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Double-Kissing Culotte Technique for Coronary Bifurcation Stenting - Technical evaluation and comparison with conventional double stenting techniques
Abstract
Aims:
To assess, whether Culotte technique could be improved by an additional kissing dilation prior main branch (MB) stenting.
Methods and results:
Double-kissing (DK) Culotte was compared to Culotte and DK-Crush techniques in bench model (n=24). Results were evaluated for stent apposition, for luminal opening and for flow dynamics. Total procedure duration of DK-Culotte was 18.3±3.4min, significantly lower than for DK-Crush (24.3±5.7min; p=0.015), however similar to Culotte (21.6±5.9min, p=0.104). In DK-Culotte overall rate of moderate (200-500mm) and significant (>500mm) malapposition was 2.1±1.9% and 0.4±0.2%; similar as compared to Culotte (3.7±3.8%, p=0.459 and 1.0±1.0%, p=0.517; respectively), and lower as compared to DK-Crush (8.1±2.5%, p<0.001 and 3.7±5.3%, p=0.002; respectively). Lower malapposition rate of DK-Culotte as compared to DK-Crush was due to less moderate and significant malapposition in proximal MB (0.0±0.0% vs. 14.0±7.6%, p<0.001 and 0.0±0.0% vs. 4.2±9.1%, p=0.026, respectively). Micro computed tomography did not show difference in luminal opening at proximal MB, distal MB or SB. There was no difference either in maximum shear rate or in areas of high shear or recirculation.
Conclusions:
Bench tests data suggest that DK approach facilitates Culotte technique. Clinical validity and relevance remains to be confirmed in larger in vivo population.
... DK culotte stent implantation procedures. DK culotte stenting was performed according to the white paper of the European Bifurcation Club and a previously published document 10,11 . The SYNERGY Megatron stent (Boston Scientific Inc., Galway, Ireland) was used in this study 15 . ...
... The DK crush technique is reported superior to other 2-stent techniques (culotte, crush, T/T-and-protrusion) 9 and might be effective for complex bifurcation 8 . From a structural point of view, the culotte technique might be considered more "physiologic", as it ensures full coverage in bifurcation segments (minimal or no neocarina, no triple layer, maintaining tubular stent architecture with fractal deformation only) 10 . Viceconte et al. showed that strut malapposition might be increased in the 2-stent techniques, mainly culotte stenting, compared with single stenting, resulting in increased stent failure 18 . ...
... A pathologic study demonstrated that strut malapposition at the bifurcation segment was related to stent failure and optimization by OCT could decrease strut malapposition toward the SB and proximal site 21 . Bench tests by Toth et al. demonstrated that DK culotte stenting was superior to conventional culotte stenting and DK-crush stenting in terms of ISA at the bifurcation 10 . However, its superiority has not been obviously shown in the clinical studies 9 . ...
The usefulness of optical frequency domain imaging (OFDI) guidance on two-stenting at left main bifurcation has not been evaluated. Here, we used a novel bench model to investigate whether pre-defined optimal rewiring with OFDI-guidance decreases acute incomplete stent apposition (ISA) at the left main bifurcation segment. A novel bench simulation system was developed to simulate the foreshortening and overlapping of daughter vessels as well as left main bifurcation motion under fluoroscopy. Double-kissing (DK) culotte stenting was performed using the novel bench model under fluoroscopy with or without OFDI-guidance. In the OFDI-guidance group, if the guidewire did not pass through the pre-defined optimal cell according to the 3-dimensional OFDI, additional attempts of rewiring into the jailed side branch were performed. The success rate of optimal jailed side branch rewiring after implantation of the first and second stent under OFDI-guidance was significantly higher than that under only angio-guidance. After completion of the DK-culotte stenting, the incidence and volume of ISA at the bifurcation segment in the OFDI-guidance group was significantly lower than that in the angio-guidance group. Online 3-dimensional OFDI-guided DK-culotte stenting according to a pre-defined optimal rewiring point might be superior to only angio-guided rewiring for reducing ISA at the bifurcation.
... The culotte technique, introduced by Chevalier [7] , is a well-established two-stent procedure that has demonstrated a favorable safety pro le and positive clinical outcomes [8,9] . Despite its rmly established role in the PCI armamentarium, recent bench test data [10] indicate that a modi cation to this technique, known as the Double Kissing (DK) culotte could facilitate the procedure's performance and potentially improve clinical outcomes. The DK-culotte technique is a variation of the classical culotte technique characterized by an additional kissing balloon (KB) in ation that follows SB stenting (inverted technique) or MB stenting (conventional technique) and precedes the second branch stent implantation. ...
... However, some data indicate that the DK-culotte technique may provide bene ts over culotte [21,22] . Recent bench testing reveals that performing additional KB dilatation before stenting the second branch may improve the culotte technique [10] . This reduces the risk of pulling the struts of the rst stent toward the ostium, which could affect the procedure's progress and the ability to perform a nal KB in ation. ...
