Simultaneous multivessel acute drug-eluting stent thrombosis

Stent thrombosis (ST) in the era of bare metal stents (BMS) using high-pressure stent deployment and combined anti-platelet therapy is an uncommon but feared complication. There is concern for an elevated risk of stent thrombosis (ST) with drug-eluting stents (DES). We describe a case of simultaneous multivessel drug-eluting stent thrombosis 8 h after deployment of paclitaxel-eluting stents in the right coronary (RCA) and left anterior descending (LAD) arteries.     

Intravascular ultrasound (IVUS) guided fixation of an accidentally crushed coronary stent

Stent deployment during coronary intervention has become more and more common recently. Inappropriate stent deployment may lead to unexpected high mortality and morbidity rates. A 62 year-old man with unstable angina presented with a bifurcation lesion after diagnostic coronary angiography. A drug-eluting stent was successfully deployed across the bifurcation lesion. However, after wire exchange and rewiring followed by high pressure balloon postdilatation, the stent was accidentally crushed under IVUS guidance. We used a looping wire technique and successfully redilated the crushed instent portion. This case suggests interventionists should not always change the wire before stent well deployment and should bear in mind the value of IVUS in managing such a complication.     

Drug-eluting stents for coronary bifurcations: insights into the crush technique.

Sirolimus-eluting stents appear to reduce substantially restenosis following percutaneous coronary bifurcation intervention. The crush technique was devised to reduce restenosis further by improving stent and drug application to the side-branch ostium. We aimed to investigate the performance of drug-eluting stent (DES) platforms with the crush technique, to identify deployment pitfalls, and to clarify the best deployment strategies. Each stage of the crush technique was photographed in a bifurcation phantom. Simultaneous side- and main-branch dilatation (kissing balloons) fully expanded the stent in the side-branch ostium, widened the gaps between stent struts covering the side branch, and eliminated main-branch distortion. With side branches angled at > 70 degrees , sequential (side- then main-branch) inflations may be needed to achieve best results. Postdilatation of the main branch with a balloon of narrower diameter than the deploying balloon caused main-branch stent distortion. These principles applied to all the bifurcation strategies and stent designs tested.     

Dislodged and mechanically distorted stent stuck within a previously implanted drug-eluting stent

Coronary stent loss during percutaneous coronary intervention is rare and is often associated with significant morbidity. Several retrieval techniques, overlying stent deployment and crushing, and surgical removal can be used to deal with a stent lost in the coronary system. We successfully treated a dislodged and mechanically distorted coil stent stuck within a previously implanted drug-eluting stent (DES) by stent-crush technique. This case might provide insight into the mechanisms responsible for the longitudinal fragility of cobalt alloy and coil-structure stents and stent fracture of DES. In the DES era, careful attention should be paid to such complications when attempting to deliver a stent to a distal vessel through a pre-existing DES.     

Late drug-eluting stent thrombosis: importance of intravascular ultrasound

We report two cases of late occurring drug-eluting stent thrombosis (ST) where coronary angiography failed to identify the cause but intravascular ultrasound (IVUS) revealed underlying mechanical problems with the initial stent deployment. Mechanical factors such as stent underexpansion and residual edge stenoses may be more important in the pathogenesis of late drug-eluting ST than previously recognized. Intravascular ultrasound is required to reliably detect these problems and optimize subsequent reintervention.     

Successful retrieval of dislodged paclitaxel-eluting stent with a nitinol loop snare: a case report

Coronary stent dislodgment or embolization before deployment is a rare but challenging complication in interventional cardiology. Intracoronary embolization of the dislodged stent is associated with a high risk of coronary occlusion, due to thrombus formation and subsequent myocardial infarction. Furthermore, systemic embolization may cause severe cerebrovascular events. Nonsurgical retrieval strategies for this complication have been suggested, but bailout cardiac surgery may be indicated if percutaneous retrieval attempts fail. To our knowledge, this is the first case report of intracoronary drug-eluting stent dislodgment, and successful retrieval was accomplished by a loop snare technique. With the increasing trend of using drug-eluting stents in percutaneous coronary intervention, the likelihood of stent dislodgment or embolization may increase. It should be kept in mind, especially by coronary interventionists, how to manage this complication.     

