How to use three-dimensional optical coherence tomography effectively in coronary bifurcation stenting

Abstract

Imaging-guided coronary bifurcation intervention has improved clinical outcomes due to the appropriate size selection of the devices and optimization of the procedure (sufficient stent expansion, reduction of stent malapposition, appropriate stent landing zone, and detection of vessel dissection). In particular, three-dimensional optical coherence tomography (3D OCT) facilitates clear visualization of stent configuration and guidewire position, which promotes optimal guidewire crossing to the side branch. Successive side branch dilation leads to wide ostial dilation with less strut malapposition. However, the link connection of the stent located on the bifurcated carina has been found to be an impediment to sufficient opening of the side branch, resulting in incomplete strut apposition. In such cases, the aggressive proximal optimization technique improves the jailing strut pattern, and 3D OCT navigates the guidewire crossing to the optimal cell that is most likely to be expanded sufficiently, which is not always a distal cell. In two-stent deployment, 3D OCT facilitates optimal guidewire crossing, which leads to less metallic carina, clustering, and overlapping. The present review describes a method of clear visualization and assessment with 3D OCT and discusses the efficacy of 3D OCT in coronary bifurcation stenting in clinical practice.

Keywords: coronary bifurcation; drug-eluting stent; guidewire; optical coherence tomography; three-dimensional image.

Figure 1

Assessment of guidewire recrossing point before side branch (SB) dilation. (A) Two-dimensional optical coherence tomography image. The guide wire (arrow) recrossed at the edge of the SB away from its center (triangle). (B) Three-dimensional image clearly demonstrates the guidewire (arrow) recrossing in the distal part of the proximal cell indicated by cross (†) and not in the optimal distal cell indicated by asterisk (*). (C) Fly-through image also shows suboptimal wiring (arrow) into the proximal cell (†) and not in the distal cell (*) (Supplementary Movie 2).

Figure 2

Assessment of guide wire recrossing point in the ostium before side branch (SB) dilation in the provisional stenting. A 51-year-old woman with Medina 1-1-1 lesion in left anterior descending artery (LAD)-diagonal bifurcation (A) was treated with crossover stenting, 3.0/28 mm Xience Alpine, (B) followed by proximal optimization technique (C) and SB dilation (D), which resulted in acceptable results (E) (Supplementary Movie 3). Two-dimensional optical frequency domain imaging in the bifurcation (F, top to bottom; pull back images from the distal) shows that the guidewire recrossed distally (yellow arrow) between the struts (triangles) at the carina. Three-dimensional vessel view (G) and carpet view (H) clearly demonstrates the guidewire recrossing point (red circle) with no link connection (yellow arrows) in the SB ostium. Final three-dimensional image shows wide opening of the SB without any jailing struts (I).

Figure 3

Optimal guidewire recrossing using 3D optical coherence tomography (OCT) imaging after jailed balloon technique. A 55-year-old man with Medina 1-1-1 lesion in left anterior descending artery (LAD)-diagonal bifurcation (A) was treated with crossover stenting with jailed balloon technique that accompanied simultaneous dilation of a 2.75/18 mm Ultimaster stent and a jailed 2.0 mm balloon (B) (Supplementary Movie 4). Since the proximal part of the jailed balloon protruded in the LAD, significant stent malapposition around the ostium of the diagonal branch inhibits optimal guidewire recrossing. First guidewire recrossing is in the rim of the ostium and outside of the link connection, which was suboptimal (C, arrow) (Supplementary Movie 5). Second guidewire recrossing is in a more proximal cell located outside of the ostium, which is also suboptimal (D, arrow) (Supplementary Movie 5). After proximal optimization with 2.75 mm balloon (E), guidewire recrossing in the optimal distal cell is confirmed in the 3D OCT imaging (F top: 3D vessel view, bottom: 3D fly-through view). After final kissing balloon inflation (KBI) with 2.75 and 2.0 mm balloons, final coronary angiography shows acceptable results (G) (Supplementary Movie 4). The 3D OCT shows a wide opening of the diagonal branch ostium without any stent deformation or malapposition (H) (Supplementary Movie 5).

Figure 4

Suboptimal guidewire recrossing in 2-stenting under angio-guidance. 3D optical coherence tomography (OCT) imaging was post-hoc analysis. (A) Culotte stenting. First guidewire recrossing to the main vessel (MV) is in the proximal cell (a, arrow) and subsequent MV dilation left jailing struts at the carinal site (b). After MV stenting, second guidewire recrossing to the side branch (SB) is optimal in the distal cell (c, arrow). Even after final kissing balloon inflation (KBI), metallic carina remains as the asterisk indicates (d: view from MV, e: view from SB). (B) Double kissing (DK)-crush stenting. After SB stent crush, first guidewire recrossing to the middle part of SB (a). First KBI made the hole in the proximal site (b). After MV stenting, second guidewire recrossing outside of the hole made by first KBI (c, recrossing point is indicated by the arrow in b). Even after second KBI, distorted struts are clustered in the proximal part of the SB ostium, indicated by the asterisk (d: view from MV, e: view from proximal to the bifurcation).