The double-kissing (DK) culotte technique, a modification of the traditional culotte stenting with additional kissing balloon inflation after first stent implantation, was compared to the conventional culotte technique in a multicenter, observational, retrospective study of 239 patients with acute coronary syndrome. Patients were treated at two high-volume centers, with 117 patients undergoing the DK culotte and 122 patients undergoing the traditional culotte technique. The primary endpoint, target lesion failure (TLF), occurred in 6.84% of the DK culotte group and 13.11% of the culotte group after a one-year period (p = 0.085). Major adverse cardiac events (MACE) were also lower in the DK culotte group (12.82% vs. 19.67%; p = 0.073), but the differences were not statistically significant. No significant differences were found in contrast medium use (220 mL vs. 230 mL; p = 0.214) or cumulative radiation dose (1868 mGy vs. 2114.5 mGy; p = 0.127). The results indicate a trend towards better clinical outcomes with the DK culotte technique without increased procedural risks. However, these findings need further validation in prospective studies. ClinicalTrials.gov: NCT06284057
... Similar to DK-crush, some operators tried to improve traditional culotte by adding additional steps of kissing balloon inflations and developed DK-culotte, which is supposed to benefit from similar improvements in procedural results and clinical outcomes as DK-crush. At the moment, bench tests favor the new technique [41], but there are no clinical data available. ...
Percutaneous treatment of the left main coronary artery is one of the most challenging scenarios in interventional cardiology, due to the large portion of myocardium at risk the technical complexity of treating a complex bifurcation with large branches. Our aim is to provide un updated overview of the current indications for percutaneous treatment of the left main, the different techniques and the rationale underlying the choice for provisional versus upfront two-stent strategies, intravascular imaging and physiology guidance in the management of left main disease, and the role of mechanical support devices in complex high-risk PCI.
... Although the DK crush has been the prominent treatment modality, 1 there are studies showing that the DK culotte stenting may have better results especially in terms of stent malapposition and metal layers at the neocarina. 2 In our case report, we demonstrate a novel minimal protruded DK nano-culotte stenting technique for the treatment of true CBL. ...
Percutaneous coronary intervention (PCI) of coronary bifurcation lesion (CBL) is challenging due to its complex anatomy resulting in difficulty in deciding on treatment procedure. Although there are advanced techniques and well-experienced operators, the optimal stenting strategy is still debated. The contemporary PCI techniques of CBL aim to achieve minimal stent protrusion to the main vessel and to minimize stent layers at the neocarina as well as the side branch (SB) ostium and proximal main vessel (PMV). In addition, it is necessary to avoid incomplete stent coverage at the SB ostium and stent malapposition. Traditional 2-stent strategies have been improved using minimal stent protrusion to the main vessel (MV) and double kissing (DK) balloon dilatation to reach optimal results. Although the DK crush has been the prominent treatment modality,1 there are studies showing that the DK culotte stenting may have better results especially in terms of stent malapposition and metal layers at the neocarina.2 In our case report, we demonstrate a novel minimal protruded DK nanoculotte stenting technique for the treatment of true CBL.
... The most practical thing to do would be to start with the diseased branch and then move on with a combo of POT (proximal optimization technique) plus double kissing balloon. This technique has been described recently, 9 and we don't have comparative studies against the DK crush technique. However, when refined 8 it achieves an excellent stent expansion and apposition across all the bifurcation segments, which should lead to clinical outcomes. ...
QUESTION: What aspects do you think might explain the significant differences reported between the results from the EBC MAIN (European bifurcation club left main coronary stent study),1 and the DKCRUSH-V (Double kissing crush vs provisional stenting for left main distal bifurcation lesions) clinical trials?2 ANSWER: Both studies differ in several aspects we could categorized into 4: those that are operator-related; study design-related; patient and lesion-related, and those associated with the results from the provisional stenting technique. The double kissing (DK) is a complex technique where most of the evidence available in the medical literature (including the DKCRUSH-V2) comes from the same group of expert operators who have been using such technique for years now.3,4 However, the operators from the EBC MAIN1 belong to the European Bifurcation Club that has spent years promoting and refining the provisional stenting technique. Regarding the study design, the group of patients randomized to 2 different stents is also different from one trial to the other: in the DKCRUSH-V only patients treated with the DK crush technique were while in the EBC MAIN most patients were treated with the culotte technique or the T stenting technique. Another different aspect between both trials is the use of systematic angiographic assessments...
Background
Acute fracture of a left main (LM) stent during angioplasty is a rare complication. Cardiologists should be aware of the risk of stent fracture (SF) following kissing balloon inflation (KBI) even if the effective diameter of the balloons does not exceed the recommended expansion limits of stents.
Case summary
A 64-year-old female with hypertension and dyslipidaemia presented with crescendo angina since three months in spite of optimal medical therapy. Coronary angiogram showed a distal LM bifurcation lesion. The patient was admitted for LM bifurcation stenting by upfront two-stent technique (inverted double-kissing Culotte technique). Following first KBI of the stent placed from left circumflex artery (LCX) to LM, there was stent deformation in the LM shaft. As we had planned the Culotte technique, we decided to exclude the fractured segment by stenting from left anterior descending artery (LAD) to LM. The stent from LAD–LM successfully excluded the fractured part of the first stent from the lumen of LM. Optical coherence tomography done after final KBI from LCX–LM revealed successful exclusion of the deformed segment of the LCX stent with mild malapposition at the site of the deformed stent. A follow-up angiogram after six months showed normal in-stent flow with no evidence of restenosis or pseudoaneurysm.
Discussion
Acute LM SF during coronary intervention can occur even if the effective cumulative diameter of the inflated balloons does not exceed the mentioned expansion limit of stents. Intravascular imaging is a helpful modality to define type of SF and its management.