Propensity-matched patient-level comparison of the TAXUS Liberté and TAXUS element (ION) paclitaxel-eluting stents

Stent design, metal alloy composition, and strut thickness may influence late lumen loss and clinical outcomes after bare metal stent deployment; however, their impact on outcomes after drug-eluting stent deployment is unknown. Although the TAXUS Liberté and ION paclitaxel-eluting stents use similar polymer and drug, the ION stent incorporates a novel thin-strut platinum chromium metal alloy and cell design. We therefore compared patient-level data from 2,298 subjects enrolled into the TAXUS ATLAS (TAXUS Liberté) and PERSEUS (ION) clinical trials. Propensity-score (1:1) matching was performed to adjust for covariate imbalance between stent types. Twelve-month major adverse cardiac events were less frequent after use of the ION compared to the TAXUS Liberté (12.7% vs 8.3%, p <0.001, unadjusted; 12.0% vs 7.5%, p = 0.007, propensity matched) largely because of decreased non-Q-wave myocardial infarction (MI; 2.9% vs 1.4%, p = 0.01, unadjusted; 3.2% vs 0.9%, p = 0.004, propensity matched). The MI difference was predominantly periprocedural and in patients treated with a single stent. In conclusion, this exploratory post hoc analysis demonstrated that the ION was associated with fewer adverse clinical events than the TAXUS Liberté because of decreased non-Q-wave MI. Stent platform-related variables may influence clinical outcomes after drug-eluting stent use despite similar polymer and drug elution. Differences in adjunctive pharmacotherapy and/or stenting technique may also be contributory.     

Thrombotic occlusion of a drug-eluting stent - is IVUS mandatory

Acute stent thrombosis is a rare but serious complication of stent implantation. Although anecdotal reports suggest that the use of drug-eluting stents (DES) may increase the risk of stent thrombosis, this has not been borne out in randomized, controlled trials. We report a case of acute stent thrombosis following implantation of a DES, with review of the literature. Despite the initial favorable procedural result, the patient developed stent thrombosis 7 days later; intravascular ultrasound (IVUS) demonstrated incomplete deployment of the stent. We recommend the use of IVUS in the management of acute stent thrombosis in order to exclude incomplete stent expansion which may underlie acute thrombotic occlusion.     

Late stent thrombosis associated with coronary aneurysm formation after sirolimus-eluting stent implantation

Stent thrombosis is a rare but potentially fatal complication of coronary stent implantation. Its occurrence late after drug-eluting stent (DES) deployment has led to concerns regarding their long-term safety. We report a case of late stent thrombosis 26 months after sirolimus-eluting stent (SES) (Cypher, Cordis Corp., Miami, Florida) implantation. This was associated with marked positive vessel remodeling and coronary aneurysm formation involving the stented segment of the coronary artery. The patient was on dual antiplatelet therapy at the time.     

Culotte bifurcation stenting with paclitaxel drug-eluting stent.

The results of using the culotte bifurcation technique have not been promising with regard to bare metal stents; however, some possible advantages with regard to drug-eluting stents (DES) must be taken into account, such as the possibility to stent provisionally, to use lower French sizes, and to completely cover the coronary wall and the new carina with a single or double stent layer. The crush technique, which aims to reach a complete coverage of the coronary wall to allow antiproliferative drugs to homogeneously distribute into the coronary walls, has been introduced. The culotte technique seems to act more physiologically, allowing the creation of a new, homogeneously covered carina, without any crushed metal inside the coronary wall. We present the case of a coronary bifurcation treated with the use of the culotte technique and paclitaxel-eluting stent deployment, with good angiographic results after 10 months of follow-up. Further data are needed to evaluate the potential utility of the culotte technique in treating bifurcation coronary lesions in the area of DES.     

Intravascular ultrasound-guided high-pressure balloon predilatation for optimal drug-eluting stent deployment in restenosis of a stent implanted 7 years earlier. Do we know the right technique for in-stent restenosis restenting?

