Complication Rates Using CASPER Dual-Layer Stents for Carotid Artery Stenting in Acute Stroke : A 3-Year Single Center Experience.

BACKGROUND AND PURPOSE: The number of acute and early stent occlusions after emergency stenting of the internal carotid artery (ICA) in patients with tandem lesions is unclear and only mentioned in a small number of publications, ranging from 0-20%. A recent article by Yilmaz et al. reported a high rate of acute in-stent occlusions of 45% within 72 h after deployment of CASPER dual layer stents. METHODS: All patients with acute ischemic stroke treated with a CASPER stent between August 2014 and April 2018 were retrospectively evaluated for occlusion rates, periinterventional medication and early complications. A total of 66 patients, 45 with tandem pathologies and 21 with proximal ICA stenosis only were enrolled. RESULTS: Thrombotic complications occurred in 16 out of 66 patients (24%) and hemorrhagic complications in 8/66 (12%) and 15 of the 16 thrombotic complications and 7/8 symptomatic intracranial hemorrhages (sICH) occurred in patients with tandem lesions and accessory intracranial thrombectomy. Of the patients with sICH five were treated in a prolonged or unknown time window. In patients with intraprocedural thrombotic complications ultrasound imaging showed patent stents in 13 of the 14 patients CONCLUSIONS: The CASPER stent system showed a high technical success rate in patients with acute stroke. The number of patients with sICH was not higher than the numbers reported in the published literature despite the early use of Gp IIb/IIIA inhibitors, whereas the number of thrombotic complications was smaller than that reported in recent studies. The majority of sICH occurred in patients treated because of tandem lesions in an unknown or prolonged time window.

Endovascular Thrombectomy of Calcified Emboli in Acute Ischemic Stroke: A Multicenter Study.

BACKGROUND AND PURPOSE: Large intracranial vessel occlusion due to calcified emboli is a rare cause of major stroke. We assessed the prevalence, imaging appearance, the effectiveness of mechanical thrombectomy, and clinical outcome of patients with large-vessel occlusion due to calcified emboli. MATERIALS AND METHODS: We performed a retrospective analysis of clinical and procedural data of consecutive patients who underwent mechanical thrombectomy due to calcified emboli in 7 European stroke centers. RESULTS: We screened 2969 patients, and 40 patients matched the inclusion criteria, accounting for a prevalence of 1.3%. The mean maximal density of the thrombus was 327 HU (range, 150-1200 HU), and the mean thrombus length was 9.2 mm (range, 4-20 mm). Four patients had multiple calcified emboli, and 2 patients had an embolic event during an endovascular intervention. A modified TICI score of ≥2b was achieved in 57.5% (23/40), with minimal-to-no reperfusion (modified TICI 0-1) in 32.5% (13/40) and incomplete reperfusion (modified TICI 2a) in 10% (4/40). Excellent outcome (mRS 0-1) was achieved in only 20.6%, functional independence (mRS 0-2) in 26.5% and 90-day mortality was 55.9%. CONCLUSIONS: Acute ischemic stroke with large-vessel occlusion due to calcified emboli is a rare entity in patients undergoing thrombectomy, with considerably worse angiographic outcome and a higher mortality compared with patients with noncalcified thrombi. Good functional recovery at 3 months can still be achieved in about a quarter of patients.

Comparison of automated and visual DWI ASPECTS in acute ischemic stroke.

BACKGROUND AND PURPOSE: To assess intra-and inter-rater agreement of the ASPECTS (Alberta Stroke Program Early CT Score) based on diffusion-weighted MRI and to compare it with fully - automated methods (eASPECTS). METHODS: DWI-ASPECTS of scans of 96 patients with acute ischemic stroke was rated by 2 experts. Automated methods based on thresholding the affected volumes of a coregistered atlas, and a regression tree learning method were established. Intra-rater, inter-rater and human-rater vs. automated methods agreements were investigated based on the intraclass correlation coefficients (ICC) and Bland Altman plots. RESULTS: Intra-rater agreement was good for both raters (ICC of 0.91 and 0.93). Inter-rater agreement was worse (ICC = 0.86) indicating a slight bias between both raters. Agreement with automated methods ranged from 0.81 to 0.87. Root-mean-squared deviation was 0.89 and 0.69 for the human raters and ranged from 0.95 to 1.24 for the automated methods. CONCLUSIONS: Agreement values are on the same order or higher compared to a literature review of CT-based ASPECTS. Automated methods perform slightly worse than human expert ratings, but they still have enough power to determine the DWI-ASPECTS with good precision in a clinical setting.

