Migration of fractured renal artery stent

An 80‐year‐old man received stent implantation for severe stenosis of the right renal artery. During the procedure, the proximal edge of the stent was successfully positioned at the ostium of the renal artery. After 6 months, follow‐up renal angiography showed transverse stent fracture without restenosis. The proximal part of the fractured stent had moved and protruded into the abdominal aorta. Three years later, the proximal part of the fractured stent had migrated from the renal artery to the wall of infrarenal aorta. This is the first reported case of stent migration of the renal artery caused by a complete transverse stent fracture. © 2011 Wiley‐Liss, Inc.     

Current and evolving stent evaluation by coronary computed tomographic angiography

Objectives : To demonstrate the variety of stent abnormalities that may be evaluated by coronary computed tomographic angiography (CTA). Background : The application of CTA to the evaluation of coronary stents has focused almost entirely on the detection of in‐stent restenosis. Methods : All CTA performed for stent evaluation at a single institution were reviewed. Results : In addition to in‐stent restenosis, stent fracture, and overlap failure, a multiplicity of stent‐related problems not previously addressed by CTA was categorized and illustrated: late stent thrombosis, jailed branches, edge stenosis, bifurcation stents, inadequate stent expansion, stent aneurysms, peri‐stent plaque, and stenting into bridged myocardium. Conclusions : CTA may be used to evaluate the full range of stent‐related problems. This work provides the framework for future studies validating these applications. © 2011 Wiley‐Liss, Inc.     

药物洗脱支架断裂的影像认识

目的借助冠状动脉造影和血管内超声的影像资料,确定支架断裂的发生和类型。方法回顾性分析北京大学人民医院2 021例冠状动脉造影和183例血管内超声（IVUS）影像资料。结果共发现3例患者的6处支架断裂,其中2例经IVUS证实。3例支架断裂均发生在西罗莫司药物洗脱支架,且均发生在冠状动脉介入术后1年以内。冠状动脉造影证实4处支架断裂为完全断裂伴断裂处支架移位。IVUS证实3处支架断裂为完全断裂,2处为部分断裂;1处断裂靠近支架重叠处;1处支架断裂伴有血管瘤形成。结论冠状动脉造影和IVUS可以帮助确定支架断裂的诊断。     

Prevalence of carotid stent fractures in a single-center experience

PURPOSE: To assess the prevalence of carotid stent fractures and quantify any associated restenosis or clinical events in a single-center experience. METHODS: Seventy-eight consecutive patients were recorded in a prospective database between 2003 and 2007. Nearly two thirds (51, 65%) were available for follow-up, which included magnified multiplanar radiography and selective duplex ultrasonographic studies to evaluate fracture and restenosis in 53 self-expanding stents (49 open-cell and 4 closed-cell designs). The images were assessed independently by 2 vascular radiologists blinded to the patients' clinical data. RESULTS: There was 1 (1.9%) stent fracture with no associated adverse events or restenosis. Six (11%) stents had an irregular "fish-scale" appearance that was easily confused for fracture and seen only in the open-cell stents. CONCLUSION: Stent fractures do occur in the carotid artery; however, they are rare and, in our experience, have no clinical sequelae. Radiological assessment should be incorporated into clinical and ultrasound surveillance protocols.     

