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.     

In-stent restenosis after carotid angioplasty-stenting: incidence and management

PURPOSE: Carotid angioplasty-stenting (CAS) has been advocated as an alternative to carotid endarterectomy (CEA) in patients with restenotic lesions after prior CEA, primary stenoses with significant medical comorbidities, and radiation-induced stenoses. The incidence of restenosis after CAS and its management remains ill defined. We evaluated the incidence and management of in-stent restenosis after CAS. METHODS: Patients with asymptomatic (61%) and symptomatic (39%) carotid stenosis of > or = 80% underwent CAS between September 1996 and May 2000; there were 50 procedures and 46 patients (26 men and 20 women). All patients were followed up clinically and underwent duplex ultrasonography (DU) at 3- to 6-month intervals. In-stent restenoses > or = 80% detected with DU were further evaluated by means of angiography for confirmation of the severity of stenosis. RESULTS: No periprocedural or late strokes occurred in the 50 CAS procedures during the 30-day follow-up period. One death (2.2%) that resulted from myocardial infarction was observed 10 days after discharge following CAS. During a mean follow-up period of 18 +/- 10 months (range, 1-44 months), in-stent restenosis was observed after four (8%) of the 50 CAS procedures. Angiography confirmed these high-grade (> or = 80%) in-stent restenoses, which were successfully treated with balloon angioplasty (3) or angioplasty and restenting (1). No periprocedural complications occurred, and these patients remained asymptomatic and without recurrent restenosis over a mean follow-up time of 10 +/- 6 months. CONCLUSIONS: We recommend CAS for post-CEA restenosis, primary stenoses in patients with high-risk medical comorbidities, and radiation-induced stenoses. In-stent restenoses occurred after 8% of CAS procedures and were managed without complications with repeat angioplasty or repeat angioplasty and restenting.     

颈内动脉狭窄处扭曲的血管内治疗

目的 探讨血管内支架成形术治疗颈内动脉狭窄处扭曲的必要性、可行性和安全性.方法 选择2003年12月至2009年12月经数字减影血管造影(DSA)检查证实的症状性颈内动脉狭窄且狭窄处伴扭曲的12例患者,采用血管内支架成形术处理颈动脉狭窄伴扭曲,分析其临床、影像学、支架成形术和随访观察资料,评价治疗效果.结果 12例颈内动脉狭窄伴扭曲的患者全部成功实施血管内支架成形术,支架置入成功率100%,无支架相关死亡或致残.12例患者共置入自膨式支架14枚,平均狭窄率由术前的85.6%下降至11.2%;扭曲角度(Metz观测分类法)由术前＜90°变为＞120°;无围手术期短暂性脑缺血发作(TIA)和脑卒中发生,临床症状改善或消失.临床随访6～72个月,发生支架同侧和对侧TIA各1例;5例患者行DSA检查,其中1例发生再狭窄并在支架远端发生新的扭曲,再次支架置入治疗,2年后CT血管造影(CTA)复查未见扭曲和支架内再狭窄;另外7例行颈部血管超声检查,未见再狭窄和扭曲.结论 血管内支架成形术治疗颈内动脉狭窄伴扭曲,技术上是可行、安全的,可能有助于减少脑缺血发生,但有待于进一步观察.

Abstract：

Objective To study the necessity, feasibility, security of carotid angioplasty and stenting (CAS) for symptomatic carotid stenosis combined with kinking. Methods Twelve patients with symptomatic carotid stenosis and kinking demonstrated by digital subtraction angiography (DSA) received CAS from December 2003 to December 2009. There were 9 male and 3 female patients, age ranged from 59 to 77 years(mean 69.3 years). All the patients' clinical, imaging, intervention and follow up data were collected and analyzed. Results All CAS procedures were successfully performed with 14 self-expandable stents placed. The mean degree of stenosis was reduced from 85. 6% before stenting to 11.2% after stenting,the angle of kinking, according to Metz' category, were improved from less than 90° to more than 120° in each case. No perioperative procedure related stroke and tranient ichemic attack (TIA) occurred. The clinical symptoms and signs of cerebral ischemia were improved or disappeared for all patients. During follow-up of these 12 patients for 6 to 72 months, one patient experienced ipsilateral carotid territory TIA and another patient experienced contralateral carotid territory TIA. DSA follow up of 5 patients demonstrated 1 case with in-stent restenosis and arterial kinking remote to the stent of internal carotid artery. CAS were performed again and CT angiography follow up demonstrated no kinking and restenosis 2 years after the intervention. Duplex scan of the other 7 patients demonstrated neither kinking nor restenosis. Conclusions CAS seems to be feasible and safe for the patients with symptomatic kinking and stenosis, and maybe helpful to lower the risk of cerebral ischemia, but further study is needed.     