Although off-label, drug-eluting stent (DES) implantation is a preferred intervention for in-bare metal stent restenosis (BMS ISR). Off-label DES implantation appears to be associated with a higher risk of stent thrombosis and lesion recurrence. Accordingly, routine BMS ISR restenting with DES is associated with more frequent subsequent thrombosis. Intravascular ultrasound (IVUS) studies point to stent underexpansion as the major mechanism of late DES failure. We report a case of a patient with BMS ISR in whom IVUS clarified initial BMS expansion; consequently, high-pressure predilatation with an angiographically oversized conventional balloon was applied prior to DES deployment; and finally, IVUS verified the stent expansion.     

Optimization of stent deployment by intravascular ultrasound

Intravascular ultrasound (IVUS) is a useful diagnostic method that provides valuable information in addition to angiography regarding the coronary vessel lumen, dimensions, plaque burden, and characteristics. The major use of IVUS in coronary intervention is to guide interventional strategies and assess optimal stent deployment. Since the introduction of the drug-eluting stent (DES), concerns about restenosis have decreased. However, high-risk lesion subsets are being routinely treated with DESs, and the incidence of suboptimal results after stent deployment, such as stent underexpansion, incomplete stent apposition, edge dissection, geographic miss, and the risk of stent thrombosis, have correspondingly increased. Thus, optimization of stent deployment under IVUS guidance may be clinically important. In this review, we focus on the potential role of IVUS in stent optimization during percutaneous coronary intervention and its clinical benefits.     

血管内超声在冠状动脉药物洗脱支架晚期血栓研究中的应用

药物洗脱支架与金属裸支架相比,减少了再狭窄的发生率,但其长期安全性却引起了人们的注意。支架置入30 d以后出现的晚期支架内血栓问题成为目前介入心脏病学的研究热点。晚期支架内血栓发生率低,但一旦发生后果严重。有研究显示其发生的原因可能包括动脉的延迟愈合、动脉瘤形成及支架贴壁不良等。现就血管内超声在冠状动脉药物洗脱支架晚期血栓研究中的应用进展做一评述。     

A modified balloon crush approach improves side branch access and side branch stent apposition during crush stenting of coronary bifurcation lesions.

OBJECTIVES: Despite the advent of drug eluting stents and newer interventional techniques designed to treat the main vessel and side branch in bifurcation stenoses, optimal treatment of the side branch remains problematic. We aimed to assess the feasibility of a modified balloon crush technique for percutaneous treatment of coronary bifurcation stenoses. BACKGROUND: Use of the crush technique in bifurcation stenoses remains limited by access to the side branch after main vessel stent deployment, as well as limitations of side branch stent deployment. The modified balloon crush technique aims to improve side branch access and stent apposition. METHODS: The modified balloon crush is similar to the previously described balloon crush technique. Following side branch stent deployment, a balloon positioned in the main vessel is deployed to crush the proximal side branch stent. A guide wire is then placed into the side branch with a subsequent high-pressure balloon inflation at the side branch ostium. This opens the stent struts at the ostium of the side branch, facilitating future passage of the guide wire following main vessel stent deployment, prior to kissing balloon inflation. RESULTS: We performed this modification of the crush technique safely in 10 patients. We were successful in obtaining side branch access in nine of ten patients following initial main vessel stent deployment. In the only failure, there was a 90 degrees angle between the main vessel and side branch. CONCLUSIONS: The modified balloon crush technique can be safely performed, while optimizing side branch access and side branch stent apposition.     

Very late stent fracture associated with a sirolimus-eluting stent

Late stent thrombosis (>1 year after implantation) is a recognised complication involving drug-eluting stents. Stent fracture is increasingly being reported as a complication of drug-eluting stent, and in particular sirolimus-eluting stent use. We report the case of very late sirolimus-eluting stent fracture resulting in an acute coronary syndrome. This case report highlights the need for greater awareness and post-marketing surveillance to detect a potential mechanism for late stent thrombosis in the drug-eluting stent era.     