Apollo支架治疗椎动脉起始部动脉粥样硬化性狭窄的效果分析

目的研究Apollo支架应用于椎动脉起始部中重度动脉粥样硬化性狭窄的安全性和长期有效性。方法回顾性分析2014年1月至2019年3月海军军医大学第一附属医院神经外科连续收治的经DSA证实椎动脉起始部狭窄≥50%、采取Apollo支架治疗且随访时间≥6个月的21例患者的临床资料,随访期间行DSA、颈部CT血管成像检查,记录患者治疗前椎动脉狭窄程度、术后即刻残余狭窄程度,围手术期临床症状改变情况,随访过程中支架内再狭窄发生率及后循环缺血事件的发生情况。结果(1)21例患者术前狭窄率为(79±15)%,支架置入成功率为100.0%,术后即刻残余狭窄率中位数为10.0(0,12.5)%,较术前明显降低(Z=-4.01,P<0.01)。1例术后当天出现高灌注现象,未发生与支架置入相关的神经功能恶化或死亡。(2)术后随访6~38个月,中位随访时间为7.0(6.8,13.0)个月,20例(95.2%)患者后循环缺血症状消失或减轻,1例症状反复发作。(3)21例患者中共12例(57.1%)出现支架内再狭窄,其中8例发生于术后6~12个月,4例发生于术后13~38个月;再次治疗患者4例中,1例存在反复后循环缺血症状。(4)6例(28.6%)出现支架断裂,其中4例支架断裂伴中重度支架内再狭窄,2例支架断裂、塌陷伴支架内轻度狭窄。结论Apollo支架治疗椎动脉起始部中重度狭窄可有效缓解狭窄,但长期随访支架内再狭窄率和支架断裂率偏高。     

Acute carotid stent thrombosis: review of the literature and long-term follow-up

BackgroundCarotid artery stenting (CAS) is a reasonable alternative to carotid endarterectomy, especially in patients at high risk for surgery. Carotid stent thrombosis can cause thrombembolic events, but fortunately, it is a very rare complication. We present two cases of carotid stent thrombosis and their long-term follow-up.Case reportsOne patient had severe bilateral carotid stenosis and the other had contralateral carotid occlusion. Both patients were on correct antithrombotic treatment and received balloon expandable stents (bare metal stent and drug-eluting stent). During CAS, large thrombus formed within the stent followed by rapid hemodynamic and neurological alteration. We gave a bolus thrombolytic in the clot, followed by continuous intra-arterial infusion. In one case, we performed additional angioplasty. Repeated angiography showed complete resolution of the thrombus, followed by progressive improvement in the neurological state. At discharge, the patients had no neurological deficits. CT scans revealed no acute ischemic lesions.One patient had in-stent restenosis 3 years later, which was treated with an additional self-expandable stent.The last follow-up was done 4 and 9 years, respectively, from the initial CAS complication. Both patients did not experience any neurological events after the last procedure.ConclusionsCarotid stent thrombosis is a rare but potentially fatal complication following CAS. Rapid invasive diagnosis and reperfusion should be done to limit cerebral ischemia. The possible causes must be sighted and reperfusion must be started. Despite an initial dramatic course, a rapid reperfusion ensures a complete neurological recovery and a good prognosis in the long term.     

MSCT冠状动脉成像在冠状动脉支架置入术后的应用

目的 探讨64排螺旋CT （MSCT）冠状动脉成像在冠状动脉支架置入后的应用价值.方法 分析行冠状动脉支架置入术后于我院2011年9月至2013年8月期间行64排MSCT冠状动脉成像的患者47例.用评分的方法客观评估多层螺旋CT血管造影（MSCTA）对冠状动脉支架的显示情况,并对支架管腔狭窄情况进行评估测量.对于中重度狭窄的患者进一步行DSA检查,并分析其与MSCTA评估结果的相关性.结果 47例患者共置入89枚冠状动脉支架,其中评为3分的支架为39枚,评为2分的支架为41枚,评为1分的支架为9枚.39枚支架没有发现狭窄,24枚支架轻度狭窄,15枚支架中度狭窄,11枚支架重度狭窄.DSA与MSCTA对中、重度狭窄的评估呈高度正相关,相关系数为r=0.804.伴钙化支架组MSCTA中、重度狭窄评估结果与DSA评估结果呈中度相关,相关系数为r=0.603.结论 MSCT冠状动脉成像能够很好地显示冠状动脉支架及其管腔狭窄,具有重要的临床价值.支架局部的钙化是影响评估准确性的因素之一.     

Incidence and clinical impact of coronary stent fracture after sirolimus-eluting stent implantation.

