Ultrasound criteria for severe in-stent restenosis following carotid artery stenting

PURPOSE: In-stent restenosis (ISR) is a known complication following carotid artery stenting (CAS). However, ultrasound criteria determining ISR are not well established. We evaluated alternative ultrasound velocity criteria for >70% ISR in our institution. METHODS: Clinical records of 256 patients undergoing 282 consecutive CAS procedures over a 42-month period were reviewed. Follow-up ultrasounds were available for analysis in 237 patients. Selective angiograms and repeat interventions were performed for >70% ISR. Ultrasound criteria including peak systolic velocity (PSV), end diastolic velocity (EDV), and internal carotid to common carotid artery ratios (ICA/CCA) were examined. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for PSV (200, 250, 300, 350, and 400 cm/s), EDV (70, 80, 90, 100 cm/s), and CCA/ICA (3, 3.5, 4, 4.5, 5). RESULTS: Twenty-two carotid angiograms were performed and 18 lesions had confirmations of >70% ISR in 11 patients including prior CEA in five patients and neck irradiation in two patients. Receiver operator characteristics (ROC) was analyzed for PSV, EDV, and CCA/ICA ratio. For 70% or greater angiographic ISR, PSV > 300 cm/s correlated to a 94% sensitivity, 50% specificity, 90% positive predictive value (PPV), and 67% negative predictive value (NPV); EDV > 90 cm/s correlated to an 89% sensitivity, 100% specificity, 100% PPV, and 67% NPV; and ICA/CCA > 4 had a 94.4% sensitivity, 75% specificity, 94% PPV, and 75% NPV. A significant color flow disturbance was detected in one patient who did not meet the aforementioned ultrasound velocity criteria. Further statistical analysis showed that an EDV of 90 cm/s provided the best discriminant value. CONCLUSION: Our study demonstrated that PSV > 300 cm/s, EDV > 90 cm/s, and ICA/CCA > 4 correlated well with >70% ISR. Although still rudimentary, these velocity criteria combined with color flow patterns can reliably predict severe ISR in our vascular laboratory. However, due to the relatively infrequent cases of severe ISR following CAS, a multicentered study is warranted to establish standard post-CAS ultrasound surveillance criteria for severe ISR.     

Risk factors for restenosis after carotid artery angioplasty and stenting

OBJECTIVES: With carotid artery stenting (CAS) becoming an ever-increasing procedure, we sought to determine risk factors for in-stent restenosis after CAS. METHODS: Consecutive patients undergoing CAS between January 2002 and October 2004 at a tertiary care hospital were retrospectively reviewed. Patient, filter, and stent selection were left to the discretion of the attending surgeon. High-risk patients were defined by significant comorbidities or a hostile neck (prior surgery or radiation, or both), and risk factor analysis was performed. In-stent restenosis was defined as >60%, and selective angiography was performed on patients with an in-stent restenosis >80% by duplex ultrasound imaging. RESULTS: Reviewed were 101 patients (55 men, 46 women) who underwent 109 CAS procedures. Comorbidities were typical for patients with atherosclerosis. In addition, 38% (n = 41) of procedures were performed in patients who had prior neck surgery, of which 29% (n = 32) had previous ipsilateral carotid endarterectomy. Seventeen patients (16%) had a history of neck cancer, and all had prior neck radiation. Median follow-up was 5 months (range, 0 to 30 months). Neurologic complications included three transient ischemic attacks (2.8%) and one nondisabling stroke (0.9%). There were two myocardial infarctions (1.9%) and no periprocedural deaths (30 days), for a combined stroke, myocardial infarction, and death rate of 2.9%. Asymptomatic in-stent restenosis developed in 12 carotids (11%), five of which required endovascular intervention, with a mean of 6 months to restenosis. Univariate Cox proportional hazard regression models were used to determine risk factors for the development of restenosis. Prior stroke, transient ischemic attack, amaurosis fugax, and prior neck cancer were all significant risk factors. When these significant risk factors from univariate analysis were put into multivariate analysis, however, the only marginally significant risk factor was prior neck cancer (P = .06). Kaplan-Meier analysis revealed a cumulative freedom from in-stent restenosis at 24 months of 88% +/- 6% in patients without neck cancer compared with 27% +/- 17% (P = .02) in patients with neck cancer. CONCLUSIONS: CAS has been shown to be safe and effective in high-risk patients, with minimal adverse events.     