In-stent restenosis of innominate artery with critical stenosis of right internal carotid artery

A lady with aortitis syndrome developed in-stent restenosis (ISR) of the innominate artery stent and critical stenosis of right internal carotid artery. The therapeutic challenge was gaining access to the carotid vessel, after treating the innominate artery ISR and all the while using distal protection to circumvent potential cerebral embolism. Percutaneous transluminal angioplasty (PTA) with or without stenting is a safe therapeutic option for re-vascularization of the supra aortic vessels. In the event of re-stenosis, re-treatment with PTA and stenting is safe. Ample evidence-base exists now for carotid artery stenting (CAS) in preference to carotid endarterectomy in patients with stenotic lesions of the carotid vessels.     

药物洗脱球囊治疗颈动脉支架植入后支架内再狭窄进展

颈动脉狭窄患者接受颈动脉支架（CAS）植入术后可发生支架内再狭窄（ISR）,发生率约5%~20%;药物洗脱球囊（DEB）技术用于治疗CAS植入后再狭窄已取得显著成效。本文对DEB治疗CAS植入术后ISR研究进展进行综述。     

Carotid artery stenting with routine cerebral protection in high-risk patients

BACKGROUND: Carotid artery stenting has emerged as an alternative treatment modality in carotid occlusive disease. This study examined our experience of carotid stenting with routine cerebral embolization protection in high-risk patients. METHODS: Clinical variables and treatment outcome of high-risk patients who underwent carotid stenting with neuroprotection were analyzed during a 26-month period. RESULTS: Sixty-eight high-risk patients with 72 carotid artery stenoses were treated. Procedural success was achieved in 70 cases (97%), and symptomatic lesions existed in 17 (24%) patients. Monorail Wallstents stents were used in all cases. Neuroprotective devices used were PercuSurge (28%) and Filterwire (72%). There was no periprocedural mortality or neuroprotective device-related complications. The 30-day stroke and death rate was 2.7%, and the overall complication rate was 6.9%. All stented vessels remained patent during the follow-up period (mean 15.3 +/- 4.2, range 1 to 23 months). Two asymptomatic in-stent restenosis (3%) occurred at 6 and 8 months, which were both successfully treated with balloon angioplasty. CONCLUSIONS: Our study showed that percutaneous carotid stenting with routine use of a cerebral protection device is a feasible and effective treatment in high-risk patients with carotid occlusive disease.     

Complications of carotid artery stenting

AIM: The aim of this study was to deal with complications that can be managed by vascular surgery. METHODS: From March 2000 through May 2004, 171 patients (112 male, 59 female, mean age 66.2 years) underwent carotid artery stenting (CAS). Of these 171 interventions, 154 were CAS with percutaneous trasluminal angioplasty (PTA), 5 CAS without PTA, and 12 patients had only a PTA. RESULTS: In 171 patients who received CAS, 5 suffered a stroke within 7 days and 3 a transient ischemic attack. Twenty-one percent of the patients developed an in-stent restenosis >50% within 6 months following the intervention. Twenty-two patients with a recurrent in-stent restenosis were treated by re-PTA. Eight patients of this group of 22 re-PTAs developed a recurrent in-stent restenosis. They were converted with patch angioplasty or PTFE interposition. These 8 conversions were performed without morbidity or mortality. CONCLUSIONS: The preferable operative technique in patients with recurrent in-stent restenosis is open conventional operation with stent removal and patch angioplasty or graft interposition. The procedure can be performed at a low risk. In our series, we had no morbidity and mortality, and no cranial nerve lesion.     