BACKGROUND: Stent fracture is one of the possible causes of restenosis after sirolimus-eluting stents (SES) implantation. The aim of our study was to evaluate the prevalence and clinical impact of coronary stent fracture after SES implantation. METHODS: From our prospective institutional database, 280 patients were treated solely with SES from August 2004 to June 2005. Among the 280 patients, 256 patients with a total of 307 lesions underwent follow-up angiography on an average of 240 days after the procedure. RESULTS: Stent fractures were observed in eight (2.6%) lesions. Of the eight lesions with stent fracture, five were located in the right coronary artery (RCA), two in the saphenous vein (SV) graft, and one in the left anterior descending coronary artery. The stent fractures were all in the locations that served as hinges during vessel movement in the cardiac contraction cycle. Seven of the eight stent fractures were adjacent to the edge of previously implanted or overlapped stent. Significant multivariate predictors of stent fracture were SV graft location (Odds ratio 35.88; 95% confidence interval 2.73-471.6, P = 0.006), implanted stent length (Odds ratio 1.04; 95% confidence interval 1.01-1.07, P = 0.02), and RCA location (Odds ratio 10.00; 95% confidence interval 1.11-89.67, P = 0.04). In-stent binary restenosis rate was 37.5% and target lesion repeat revascularization rate was 50.0% in patients with stent fracture. CONCLUSIONS: Stent fracture was likely to be affected by mechanical stress provoked by rigid structures and hinge points. Stent fracture might be associated with the high incidence of target lesion revascularization.     

Applications of multislice coronary computed tomographic angiography to percutaneous coronary intervention: How did we ever do without It?

By providing data previously available only by intravascular ultrasound, 64‐slice multidetector computed tomographic angiography (CTA) will impact percutaneous coronary intervention (PCI) in multiple areas: (1) pre‐PCI patient selection; (2) identification of significant lesions; (3) in‐stent restenosis; (4) procedure planning: stent sizing, choice of intervention, and equipment, chronic total occlusions, 3D‐CTA in the catheterization laboratory; (5) plaque evaluation and identification of high‐risk lesions; (6) postcatheterization decisions, and (7) structural heart disease. The likely outcome is transformation of the catheterization laboratory into a streamlined interventional suite, utilizing on‐line CTA data in an interactive format. © 2008 Wiley‐Liss, Inc.     

Stent Fracture in the Coronary and Peripheral Arteries

Inherent risks of stenting include restenosis and thrombosis. Recently, stent fractures have been recognized as a complication that may result in thrombosis, perforation, restenosis, and migration of the stent resulting in morbidity and mortality. Stent fractures were originally seen in the superficial femoral arteries but have since then been reported in almost all vascular sites including the coronary, renal, carotid, iliac, and femoropopliteal arteries. Fractures are the result of the complex interplay between stent manufacturing, the stented segment, pulsatile and nonpulsatile biomechanical forces, and plaque morphology at a particular vascular site. The presentation of a patient with a fracture is highly variable, ranging from asymptomatic in nature, detected on routine screening without any sequelae, to sudden cardiac death related to a thrombosed coronary artery. Despite being recognized as an important complication, consensus on routine surveillance and diagnostic methods to detect fractures continues to be lacking. Fortunately, most cases are relatively benign and can be managed conservatively if detected. In the setting of recurrent symptoms, further intervention is usually sought. In review of the literature most cases are managed with placement of a stent over the fractured area, the stent‐in‐stent technique, but several other alternatives may be available. As the knowledge of the variables that make stents prone to fracture are identified, better technologies and techniques can be employed to minimize the risk of this complication. This article reviews the available literature on stent fractures and complications using data found on PubMed, MEDLINE, the Manufacturer and User Facility Device Experience (MAUDE) database, and the Cochrane databases. (J Interven Cardiol 2010;23:411–419)     

Renal artery stent fracture with refractory hypertension: A case report and review of the literature

