Cerebral protection during carotid stenting using flow reversal

BACKGROUND: Carotid angioplasty and stenting can be used in stroke prevention in high-risk patients. As embolic complications can occur during carotid angioplasty and stenting, a device was developed to protect from cerebral embolization. METHODS: Between September 1999 and May 2002, carotid angioplasty and stenting was performed in 100 patients (84 men; mean age, 69.2 years) with symptomatic (26%) or asymptomatic (74%) severe carotid artery stenosis. Wallstents were used in all cases with selective pre-dilatation. Cerebral protection devices (Parodi Anti-Emboli System [PAES], ArteriA, San Francisco, Calif) were used in all patients. All patients were evaluated by a neurologist, both before and after the procedure. According to the criteria set forth by the large trials, the occurrence of minor, major or fatal stroke and myocardial infarction (end points) within 30 days and follow-up were determined as end points. Data were collected prospectively. RESULTS: The overall perioperative stroke and death rate was 3% (1 noncorresponding minor stroke, 1 hemorrhagic stroke, and 1 cardiac event). Four patients developed postoperative transient neurologic events (three related to hemodynamic instability and the fourth due to postoperative embolization). The overall technical success rate for carotid angioplasty (protection device placed in position percutaneously) was 99%. CONCLUSION: The efficacy and safety of carotid angioplasty and stenting with PAES are confirmed. This innovative protection device may prevent the debris released by angioplasty from entering the cerebral circulation. Further investigation is warranted.     

Advantages and indications of transcervical carotid artery stenting with carotid flow reversal

AIM: The aim of this Italian prospective registry was to evaluate the applicability and efficacy of the Mo.Ma Device (Invatec, Roncadelle, Italy) for the prevention of cerebral embolization during carotid artery stenting (CAS) in a real world population. METHODS: In 4 Italian centers, 416 patients (300 men; mean age 71.6+/-9 years) between October 2001 and March 2005 were enrolled in a prospective registry. Two-hundred and sixty-four symptomatic (63.46%) with >50% diameter stenosis and 152 (36.54%) asymptomatic patients with >70% diameter stenosis were included. The Mo.Ma Proximal Flow Blockage Embolic Protection System was used to perform protected CAS, achieving cerebral protection by endovascular clamping of the common carotid artery (CCA) and of the external carotid artery (ECA). RESULTS: Technical success, defined as the ability to establish protection with the Mo.Ma device and to deploy the stent, was achieved in 412 cases (99.03%). The mean duration of flow blockage was 4.91+/-1.1 min. Transient intolerances to flow blockage were observed in 24 patients (5.76%), but in all cases the procedure was successfully completed. No peri-procedural strokes and deaths were observed. Complications during hospitalization included 16 minor strokes (3.84%), 3 transient ischemic attacks (0.72%), 2 deaths (0.48%) and 1 major stroke (0.24%). This resulted in a cumulative rate at discharge of 4.56% all strokes and deaths, and of 0.72% major strokes and deaths. All the patients underwent thirty-day follow-up. At thirty-day follow-up, there were no deaths and no minor and major strokes, confirming the overall cumulative 4.56% incidence of all strokes and deaths rate, and of 0.72% rate of major strokes and deaths at follow up. In 245 cases (58.89%) there was macroscopic evidence of debris after filtration of the aspirated blood. CONCLUSIONS: This Italian multicenter registry confirms and further supports the efficacy and applicability of the endovascular clamping concept with proximal flow blockage in a broad patient series. Results match favorably with current available studies on carotid stenting with cerebral protection.     

Value of diffusion-weighted MRI during carotid angioplasty and stenting.