脑保护装置下支架置入术治疗重度颈动脉狭窄

目的探讨脑保护装置下行颈动脉支架置入术(CAS)治疗重度颈动脉狭窄的近期疗效和安全性。方法回顾性分析2013年10月—2014年12月收治的48例接受CAS治疗的重度颈动脉狭窄患者临床资料,术后随访观察支架内再狭窄、短暂性脑缺血发作(TIA)、脑卒中及死亡事件的发生率。结果48例患者均CAS成功,术前平均狭窄率为(85.27±11.52)%,术后残余狭窄率为(18.12±3.36)%,差异有统计学意义(P0.01)。术后随访无新发TIA、脑梗死及死亡患者,但3例患者出现支架内重度再狭窄。结论支架置入术治疗重度颈动脉狭窄是安全、有效的,但远期疗效有待观察。     

股腘动脉支架内再狭窄的腔内治疗进展

近年来,随着血管内支架置入术在股腘动脉狭窄与闭塞疾病中的广泛应用,支架内再狭窄(ISR)的发生率也在逐年上升。虽然药物涂层球囊(DCB)的使用减轻了ISR的患病率,但ISR的治疗仍然是一个难点。虽然普通球囊(POBA)、切割球囊、冷冻球囊,再次支架植入已经在ISR的治疗中得到应用,但效果均不满意。而减容技术以及DCB分别有一定的局限性,将两者联合使用可以发挥各自的优势,可能是未来治疗股腘动脉ISR的有效途径。     

Carotid angioplasty and stenting for postendarterectomy stenosis: long-term follow-up

BACKGROUND: Carotid angioplasty and stenting (CAS) for recurrent stenosis after carotid endarterectomy (CEA) has been proposed as an alternative to redo CEA. Although early results are encouraging, the extended durability remains unknown. We present the long-term surveillance results of CAS for post-CEA restenosis. METHODS: Between 1998 and 2004, 57 CAS procedures were performed in 55 patients (36 men) with a mean age of 70 years. The mean interval between CEA and CAS was 83 months (range, 6 to 245). Nine patients (16%) were symptomatic. RESULTS: CAS was performed successfully in all patients. No deaths or strokes occurred. A periprocedural transient ischemic attack (TIA) occurred in two patients. During a mean follow-up of 36 months (range, 12 to 72 months), two patients exhibited ipsilateral cerebral symptoms (1 TIA, 1 minor stroke). In 11 patients (19%), in-stent restenosis (> or =50%) was detected post-CAS at month 3 (n = 3), 12 (n = 3), 24 (n = 2), 36 (n = 1), 48 (n = 1), and 60 (n = 1). The cumulative rates of in-stent restenosis-free survival at 1, 2, 3, and 4 years were 93%, 85%, 82%, and 76%, respectively. Redo procedures were performed in six patients, three each received repeat angioplasty and repeat CEA with stent removal. The cumulative rates of freedom from reintervention at 1, 2, 3, and 4 years were 96%, 94%, 90%, and 84%, respectively. CONCLUSION: Carotid angioplasty and stenting for recurrent stenosis after CEA can be performed with a low incidence of periprocedural complications with durable protection from stroke. The rate of in-stent recurrent stenosis is high, however, and does not only occur early after CAS but is an ongoing process.     

下肢动脉硬化闭塞症腔内治疗后支架内再狭窄的治疗

目的:探讨下肢动脉硬化闭塞症(ASO)腔内治疗后支架内再狭窄的治疗体会。方法:回顾性分析2012年6月至2014年12月收治的支架内再狭窄的31例下肢ASO患者(49条肢体)资料,其中狭窄病变37条肢体,闭塞病变12条肢体;病变长度8.5~35 cm,平均(25.2±7.5)cm。结果:所有患者均接受腔内治疗,包括单纯球囊扩张成形术35例,球囊扩张后导管溶栓术3例,球囊扩张后支架植入术3例,导管溶栓后球囊扩张术7例,斑块旋切术1例。术后所有患者症状均不同程度缓解,平均踝肱指数较术前明显升高(P0.05)。28例获得随访3~32个月,平均(16.2±5.8)个月,期间出现再狭窄6例(21.4%),均再次行球囊扩张成形术,无截肢及死亡病例。结论:结合其他腔内疗法,球囊扩张术治疗下肢动脉支架内再狭窄疗效满意。     