Figure 5

Representative optimal and suboptimal cases of 2-stent on 3D optical coherence tomography (OCT) assessment. (A) Culotte stenting. In a suboptimal case (left column), metallic carina remains (asterisks in pullback views from the main vessel [MV] and side branch [SB]) and there is insufficient stent expansion in the main branch ostium with malapposed strut at the lateral site (arrow in the view from proximal MV). In an optimal case (right column), both branch ostia are well-expanded with good apposition. (B) Double kissing (DK)-crush stenting. In a suboptimal case (left column) due to suboptimal wiring outside of the hole made by first kissing balloon inflation (KBI), jailing struts remain at the SB ostium (asterisks). In an optimal case (right column), metallic carina remains (arrows), but it is located in a neutral position between both branches and creates no limitation for MV stent expansion or incomplete stent crush.

Figure 6

3D optical coherence tomography (OCT) guided guidewire crossing in a one-string culotte stenting. A 63-year-old man who underwent a 3.5/28 mm Xience Alpine stent implantation for chronic total occlusion of the proximal left anterior descending artery (LAD) previously was treated for the progression of stenosis in left main (LM) to the left circumflex artery (LCX) (A). Medina 1-0-1 lesion in the LM bifurcation (B) was identified (Supplementary Movie 6) and LAD stent was minimally protruded in the LCX ostium (B bottom scheme). First guidewire crossing to the most proximal cell of the LAD stent failed (C) and second crossing using a double-lumen catheter succeeded (D) (Supplementary Movie 7). After the dilation of the cell to one string using a 2.5 mm balloon (E), a 3.0/26 mm resolute integrity stent was deployed from LM to proximal LCX (F) to perform one-string culotte stenting. After proximal optimization using a 4.0 mm balloon (G), guidewire recrossing to the LAD in the optimal cell is confirmed in the 3D OCT imaging and final KBI using 4.0 and 2.5 mm balloons is completed (H). Final coronary angiography shows acceptable results (I) (Supplementary Movie 6), and OCT images show adequate dilation without significant incomplete strut apposition in both branch ostia and one-string metal overlapping in the LM (J−1: pullback from LCX, J-2: pullback from LAD, J-3: 2D image of the bifurcation in the pullback from LCX) (Supplementary Movie 8).

Figure 7

Assessment of guidewire recrossing point in double kissing (DK)-crush stenting with three-dimensional optical coherence frequency-domain imaging (OFDI). A 68-year-old man with Medina 0-1-1 lesion in left anterior descending artery (LAD)-diagonal bifurcation (A) (Supplementary Movie 9) was treated with DK-crush stenting. After a Ultimaster 2.25/38 mm stent was implanted in diffusely diseased diagonal branch with 3 mm protruded into the LAD (B top panel), a 3.0 mm balloon placed in the LAD crushed the proximal site of the side branch stent (B bottom panel). The guidewire recrossed inside the crushed stent, which is confirmed with two-dimensional and three-dimensional OFDI images (C top and bottom panels, yellow arrowheads: guidewires) (Supplementary Movie 10). First kissing balloon inflation (KBI) using 3.0 mm and 2.25 mm balloons was performed (D). Side branch stent is crushed more in the two-dimensional OFDI image (E top panel) and side branch ostium is open wide in the three-dimensional image (E bottom panel) (Supplementary Movie 10). Xience Alpine 2.5/28 and 3.0/23 mm stents were implanted in the middle LAD and left main and proximal LAD, respectively (F top and bottom panels). The OFDI image shows that the guidewire recrossed in the cell on the hole made by the first KBI (G, yellow arrow) (Supplementary Movie 10). Second KBI was performed using 3.0 and 2.25 mm balloons (H). Final coronary angiography shows acceptable results (I) (Supplementary Movie 9) and OFDI images show adequate dilation in both branch ostia with minimal metallic carina (J: pullback from LAD, K: pullback from diagonal branch) (Supplementary Movie 10).

