Extracranial Carotid Stenting Research Articles

Initial experience of subcutaneous nitroglycerin for distal transradial access in neurointerventions.

Background: Transradial access (TRA) for diagnostic and interventional neuroendovascular procedures has gained significant popularity in recent years due to its improved safety profile and appeal to patients compared with transfemoral access. However, risks of TRA include hand ischemia in cases of poor ulnar collateral circulation and inability to cannulate the radial artery due to its relatively small diameter. By accessing the radial artery distal to the superficial palmar arch where ulnar collateral blood flow arises, in the anatomic snuffbox, the risk of hand ischemia is theoretically eliminated. The use of subcutaneous nitroglycerin and lidocaine to improve rates of success in radial artery access has been reported in the cardiac literature, however, has yet to be described for neurointerventional procedures. We discuss our technique and report our initial experience using subcutaneous nitroglycerin and lidocaine cocktail for access to the distal transradial artery in a variety of neuroendovascular procedures.Methods: A retrospective review of our institution’s database of neurointerventional and diagnostic procedures performed using dTRA was conducted, and 64 patients were identified between February and December 2020. Patient demographics, clinical data, procedural details, and radiographic information were collected and analyzed.Results: A total of 64 patients underwent neurointerventional procedures using the subcutaneous injection for dTRA access. The procedures performed included diagnostic cerebral angiograms (n = 47), stent and balloon assisted aneurysm coiling (n = 5), flow diversion (n = 2), intra-saccular device placement (n = 1), mechanical thrombectomy (n = 1), tumor embolization (n = 1), middle meningeal artery embolization (n = 2), extracranial carotid stent placement (n = 2), and arteriovenous malformation embolization (n = 3). While no complications of hand ischemia were appreciated, the access site conversion rate was 3.1%; 2 cases required a switch to femoral artery access due to proximal vessel tortuosity and aortic anatomical variations, and not due to access site complication. Furthermore, on repeat angiograms by the same proceduralist, distal TRA (dTRA) was successful in 100% of the cases.Conclusion: dTRA using subcutaneous nitroglycerin and lidocaine is a safe and effective method for neurointerventional and diagnostic procedures.

Carotid stent occlusion after emergent stenting in acute ischemic stroke: Incidence, predictors and clinical relevance

Background and aimsEmergent stent placement may be required during neurothrombectomy. Our aim was to investigate the incidence, predictors and clinical relevance of early extracranial carotid stent occlusion following neurothrombectomy. MethodsWe retrospectively analyzed a cohort of 761 consecutive neurothrombectomies performed at our center between May 2010 and August 2018, from whom a total of 106 patients had acute internal carotid artery occlusions. Early stent occlusion was defined as complete vessel occlusion within 24 h of neurothrombectomy. Clinical outcome was evaluated at day 90 with the modified Rankin Score scale (mRS). Pretreatment, procedural and outcome variables were recorded and analyzed using logistic regression. ResultsCarotid stenting was performed in 99 (13%) patients. Of those, 22 (22%) had early stent occlusion at follow-up. Stent occlusion was associated with a lower use of post-stenting angioplasty [adjusted OR (aOR) = 11.2, 95%CI = 2.49–50.78, p = 0.002)], increased residual intrastent stenosis (aOR = 2.1, 95%CI = 1.38–3.06, p < 0.001) and unsuccesful intracranial recanalization (modified TICI score 0-2a) (aOR = 13.5, 95%CI = 1.97–92.24, p = 0.008). Stent occlusion was associated with poor clinical outcome at day 90 (poorer mRS shift, aOR = 3.9, 95%CI = 1.3–11.3, p = 0.014; mRS>2, aOR = 6.3, 95%CI = 1.8–22.7, p = 0.005), and with an increased rate of symptomatic intracranial hemorrhage at 24 h (14% versus 1%, p = 0.033). ConclusionsEarly carotid stent occlusion occurred in one out of five neurothrombectomies and was associated with periprocedural factors that included increased residual intrastent stenosis, a lower use of post-stenting angioplasty and unsuccessful intracranial recanalization. Further investigation is warranted for the evaluation of strategies aimed to prevent carotid stent occlusion.

Functional Outcome and Safety of Intracranial Thrombectomy After Emergent Extracranial Stenting in Acute Ischemic Stroke Due to Tandem Occlusions.