Utility and accuracy of duplex ultrasonography in evaluating in-stent restenosis after carotid stenting

Background

Stents alter flow velocities after carotid artery stenting (CAS). To identify criteria for in-stent restenosis (ISR), velocities obtained by duplex ultrasonography (DU) after CAS were analyzed.

Methods

Carotid angiography and DU were performed after 129 CAS procedures. The 2 × 2 table method and receiver operating characteristic curves were used to assess the ability of DU to detect ISR.

Results

The median follow-up period was 21.2 months (interquartile range 14-32 months). Overall, 6 patients (4.7%) had significant ISR by angiography. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the validated criteria for nonstented arteries were 100%, 85%, 25%, and 100%, respectively, to determine ISR. Newly validated criteria revealed optimal detection of ISR, with 100% sensitivity, 99% specificity, PPV of 66%, and NPV of 100%. Patients with abnormal findings on initial DU revealed increased velocities by >80% when ISR occurred.

Conclusions

DU can accurately detect ISR after CAS, but velocity criteria require modification and validation at each vascular laboratory. For patients with abnormal findings on initial DU, significant changes in velocities suggest ISR.     

超声多普勒血流速度诊断肾动脉支架植入术后支架内再狭窄

目的 分析超声多普勒血流速度诊断支架植入术治疗重度粥样硬化性肾动脉狭窄（ARAS）术后支架内再狭窄的价值。方法 回顾性分析85例（94条肾动脉）肾动脉支架植入术后重度ARAS患者，根据术后12个月超声造影（CEUS）所示支架内径狭窄比判定狭窄程度，以<30%为无再狭窄，30%~50%为轻度再狭窄，51%~70%为中度再狭窄，>70%为重度再狭窄；对比其支架内收缩期峰值血流速度（PSV）及肾动脉PSV与腹主动脉PSV比值（RAR）。采用受试者工作特征（ROC）曲线分析PSV、RAR对支架内再狭窄的诊断价值。结果 94条植入支架后肾动脉中，术后12个月2条支架闭塞。92条未闭塞动脉中，58条无再狭窄，15条轻度再狭窄，11条中度再狭窄，8条重度再狭窄。不同程度再狭窄肾动脉支架内PSV及RAR差异均有统计学意义（P均<0.01），且PSV、RAR随狭窄程度增高而逐渐加大（P均<0.05）。以PSV>162.50 cm/s作为判断支架内径狭窄比>30%的阈值，其敏感度、特异度均为100%；以RAR>2.28作为阈值，敏感度为100%，特异度为96.60%。对于支架内径狭窄比>50%，以PSV>219.55 cm/s作为诊断阈值，其敏感度为100%，特异度为98.60%；以RAR>3.17作为阈值，敏感度为100%，特异度为94.50%。以PSV>310.53 cm/s作为支架内径狭窄比>70%的诊断阈值，敏感度为100%，特异度为100%；以RAR>4.33作为阈值，敏感度为100%，特异度为100%。结论 超声多普勒血流速度对于诊断肾动脉支架植入术治疗重度ARAS术后支架内再狭窄的效能较高。     

Prosthetic bypass for restenosis after endarterectomy or stenting of the carotid artery

Objective

The objective of this study was to evaluate the results of prosthetic carotid bypass (PCB) with polytetrafluoroethylene (PTFE) grafts as an alternative to carotid endarterectomy (CEA) in treatment of restenosis after CEA or carotid artery stenting (CAS).