Objectives: This study aimed to assess the bioresorbable vascular scaffold (BVS) performance with culotte stenting techniques and evaluate bifurcated scaffold morphologies.
Methods: Conventional culotte stenting (CCS), double kissing mini-culotte stenting (DKMCS), and double kissing single-ring culotte stenting (DKSRCS) were executed in silicone bifurcated models. Procedures concluded with final kissing balloon inflation and proximal optimization technique. Microcomputed tomography assessed morphological parameters like side branch (SB) residual ostial stenosis and neocarina length (LNC) quantitatively. Optical coherence tomography (OCT) measured strut malapposition rates (SMR).
Results: Quantitative assessments showed that BVS, in comparison with CCS, had significantly enhanced scaffold expansion at the SB ostium (6.29 ± 0.36 mm² vs 6.71 ± 0.37 mm², P = 0.05; 6.29 ± 0.36 mm² vs 6.78 ± 0.26 mm², P = 0.05, respectively), and decreased SB ostial stenosis(0.14% ± 0.04% vs 0.08% ± 0.04%, P < 0.05; 0.14% ± 0.04% vs 0.08 ± 0.03%, P < 0.05, respectively), LNC (0.49 ± 0.10 mm vs 0.30 ± 0.08 mm, P < 0.05; 0.49 ± 0.10 mm vs 0. 28 ± 0.06 mm, P < 0.05, respectively) and gap width(1.48 ± 0.06 mm vs 1.21 ± 0.06 mm, P < 0.05; 1.48 ± 0.06 mm vs 1.10 ± 0.04 mm, P < 0.05, respectively) in both DKMCS and DKSRCS. Notably, DKMCS and DKSRCS demonstrated reduced SMR, especially in scaffold overlap areas, as revealed by OCT.
Conclusions: DKMCS and DKSRCS offer superior morphological outcomes for BVS models than CCS, suggesting BVS as a viable and effective technique for culotte stenting.
Objective
This study aimed to compare the clinical outcomes of double kissing mini-culotte (DKMC) stenting with those of mini-culotte (MC) stenting in treating patients with true coronary bifurcation lesions (CBLs) in the clinical real world.
Methods
This retrospective observational cohort study included 180 consecutive patients with true CBLs (Medina type 1,1,1; 1,0,1; 0,1,1). All eligible patients underwent coronary angiography and percutaneous coronary intervention with two-stent techniques in our hospital; among them, 97 received DKMC treatment and 83 MC treatment. The primary clinical endpoints were the major adverse cardiovascular events (MACE), which included cardiac death, myocardial infarction, and target vessel/lesion revascularization (TVR/TLR). The secondary endpoints were stent thrombosis, in-stent restenosis, and individual components of MACE.
Results
Quantitative coronary angiography analysis (at 5 years) revealed that late lumen loss (0.25 ± 0.41 mm vs. 0.14 ± 0.32 mm, P = 0.032) and segmental diameter restenosis of the side branch (27.84 ± 12.34% vs. 19.23 ± 9.76%, P = 0.016) were lower in the DKMC treatment group than that in the MC treatment group. Notably, compared to that in the MC treatment group, the cumulative event rate of MACE at 5 years (22.8% vs. 8.3%, P = 0.007) and TVR/TLR (17.7% vs. 6.3%, P = 0.018) was higher in the DKMC treatment group, driven mainly by TVR/TLR. Especially, the DKMC group was related to a significant reduction in the primary and secondary endpoints in high-risk patients.
Conclusion
DKMC treatment was associated with less late lumen loss and restenosis in the side branch and a lower rate of cumulative MACE and TVR/TLR. DKMC treatment is more effective for treating true CBLs than MC treatment; however, these findings warrant further confirmation through a randomized clinical trial.
The left main coronary artery disease (CAD) is a complex subset of CAD with constantly evolving guidelines in management and treatment. Indications for revascularization and the strategies of revascularization (Percutaneous intervention versus bypass surgery) are the subject of many trials and metanalysis. If percutaneous intervention is planned, meticulous planning and imaging to guide intervention are mandated. Step-wise layered provisional strategy is the treatment of choice with a systematic two-stent strategy reserved for complex bifurcation.
The current European Society of Cardiology (ESC) guideline recommendations give equal consideration to percutaneous coronary interventions (PCI) and bypass surgery for the treatment of main stem stenosis. Because of the anatomical setting, interventional treatment of main stem stenosis represents a complex PCI procedure. For this reason, extensive planning of the PCI with the use of intravascular imaging is necessary to assess the extent of calcification in the main stem itself and also in the proximal vascular segment of the anterior interventricular branch (left anterior descending, LAD) and the circumflex branch (RCX). Furthermore, an assessment of the vessel diameter is necessary for planning the PCI as well as for stent selection. Especially in the case of severely calcified lesions, careful and routine dissection of the lesion to be treated is essential. For this purpose, so-called cutting balloons, scoring balloons or debulking devices (rotational atherectomy, orbital atherectomy) can be used. In the case of a main stem stenosis involving the bifurcation, the choice of stent strategy depends on the extent of calcification of the daughter vessels (LAD and RCX), as well as the complexity of the bifurcation stenosis. The superiority of the so-called double kissing (DK) crush technique over a single stent strategy could be confirmed in a randomized trial and should be used in main stem bifurcation stenoses with pronounced calcification of the proximal segments of the LAD and RCX (stenosis length > 10 mm, and > 70% diameter stenosis). The already established 2‑stent strategies for the treatment of bifurcation stenosis could be modified or further developed. In preliminary studies the advantage of the so-called DK nano-crush technique and the DK culotte technique could be shown, whereby these initial results still have to be confirmed by larger randomized studies.