Background and Purpose: Various endovascular approaches to treat acute ischemic stroke caused by extra- intracranial tandem occlusions (TO) exist: percutaneous transluminal angioplasty with or without emergent extracranial carotid stenting (ECS) due to high-grade stenosis preceded or followed by intracranial mechanical and/or aspiration thrombectomy (MT). Which treatment strategy to use is still a matter of debate.Methods: From our ongoing prospective stroke registry we retrospectively analyzed 1,071 patients with anterior circulation stroke getting endovascular treatment within 6 h of symptom onset. ECS prior to intracranial MT for TO (n = 222) was compared to MT as standard of care (control group; acute intracranial vessel occlusion without concomitant ipsilateral ICA-occlusion or high-grade stenosis [C; n = 849]). Good functional outcome (mRS ≤ 2 at 3 months), mortality rates, frequencies of symptomatic intracranial hemorrhage (sICH) and successful recanalization (Thrombolysis in Cerebral Infarction Score [TICI] 2b or 3) were assessed. In subgroup analyses we tried to detect possible influences of stroke etiology, dual inhibition of platelet aggregation (IPA; clopidogrel [CLO]: n = 83; ticagrelor [TIC]: n = 137; in combination with Aspirin) and intravenous thrombolysis (IVT).Results: Functional outcome was superior in TO (mRS 0–2: 44.6%) when compared with controls (36.0%; OR [95% CI]: 3.49 [1.59–7.67]; p = 0.002). There was no difference in all-cause mortality at 3 months (TO: 21.6%; C: 27.7%; 0.78 [0.47–1.29]; p = 0.324), in-hospital mortality (0.76 [0.45–1.30]; p = 0.324), sICH (TO: 3.2%; C: 5.0%; 0.70 [0.30–1.59]; p = 0.389), and TICI 2b/3 (TO: 89.1%; C: 88.3%; p = 0.813). In subgroup-analysis, TIC and CLO did not differ in functional outcome (TIC: 45.3%; CLO: 44.6%; 1.04 [0.51–2.09]; p = 0.920) and mortality rates (all-cause mortality: TIC: 23.4%; CLO: 16.9%; 0.75 [0.27–2.13]; p = 0.594). sICH was more frequent in TIC (n = 7 [5.1%]) vs. CLO (n = 0; p = 0.048).Conclusion: In our pre-selected cohort, ECS prior to intracranial MT in TO allowed for a good functional outcome that was superior compared to a control population. Mortality rates did not differ. Despite a dual IPA in TO, there was no increase in sICH. CLO and TIC for dual IPA did not differ in terms out outcome and mortality rates. A significant increase in sICH was observed after initial loading with TIC.

Carotid angioplasty-assisted mechanical thrombectomy without urgent stenting may be a better option in acute tandem occlusions.

Background The aim of the study was to assess the efficacy of balloon angioplasty-assisted mechanical thrombectomy without urgent stenting in the carotid artery as another approach for endovascular treatment of tandem occlusions. Methods Fifteen consecutive cases of tandem occlusions treated with the endovascular approach between January 2014 and May 2016 were reviewed. The study cohort included patients with an etiology of large vessel atherosclerosis. Extracranial carotid stenting was performed in another session if post-thrombectomy mRS modified Rankin Score (mRS) was 0-2. Good clinical outcome was determined by follow-up at 7-10, 30 and 90 days according to the mRS. Results Most patients (80%) were male. Eight (53.4%) patients received intravenous thrombolysis before angiography. Proximal revascularization was successful in 100% of cases with balloon angioplasty internal carotid artery (ICA) origin. Successful recanalization (modified thrombolysis in cerebral infarction (mTICI) 2b-3) (mTICI 2 b-3) occurred in 12 cases (80%) and good clinical outcomes were achieved in 10 patients (66.7%). Cervical ICA stent placement was performed in 10 patients with good clinical outcomes. No symptomatic intracranial hemorrhage occurred after delayed ICA stenting Conclusions This is the first reported case series to evaluate this approach for endovascular treatment of tandem occlusions. Carotid angioplasty-assisted mechanical thrombectomy without urgent stenting seems to be a safer approach.