INTRODUCTION: The incidence of neurological injury following carotid angioplasty and stenting is of great interest to those advocating it as an alternative to endarterectomy in the management of critical carotid stenosis. A significant inter-observer variation exists in determining the presence or absence of a neurological deficit following the procedure objective imaging would be advantageous. In this study, we sought to assess diffusion weighted MRI as a diagnostic tool in evaluating the incidence of neurological injury following carotid angioplasty and stenting (CAS). PATIENTS AND METHODS: The first 110 cases of CAS in our unit were included in this series. The procedure was abandoned in three patients. Patients underwent intracranial and extracranial MR angiography, together with diffusion-weighted MRI (DWI) prior to and following CAS and had a formal neurological assessment in the intensive care unit after the procedure. RESULTS: One hundred and ten Procedures were attempted in 98 patients. Twenty-eight percent were asymptomatic. Following CAS, 7.2% of patients had a positive neurological exam (two major strokes with one fatality) and 21% had positive DWI scans, equating to a sensitivity of 86% and a specificity of 85% for DWI in detecting cerebral infarction following CAS. The positive predictive value of the test was 0.3 and negative predictive value 0.99. The major stroke and death rate was 1.8%. While the use of a cerebral protection device appeared to significantly reduce the incidence of cerebral infarction (5% vs. 25%, p = 0.031) this may be a reflection of the learning curve encountered during the study. CONCLUSION: The incidence of subclinical DWI detected neurological injury was significantly higher than clinical neurological deficit following CAS. Conventional methods of neurological assessment of patients undergoing CAS may be too crude to detect subtle changes and more sensitive tests of cerebral function are required to establish whether these subclinical lesions are relevant.     

Gender differences in blood flow velocities after carotid angioplasty and stenting

Gender differences have been demonstrated in blood flow velocities by duplex ultrasonography (DU) in patients with carotid stenosis. Currently, DU is the most widely used method of follow-up monitoring after carotid angioplasty and stenting (CAS). To identify possible gender differences in carotid flow velocities, we analyzed our experience with DU obtained before and immediately after CAS. In a series of 47 CAS procedures over a 2.5-year period performed in 31 men and 15 women, carotid angiograms and duplex flow velocities were obtained preoperatively and within 24 hr after CAS. Carotid velocity profiles were compared with the angiographic degree of carotid stenosis. Gender differences in blood velocities were assessed using parametric and nonparametric statistical tests. Overall, women had median blood velocities 5-10% higher than men, although the differences were not statistically significant. DU obtained immediately after CAS revealed that median blood flow velocities were very similar among men and women (P > 0.4). In conclusion, although women have higher carotid blood flow velocities than men do, gender differences are notably absent on follow-up DU after carotid stenting. Our data indicate that similar criteria should be used after CAS for interpreting carotid velocity profiles in both women and men.     

Transcervical carotid stenting with internal carotid artery flow reversal: feasibility and preliminary results

OBJECTIVE: Transfemoral carotid artery stenting (CAS), with or without distal protection, is associated with risk for cerebral and peripheral embolism and access site complications. To establish cerebral protection before crossing the carotid lesion and to avert transfemoral access complications, the present study was undertaken to evaluate a transcervical approach for CAS with carotid flow reversal for cerebral protection. METHODS: Fifty patients underwent CAS through a transcervical approach. All patients with symptoms had greater than 60% internal carotid artery (ICA) stenosis, and all patients without symptoms had greater than 80% ICA stenosis. Twenty-one patients (42%) had symptomatic disease or ipsilateral stroke, and 8 patients (16%) had contralateral stroke. Four patients (8%) had recurrent stenosis, 7 patients (14%) had contralateral ICA occlusion, and 1 patient (2%) had undergone previous neck radiation. Twenty-seven procedures (54%) were performed with local anesthesia, and 23 (46%) with general anesthesia. Using a cervical cutdown, flow was reversed in the ICA by occluding the common carotid artery and establishing a carotid-jugular vein fistula. Pre-dilation was selective, and 8-mm to 10-mm self-expanding stents were deployed and post-dilated with 5-mm to 6-mm balloons in all cases. RESULTS: The procedure was technically successful in all patients, without significant residual stenoses. No strokes or deaths occurred. There was 1 wound complication (2%). All patients were discharged within 2 days of surgery. Mean flow reversal time was 21.4 minutes (range, 9-50 minutes). Carotid flow reversal was not tolerated in 2 patients (4%). Early in the experience, carotid flow reversal was not possible in 1 patient, and there were 1 major and 3 minor common carotid artery dissections, which resolved after stent placement. One intraoperative transient ischemic attack (2%) occurred in 1 patient in whom carotid flow was not reversed, and 1 patient with a contralateral ICA occlusion had a contralateral transient ischemic attack. At 1 to 12 months of follow-up, all patients remained asymptomatic, and all but 1 stent remained patent. CONCLUSION: Transcervical CAS with carotid flow reversal is feasible and safe. It can be done with the patient under local anesthesia, averts the complications of the transfemoral approach, and eliminates the increased complexity and cost of cerebral protection devices. Transcervical CAS is feasible when the transfemoral route is impossible or contraindicated, and may be the procedure of choice in a subset of patients in whom carotid stenting is indicated.     