Endovascular Treatment of Unruptured MCA Bifurcation Aneurysms Regardless of Aneurysm Morphology: Short- and Long-Term Follow-Up.

BACKGROUND AND PURPOSE: The optimal treatment of unruptured middle cerebral aneurysms is still under debate. Although today almost any aneurysm can be treated endovascularly, there is a lack of data comparing endovascular and microsurgical repair of MCA aneurysms. The aim of our analysis is to provide data on the efficacy, clinical outcome, complications and re-treatment rates of endovascular treatment of this subtype of aneurysms. MATERIALS AND METHODS: Between May 2008 and July 2017, endovascular treatment of 1184 aneurysms in 827 patients was performed in our department. Twenty-four percent of these aneurysms were located at the MCA, and 150 unruptured MCA bifurcation aneurysms treated with coiling, stent-assisted-coiling, or endovascular flow diverter (WEB device) were identified for this retrospective data analysis. Ninety-six percent of all aneurysms, ruptured and unruptured, were treated by an endovascular approach, which yields a low selection bias for aneurysms suitable for endovascular treatment. Follow-up examinations were performed after 12 and 36 months and then every 1-3 years after embolization. Procedures were analyzed for periprocedural complications, outcome, and retreatment rate of the WEB (n = 38) and coiling with (n = 45) or without stent assistance (n = 67). RESULTS: The procedure-associated good clinical outcome (mRS ≦ 2) was 89.9%, and the mortality rate was 2.7%. Short-term follow-up good clinical outcome/mortality rates were 91.3%/0.7%. At discharge, 137 patients had an mRS of 0-2 (91.3%) and 13 had an mRS of 3-6 (8.7%). The retreatment rate was significantly higher in the WEB group (21.1%) compared with the coiling group with (5.9%) or without (2.2%) stent placement (P < .05). CONCLUSIONS: Regardless of the architecture of MCA bifurcation aneurysms, the endovascular treatment can be performed with low morbidity/mortality rates. The higher retreatment rate in the WEB group correlates with the learning curve in choosing the right device size.

Facing the Time Window in Acute Ischemic Stroke: The Infarct Core.

BACKGROUND: Increasing numbers needed to treat within the first hours after ischemic stroke onset indicate a strong time dependency of the viability of brain tissue. However, this time dependency is not reflected in recent randomized controlled trials of endovascular stroke treatment. This study evaluates whether and to which extent a time dependency exists in patients with embolic carotid T or M1 occlusions within the first 6 h of stroke onset. METHODS: Patient data were retrieved from the Freiburg stroke data bank. Time from onset to acquisition of the diffusion weighted images (DWIs) varied between 49 and 357 min. Ischemic lesions were semiautomatically segmented on apparent diffusion coefficient maps with a threshold of 600 × 10 (- 6) mm(2)/s. Occlusion location and thrombus length were determined with magnetic resonance angiography, T2*, and more recently susceptibility weighted image (SWI) sequences. A hyperintense vessel sign in FLAIR images as a possible surrogate for collaterals was also identified. RESULTS: A total of 155 patients with occlusions of the carotid T (n = 26), proximal M1 segment (n = 44), and distal M1 segment (n = 85) of the middle cerebral artery between 2011 and 2015 were included. Infarct volumes varied from 0.3 to 180.2 mL. Infarct size did not correlate with stroke onset to DWI times. Infarct volumes also did not associate with different locations of vessel occlusion, thrombus length, presence of the hyperintense vessel sign and initial infarct growth. CONCLUSION: We found no significant time dependency of the viability of brain tissue with embolic carotid T or M1 occlusions between 1 and 6 h after stroke onset. The early infarction volume is thus probably determined in the hyperacute phase by the quality of leptomeningeal collaterals and comparatively stable in this time period.

[Mechanical thrombectomy for acute ischemic stroke : current evidence and open questions]. / Mechanische Thrombektomie beim ischämischen Schlaganfall : Studienlage und offene Fragen.