A 73‐year‐old man with resistant hypertension and impaired renal function underwent stenting for right renal artery (RRA) stenosis. Two years later, he presented with uncontrolled hypertension and worse renal function. Renal arteriogram revealed RRA stent fracture with in‐stent restenosis. Another stent was deployed. Four months later, however, renal arteriogram revealed in‐stent restenosis again. This time, balloon angioplasty alone was performed. He had been symptom‐free with stable condition at 2‐year follow‐up. A literature review disclosed six renal artery stent fracture cases, including the present one, who developed in‐stent stenosis resulted from stent fracture. Two major anatomy features of renal artery stenosis were suggestive for development of stent fracture: (1) renal artery entrapment by diaphragmatic crus, and (2) mobile kidney with acute angulation at proximal segment of the renal artery. It is important to detect this etiology of renal artery stenosis because stenting in these vessels may contribute to in‐stent restenosis or stent fracture. Management of renal artery stent fracture, including endovascular treatment or aortorenal bypass, should be considered on a case‐by‐case basis in relation to clinical settings. © 2009 Wiley‐Liss, Inc.     

Acute coronary syndrome due to early multiple and complete fractures in sirolimus‐eluting stent: A case report and brief literature review

Despite drug eluting stents (DES), as compared to bare metal stents, have reduced in‐stent restenosis, complex and long lesions remains a challenge for interventional cardiologist. Their treatment is often associated with an unfavorable outcome, related to in‐stent restenosis, stent thrombosis, and target lesion revascularization. These complications may derive from the contact between metallic structures and coronary artery endothelium, and consequent overexpression of platelet activating factors, growth factors, and inflammatory cytokines. Recently, an additional mechanism has emerged as new cause of these complications: “stent fracture.” Several factors are involved in this phenomenon including material and stent platform, target vessel features, stent implantation technique, and implant duration. We reported a case of 69 years old man with rare early and complex DES fractures on right coronary that caused acute coronary syndrome 36 hr after a previous percutaneous coronary intervention.© 2012 Wiley Periodicals, Inc.     

Stent fracture associated with drug‐eluting stents: Clinical characteristics and implications

Objective : To evaluate the clinical characteristics and implications of stent fracture in drug‐eluting stents. Background : Approximately 2.5 million drug‐eluting stents are implanted every year worldwide. In 10 randomized controlled trials involving 2,602 patients, no incidence of stent fracture was recognized or reported. Methods : From April 2003 to December 2005, 2,728 patients underwent drug‐eluting stenting. The angiograms of all 530 patients who underwent repeat angiography were analyzed to identify the presence of stent fracture. We then documented the incidence of adverse events associated with drug‐eluting stent fracture and systematically analyzed the clinical, procedural, and structural factors, which might predispose to stent fracture. Results : Stent fracture was identified in 10 patients. None of these fractures were detectable at the time of stent placement. The median time interval from stent implantation to detection of fracture at repeat angiography was 226 days (range, 7–620 days). Adverse clinical outcomes associated with stent fracture occurred in 7 patients (6 patients had binary restenosis and 1 patient had stent thrombosis), all necessitating repeat intervention. Analysis of potential predisposing clinical, procedural, and structural factors revealed that 4 patients had excessive tortuosity in the proximal segment, and overlapping stents were used in 5 cases. All fractures occurred in sirolimus‐eluting stents. Conclusions : Stent fracture may represent a new potential mechanism of restenosis and stent thrombosis in drug‐eluting stents. Predisposing clinical and procedural factors may be vessel tortuosity and use of overlapping stents. The most important predisposing factor, however, may be stent structure, since all fractures occurred in sirolimus‐eluting stents. © 2006 Wiley‐Liss, Inc.     

