCT images from the LAD demonstrate complete coverage of the ostium with no evidence of double scaffold layers in the MB and an adequate MB scaffold area (8.93 mm 2) (Fig. 2). 3. Discussion
⁎ Corresponding author at: EMO-GVM Centro Cuore Columbus, 48 Via M. Buonarroti, 20145 Milan, Italy. Tel.: +39 024812920; fax: +39 0248193433. E-mail address: [email protected] (A. Colombo). 1 Dr Miyazaki and Dr Costopoulos are co-joint first authors for this article.
The permanent presence of a metallic segment that remains beyond its intended function of preventing recoil and providing sufficient radial support following implantation can be associated
1553-8389/$ – see front matter © 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.carrev.2014.01.015
Please cite this article as: Miyazaki T, et al, Strategy for optimal side-branch positioning of bioresorbable vascular scaffolds in dedicated 2stent techniques: Insights from op..., Cardiovasc Revasc Med (2014), http://dx.doi.org/10.1016/j.carrev.2014.01.015
2
T. Miyazaki et al. / Cardiovascular Revascularization Medicine xxx (2014) xxx–xxx
Fig. 1. Angiographic and schematic images demonstrating technique for side-branch scaffold positioning. A. Initial angiographic image demonstrating significant disease in the mainand side-branch on a LAD/Dg bifurcation (arrow and arrowhead). B. Angiographic and schematic images demonstrating side-branch scaffold and main-branch balloon positions prior to scaffold deployment. B1) demonstrates inaccurate positioning of the scaffold (yellow arrow pointing to the balloon marker being too distal). B2) demonstrates accurate positioning ensuring ostial coverage and no protrusion of side branch scaffold. The main branch balloon is positioned so that the side branch ostium corresponds to its mid length. The side-branch scaffold balloon marker is positioned within the area of an imaginary triangle (green dotted line) as shown in the diagram taking into consideration the effect the bifurcation angle has on the position of the side-branch scaffold (an angle that approaches 90o requires less protrusion into the triangle as compared to a bifurcation with more shallow angle).
with a number of drawbacks. More specifically, it prevents lumen expansion due to positive remodelling and can interfere with vessel geometry and endothelial function. It can also be a source of inflammation predisposing to neoatherosclerosis and thus in-stent
restenosis and late or very late stent thrombosis (ST) [2]. BVS can theoretically address a number of these issues, something that may particularly important in complex lesions such as those at bifurcation sites requiring a dedicated 2-stent strategy. Here, we propose a 2-
Fig. 2. Final angiographic and optical coherence tomography (OCT) images demonstrating good ostial coverage with no evidence of protrusion. A. Final angiographic image. Numerals are corresponding to figure C. B. Cross sectional OCT image of at the bifurcation site prior to implantation of BVS in main- branch demonstrates SB scaffolds (arrowheads). C. Cross sectional OCT image following BVS implantation in main-branch (arrows) with no evidence of double scaffold layers in the distal and proximal edges of the diagonal ostium. D. Longitudinal OCT image of bifurcation site demonstrating that the side-branch ostium is completely covered by the side-branch scaffold with no obvious evidence of protrusion or crushed.
Please cite this article as: Miyazaki T, et al, Strategy for optimal side-branch positioning of bioresorbable vascular scaffolds in dedicated 2stent techniques: Insights from op..., Cardiovasc Revasc Med (2014), http://dx.doi.org/10.1016/j.carrev.2014.01.015
T. Miyazaki et al. / Cardiovascular Revascularization Medicine xxx (2014) xxx–xxx
stent strategy with BVS that although may not 100% guarantee the absence of protrusion it can help to reduce this, whilst ensuring that the SB ostium is covered. This can help avoid other 2-stent techniques, which can result in excessive scaffold overlap. This may be particularly important with BVS as these devices have thicker struts (150 μm) as compared to conventional stents. A double strut layer in the case of a ‘culotte’ technique leads to approximately a 160 μm circumferential strut layer in the case of currently utilized stents and to 300 μm in the case of BVS. With regards to the ‘mini-crush’ technique, this leads to a triple strut layer on one side of the vessel which would correspond to a strut layer of approximately 240 μm in the case of conventional stents and to 450 μm in the case of BVS. Although BVS inherently are more biocompatible that current stents it is still important to minimize overlap as this may increase the risk of adverse events as experience with conventional stents dictates (although no data is available with regards to this in the case of BVS). This is also paramount in the smaller vessels (b 2.5 mm) where multiple BVS layers can lead to lumen compromise. Furthermore, assuming that SB flow following MB stenting is acceptable, the eventual scaffold resorption allows the use of this strategy without additional post-dilatation of the MB scaffold cell towards the SB or kissing inflation [3]. Finally it is important to note that in especially challenging cases where angiography or intravascular ultrasound is
3
not sufficient to delineate the anatomy of the bifurcation intended to treat, 3D OCT can provide important information regarding the carina shape and angle as well as the orientation of the SB relative to the MB allowing thus more accurate procedural planning.
4. Conclusion BVS offer the potential of revolutionizing the treatment of coronary artery disease. Through this case we propose a strategy for the treatment of bifurcations that require a 2-stent approach that can help reduce scaffold overlap, particularly important in view of the thick struts of these devices.
References [1] Gogas BD, Farooq V, Onuma Y, Serruys PW. The ABSORB bioresorbable vascular scaffold: an evolution or revolution in interventional cardiology? Hellenic J Cardiol 2012;53(4):301–9. [2] Latib A, Costopoulos C, Naganuma T, Colombo A. Which patients could benefit the most from bioresorbable vascular scaffold implant: from clinical trials to clinical practice. Minerva Cardioangiol 2013;61(3):255–62. [3] Okamura T, Serruys PW, Regar E. Cardiovascular flashlight. The fate of bioresorbable struts located at a side branch ostium: serial three-dimensional optical coherence tomography assessment. Eur Heart J 2010;31(17):2179.
Please cite this article as: Miyazaki T, et al, Strategy for optimal side-branch positioning of bioresorbable vascular scaffolds in dedicated 2stent techniques: Insights from op..., Cardiovasc Revasc Med (2014), http://dx.doi.org/10.1016/j.carrev.2014.01.015