Abstract TP124: Tapered Stent Geometry Provides Strong Hemodynamic Effect After Carotid Stenting

Objective: In the last years, development of materials allowed notably improvements in interventional approach to stroke. Tapered stents were specifically designed for extracranial carotid stenting (CAS) to deal with vessels mismatch decreasing the risk of thrombosis. Nevertheless, as to whether the stent geometry may affect the hemodynamic consequences of CAS remains uncertain. This study aims to investigate the impact of stent configuration on postprocedural sustained hemodynamic depression (HD) requiring action of care after carotid stenting (CAS). Methods: Data on 391 consecutive CAS performed over a 4-year period (2011-2014) were reviewed. Postprocedural sustained HD was defined as any severe hypotension (&lt;90mmHg) or bradicardia (&lt;50beats/min) persisting at &gt;2 measurements after the end of the procedure and requiring care support or delaying hospital discharge. Stent configuration (tapered or straight) was tested for association with sustained HD using multivariable models adjusted for other confounders (medical therapy, comorbidities, symptoms, stenosis, carotid plaque and demographics).The relation with stroke and death outcomes within 30 days of treatment was also analyzed. Results: Mean age of patients was 70.7y + 7.14 and 66.2% were males. Sustained HD developed after 144 (36.8%) CAS. Tapered stents were applied in 289 (73.9%) CAS, and more frequently in patients with higher degree of stenosis (mean 79% vs 77%, in tapered and straight stents respectively; P=0.007) or asymptomatic (93.8% vs. 85.3% in tapered and straight stents respectively;P=0.012). Diabetes (HR 1.6, 95% CI, 1.01-2.44;P=0.044) and tapered stent configuration (HR, 1.7, 95% CI, 1.05-2.82;P=0.033) were the only factors that showed independent association with sustained HD. At 30-day, 3 strokes and no death occurred. There was no statistically significant association between 30-day outcomes and sustained HD depression or stent configuration. Conclusions: A strong hemodynamic effect, requiring additional actions of care or prolonged hospital stay, is expected after CAS when using tapered stent configuration. These findings alert on the overall benefit and costs of CAS and the requirements for accurate material selection especially in diabetic patients.

Effectiveness and safety of extracranial carotid stent placement: a nationwide self-controlled case-series study.

Carotid angioplasty and stent (CAS) placement has emerged as an attractive revascularization strategy for patients with internal carotid artery stenosis. However, the effectiveness and safety of CAS were not fully evaluated, mainly because of methodological difficulties in finding an appropriate comparison group. Patients who underwent CAS were identified from Taiwan's National Health Insurance claims database between 2005 and 2008. The incidence rate of ischemic stroke after CAS was compared with that of the year prior to the procedure using a self-controlled case series analysis and a conditional Poisson regression model. Logistic regression was conducted to identify factors associated with poor outcome. A total of 1258 patients who had undergone CAS were included, and 73 cases (5.8%) of death or ischemic stroke occurred during the index hospitalization. Within 1 year after CAS, 74 patients died and 80 experienced an ischemic stroke. Of the 1184 patients who were followed for 360 days, the rate ratio for ischemic stroke decreased to 0.21 (95% CI: 0.08-0.51) between 31 and 180 days, and 0.10 (95% CI: 0.03-0.32) between 181 and 360 days. Statin therapy was associated with a reduced risk of death or ischemic stroke in the 1(st) month (odds ratio of 0.53; 95% CI: 0.32-0.90). Conversely, the use of nonsteroidal anti-inflammatory agents, possibly histamine-2 receptor blockers, and CAS performed by low-volume operators were associated with a twofold increased risk. CAS reduced the long-term risk for ischemic stroke. Self-controlled case series analysis might be an appropriate design for evaluating device safety and effectiveness.

Abstract T P24: Neurointervention for Acute Ischemic Stroke Caused by Carotid Dissection