Management of in-sent restenosis after carotid artery stenting in high-risk patients

BACKGROUND: Carotid artery stenting (CAS) has emerged as an acceptable treatment alternative in patients with carotid bifurcation disease. Although early results of CAS have been promising, long-term clinical outcomes remain less certain. We report herein the frequency, management, and clinical outcome of in-stent restenosis (ISR) after CAS at a single academic institution. METHODS: Clinical records of 208 CAS procedures in 188 patients with carotid stenosis of 80% or greater, including 48 (26.5%) asymptomatic patients, during a 42-month period were analyzed. Follow-up serial carotid duplex ultrasound scans were performed. Selective angiography and repeat intervention were performed when duplex ultrasound scans showed 80% or greater ISR. Treatment outcomes of ISR interventions were analyzed. RESULTS: Over a median 17-month follow-up, 33 (15.9%) ISRs of 60% or greater were found, according to the Doppler criteria. Among them, seven patients (3.4%) with a mean age of 68 years (range, 65-87 years) developed high-grade ISR (> or =80%), and they all underwent further endovascular interventions. Six patients with high-grade ISR were asymptomatic, whereas one remaining patient presented with a transient ischemic attack. Five of seven ISRs occurred within 12 months of CAS, and two occurred at 18 months' follow-up. Treatment indications for initial CAS in these seven patients included recurrent stenosis after CEA (n = 4), radiation-induced stenosis (n = 1), and high-cardiac-risk criteria (n = 2). Treatment modalities for ISR included balloon angioplasty alone (n = 1), cutting balloon angioplasty alone (n = 4), cutting balloon angioplasty with stent placement (n = 1), and balloon angioplasty with stent placement (n = 1). Technical success was achieved in all patients, and no periprocedural complications occurred. Two patients with post-CEA restenosis developed restenosis after ISR interventions, both of whom were successfully treated with cutting balloon angioplasty at 6 and 8 months. The remaining five patients showed an absence of recurrent stenosis or symptoms during a mean follow-up of 12 months (range, 3-37 months). By using the Kaplan-Meier analysis, the freedom from 80% or greater ISR after CAS procedures at 12, 24, 36, and 42 months was 97%, 97%, 96%, and 94%, respectively. CONCLUSIONS: Our study showed that ISR after CAS remains uncommon. Successful treatment of ISR can be achieved by endovascular interventions, which incurred no instance of periprocedural complications in our series. Patients who developed ISR after CEA were likely to develop restenosis after IRS intervention. Diligent ultrasound follow-up scans are important after CAS, particularly in patients with post-CEA restenosis.     

Alert for increased long-term follow-up after carotid artery stenting: results of a prospective, randomized, single-center trial of carotid artery stenting vs carotid endarterectomy

BACKGROUND: Carotid endarterectomy (CEA) has been shown to be effective in stroke prevention for patients with symptomatic or asymptomatic carotid artery stenosis. Although several prospective randomized trials indicate that carotid artery stenting (CAS) is an alternative but not superior treatment modality, there is still a significant lack of long-term data comparing CAS with CEA. This study presents long-term results of a prospective, randomized, single-center trial. METHODS: Between August 1999 and April 2002, 87 patients with a symptomatic high-grade internal carotid artery stenosis (>70%) were randomized to CAS or CEA. After a median observation time of 66 +/- 14.2 months (CAS) and 64 +/- 12.1 months (CEA), 42 patients in each group were re-evaluated retrospectively by clinical examination and documentation of neurologic events. Duplex ultrasound imaging was performed in 61 patients (32 CAS, 29 CEA), and patients with restenosis >70% were re-evaluated by angiography. RESULTS: During the observation period, 23 patients (25.2%) died (10 CAS, 13 CEA), and three were lost to follow up. The incidence of strokes was higher after CAS, with four strokes in 42 CAS patients vs none in 42 CEA patients. One transient ischemic attack occurred in each group. A significantly higher rate of restenosis >70% (6 of 32 vs 0 of 29) occurred after CAS compared with CEA. Five of 32 CAS patients (15.6%) presented with high-grade (>70%) restenosis as an indication for secondary intervention or surgical stent removal, and three presented with neurologic symptoms. No CEA patients required reintervention (P < .05 vs CAS). A medium-grade (<70%) restenosis was detected in eight of 32 CAS patients (25%) and in one of 29 CEA patients (3.4%). In five of 32 CAS (15.6%) and three of 29 CEA patients (10.3%), a high-grade stenosis of the contralateral carotid artery was observed and treated during the observation period. CONCLUSION: The long-term results of this prospective, randomized, single-center study revealed a high incidence of relevant restenosis and neurologic symptoms after CAS. CEA seems to be superior to CAS concerning the development of restenosis and significant prevention of stroke. However, the long-term results of the ongoing multicenter trials have to be awaited for a final conclusion.     