对侧颈动脉闭塞患者颈动脉成形支架置入术的临床分析

目的 探讨对侧颈动脉闭塞患者颈动脉成形支架置入术(CAS)的有效性及安全性.方法 回顾性分析2001年1月至2010年1月治疗的56例对侧颈动脉闭塞、同侧颈动脉狭窄患者的病例特点及CAS的疗效.患者均经数字减影血管造影(DSA)证实为一侧颈动脉闭塞、另一侧颈动脉狭窄,狭窄程度在50%～90%,平均72%±15%.经常规准备后在远端脑保护装置保护下行CAS.结果 56例对侧颈动脉闭塞、同侧颈动脉狭窄患者行CAS的技术成功率100%,术后颈动脉直径狭窄率即术后残余狭窄率为0～30%,平均为13%±8%.患者术后脑缺血症状均获改善,仅1例于术后3 d发生原脑梗死部位的慢性出血(CAS侧),开颅手术后遗留轻微神经功能障碍,无缺血性并发症发生,无死亡病例.患者随访6个月～3年,平均27个月,均无脑缺血症状发作,经颈部血管彩色超声复查47例、DSA复查2例均未发现支架内再狭窄.结论 对侧颈动脉闭塞的高危患者的CAS治疗是安全、有效的,严格的病例筛选、经验丰富的医生操作及术后严谨的综合处理均可以降低手术并发症的发生.

Abstract：

Objective To discuss the efficiency and safety of carotid angioplasty stenting (CAS) in patients with contralateral carotid artery occlusion. Methods From January 2001 to January 2010,56 carotid artery stenosis patients with contralateral carotid artery occlusion were performed CAS and the feature and results of these cases were analyzed retrospectively. All the cases were confirmed to be carotid artery stenosis with contralateral carotid artery occlusion by digital subtraction angiography (DSA). The diameter stenosis rate was 72% ± 15%. CAS were performed with distal protection device in 56 cases. Results The technique success rate of CAS were 100% in all the 56 patients with contralateral carotid artery occlusion and postprocedure stenosis rate descended to 13% ± 8%, and the symptoms of cerebral ischemia were all improved. Only 1 case occurred remote hemorrhage in the position of previous cerebral infarction in the side of CAS after the procedure, and recovered with light neurological deficit after the craniotomy to remove the hematoma. No ischemic complications or death occurred. During the following up of 6 months to 3 years, no cerebral ischemic symptoms reoccurred. The rechecking results of color Doppler of 47 cases and DSA of 2 cases showed no restenosis in-stent. Conclusions CAS is safe and effective for the patients with contralateral carotid artery occlusion. Critical election of the case, operation of skilled doctors and scrupulous postprocedure general management can decrease the rate of complication.     

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.     

Carotid endarterectomy for treatment of in-stent restenosis

In-stent restenosis (ISR) after carotid angioplasty and stenting is becoming evident as more patients undergo carotid stenting and duplex scan surveillance. While redo endovascular therapy has been immediately successful, recurrent stenosis remains a problem. The ideal management of ISR has not been determined. Three cases of symptomatic ISR that were successfully treated by standard carotid endarterectomy (CEA) with removal of the stent are reported herein. Current options for management of ISR are reviewed from the literature.     

Successful recanalization by in-stent percutaneous transluminal angioplasty with distal protection for acute carotid stent thrombosis

A 71-year-old male presented with severe left cervical internal carotid artery stenosis manifesting as repeated transient ischemic attacks consisting of right hemiparesis and motor aphasia. Carotid artery stenting (CAS) under distal protection was performed to prevent further ischemic events. This procedure was uneventful. However, the patient exhibited progressive right hemiparesis and motor aphasia 3 days after CAS. Emergent angiography revealed carotid artery occlusion due to in-stent thrombosis. In-stent percutaneous transluminal angioplasty (PTA) was performed under distal protection. The carotid artery was recanalized with small residual thrombus. The neurological deficits almost completely disappeared after PTA. Follow-up angiography 9 months after stenting showed restenosis but no in-stent thrombosis. Carotid thrombosis after CAS can be resolved by in-stent PTA under distal protection and subsequent treatment with antithrombotic agents.     

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.     