Interventional treatment of bifurcation lesions, especially true complex bifurcation lesions, continue to be a challenge for interventional cardiologists. A primary one stent strategy is always preferred for simple bifurcation lesions, whereas studies in recent years have shown that a two stent strategy may be advantageous for true bifurcations, i.e. those involving at least the distal main branch as well as the side branch. This seems to be even more pronounced when the lesion presents as complex, i.e., the side branch shows high-grade stenosis over longer stretches and the complete lesion fulfils certain criteria, e.g., severe calcification and a bifurcation angle < 45° or > 70°. According to the latest randomized trials and meta-analyses, the double kissing (DK) crush and double kissing mini-crush (DKMC) techniques in particular seem to be advantageous for these lesions; however, in recent years the established techniques have been continuously refined and further developed. The DK culotte technique and the nano-crush technique deserve special attention. Both techniques seem to further improve and simplify the existing underlying strategies; however, further studies to prove the superiority of these techniques over the established ones are still pending. Overall, the implementation of the available randomized study results, the further development of the techniques and also of the materials can continuously improve the outcome of the patients after interventional treatment of bifurcation lesions. This is also confirmed by the latest registry data, which for the first time could show equal event rates in patients after treatment of complex lesions compared to simple lesions in the clinical practice.
QUESTION: What aspects do you think might explain the significant differences reported between the results from the EBC MAIN (European bifurcation club left main coronary stent study),1 and the DKCRUSH-V (Double kissing crush vs provisional stenting for left main distal bifurcation lesions) clinical trials?2 ANSWER: The EBC MAIN trial has proven the non-inferiority of the step-by-step provisional stenting technique approach compared to the early double stenting strategy in 467 patients with distal left main coronary artery bifurcation disease (Medina 1,1,1 or 0,1,1). No significant differences were reported regarding the overall rate of major adverse cardiovascular events, target lesion failure, acute myocardial infarction, and stent thrombosis.1 On the other hand, the DKCRUSH V trial randomized 482 patients with distal left main coronary artery bifurcation disease (Medina 1,1,1 or 0,1,1) to receive treatment with the provisional technique vs the DK-crush technique. The latter had a lower rate of major adverse cardiovascular events with statistically significant differences regarding target lesion failure (10.7% vs 5%) (hazard ratio, 0.42; 95% confidence interval, 0.21-0.85; P = .02), acute myocardial infarction (2.9% vs 0.4%; P = .03), and stent thrombosis (3.3% vs 0.4%; P = .02) at 1-year follow-up.2 Results were better in the most complex coronary bifurcation lesions...
PREGUNTA: ¿Qué aspectos considera que pueden explicar las notables diferencias entre los resultados de los ensayos EBC MAIN (European Bifurcation Club Left Main Coronary Stent Study)1 y DKCRUSH-V (Double Kissing Crush versus Provisional Stenting for Left Main Distal Bifurcation Lesions)2? RESPUESTA: Ambos estudios difieren en varios aspectos que podríamos resumir en cuatro: relacionados con los operadores, con el diseño del estudio, con el tipo de pacientes y lesiones incluidos, y con los resultados de la técnica de stent provisional. El double kissing (DK) crush es una técnica compleja, en la que una gran mayoría de la evidencia existente en la literatura (incluido el DKCRUSH-V2) proviene del mismo grupo de operadores expertos que han venido utilizando la técnica durante años3,4. Por el contrario, los operadores del EBC MAIN1 pertenecen al European Bifurcation Club, que ha promocionado y depurado la técnica de stent provisional durante años. En cuanto al diseño, el grupo de pacientes asignados a 2 stents también difiere entre ambos estudios: en el DKCRUSH-V solo se trataron con DK crush, mientras que en el EBC MAIN la mayoría recibieron culotte o stent en T. Otro aspecto diferencial entre los estudios es el uso de reevaluación angiográfica sistemática al año en el DKCRUSH-V (66%...
PREGUNTA: ¿Qué aspectos considera que pueden explicar las notables diferencias entre los resultados de los ensayos EBC MAIN (European Bifurcation Club Left Main Coronary Stent Study)1 y DKCRUSH-V (Double Kissing Crush versus Provisional Stenting for Left Main Distal Bifurcation Lesions)2? RESPUESTA: El estudio EBC MAIN ha demostrado la no inferioridad de la técnica paso a paso del stent provisional comparado con la estrategia inicial de 2 stents en 467 pacientes con enfermedad de tronco distal en bifurcación (Medina 1,1,1 o 0,1,1). No hubo diferencias en cuanto a eventos adversos cardiovasculares mayores globales, fallo de la lesión diana, infarto agudo de miocardio y trombosis del stent1. Por otro lado, el estudio DKCRUSH V aleatorizó a 482 pacientes con enfermedad de tronco distal en bifurcación (Medina 1,1,1 o 0,1,1) para recibir tratamiento con técnica provisional frente a DK-crush. La estrategia de DK-crush tuvo una menor incidencia de eventos adversos cardiovasculares mayores, con diferencias estadísticamente significativas en cuanto a fallo de la lesión diana (10,7 frente a 5%) (hazard ratio = 0,42; intervalo de confianza del 95%, 0,21-0,85; p = 0,02), infarto agudo de miocardio (2,9 frente a 0,4%; p = 0,03) y trombosis del stent (3,3 frente a 0,4%; p = 0,02) en el...