Introduction: Data related to the treatment of patients with acute ischemic stroke caused by carotid artery dissection is scarce. Methods: We retrospectively reviewed our interventional stroke database Sep 2010 - Jan 2014 to investigate the clinical and radiological characteristics of patients presenting with tandem cervical and intracranial occlusions due to cervical carotid dissection. Results: Out of 504 consecutive patients treated with endovascular therapy for acute ischemic stroke during the study period, 12 (2.5%) patients were observed to have cervical carotid artery dissection as the underlying etiology. Mean age was 56±13 years, 75% were male, 50% received IV t-PA, mean NIHSS was 20±5, 75% had CT ASPECTS≥7, and mean time from last known normal to groin puncture was 6±3 hours. There were 4 MCA M1, 1 MCA M2 and 7 ICA-T occlusions. Extracranial carotid stent was used in 58% and angioplasty in 8% of cases. In 33% of the cases, the carotid dissection was not stented due to the fear of hemorrhagic transformation in cases of IV thrombolysis (presumably increased risk if dual antithrombotics used). IA tPA was used in 41% of cases, while Merci in 16%, Penumbra in 58%, and stentretrivers in 50%. Intracranial TICI 2b-3 reperfusion was achieved in 91% of patients, with PH2 hemorrhage in 8% and mRS at 90 days in 45% of cases. Conclusions: Carotid dissections with associated intracranial occlusions are often refractory to IV tPA and present with a high stroke severity. These lesions are amenable to endovascular therapy resulting in high rates of reperfusion with an acceptable safety profile.

Abstract W P171: Intracranial Blood Flow Changes After Extracranial Carotid Stenting

Objectives: To determine the effects of extracranial carotid stenting on intracranial blood flow. Methods: Records of patients who underwent stenting for extracranial carotid stenosis at our institution between 2004-2012 and had flow rates obtained pre and post stenting using quantitative magnetic resonance angiography were retrospectively reviewed. Measurements of degree of stenosis, stenosis length, and residual lumen were made from cerebral angiography images. Results: 18 patients with complete anatomic and flow data were included. Mean age was 66 years with 61% presenting with symptomatic stenosis. Degree of stenosis ranged from 60% to 90%. Internal carotid artery (ICA) mean flow improved significantly post stenting from 174.9 +/- 83.6 mL/min to 250.7 +/- 91.2 mL/min ( P =0.011). Ipsilateral middle cerebral artery (MCA) flow, however, was not significantly altered post stenting (101.8 +/- 47.7 mL/min vs. 111.3 +/- 37.4 mL/min; P =0.15). Multiple regression analysis revealed that improvement in residual lumen, but not percentage stenosis (p=0.45) or stenosis length (p=0.992), is an independent predictor of increased change in ipsilateral ICA flow ( P =0.005). Degree of stenosis, stenosis length, residual lumen, and ICA flow post-stenting were not predictive of ipsilateral MCA flow ( P =0.65,0.37,0.25,0.79). The ratio of ipsilateral to contralateral ICA flow improved from 0.67 +/- 0.36 at baseline to 0.94 +/- 0.34 after stenting ( P =0.007). The ratio of ipsilateral to contralateral MCA flow was 1.08 +/- 0.59 at baseline, and was unchanged at 1.09 +/- 0.46 after stenting ( P =0.91). Conclusions: ICA flow compromise was evident in the setting of carotid stenosis, which improved by 43% on average post stenting. Improvement in residual lumen at the site of stenosis was the strongest predictor of increased flow, indicating that this parameter is the best indicator of a hemodynamically successful intervention. Unlike ICA flow, intracranial flow measured in the MCA was not significantly compromised at baseline compared to the contralateral hemisphere, nor significantly altered after stenting. This reflects compensatory intracranial collateral supply pre-stenting, which redistributes once the ipsilateral ICA is revascularized.

E-021 Acute Interventional Treatment of Atherosclerotic Carotid Occlusion and Intracranial Thromboembolism

The patient presenting with acute carotid occlusion and intracranial embolism poses additional challenges compared with the patient with intracranial embolism and no cervical carotid obstruction. There are technical challenges of...

Elevated Levels of Pre‐Procedural High‐Sensitivity C‐Reactive Protein Is Associated with Midterm Restenosis after Extra‐ and Intracranial Stenting