颈动脉窦区浸润阻滞在颈动脉支架成形术中的应用

目的观察颈动脉窦区浸润阻滞在颈动脉支架成形术(CAS)中预防颈动脉窦反射(CSR)的作用。方法选择2019年8月至2020年1月择期症状性颈动脉C_1段狭窄行CAS的患者40例,男27例,女13例,年龄54～81岁,BMI 19～32 kg/m~2,ASAⅡ或Ⅲ级。采用随机数字表法将患者分为两组:颈动脉窦区浸润阻滞组(B组)和阿托品预防组(C组),每组20例。B组在超声引导下应用1%利多卡因5 ml在颈动脉窦区进行浸润阻滞,注射后5 min球囊引导导管到位,行球囊扩张,并置入颈动脉支架;C组预防性静脉注射阿托品0.5 mg,注射后5 min球囊引导导管到位后,开始球囊扩张及置入颈动脉支架。所有患者在局麻监测下完成CAS。记录颈动脉窦浸润阻滞后/静脉注射阿托品后5 min(T_1)、球囊扩张即刻(T_2)、支架置入后5 min(T_3)、10 min(T_4)、20 min(T_5)及术毕即刻(T_6)的HR及T_1和T_3—T_6时的SBP,并计算T_2—T_6时HR与T_3—T_6时SBP降低幅度。CSR定义为:与T_1时比较,T_2—T_6时HR降低幅度10%、或心动过缓(HR60次/分)、或低血压(SBP90 mmHg),分别记录HR降低幅度10%、心动过缓和低血压的发生情况。记录应用阿托品及多巴胺补救例数。记录声音嘶哑、呼吸困难、局麻药中毒、误伤血管、心脏骤停及术后心脑血管相关不良反应的发生情况。结果 T_2时B组HR降低幅度明显小于C组(P0.05),T_3—T_6时两组SBP、HR降低幅度差异无统计学意义。B组心动过缓发生率明显低于C组(P0.05),阿托品补救发生率明显低于C组(P0.05)。C组于T_2时出现心脏骤停1例,20 s后逐渐恢复自主循环,术后3 d死于大面积脑梗死1例;B组发生声音嘶哑4例,于术后1 h内恢复正常;其余未发生呼吸困难、局麻药中毒、误伤血管、心脏骤停及术后心脑血管相关不良反应。结论超声引导下1%利多卡因颈动脉窦区浸润阻滞,可有效地预防颈动脉支架成形术中颈动脉窦反射,维持血流动力学稳定。     

Technical tips for carotid angioplasty and stenting

Angioplasty and stenting of the carotid artery has become an accepted procedure in properly selected patients with carotid artery stenosis. The potential for devastating neurologic complications and significant hemodynamic changes separates endovascular treatment of the carotid artery from other percutaneous peripheral vascular procedures. In this article, the technique for carotid artery angioplasty and stenting is described and the strategies for management of the hemodynamic changes occuring with carotid stenting are reviewed.     

颈动脉狭窄手术及介入治疗的围术期管理

背景 脑卒中是造成人类死亡的主要原因之一.15％～20％的缺血性脑血管病归因于颈动脉狭窄或闭塞,颈动脉内膜剥脱术(carotid endarterectomy,CEA)和颈动脉血管腔内球囊成形及支架植入术(carotid angioplasty and stenting,CAS)对预防缺血事件发生有效,但围手术期卒中、死亡等并发症对围术期管理提出挑战. 目的 对颈动脉狭窄手术及介入治疗围术期管理进行综述. 内容 重点阐述CEA和CAS围术期危险因素控制、术前评估、麻醉方法与管理、术中神经功能监测和脑保护. 趋向 积极谨慎的围术期管理是保证颈动脉狭窄患者围术期脑氧供需平衡、降低围术期并发症的有效措施.     