Stepwise layered provisional stenting (PS) is the most commonly used strategy to treat coronary bifurca-tion lesions (CBL). The term "stepwise layered" emphasises the versatility of this approach that allows the adjustment of the procedure plan according to the CBL complexity, starting with stent implantation in one branch and implantation of a second stent in the other branch only when required. A series of refinements have been implemented over the years to facilitate the achievement of predictable procedural results using this approach. However, despite its simplicity and versatility, operators using this technique require full knowledge of the pitfalls of each procedural step. Part I of this 16 th European Bifurcation Club consensus paper provides a detailed step-by-step overview of the pitfalls and technical troubleshooting during the implantation of the first stent using the PS strategy for the treatment of CBL. KEYWORDS • bifurcation • drug-eluting stent • left main EuroIntervention 2022;18-online publish-ahead-of-print May 2022 2 Abbreviations aSB assigned side branch CBL coronary bifurcation lesions DK-crush double-kissing crush dMV distal main vessel EBC European Bifurcation Club KBI kissing balloon inflation LAD left anterior descending LM left main MV main vessel pMV proximal main vessel POT proximal optimisation technique PS provisional stenting SB side branch TAP T and small protrusion
Coronary bifurcation lesions (CBLs) account for 15%-20% of all percutaneous coronary interventions. The complex nature of these lesions is responsible for poorer procedural, early and late outcomes. This complex lesion subset has received great attention in the interventional cardiac community, and multiple stenting techniques have been developed. Of these, the provisional stenting technique is most often the default strategy; however, the elective double stenting (EDS) technique is preferred in certain subsets of complex CBLs. The double kissing crush technique may be the preferred EDS technique because of its efficacy and safety in comparative trials; however, this technique consists of many steps and requires training. Many new methods have recently been added to the EDS techniques to provide better stent scaffolding and to reduce early and late adverse outcomes. Intravascular imaging is necessary to determine the interventional strategy and postinterventional results. This review discusses the basic concepts, contemporary percutaneous interventional technical approaches, new methods, and controversial treatment issues of CBLs.
The 15th European Bifurcation Club (EBC) meeting was held in Barcelona in October 2019 and it facilitated a renewed consensus on coronary bifurcation lesions (CBL) and unprotected left main (LM) percutaneous interventions. Bifurcation stenting techniques continue to be refined, developed and tested. It remains evident that provisional approach with optional side-branch treatment utilising T, T and small protrusion (TAP) or culotte continue to provide flexible options for the majority of CBL patients. Debate persists regarding the optimal treatment of side branches, including assessment of clinical significance and thresholds for bail-out treatment. In more complex CBL, especially when involving the LM, adoption of dedicated 2-stent techniques should be considered. Operators using such techniques have to be fully familiar with their procedural steps and should acknowledge associated limitations and challenges. When using 2-stent techniques, failure to perform a final kissing inflation is regarded as a technical failure, since it may jeopardize clinical outcome. The development of novel technical tools and drug regimens deserve attention. In particular, intra-coronary imaging, bifurcation simulation, drug-eluting balloon technology and tailored anti-platelet therapy are identified as promising tools to enhance clinical outcomes. In conclusion, the evolution of a broad spectrum of bifurcation PCI components have resulted from studies extending from bench testing to randomised controlled trials. However, further advances are still needed to achieve the ambitious goal of optimizing the clinical outcomes for every patient undergoing PCI on a CBL.
The European Bifurcation Club recommends an approach to a bifurcation stenosis which involves careful assessment, planning and a sequential provisional approach. In the minority of lesions where two stents are required, careful deployment and optimal expansion are essential to achieve a long-term result.
This Consensus Document is the first of two reports summarizing the views of an expert panel organized by the European Association of Percutaneous Cardiovascular Interventions (EAPCI) on the clinical use of intracoronary imaging including intravascular ultrasound (IVUS) and optical coherence tomography (OCT). The first document appraises the role of intracoronary imaging to guide percutaneous coronary interventions (PCIs) in clinical practice. Current evidence regarding the impact of intracoronary imaging guidance on cardiovascular outcomes is summarized, and patients or lesions most likely to derive clinical benefit from an imaging-guided intervention are identified. The relevance of the use of IVUS or OCT prior to PCI for optimizing stent sizing (stent length and diameter) and planning the procedural strategy is discussed. Regarding post-implantation imaging, the consensus group recommends key parameters that characterize an optimal PCI result and provides cut-offs to guide corrective measures and optimize the stenting result. Moreover, routine performance of intracoronary imaging in patients with stent failure (restenosis or stent thrombosis) is recommended. Finally, strengths and limitations of IVUS and OCT for guiding PCI and assessing stent failures and areas that warrant further research are critically discussed.