Perfil Aterosclerótico da Artéria Carótida como Preditor de Risco para Reestenose após Implante de Stent Coronário

Background:The incidence of restenosis of the coronary artery after a bare-metal stent implant has been lower than in simple balloon angioplasty; however, it still shows relatively high rates.Objective:The aim of this study was to find new risk indicators for in-stent restenosis using carotid ultrasonography, that, in addition to the already existing indicators, would help in decision-making for stent selection.Methods:We carried out a cross-sectional prospective study including 121 consecutive patients with chronic coronary artery disease who had undergone percutaneous coronary intervention with repeat angiography in the previous 12 months. After all cases of in-stent restenosis were identified, patients underwent carotid ultrasonography to evaluate carotid intima-media thickness and atherosclerosis plaques. The data were analyzed by Cox multiple regression. The significance level was set a p<0.05.Results:Median age of patients was 60 years (1^st quartile = 55, 3^rd quartile = 68), and 64.5% of patients were male. Coronary angiography showed that 57 patients (47.1%) presented in-stent restenosis. Fifty-five patients (45.5%) had echolucent atherosclerotic plaques in carotid arteries and 54.5% had echogenic plaques or no plaques. Of patients with who had echolucent plaques, 90.9% presented coronary in-stent restenosis. Of those who had echogenic plaques or no plaques, 10.6% presented in-stent restenosis. The presence of echolucent plaques in carotid arteries increased the risk of coronary in-stent restenosis by 8.21 times (RR=8.21; 95%CI: 3.58-18.82; p<0.001).Conclusions:The presence of echolucent atherosclerotic plaques in carotid artery constitutes a risk predictor of coronary instent restenosis and should be considered in the selection of the type of stent to be used in coronary angioplasty.     

Sirolimus‐eluting stent fracture detection by three‐dimensional optical coherence tomography

Stent fracture has emerged as a complication of drug‐eluting stent and is now recognized as contributing to in‐stent restenosis and possibly stent thrombosis. Although optical coherence tomography (OCT) can detect stent fractures in the absence of circumference struts, it is challenging to visualize stent fractures with only cross‐sectional OCT images. We describe two cases of restenosis with stent fracture detected by a novel three‐dimensional OCT image reconstruction technique. This technique allows identification of a single stent fracture even in the absence of angiographic signs. © 2011 Wiley Periodicals, Inc.     

自膨式颈动脉支架治疗椎动脉起始部中重度狭窄的疗效分析

目的探讨采用自膨式颈动脉支架治疗椎动脉起始部中、重度狭窄的短期疗效、安全性及预防再狭窄的作用。方法回顾性分析采用白膨式颈动脉支架对椎动脉起始部狭窄率〉50％,并且常规药物治疗无效的23例患者的临床资料。术后采用血管超声、MR血管成像及DSA进行影像学随访。结果（1）23例患者均成功置人支架（技术成功率为100％）,平均狭窄率从术前的（70±8）％降至（10±6）％。无手术并发症发生。（2）术后临床随访3～25个月,无一例患者出现短暂性脑缺血发作或卒中复发;19例症状改善。21例超声随访无再狭窄发生,12例接受6个月以上的缸管造影随访,无一例发生支架内再狭窄或支架变形。结论应用自膨式颈动脉支架治疗椎动脉起始部中、重度狭窄,短期是安全、有效的,可防止支架变形并降低支架内再狭窄的危险;但长期疗效尚有待进一步观察。     

Self‐expandable esophageal stents placement for the palliation of dysphagia as a result of lung cancer

We report our experience with self‐expandable metallic stents for the palliation of malignant dysphagia and tracheoesophageal fistulae caused by lung cancer. Esophageal self‐expandable metallic stents were deployed in 28 patients with malignant dysphagia as a result of lung cancer between August 2002 and January 2009. Mean age was 62.1 (42–77) with 26 male patients. Twenty‐three patients received previous chemo‐radiotheraphy and two had pneumonectomy. Tracheoesophageal fistulae were coexisting in eight patients. Stents were inserted under fluoroscopic control over guide‐wire with the patient under conscious sedation. One stent was used in all patients except one fistula patient with two stents. Immediate improvement after stent insertion was seen in all patients. Fistulae were sealed off in all. No complication was seen except transitional pain in 12 patients (42%). During the follow‐up, all patients remained asymptomatic with no clinical appearance of dysphagia symptoms except one patient whom gastrostomy was applied. All patients with fistulae died with a mean survival of 15.4 weeks. Dysphagia patients without a fistulae died with mean survival of 6 months except one patient with 1 month follow‐up. Self‐expandable esophageal metallic stent insertion can manage malignant dysphagia in lung cancer patients with significant survival period via nonsurgical approach.     