Intrapatient comparison of restenosis between carotid artery angioplasty with stenting and carotid endarterectomy

AIM: Comparison of restenosis in patients who underwent both carotid artery angioplasty with stenting (CAS) and contralateral carotid endarterectomy (CEA). METHODS: From our CAS data registry (1998-present) all patients with a history of contralateral CEA at any other time were selected (n = 63). Mean age was 70.6, SD = 6.8 for CAS and 68.2, SD = 6.1 for CEA and symptomatic carotid artery stenosis was present in 24% of patients pre-CAS and 40% pre-CEA. All CEAs were primary interventions, 19% of CAS were secondary to restenosis after previous ipsilateral CEA. All patients were followed up prospectively with duplex at 1 year (CAS: n = 58, CEA: n = 59), 2 years (CAS: n = 44, CEA: n = 53), 3 years (CAS: n = 27, CEA: n = 41), and every year thereafter. Within each patient we compared restenosis (>50%) between CAS and CEA procedures. RESULTS: After a follow-up of 28.7 months for CAS (SD = 16.9) and 54.4 months for CEA (SD = 39.5) the rate of = or > 50% restenosis for CAS vs CEA at 1, 2, and 3 years was 23% vs 10%; 31% vs 19%; and 34 vs 24%, respectively (log rank P = NS). CONCLUSIONS: Our intrapatient comparison of patients who underwent both CAS and contralateral CEA did not reveal significant difference in restenosis between both procedures.     

Case of symptomatic subacute in-stent thrombosis after carotid angioplasty and stenting for severe carotid stenosis

We report a case of symptomatic subacute in-stent thrombosis after carotid artery angioplasty and stenting (CAS). The patient was a 72-year-old man who had severe asymptomatic right carotid artery stenosis. He received CAS with distal protection, and gained 100% opening of the right carotid artery. The administration of dual antiplatelet therapy (Aspirin 100 mg/day+Cilostazol 100 mg/day), which had been given since two weeks before the procedure, was continued afterwords. On the seventh day after the stent placement, the patient showed sudden onset of left hemiparesis and conjugated deviation of both eyes to the right side and followed by falling into a comatose state. Emergency angiography showed near occlusion of the right carotid artery, suggesting subacute in-stent thrombosis. In conjunction with the intravenous administration of tissue plasminogen activator (1300,000 IU), we performed additional stent placement on the stented portion of the ICA and gained full recanalization of the ICA about three hours after the onset of the symptoms. The patient showed rapid recovery and returned home with slight clumsiness of his right hand. Symptomatic subacute in-stent thrombosis after CAS is a rather rare complication. We discuss on the possible cause of this and stress the necessity of an additional emergency stenting to gain rapid recanalization.     

Operative management of carotid artery in-stent restenosis: first experiences and duplex follow-up.

OBJECTIVES: Carotid Artery Stenting (CAS) may be comparable to Carotid Endarterectomy (CEA) as a durable and effective procedure in stroke prevention. Concern remains about the incidence of restenosis after stenting and its management. We evaluated the surgical management of restenosis after CAS. DESIGN: prospective study. METHODS: between December 1997 and April 2001, 217 CAS procedures were performed in 217 patients (155 men and 62 women; age 70 years +/- 8.2). After a mean of 8 months post-stenting four patients (two symptomatic, two asymptomatic with contralateral occlusion) with severe haemodynamic in-stent restenosis (90-99%) had surgical reintervention. RESULTS: standard CEA with removal of the stent was performed in all four patients. No major complications occurred. Intima hyperplasia showed to be the predominant mechanism leading to in-stent restenosis. All four surgically treated patients remained asymptomatic and without recurrent restenosis over a mean follow-up time of 13 months (range 3-20 months). CONCLUSION: the optimal treatment of in-stent restenosis has yet to be defined, but standard CEA with removement of the stent appears to be feasible.     