Figure 8

Optical coherence tomography (OCT)-guided culotte stenting after rotational atherectomy in the calcified bifurcation lesion. A 72-year-old man with Medina 0-1-1 calcified lesion in left anterior descending artery (LAD)-diagonal bifurcation (A) was treated with culotte stenting after rotational atherectomy in both branches (Supplementary Movie 11). Rotational atherectomy using 1.75 mm and 2.15 mm burrs was performed in both LAD and diagonal branch, and OCT shows adequate ablation. A Ultimaster 3.0/33 mm stent was implanted from proximal LAD to diagonal branch (B) followed by proximal optimization with a 3.75 mm balloon (C). 3D OCT showed the guidewire recrossed in the distal cell which occupied most largely in the diagonal branch ostium in the Link-free type that some proximal hoops of the far-distal cells with link-connection remained at the carina (D). After the dilation of diagonal branch ostium, an Ultimaster 3.0/33 mm stent was deployed in the LAD (E) followed by proximal optimization with a 3.75 mm balloon (F). The guidewire seemed to recross in the middle part of the jailing cells (G-2, point a), and more distal part (G-1, point b) seemed to be optimal. However, the strut alignment of the MV stent was indicated as pink lines and the most distal strut indicated by yellow lines was turned out to be the remained hoop of the SB stent at the carina (G-2) (Supplementary Movie 12). After confirmation of optimal distal wiring, kissing balloon inflation with two 3.0 mm balloons. Final angiography was acceptable (H) and 3D OCT showed no significant stent deformation or malapposition except for minimal remaining the meal hoop (I).

Figure 9

Classification of jailing strut configuration on the side branch ostium. In the scheme (left: in-phase type stent, right: out-of-phase type stent), orange line indicates the carina, red color indicates the link between hoops connecting to the carina, yellow asterisks, and white dots indicate the distal and proximal recrossing position. Middle column: 3D optical coherence tomography (OCT) image of guidewire recrossing point. Right column: 3D OCT image after final kissing balloon inflation (KBI). (A) Link-free (LF) type, (B) Link-connecting (LC) type, (C) No or less jailing (NLJ) type.

Figure 10

Push-fold method for complete removal of jailing struts in the side branch (SB) ostium. A 78-year-old man with Medina 1-1-0 lesion in LM bifurcation with a drop of fractional flow reserve (FFR) of 0.76 (A). After cross-over stenting from LM to LAD with a Xience Alpine 3.5/28 mm stent and subsequent proximal optimization in LM with a 4.5 mm balloon, guidewire recrossing to the distal cell (green cell) was difficult even after several attempts and finally crossed to the proximal cell (yellow cell, white arrow) (B). For the removal of the jailing struts in the SB ostium, an inflated 2.5/4 mm balloon was pushed from LM to LCX (C). Final 3-D OCT demonstrated complete removal of the jailing struts in the SB ostium (D-1, pull back from main vessel [MV]), and the jailing strut folded toward the carina (D-2, pull back from SB).

Figure 11

Scheme of side branch (SB) compromise after crossover stenting in the main vessel (MV) and subsequent SB dilation. (A) SB compromise after MV stenting with >75% stenosis on angiography and shifted carina (top and middle panels). When fractional flow reserve (FFR) is preserved at ≥0.80, it is recommended to defer SB treatment. The actual condition of the SB ostium is that the shifted carina narrows the SB ostium, which remains a sufficient area to not be physiologically significant stenosis, and the aligned struts jail the SB ostium (bottom panel). (B) Condition after SB dilation. In coronary angiography, SB stenosis is relieved with the correction of the shifted carina to the neutral position (top and middle panels). In the optimal treatment after optimal guidewire recrossing in link-free jailing strut configuration, ideal removal of jailing struts and adequate SB dilation are achieved (bottom left panel). However, suboptimal guidewire recrossing to the proximal cell or in the link-connecting type results in inadequate SB ostial dilation with clustering of jailing struts (bottom left panels). The success rate of optimal SB treatment is low (<50%) under angio-guidance, so dramatic improvement is feasible under 3D optical coherence tomography guidance.

Figure 12

Optical coherence tomography (OCT) image of intimal proliferation on jailing struts at long-term follow-up period. A. One-year follow-up after crossover stenting with a synergy stent in the left anterior descending artery (LAD) without the fenestration of the diagonal branch. (A-1) 3D vessel view shows complete intimal coverage on the stent struts even in the jailing struts on the diagonal branch ostium with some luminal narrowing. (A-2) 2D imaging on the bifurcated site. (A-3) magnified view of the jailing struts. Complete intimal coverage of all surfaces of the struts was completed. (B) 3D OCT image after culotte stenting in LAD and diagonal branch using resolute integrity stents with significant metallic carina formation remaining (B-1: immediately after stenting, perpendicular view, (B-2) view from proximal to the bifurcation). (B-3) Two-year follow-up. 3D OCT image shows intimal coverage along the struts of the metallic carina, with several holes remaining (Supplementary Movie 13).