High-sensitivity C-reactive protein (hsCRP) is an inflammatory marker associated with subsequent coronary events and neointimal hyperplasia after coronary artery stent placement. We sought to determine if elevated levels of hsCRP are associated with restenosis after placement of extra- and intracranial stents. We retrospectively reviewed 73 consecutive patients at Michigan State University from July 2006 until June 2007 who underwent treatment with carotid artery stent placement or intracranial stent placement. Data were collected in regards to demographics, pre-procedural hsCRP, and LDL levels, and angiographic variables characterizing the lesion before and after treatment. A binary logistic regression model was constructed to determine independent predictors of restenosis. A total of 73 patients with a mean age of 69 +/- 11 years were studied. A total of 57 patients were treated with extracranial carotid stenting, 22 (38%) of whom were symptomatic, while 16 patients underwent intracranial stenting (all were symptomatic). There were 9 patients (4 intracranial stents [25%] and 5 carotid stents [8.8%]) who developed a restenosis of >50%. In binary logistic regression modeling, the following variables were found to be independently predictive of developing restenosis: smaller vessel diameter (OR .49, 95% CI .23-.98, P-value .046) and elevated hsCRP (OR 2.2, 95% CI 1.29-6.66, P-value .018). Elevated levels of pre-procedural hsCRP may be predictive of the development of neointimal hyperplasia in patients treated with extra- or intracranial stenting procedures. Future prospective multicenter studies will be required to confirm these findings.

Initial Experience in Establishing an Academic Neuroendovascular Service: Program Building, Procedural Types, and Outcomes

To report our initial experience in setting up a neuroendovascular service in a university-based comprehensive stroke center. We determined the rates of referral path, procedural type, and independently adjudicated 1-month outcomes (actual rates) in first 150 procedures (120 patients) and subsequently compared with rates derived from pertinent clinical trials after adjustment for procedural type (predicted rates). The patients were referred from the emergency department (n= 44), transferred from another hospital (n= 13), or admitted for elective procedures from the clinic (n= 63). The procedures included treatment of acute ischemic stroke (n= 12); extracranial carotid stent placement (n= 33); extracranial vertebral artery stent placement (n= 13); intracranial angioplasty and/or stent placement (n= 12); embolization for intracranial aneurysms (n= 35), arteriovenous malformations (n= 5), and tumors (n= 10); cerebral vasospasm treatment (n= 26); and others (n= 4). The technical success rate was 100% for intracranial aneurysm obliteration and extracranial carotid artery stent placement, and 95% for those undergoing intracranial or vertebral artery stent placements; and partial or complete recanalization was achieved in 72% of patients undergoing intra-arterial thrombolysis. After adjusting for procedural type, the actual adverse event rate of 3% compared favorably with the predicted rate of 7% based on the results of clinical trials. We provide estimates of procedure volumes and outcomes observed in the initial phase of setting up a neuroendovascular service with an active training program.

Hemodynamic instability after extracranial carotid stenting

Hemodynamic instability (hypertension, hypotension and bradycardia) is a well-known complication of carotid endarterectomy. Carotid angioplasty and stenting (CAS) is becoming a valuable alternative treatment for patients with severe carotid stenosis and increased surgical risk. CAS implies instrumentation of the carotid bulb, so baroceptor dysfunction may provoke hemodynamic instability. The aim of this work was to calculate the incidence of this complication and to detect factors to predict it. Medical records and angiograms of 51 consecutive patients submitted to CAS for severe atherosclerotic stenosis (40 cases) or postsurgical restenosis (11 cases) were retrospectively reviewed in order to detect the occurrence of intra- and post-procedural hypertension (systolic blood pressure >160 mmHg), hypotension (systolic blood pressure <90 mmHg) and bradycardia (heart rate <60 beats/min). The relationship between clinical, procedural and angiographic factors and the occurrence of hemodynamic instability was assessed with univariate and multivariate analysis (logistic regression). Transient mild systolic post-procedural hypertension occurred in five cases (10%); preprocedural hypertension, asymptomatic stenosis and ipsilateral post-surgical restenosis predicted this. Hypotension with bradycardia also occurred in five cases (10%), one with neurological sequelae. Transient periprocedural bradycardia occurred in 19 cases (37%). Severe bradycardia without hypotension arose in one case only. Factors predicting post-procedural hypotension included the presence of a fibrous plaque and the ratio between the pre- and post-stenting diameter of the internal carotid artery. Peri-procedural bradycardia predicted post-procedural bradycardia. None of these factors were confirmed by multivariate analysis as a significant prognostic predictor. Mild systolic hypertension may occur after CAS, but is resolved by medical treatment. Prolonged hypotension and bradycardia may also arise and this can be dangerous because it may cause neurological deterioration due to hypoperfusion. These complications cannot be predicted by clinical, procedural, and angiographic factors.

(PS 9 頭蓋外血行再建の的確な診断と治療)

(PS 9 頭蓋外血行再建の的確な診断と治療)