In-stent recurrent stenosis after carotid artery stenting: life table analysis and clinical relevance

OBJECTIVES: Carotid artery stenting has been proposed as an alternative to carotid endarterectomy in cerebral revascularization. Although early results from several centers have been encouraging, concerns remain regarding long-term durability of carotid artery stenting. We report the incidence, characteristics, and management of in-stent recurrent stenosis after long-term follow-up of carotid artery stenting. METHODS: Carotid artery stenting (n = 122) was performed in 118 patients between September 1996 and March 2003. Indications included recurrent stenosis after previous carotid endarterectomy (66%), primary lesions in patients at high-risk (29%), and previous ipsilateral cervical radiation therapy (5%). Fifty-five percent of patients had asymptomatic stenosis; 45% had symptomatic lesions. Each patient was followed up with serial duplex ultrasound scanning. Selective angiography and repeat intervention were performed when duplex ultrasound scans demonstrated 80% or greater in-stent recurrent stenosis. Data were prospectively recorded, and were statistically analyzed with the Kaplan-Meier method and log-rank test. RESULTS: Carotid artery stenting was performed successfully in all cases, with the WallStent or Acculink carotid stent. Thirty-day stroke and death rate was 3.3%, attributable to retinal infarction (n = 1), hemispheric stroke (n = 1), and death (n = 2). Over follow-up of 1 to 74 months (mean, 18.8 months), 22 patients had in-stent recurrent stenosis (40%-59%, n = 11; 60%-79%, n = 6; > or =80%, n = 5), which occurred within 18 months of carotid artery stenting in 13 patients (60%). None of the patients with in-stent recurrent stenosis exhibited neurologic symptoms. Life table analysis and Kaplan-Meier curves predicted cumulative in-stent recurrent stenosis 80% or greater in 6.4% of patients at 60 months. Three of five in-stent recurrent stenoses occurred within 15 months of carotid artery stenting, and one each occurred at 20 and 47 months, respectively. Repeat angioplasty was performed once in 3 patients and three times in 1 patient, and repeat stenting in 1 patient, without complications. One of these patients demonstrated asymptomatic internal carotid artery occlusion 1 year after repeat intervention. CONCLUSIONS: Carotid artery stenting can be performed with a low incidence of periprocedural complications. The cumulative incidence of clinically significant in-stent recurrent stenosis (> or =80%) over 5 years is low (6.4%). In-stent restenosis was not associated with neurologic symptoms in the 5 patients noted in this cohort. Most instances of in-stent recurrent stenosis occur early after carotid artery stenting, and can be managed successfully with endovascular techniques.     

Duplex ultrasound velocity criteria for the stented carotid artery

OBJECTIVES: Ultrasound velocity criteria for the diagnosis of in-stent restenosis in patients undergoing carotid artery stenting (CAS) are not well established. In the present study, we test whether ultrasound velocity measurements correlate with increasing degrees of in-stent restenosis in patients undergoing CAS and develop customized velocity criteria to identify residual stenosis > or =20%, in-stent restenosis > or =50%, and high-grade in-stent restenosis > or =80%. METHODS: Carotid angiograms performed at the completion of CAS were compared with duplex ultrasound (DUS) imaging performed immediately after the procedure. Patients were followed up with annual DUS imaging and underwent both ultrasound scans and computed tomography angiography (CTA) at their most recent follow-up visit. Patients with suspected high-grade in-stent restenosis on DUS imaging underwent diagnostic carotid angiograms. DUS findings were therefore available for comparison with luminal stenosis measured by carotid angiograms or CTA in all these patients. The DUS protocol included peak-systolic (PSV) and end-diastolic velocity (EDV) measurements in the native common carotid artery (CCA), proximal stent, mid stent, distal stent, and distal internal carotid artery (ICA). RESULTS: Of 255 CAS procedures that were reviewed, 39 had contralateral ICA stenosis and were excluded from the study. During a mean follow-up of 4.6 years (range, 1 to 10 years), 23 patients died and 64 were lost. Available for analysis were 189 pairs of ultrasound and procedural carotid angiogram measurements; 99 pairs of ultrasound and CTA measurements during routine follow-up; and 29 pairs of ultrasound and carotid angiograms measurements during follow-up for suspected high-grade in-stent restenosis > or =80% (n = 310 pairs of observations, ultrasound vs carotid angiograms/CTA). The accuracy of CTA vs carotid angiograms was confirmed (r(2) = 0.88) in a subset of 19 patients. Post-CAS PSV (r(2) = .85) and ICA/CCA ratios (r(2) = 0.76) correlated most with the degree of stenosis. Receiver operating characteristic analysis demonstrated the following optimal threshold criteria: residual stenosis > or =20% (PSV >or =150 cm/s and ICA/CCA ratio > or =2.15), in-stent restenosis > or =50% (PSV > or =220 cm/s and ICA/CCA ratio > or =2.7), and in-stent restenosis > or =80% (PSV 340 cm/s and ICA/CCA ratio > or =4.15). CONCLUSIONS: Progressively increasing PSV and ICA/CCA ratios correlate with evolving restenosis within the stented carotid artery. Ultrasound velocity criteria developed for native arteries overestimate the degree of in-stent restenosis encountered. These changes persist during long-term follow-up and across all grades of in-stent restenosis after CAS. The proposed new velocity criteria accurately define residual stenosis >or =20%, in-stent restenosis >or =50%, and high-grade in-stent restenosis > or =80% in the stented carotid artery.     