Transcervical carotid stenting with flow reversal protection: experience in high-risk patients

BACKGROUND: Carotid angioplasty and stenting (CAS) with cerebral embolic protection is a safe alternative to carotid endarterectomy in high-risk patients. Among the various systems proposed for cerebral protection, transcervical CAS avoids crossing the lesion without protection and eliminates the complications associated with transfemoral access. This study analyzes our experience and the results obtained with a transcervical stenting technique for carotid revascularization. METHODS: From January 2005 to June 2006, 62 CAS were performed in our center in high-risk patients with >70% stenosis (38.7% had a previous neurologic event and 61.3% were asymptomatic). The indications for CAS were severe heart disease (45.1%), severe pulmonary disease (6.4%), paralysis of the contralateral laryngeal nerve (6.4%), recurrent stenosis (3.2%), and high carotid lesion (1.6%). Twenty-one patients were >80 years old. A complete neurologic examination was performed by a stroke neurologist in all patients before and after stenting. The protection system used was carotid flow reversal by transcervical access. Transcranial Doppler monitoring was done during the procedure in 35 patients. We analyzed technical success, the presence of high-intensity transient signals during the procedure, neurologic morbidity and mortality at 30 days and 6 months, and stent patency at 6 months (range, 1 to 18 months). Technical success was 96.8%. Perioperative high-intensity transient signals were observed in two patients (5.7%). In the immediate postoperative period, one patient had a transient ischemic attack of the anterior cerebral artery and another had a stroke, with contralateral hemiplegia. At 48 hours after discharge, a third patient returned to the hospital with a severe cerebral hemorrhage that required surgical drainage; hence, neurologic morbidity was 4.9%. There were no deaths at 6 months. Among the total, 98.4% of the stents remained patent, two showed restenosis of 50% to 70%, and one restenosis of >70%. No patients presented a neurologic event during the follow-up. CONCLUSIONS: Transcervical carotid artery stenting with flow reversal cerebral protection is a relatively simple, safe technique that avoids instrumentation of the aortic arch and crossing the target lesion without protection. It is less expensive than techniques requiring a filter device and provides excellent outcome with an acceptable incidence of complications.     

Current evidence for transcarotid artery stenting with flow reversal as the preferred carotid artery stenting approach

Although the transfemoral approach to carotid artery stenting offers a minimally invasive method for treatment of carotid atherosclerotic disease, this technique for carotid revascularization has unfortunately not led to equivalent overall outcomes of stroke or death compared with endarterectomy in symptomatic or high-risk patients. Transcarotid artery revascularization (TCAR) with a flow reversal neuroprotection system was designed to reduce the embolic risk associated with the transfemoral approach, but randomized trials have yet to be published comparing transfemoral carotid artery stenting with TCAR. Regardless, many surgeons and interventionalists have already adopted TCAR as the preferred modality for carotid artery stenting, given the accumulating evidence supporting the reduced stroke or death benefits of TCAR over the transfemoral approach.     