The 2017 European Bifurcation Club (EBC) meeting was held in Porto (Portugal) and allowed a multidisciplinary international faculty to review and discuss the latest data collected in the field of coronary bifurcation interventions. In particular, the topic of percutaneous coronary intervention (PCI) on left main coronary artery (LM) disease was highlighted as a contemporary priority. Herein, we summarise the key LM anatomy features, the diagnostic modalities and available data that are relevant for a patient's procedural management. Since the clinical outcomes of patients undergoing PCI on LM disease may depend on both PCI team organisation and PCI performance, the optimal catheterisation laboratory set-up and the rationales for device and technique selection are critically reviewed. The best lesion preparation modalities, the different DES implantation technique choices and the strategies to be considered during PCI on unprotected LM for optimal PCI results are reviewed step by step.
Coronary bifurcation lesions are accounted in about 20% of all percutaneous coronary interventions and despite all-round improvements in their treatment are still perceived as complex lesion subset in interventional cardiology. Treatment of bifurcations, being technically demanding primarily due to the unique bifurcation anatomy, is related to lower procedural success rate and increased rates of long-term adverse cardiac events. According to published data, provisional approach remains a default strategy for majority of bifurcation PCI, but when perfected, two-stent bifurcation techniques can also yield good clinical outcomes. In this paper, we summarize in stepwise fashion technical aspects of optimal, evidence-based bifurcation treatment aiming to accomplish best procedural results and favorable long-term prognosis.
Background:
Provisional stenting (PS) is the most common technique used to treat distal left main (LM) bifurcation lesions in patients with unprotected LM coronary artery disease undergoing percutaneous coronary intervention. The double kissing (DK) crush planned 2-stent technique has been shown to improve clinical outcomes in non-LM bifurcations compared with PS, and in LM bifurcations compared with culotte stenting, but has never been compared with PS in LM bifurcation lesions.
Objectives:
The authors sought to determine whether a planned DK crush 2-stent technique is superior to PS for patients with true distal LM bifurcation lesions.
Methods:
The authors randomized 482 patients from 26 centers in 5 countries with true distal LM bifurcation lesions (Medina 1,1,1 or 0,1,1) to PS (n = 242) or DK crush stenting (n = 240). The primary endpoint was the 1-year composite rate of target lesion failure (TLF): cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization. Routine 13-month angiographic follow-up was scheduled after ascertainment of the primary endpoint.
Results:
TLF within 1 year occurred in 26 patients (10.7%) assigned to PS, and in 12 patients (5.0%) assigned to DK crush (hazard ratio: 0.42, 95% confidence interval: 0.21 to 0.85; p = 0.02). Compared with PS, DK crush also resulted in lower rates of target vessel myocardial infarction I (2.9% vs. 0.4%; p = 0.03) and definite or probable stent thrombosis (3.3% vs. 0.4%; p = 0.02). Clinically driven target lesion revascularization (7.9% vs. 3.8%; p = 0.06) and angiographic restenosis within the LM complex (14.6% vs. 7.1%; p = 0.10) also tended to be less frequent with DK crush compared with PS. There was no significant difference in cardiac death between the groups.
Conclusions:
In the present multicenter randomized trial, percutaneous coronary intervention of true distal LM bifurcation lesions using a planned DK crush 2-stent strategy resulted in a lower rate of TLF at 1 year than a PS strategy. (Double Kissing and Double Crush Versus Provisional T Stenting Technique for the Treatment of Unprotected Distal Left Main True Bifurcation Lesions: A Randomized, International, Multi-Center Clinical Trial [DKCRUSH-V]; ChiCTR-TRC-11001213).
Background:
For the treatment of coronary bifurcation lesions, a provisional strategy is superior to systematic 2-stent techniques for the most bifurcation lesions. However, complex anatomies with large side branches (SBs) with significant ostial disease length are considered by expert consensus to warrant a 2-stent technique upfront. This consensus view has not been scientifically assessed.
Methods and results:
Symptomatic patients with large caliber true bifurcation lesions (SB diameter ≥2.5 mm) and significant ostial disease length (≥5 mm) were randomized to either a provisional T-stent strategy or a dual stent culotte technique. Two hundred patients aged 64±10 years, 82% male, were randomized in 20 European centers. The clinical presentations were stable coronary disease (69%) and acute coronary syndromes (31%). SB stent diameter (2.67±0.27 mm) and length (20.30±5.89 mm) confirmed the extent of SB disease. Procedural success (provisional 97%, culotte 94%) and kissing balloon inflation (provisional 95%, culotte 98%) were high. Sixteen percent of patients in the provisional group underwent T-stenting. The primary end point (a composite of death, myocardial infarction, and target vessel revascularization at 12 months) occurred in 7.7% of the provisional T-stent group versus 10.3% of the culotte group (hazard ratio, 1.02; 95% confidence interval, 0.78-1.34; P=0.53). Procedure time, x-ray dose, and cost all favored the simpler procedure.
Conclusions:
When treating complex coronary bifurcation lesions with large stenosed SBs, there is no difference between a provisional T-stent strategy and a systematic 2-stent culotte strategy in a composite end point of death, myocardial infarction, and target vessel revascularization at 12 months.
Clinical trial registration:
URL: http://www.clinicaltrials.gov. Unique identifier: NCT 01560455.
Aims
Randomized trials of coronary bifurcation stenting have shown better outcomes from a simple (provisional) strategy rather than a complex (planned two-stent) strategy in terms of short-term efficacy and safety. Here, we report the 5-year all-cause mortality based on pooled patient-level data from two large bifurcation coronary stenting trials with similar methodology: the Nordic Bifurcation Study (NORDIC I) and the British Bifurcation Coronary Study: old, new, and evolving strategies (BBC ONE).