Carotid artery stenting in a vascular surgery practice

PURPOSE: We tested the clinical applicability, technical results, and morbidity of carotid angioplasty-stenting (CAS) in the treatment of severe stenosis of the internal carotid artery (ICA) in patients deemed to be high-risk candidates for carotid endarterectomy (CEA). METHOD: After an initial series (1994-1997) of 52 interventions, we adopted the use of a transfemoral access technique and self-expanding stents in late 1997. From Dec 1, 1997, to Mar 31, 2001, 135 CAS procedures were performed on 132 patients with more than 70% (symptomatic) or more than 80% (asymptomatic) stenoses of the ICA. Sixty percent of the patients had no symptoms, and 40% of patients had symptoms. The interventional technique was standardized with the use of a 7F long interventional sheath, balloon pre-dilatation of the stenotic lesion, placement of a self-expanding stent (Wallstent in 12 patients and a SMART stent in 120 patients), and post-balloon dilatation when necessary. Brain protection devices were not used. Patients were given clopidogrel and aspirin before and after the procedure and heparin during the intervention. RESULTS: All procedures except two were completed as planned, with access failure in three patients (2.2%). Residual in-stent stenosis of less than 20% was detected in 14 of 132 stented vessels (11%) and accepted as a satisfactory angiographic outcome. Neurologic complications included one patient with a single-episode transient ischemic attack (TIA; motor-sensory deficit of the hand) occurring 2 hours after CAS. One patient sustained a major stroke after thrombosis of the stented ICA, which occurred 3 days after the CAS procedure and 24 hours after open-heart surgery. A third patient sustained a minor stroke that began intraprocedurally after post-balloon dilatation of the stent, and a fourth patient had another minor stroke with transient aphasia (beginning during the procedure and resolving after 4 hours) and monoparesis of the hand, which resolved after 1 week. All stented vessels remained patent during the follow-up period (range, 2-41 months; mean, 16 plus minus 9 months), with four instances of hemodynamically significant in-stent restenosis. Re-intervention with balloon angioplasty was undertaken successfully at 4 months in one patient with restenosis. The periprocedural mortality rate was 0. CONCLUSION: Carotid stenting can be performed with acceptable safety on carefully selected patients by using meticulous, standardized interventional techniques. It may offer a possibly superior therapeutic alternative for non-CEA candidates. Evolving technological improvements and brain protection devices are likely to enhance its role in the treatment of carotid artery disease in the future. Surgical endarterectomy remains the standard of care for most patients at the present time.     

Treatment of restenosis

Carotid restenosis after endarterectomy is observed in up to 24.1% of patients with long-term follow up. Indication for reintervention in asymptomatic patients however should be reserved for greater than 80% stenosis. Treatment options include repeat surgical reconstruction as well as intraoperative or percutaneous balloon angioplasty +/- stenting. We compared our past experience with 66 operative reconstructions in 64 patients with a recent series of 60 patients who underwent intraoperative balloon-dilatation and stenting. After conventional surgery 2 patients (3.1%) suffered a permanent neurological deficit, one patient developed a TIA (1.5%). After intraoperative dilation and stenting 8 patients (13.3%) suffered a stroke; 2 patients died after surgery (one stroke, one myocardial infarction) (mortality 3.3%). When compared to conventional operative repair intraoperative carotid balloon angioplasty and stenting of restenosis is complicated by a substantial increase in morbidity and mortality and cannot be recommended as routine therapy.