Access site complications with carotid angioplasty and stenting

BACKGROUND: Carotid angioplasty and stenting is a relatively new therapeutic alternative to CEA for treatment of carotid stenosis. The percutaneous transfemoral approach, the standard technique for angioplasty and stent deployment, may not be feasible in all patients. We present our experience with access site complications that occurred with CAS. METHODS: One hundred thirty-two CAS procedures were performed at our institution in the past 5 years for symptomatic (62.1%) or asymptomatic (37.9%) carotid stenosis. Mean age of patients was 70.72 +/- 6.53 years and the mean degree of stenosis of the treated carotids was 80.74% +/- 11.83%. The transfemoral approach was the access route in 126 CAS, the transbrachial approach was used in 2 CAS procedures, and direct carotid exposure was used in 5 patients. RESULTS: All CAS procedures were done successfully; 4 (3%) access site complications were detected, 3 (2.4%) groin hematomas with transfemoral approach and 1 hematoma on the left side of the neck, in patients treated with direct carotid cutdown. Surgical repair of FSA was successfully performed for the patients with groin hematoma, whereas surgical wound exploration in the neck for the remaining patient revealed no identifiable cause. All patients received blood transfusion for correction of associated hypovolemia or hemorrhagic anemia. No patients had experienced access site-related additional cardiac, systemic, or neurologic events. CONCLUSIONS: The authors' experience demonstrates that access site complications are rare events with CAS despite the large diameter of implantable devices and liberal anticoagulant and antiplatelet therapy. Transbrachial and direct carotid approaches are relatively safe, accepted alternatives in the setting of contraindicated femoral access.     

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目的探讨颈动脉支架成形术治疗高危颈动脉狭窄的可行性、安全性及短期疗效一方法自200l年8月至2003年7月，共采用颈动脉支架成形术治疗高危颈动脉狭窄8例，术前平均狭窄程度分别为(74.13=13.38)％，均为症状性病人结果狭窄位于颈内动脉6例，位于颈总动脉2例，所有病人均成功地植入支架术后狭窄程度均≤10％。全部病人无临床并发症，5例临床症状消失，3例临床症状不同程度好转随访3～27个月，无短暂性脑缺血发作(TIA)等缺血性神经损害发生；影像学检查无显著再狭窄。结论颈动脉支架成形术治疗颈动脉狭窄安全有效，尤其适合于颈动脉内膜切除术高危的病人，脑保护装置可以有效减少因硬化斑块或血枪引起的并发症     

Postprocedural microembolic events following carotid surgery and carotid angioplasty and stenting

OBJECTIVE: The relative safety of percutaneous carotid interventions remains controversial. Few studies have used diffusion-weighted magnetic resonance imaging (DW-MRI) to evaluate the safety of these interventions. We compared the incidence and distribution of cerebral microembolic events after carotid angioplasty and stenting (CAS) with distal protection to standard open carotid endarterectomy (CEA) using DW-MRI. METHODS: From November 2004 through August 2006, 69 carotid interventions (27 CAS, and 42 CEA) were performed in 68 males at a single institution. Pre- and postprocedure DW-MRI exams were obtained on each patient undergoing CAS and the 20 most recent CEA operations. These 46 patients (47 procedures as one patient underwent bilateral CEAs in a staged fashion) constitute our study sample, and the hospital records of these patients (27 CAS and 20 CEA) were retrospectively reviewed. The incidence and location of acute, postprocedural microemboli were determined using DW-MRIs and assessed independently by two neuroradiologists without knowledge of the subjects' specific procedure. RESULTS: Nineteen CAS patients (70%, 95% confidence interval [CI]: 42%-81%) demonstrated evidence of postoperative, acute, cerebral microemboli by DW-MRI vs none of the CEA patients (0%, 95% CI: 0%-17%) (P < .0001). Of the 19 CAS patients with postoperative emboli, nine (47%) were ipsilateral to the index carotid lesion, three (16%) contralateral, and seven (36%) bilateral. The median number of ipsilateral microemboli identified in the CAS group was 1 (interquartile ranges [IQR]: 0-2, range 0-21). The median number of contralateral microemboli identified in the CAS group was 0 (IQR: 0-1, range 0-5). Three (11%) CAS patients experienced temporary neurologic sequelae lasting less than 36 hours. These patients suffered 12 (six ipsilateral and six contralateral), 20 (19 ipsilateral and one contralateral), and zero microemboli, respectively. By univariate analysis, performing an arch angiogram prior to CAS was associated with a higher risk of microemboli (median microemboli 5 vs none, P =.04) CONCLUSIONS: Although our early experience suggests that CAS may be performed safely (no permanent neurologic deficits following 27 consecutive procedures), cerebral microembolic events occurred in over two-thirds of the procedures despite the uniform use of distal protection. Open carotid surgery in this series seems to offer a lower risk of periprocedural microembolic events detected by DW-MRI.