Methods and results
Both multicentre randomized trials compared simple (provisional T-stenting) vs. complex (culotte, crush, and T-stenting) techniques, using drug-eluting stents. We analysed all-cause death at 5 years. Data were collected from phone follow-up, hospital records, and national mortality tracking. Follow-up was complete for 890 out of 913 patients (97%). Both Simple and Complex groups were similar in terms of patient and lesion characteristics. Five-year mortality was lower among patients who underwent a simple strategy rather than a complex strategy [17 patients (3.8%) vs. 31 patients (7.0%); P = 0.04].
Conclusion
For coronary bifurcation lesions, a provisional single-stent approach appears to be associated with lower long-term mortality than a systematic dual stenting technique.
Background:
Experimental studies suggest that low wall shear stress (WSS) promotes plaque development and high WSS is associated with plaque destabilization. We hypothesized that low-WSS segments in patients with coronary artery disease develop plaque progression and high-WSS segments develop necrotic core progression with fibrous tissue regression.
Methods and results:
Twenty patients with coronary artery disease underwent baseline and 6-month radiofrequency intravascular ultrasound (virtual histology intravascular ultrasound) and computational fluid dynamics modeling for WSS calculation. For each virtual histology intravascular ultrasound segment (n=2249), changes in plaque area, virtual histology intravascular ultrasound-derived plaque composition, and remodeling were compared in low-, intermediate-, and high-WSS categories. Compared with intermediate-WSS segments, low-WSS segments developed progression of plaque area (P=0.027) and necrotic core (P<0.001), whereas high-WSS segments had progression of necrotic core (P<0.001) and dense calcium (P<0.001) and regression of fibrous (P<0.001) and fibrofatty (P<0.001) tissue. Compared with intermediate-WSS segments, low-WSS segments demonstrated greater reduction in vessel (P<0.001) and lumen area (P<0.001), and high-WSS segments demonstrated an increase in vessel (P<0.001) and lumen (P<0.001) area. These changes resulted in a trend toward more constrictive remodeling in low- compared with high-WSS segments (73% versus 30%; P=0.06) and more excessive expansive remodeling in high- compared with low-WSS segments (42% versus 15%; P=0.16).
Conclusions:
Compared with intermediate-WSS coronary segments, low-WSS segments develop greater plaque and necrotic core progression and constrictive remodeling, and high-WSS segments develop greater necrotic core and calcium progression, regression of fibrous and fibrofatty tissue, and excessive expansive remodeling, suggestive of transformation to a more vulnerable phenotype. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT00576576.
Classic crush has a lower success rate compared to final kissing balloon inflation (FKBI). We previously reported the double-kissing (DK) crush technique that involves double-kissing along with double-crushing for the treatment of true bifurcation coronary lesions in 2005.
This is a consecutive, nonrandomized, open-label study. Eighty-eight consecutive patients with single, true coronary bifurcation lesions according to Lefevre Classification2 and side branch diameter >2.0 mm were enrolled. The first 44 patients (from October 2004 to January 2005) were assigned to the classic crush treatment arm and the next 44 patients (from February 2005 to June 2005) were assigned to the DK crush technique arm, respectively. Data within 30 days were analyzed. Patients in the DK crush group, compared to those in classic crush group, were characterized by longer lesion length in the side branch (13.5 +/- 3.4 mm vs 7.8 +/- 3.1 mm; p <0.05), shorter procedural time (44 +/- 12 minutes vs 68 +/- 17 minutes; p <0.05 ), higher success rate of FKBI (100% vs 70%; p <0.01), and lower contrast volume required (102 +/- 38 mm vs 176 +/- 46 mm; p <0.05). There was a trend toward a larger distal angle between the main vessel and the side branch (57 +/- 180 vs 47 +/- 150) in the DK crush group, as well as longer lesion length in the main vessel (24.3 +/- 8.6 mm vs 21.1 +/- 7.3 mm), though without significant differences (p >0.05). Subacute stent thrombosis was detected in 2 patients with failure of FKBI in the classic crush group (4.3%). In addition, patients in the classic crush group were characterized by a smaller minimum lumen diameter (MLD) at the side branch ostium (2.74 +/- 0.12 mm vs 3.01 +/- 0.13 mm; p <0.01) and had a higher degree of residual stenosis at the ostial side branch (17.4 +/- 11.2% vs 7.3 +/- 8.6%; p <0.05).
Compared with classic crush, DK crush has the potential to improve the clinical outcome in patients with coronary bifurcation lesions. Further randomized, prospective, multicenter studies are required to confirm these differences between the classic crush and DK crush techniques.
Atherosclerotic plaques develop in low shear stress regions. In the more advanced phase of the disease, plaques are exposed to altered shear stress levels, which could influence plaque composition. We investigated changes in plaque composition in human coronary arteries over a 6-month period and how these changes are related to shear stress.
We took images of eight coronary arteries to obtain the 3D shape of the arteries. Lumen data were combined with computational fluid dynamics to obtain shear stress. Palpography was applied to measure strain at baseline and at 6-month follow-up. The change in strain from baseline to follow-up served as a marker for the change in plaque composition. We identified 17 plaques, and each plaque was divided into four regions: the upstream, throat, shoulder and downstream region. Shear stress and strain in the downstream region was significantly lower than in the other regions. There was no significant change in strain for the four different plaque regions. However, we observed that those plaque regions exposed to high shear stress showed a significant increase in strain.