Multiple Stent Fractures After Everolimus-Eluting Stent Implantation Causing Acute Myocardial Infarction: A Case Report

Stent fracture is an uncommon complication of drug-eluting stent implantation, but it has a clinical significance because of its potential association with adverse cardiac events such as in-stent restenosis, target lesion revascularization, and stent thrombosis. Multiple stent fractures account for a small proportion, but they may lead to more serious complications. Newer generation drug-eluting stents are designed for improved safety and efficacy compared with early generation drug-eluting stents. Multiple stent fractures after newer generation drug-eluting stent implantation are a rare case.We report a case of 25-year-old male who presented with acute myocardial infarction caused by multiple stent fractures after everolimus-eluting stents implantation and was treated by balloon angioplasty.Physicians should be aware of the possibility of multiple stent fractures even after newer generation drug-eluting stent implantation.     

药物洗脱支架术后极晚期血栓形成原因及防治进展

药物洗脱支架能有效减少支架再狭窄率和靶血管的再次血运重建,但与金属裸支架相比,药物洗脱支架极晚期血栓（VLST）发生率呈上升趋势。研究显示药物洗脱支架术后再内皮化延迟、抗血小板药物抵抗、PCI操作技术与晚期血栓形成有密切相关。本文就 VLST形成原因、危险因素及防治策略作以下综述。     

Should the left main be covered entirely with drug-eluting stents in percutaneous intervention

Restenosis after percutaneous intervention in the left main coronary artery may present as sudden cardiac death. Although drug-eluting stents have demonstrated promising results, there remains the question about appropriate length of the left main artery to be covered with the stent. We describe a patient who received two drug-eluting stents with the balloon crushing technique in the distal left main coronary artery. Three months later, this patient presented with a new lesion in the segment of the left main artery not covered with stent, but instead at the site where the balloon was inflated in the initial procedure.     

Drug-Eluting Stent Thrombosis 1,659 Days after Stent Deployment: Case Report and Literature Review

Drug-eluting stents are considered to be superior to bare-metal stents in reducing restenosis rates at 6 months. However, drug-eluting stents appear to be subject to stent thrombosis, a concern that has been reported more frequently in recent times.In November 2003, a 64-year-old man with a medical history of hypertension, type 2 diabetes mellitus, and coronary artery disease underwent percutaneous coronary intervention for the deployment of a sirolimus-eluting stent in the left anterior descending coronary artery. He experienced no complications. More than 4 years later, at age 69, he underwent neurosurgical treatment for a subdural hematoma that resulted from a fall, and he was advised to stop taking aspirin and clopidogrel. Thirty-three days later—1,659 days after stent deployment—he presented with a clinical event that was associated with very late stent thrombosis. After undergoing emergent coronary angiography and the placement of 2 bare-metal stents, he resumed antiplatelet therapy, recovered uneventfully, and was discharged from the hospital in stable condition.To the best of our knowledge, 1,659 days is the longest reported interval between the deployment of a drug-eluting stent and the occurrence of a clinical event that was associated with very late stent thrombosis. Herein, we discuss the case of our patient, review the pertinent medical literature, reinforce the importance of continuous and uninterrupted antiplatelet therapy in drug-eluting stent recipients, and offer considerations regarding the use of drug-eluting stents.Key words: Angioplasty, transluminal, percutaneous coronary/adverse effects; coronary artery disease/therapy; coronary restenosis/epidemiology/etiology/prevention & control; coronary thrombosis/etiology; coronary vessels/pathology; drug-eluting stents/adverse effects; drug therapy, combination; platelet aggregation inhibitors/administration & dosage/therapeutic use; thrombosis/epidemiology/etiology; time factorsDrug-eluting stents (DESs) with sirolimus have reduced the rate of repeat revascularization of target lesions. These stents reduce restenosis rates at 6 months and, for that reason, are considered to be superior to bare-metal stents.¹ However, there have been several reports of very late DES thrombosis (>360 d),² which we review here as we describe the case of our patient. We also offer recommendations to physicians regarding the use of DESs, the value of uninterrupted antiplatelet therapy, and the selection of patients in whom DESs will potentially be deployed.     

New bifurcation stenting technique: shunt stenting.

The optimal treatment of bifurcation lesions remains controversial. We describe a new technique we term shunt stenting. This technique incorporates both the new technology of drug-eluting stents and a novel procedure for optimizing the ostial side branch stent positioning. To date, early angiographic and clinical follow-up have been encouraging.