Late carotid restenosis: aetiologic factors for recurrent carotid artery stenosis during long-term follow-up

During a fourteen-year-period 257 patients underwent carotid endarterectomy in an unselected population of 700,000 inhabitants. The incidence of haemodynamically significant restenosis was 13.5% in 133 vessels in 116 patients studied by duplex scanning 28 to 209 months following carotid endarterectomy. The most striking differences between patent and restenosed cases were in serum cholesterol, triglyceride and HDL-cholesterol levels. The patients with a long-term low cholesterol (less than 6.5 mmol/l), low triglyceride (less than 1.42 mmol/l) and high HDL cholesterol (greater than 1.0 mmol/l) levels had significantly less high grade restenosis (P less than 0.05). Apolipoprotein A-I and B had no significant effect, but if the lowest limit of normal apolipoprotein A-I level was considered as 1.27 g/l the difference was significant. The frequency of a high-grade restenosis in patients with diabetes mellitus and coronary heart disease was not significantly increased, but supports the view that these are risk factors in the development of atherosclerotic changes in an operated carotid artery. The incidence of recurrent stenosis appears to be unrelated to hypertension, claudication, obesity, smoking, operative factors or to the indication for surgery. Men were more prone than women to get a high-grade restenosis. Postoperative treatment with acetylsalicylic acid was most effective, the incidence was only half of that expected, whereas the anticoagulants or a combination of acetylsalicylic acid and dipyridamole were of no benefit. Haematocrit, RBC, platelet count and thrombocrit were contradictory.     

An uncommon cause for carotid artery stenosis after carotid stenting

Carotid artery stenting (CAS) has evolved as a minimally invasive alternative to carotid endarterectomy, particularly among patients with prior neck surgery or external beam radiation for malignancy. Restenosis after CAS remains low yet is typically due to neointimal hyperplasia and manifests within the first 2 years after stent placement. We present an unusual case of carotid artery stenosis 18 months after angioplasty and stenting as a result of recurrent malignancy, which was treated with repeat stent placement.     

Subarachnoid hemorrhage after carotid artery stenting

We describe subarachnoid hemorrhage (SAH) in a 66-year-old man, who underwent technically successful carotid stenting for a string-stenosis of the right internal carotid artery (ICA) in a presence of contralateral ICA occlusion with recurrent right hemisphere transient ischemic attacks. At 2 hours, the patient developed headache and vomiting, but no focal neurological deficits. Performed transcranial color-coded Doppler (TCCD) showed over 2.8-fold increase of the peak systolic velocity in the right middle cerebral artery. The emergent CT of the brain showed SAH with the right hemisphere edema. Patient was treated with Nimodipine in continuous infusion, diuretics i.v. and additional hypotensive therapy depending on blood pressure values. Clopidogrel was stopped for 5 days. Over next 4 weeks, a gradual cerebral velocities decrease was observed on TCCD, which was related to clinical and CT resolution.     

Carotid artery stenting after carotid endarterectomy

Atherosclerotic carotid artery disease remains an important cause of cerebrovascular ischemic disease. We present a patient with residual stenosis of the distal internal carotid artery following carotid endarterectomy that was treated with stenting. The case highlights the potential complimentary benefits of carotid endarterectomy and carotid stenting.     

颈动脉支架术后视网膜动脉栓塞1例

<正>患者男,74岁,因间歇头晕,下肢乏力1月余入院。既往高血压病史10年,慢性胃炎,右手震颤10年。入院体检:体温36.6℃,脉搏规则、85次/分,呼吸规则、19次/分,血压138mmHg/74mmHg,神志清,查体合作,双侧视力粗测正常,左侧颈部检查未闻及血管杂音,右侧颈部可闻及血管杂音。经颈动脉彩色多普勒超声和CTA提示颈动脉狭窄,欲接受颈动脉支架治疗。入院2天后接受主动脉弓+全脑血管造影示左