Plaque regions exposed to high shear stress showed an increase in strain over time. This indicates that shear stress may modulate plaque composition in human coronary arteries.
This study provides insights into "crush" coronary bifurcation stenting through imaging of bench deployments.
Although the strategy of provisional side-branch stenting is widely accepted for suitable bifurcation lesions, there is no consensus on the best option for elective stenting with 2 stents. The crush technique has the potential to scaffold and apply the drug to the side-branch ostium where restenosis is most common.
Sequential steps of crush stent deployment and post-dilation were undertaken in silicone phantoms and recorded on cine angiography and microcomputed tomography. We assessed the effect of deployment strategies, post-dilation strategies, and cell size on side-branch ostial area.
Side-branch ostial coverage by metal struts was 53% (95% confidence interval [CI]: 46 to 59) after 1-step kissing post-dilation and was reduced by 2-step kissing post-dilation to 33% (95% CI: 28 to 37; p < 0.0001). Although the residual stenosis after the classical crush strategy was 47% (95% CI: 39 to 53), it was 36% (95% CI: 31 to 40; p = 0.002) after mini-crush deployment. Stents with larger cell size (>3.5 mm diameter) had a residual stenosis of 37% (95% CI: 32 to 42) after crush deployment that was less than the residual stenosis for stents with smaller cell size (52%; 95% CI: 44 to 60; p < 0.0001).
Side-branch ostial stenosis after crush stenting was minimized by mini-crush deployment, 2-step kissing post-dilation, and the use of stents with larger cell size. It is unknown if optimizing stent deployment at bifurcation lesions will reduce clinical stent thrombosis and restenosis.
Coronary angioplasty of bifurcation lesions remains a technical challenge. Balloon angioplasty induces recoil and the "snow-plow" effect with a risk of side branch occlusion. The late result is associated with a high rate of reintervention. Randomized studies in nonbifurcated lesions have demonstrated better short- and midterm results after stent placement. We propose the "culotte" technique as a new technique to place intracoronary stents in bifurcation lesions: implantation of 2 similar stents in 2 steps in the main branch and in the side branch with overlapping of the 2 stents in the main branch before bifurcation. We performed this technique in 50 patients (in the left anterior diagonal branch in 33, in the left circumflex obtuse marginal branch in 12, in the right coronary artery in 4, and in the left main coronary artery in 1). The clinical success rate was 94% with 3 non-Q-wave myocardial infarctions. Late results indicated a 24% target lesion revascularization rate, which improved when a true kissing balloon inflation was used to achieve final deployment of both stents. This culotte technique is highly feasible and provides excellent short-term results. Assessment of its midterm benefit requires further study.
The purpose of this research was to evaluate the long-term outcomes after implantation of drug-eluting stents (DES) in bifurcation lesions with the "crush" technique.
The long-term outcome of "crush" stenting technique has yet to be determined.
We identified 181 consecutive patients who were treated with DES with the "crush" stent technique from April 2002 to April 2004. Based on the usage of final kissing balloon post-dilation (FKB), the patients were divided into an FKB group (n = 116) and a non-FKB group (n = 65).
Clinical follow-up at nine months was available in all patients, and angiographic follow-up in 80% of patients. Three cases (1.7%) of intraprocedural stent thrombosis and five (2.8%) cases of postprocedural stent thrombosis occurred. Restenosis rate of the main branch in the entire cohort lesions was 11.5%. Restenosis rate of the side branch was lower in the FKB group than that in the non-FKB group (11.1% vs. 37.9%, p < 0.001). The target lesion revascularization (TLR) rate for all patients was 14.9%. The lack of FKB was a predictor for TLR (hazard ratio [HR] 4.17; 95% confidence interval [CI] 1.30 to 14.3, p = 0.02). Diabetes was also a predictor for TLR (HR 1.79; 95% CI 1.14 to 2.80, p = 0.01). Premature discontinuation of dual antiplatelet therapy (odds ratio [OR] 16.8; 95% CI 1.31 to 159.5, p = 0.03) and age (OR 1.10; 95% CI 1.00 to 1.21, p = 0.048) was associated with the occurrence of postprocedural stent thrombosis.
Compared to the absence of FKB, the "crush" stenting technique with FKB appears to be associated with more favorable long-term outcomes. When utilizing the "crush" stenting technique, FKB is mandatory.
Active contour segmentation and its robust implementation using level set methods are well-established theoretical approaches that have been studied thoroughly in the image analysis literature. Despite the existence of these powerful segmentation methods, the needs of clinical research continue to be fulfilled, to a large extent, using slice-by-slice manual tracing. To bridge the gap between methodological advances and clinical routine, we developed an open source application called ITK-SNAP, which is intended to make level set segmentation easily accessible to a wide range of users, including those with little or no mathematical expertise. This paper describes the methods and software engineering philosophy behind this new tool and provides the results of validation experiments performed in the context of an ongoing child autism neuroimaging study. The validation establishes SNAP intrarater and interrater reliability and overlap error statistics for the caudate nucleus and finds that SNAP is a highly reliable and efficient alternative to manual tracing. Analogous results for lateral ventricle segmentation are provided.