CT angiography of stented carotid arteries: comparison with Doppler ultrasonography.

PURPOSE: To determine whether computed tomographic angiography (CTA) is a feasible modality for assessing stented carotid arteries and whether in-stent restenosis based on CTA concurs with ultrasonography (US). METHODS: A retrospective review was conducted of 37 follow-up CTA and US images from 27 patients (23 men; median age 70 years, range 56-77) who received 34 nitinol carotid stents. CTA and US images were compared with respect to assessability and percent stenosis. Both visual estimation (>or=50% or not) and the NASCET method were used to determine percent stenosis in CTA images. For US, a determination of >or=50% stenosis was based on peak systolic velocity (>or=200 cm/s) and an internal carotid artery to common carotid artery ratio >or=2.5. Percent stenosis values by CTA were also compared to values (n=7, 21%) determined by catheter angiography. RESULTS: CTA and US images were "totally assessable" in 27 (73%) and 15 (41%), "totally non-assessable" in 0 (0%) and 3 (8%), and "partially assessable" in 10 (27%) and 19 (51%), respectively. Assessability of CTA images was equal to or better than that of US images in 33 (89%). The percent stenoses by CTA and US were comparable in 20 cases. CTA found >or=50% stenosis using the NASCET method in 4 of 20 stents; none of these showed >or=50% stenosis by visual estimation of CTA or by spectral Doppler US. Compared with catheter angiography, CTA overestimated percent stenosis from 34% to 66% (mean 53%). US confirmed 2 angiographically proven restenoses, but CTA identified only 1. CONCLUSION: CTA provides better image quality for stented carotid arteries than US, but it might be inferior to US in determining restenosis in assessable cases. Therefore, CTA is likely to be an alternative to US in cases of non-assessability. A large-scale study including more restenosis cases is warranted to reveal which modality is more reliable for diagnosis of restenosis.     

Traitement endovasculaire d’une ischémie aiguë survenue après fracture d’un stent poplité

Angioplasty stenting of popliteal artery lesions is a common procedure in endovascular surgery. Stent fractures in popliteal artery maybe asymptomatic or cause restenosis, false-aneurysm or acute thrombosis. We report one case of acute limb ischemia occurred after a popliteal stent fracture placed four months earlier. The patient underwent an angioplasty stenting, completed with thrombolysis and thrombectomy. This case-report aims to illustrate complications of stent fracture in popliteal artery and possibility's to manage it by endovascular approach.     

128层螺旋CT冠状动脉成像与选择性冠状动脉造影诊断冠心病价值的比较

目的 评价128层螺旋CT(MSCT)冠状动脉成像诊断冠状动脉疾病的价值.方法 对临床怀疑或确诊冠心病的非选择性连续78例患者进行128层MSCT冠状动脉成像,其中有15例患者既往置入冠状动脉支架.以选择性冠状动脉造影结果作为评价标准,探讨128层MSCT在诊断冠状动脉疾病及评价支架后再狭窄的临床价值.结果 基于冠状动脉血管节段分析,879个冠状动脉节段中有821节段(93%)进入统计学分析,128层MSCT诊断冠状动脉病变的敏感性87%,特异性97%,阳性预测值83%,阴性预测值97%.对15例共置入22个支架的患者中,有4个(18%)支架MSCT图像显示支架伪影,图像模糊,未能判断支架内血管腔通畅情况,其余18个支架MSCT结果与选择性冠状动脉造影比较,MSCT诊断支架再狭窄的敏感性为100%,特异性77%,阳性预测值63%,阴性预测值100%.结论 128层MSCT冠状动脉成像对冠状动脉疾病的诊断和支架再狭窄的评价具有较高价值,可以作为一项无创检查技术用于对临床怀疑为冠心病的患者进行筛查.