Thank you for invitation to Sky Bifurcation Club webinar. I'm Yoshinobu Funasato from Kyushu Medical Center in Japan. My topic is OCT in colony bifurcation stenting, there is no conflict of interest. We respect the laws of imaging in bifurcation PCI as follows. In pre-procedure of optimal selection of devices and PCI strategy are important. First, measurement of dimension of lumen and vessel in member cell and side glands. Second, assessment of atherosclerotic plaque morphology, burden, non-tunal distribution, calcification, and negative remodeling. Third, detection of angiographically silent disease. Fourth, assessment of the risk of side-blanch compromise. In post-PCI optimization of procedure is crucial for better clinical outcome. The followings should be assessed in imaging. First, stent apposition. Second, stent expansion. Third, full region coverage by the stent. Fourth, stent etch dissection. Fifth, plaque prolapse inside stent. Sixth, side-blanch residual stenosis and dissection. Seventh, optimal guideway recrossing before side-blanch dilation and subsequent adequate clearance of jailing struts after side-blanch dilation. According to the bench testing, we believe this distal strut wiring can achieve the wider opening for the side-blanch. On the contrary, proximal wiring promotes protrusion of the distal strut into the member cell. However, guideway recrossing in the far distal cell, which means 90% of the strut cell embedded in the distal side, causes significant stent deformation induced by side-blanch dilation. Here you can see side-blanch balance straightening causes the expansion of the distal cell into the proximal side. This is the actual clinical case, guideway recrossing into the far distal cell. As a result, final case environment inflation causes the stent deformation in the distal side extension to the distal strut to the proximal side. On the contrary, guideway recrossing in the proximal side. As you can see, 3D-OCT demonstrated guideway recrossing in the proximal cell clearly. However, on-site, we only performed 2D-OCT guidance. We cannot identify the guideway recrossing point precisely, so we performed side-blanch dilation and subsequent report. As a result, adjacent cell was protruded into the membranous lumen and subsequent report induced turned back to the distal side to the protruded cell. In the 3D-OCT bifurcation registry, 3D-OCT guidance efficacy for the successful rate of the optimal guideway recrossing, initial success rate by angio-guidance is only 66%. It is elevated to around 90% by accumulating 3D-OCT guidance. And especially in the left main, initial success rate by angio-guidance is only 56%. This is a comparison between the 2D and 3D-OCT guidance concerning the incompressible opposition. Especially in the left main bifurcation cases, 3D-OCT guidance significantly lower percentage of the incompressible opposition compared to 2D-OCT guidance. Optimum study is a randomized controlled trial comparing the 3D-OCT guidance and angio-guidance in the provisional bifurcation stenting. On the 3D-OCT guidance, significantly lower percentage of the incompressible opposition compared to the angio-guided. From the 3D-OCT bifurcation registry, we also clarify the effect of the stent-link connection on remain-jet threat after case-in-variant inflation. According to the existence of the link connection at the carrier side, we divided it into two types, free carrier type and connecting to carrier type. In the free carrier type, the optimal wiring can achieve the wide side-bench opening. On the contrary, in link connecting type, even after optimal wiring, the link connection still remains after case-in-variant inflation. We also analyze the predictor of the incompressible opposition on side-bench optimum side. Link connecting type and optimal digital recrossing are the strong predictors of the incompressible opposition. This is the actual clinical case of the link-free type. The upper case, first attempt of the guide wire recrossing failed to the optimal wiring, and the second attempt succeeded in the optimal wiring, and the final case-in-variant inflation promotes the wide opening for the side-bench. In the lower case, similarly, the first attempt failed, and the second attempt succeeded in the optimal wiring, and the wide opening for the side-bench was obtained. This is the link connecting type. In the upper case, guide wire recrossing to the larger digital cell, it resulted in sufficient expansion in the side-bench ostium. On the contrary, in the lower case, guide wire recrossing in the smaller digital cell. As a result, the final case-in-variant inflation cannot achieve the optimal side-bench dilation, and link connection still remains in the center of the side-bench ostium. Therefore, we add the new type for the jailed external patterns, the link-free type and the link-connecting type, and the no or less jailing type. In the link-free type, 3D OCD-guided optimal side-bench dilation was strongly recommended. In link-connecting type, aggressive path change to the link-free or no or less jailing type was recommended. And secondly, guide wire recrossing to the larger digital cell is recommended. And the no or less jailing type, we have confidence to leave the side-bench undilated. There are weak points of OCD observation in LMCA bifurcation. First, a difficulty in obtaining clear visualization in proximal LMCA, and frequent observation requires lots of contrast medium. In such case, which has LM-osteo region or big left main, avoids some disease in the branched area, in this case, LED-osteo region. In this case, OCD observation is very difficult. In such case, we use see-through technique using guiding extension catheter, especially a telescope is very useful to see the proximal side using the back flow from the tip of the guide extension catheter. Telescope has a helical core in this body, so infrared light can penetrate into a space of the core. This is the actual case, OCD pullback from the LED to left main. Here you can see there is a calcified region, and tip of the guide extension catheter can penetrate the infrared light. This is the body of the guide extension catheter. Telescope has a helical core into a space of the core. We can see the left main body. Another problem is contrast medium. This is a case of diffuse LED region. We treat the region with two drug editing stand. We compare image quality between the contrast medium and low molecular weight dextran. Low molecular weight dextran is useful to create visualization and remove the red blood cell from the observed blood cell. Here you can see there is no significant difference between the contrast medium and dextran. Our Japanese colleague, Dr. Kurogi, recently demonstrated the efficacy of dextran for OCD or OCD guidance. Here you can see in terms of the amount of the contrast medium, they compared OCD guidance and the IBAS guidance in propensity match analysis, there is no significant difference between the amount of the contrast medium between them. This is the case of the 72-year-old male with AFOD angina. Here you can see LED diagonal bifurcation region. We decided to treat this region with two stand by minimal cure-out stenting. Firstly, we implanted diagonal branch stenting with 2.25-minute stand. And then LED wiring was performed. This is the 3D OCD images after rewiring to the LED. Here you can see a guide wire recrosses the most proximal side of the diagonal branch stand. So this is the one-string cure-out stenting. After opening LED ostium, LED stenting with 3.0-minute stand was performed. And then repot was performed by a 3.5-minute balloon. Then rewiring to the diagonal branch was performed and 3D OCD images exist. And then wiring to the middle cell. However, we considered far distance cell crossing with link connecting type is not suitable for this region. So this recrossing point is optimal for this case. So we directed with this cell. And case model inflation was performed and repot was performed. And this is the final angiography. And both branches are beautifully directed. This is my conclusion slide. OCD guidance in bifurcation PCI is useful in PCI for accurate region assessment and optimal device selection in each branch. In the PCI optimization, it is also useful for checking the sufficient stent expansion. And in terms of optimal wiring, 3D OCD guidance elevates the success rate for the optimal disturb wiring. And it is also useful to stratify the side-branch dilation according to J-ring strut pattern on the side-branch ostium and prevention of abnormal wiring. This would lead to less incomplete stent apposition, J-ring struts, and deformation. Thank you for attention.

Optical Coherence Tomography

colony bifurcation stenting

stent apposition

guidewire recrossing

left main coronary artery