OBJECTIVE: To determine the importance of mechanical thrombectomy (MT) in the treatment of ischemic stroke. MATERIAL AND METHODS: Analysis and comparison of randomized controlled trials (RCT) of MT versus i.v. thrombolysis (IVT) considering pathophysiological and logistic aspects. RESULTS: The use of MT is more effective than IVT for internal carotid artery terminus (ICAT), M1 segment and tandem occlusions, i.e. proximal internal carotid artery (ICA) occlusion or stenosis, even in patients older than 75-80 years of age. Due to the small sample sizes this question cannot be answered for patients with M2 occlusions. It is still uncertain whether MT is needed in patients with a low National Institutes of Health stroke scale (NIHSS) score, whether IVT is needed before MT and what type of imaging should be performed. Approximately one third of eligible patients currently undergo MT in Germany. Results from RCTs with stent retrievers for patients with vertebrobasilar artery occlusions are lacking. CONCLUSION: After becoming established as a first-line therapy for patients with ICAT, M1 segment and tandem occlusions, the effectiveness of MT with stent retrievers has to proven in patients with more distal occlusions, low NIHSS scores and even vertebrobasilar artery occlusions.

Emergency Stenting of the Extracranial Internal Carotid Artery in Combination with Anterior Circulation Thrombectomy in Acute Ischemic Stroke: A Retrospective Multicenter Study.

BACKGROUND AND PURPOSE: Several small case series reported a favorable clinical outcome for emergency stent placement in the extracranial internal carotid artery combined with mechanical thrombectomy in acute stroke. The rate of postinterventional symptomatic intracranial hemorrhages was reported to be as high as 20%. Therefore, we investigated the safety and efficacy of this technique in a large multicentric cohort. MATERIALS AND METHODS: The data bases of 4 German stroke centers were screened for all patients who received emergency stent placement of the extracranial internal carotid artery in combination with mechanical thrombectomy of the anterior circulation between 2007 and 2014. The primary outcome measure was the rate of symptomatic intracranial hemorrhage according to the European Cooperative Acute Stroke Study III criteria; secondary outcome measures included the angiographic revascularization results and clinical outcome. RESULTS: One hundred seventy patients with a median age of 64 years (range, 25-88 years) were treated. They presented after a median of 98 minutes (range, 52-160 minutes) with a median NIHSS score of 15 (range, 12-19). Symptomatic intracranial hemorrhages occurred in 15/170 (9%) patients; there was no statistically significant difference among groups pertaining to age, sex, intravenous rtPA, procedural timings, and the rate of successful recanalization. In 130/170 (77%) patients, a TICI score of ≥ 2b could be achieved. The in-hospital mortality rate was 19%, and 36% of patients had a favorable outcome at follow-up. CONCLUSIONS: Emergency stent placement in the extracranial internal carotid artery in combination with anterior circulation thrombectomy is effective and safe. It is not associated with a significantly higher risk of symptomatic intracranial hemorrhage compared with published series for mechanical thrombectomy alone.

Two in One: Endovascular Treatment of Acute Tandem Occlusions in the Anterior Circulation.

PURPOSE: Acute major stroke with high-grade stenosis or occlusion of the extracranial internal carotid artery (ICA) and additional intracranial large artery occlusion is increasingly treated with a mechanical endovascular approach by extracranial stenting and intracranial thrombectomy due to poor response to systemic thrombolysis with recombinant tissue plasminogen activator (rtPA). This article presents a single centre cohort of this challenging subtype of stroke, describing the technical procedure and analysing the angiographic and clinical outcome. METHODS: Clinical and imaging data of all consecutive patients between July 2008 and March 2013 with intracranial artery occlusion in the anterior circulation and additional occlusion or pseudo-occlusion of the cervical ICA were retrospectively analysed with respect to demographical and clinical characteristics. Technical approach, recanalization rate, recanalization time and short-term clinical outcome were determined. RESULTS: A total of 43 patients with tandem occlusion in the anterior circulation met the inclusion criteria. Out of these, 32 (74.4%) occlusions and 11 (25.6%) pseudo-occlusions of the extracranial ICA with additional occlusion of the distal segment of the ICA in 7.0% (3/43), the M1-segment of the middle cerebral artery (MCA) in 81.4% (35/43) or the M2-segment of the MCA in 11.6% (5/43) of cases were treated with combined endovascular approach including extracranial stenting with angioplasty and intracranial mechanical thrombectomy. In 76.7% of cases, an angiographic recanalization result of 2b or 3 using the Thrombolysis in Cerebral Infarction (TICI) score was achieved. Mean time from first angiographic series to recanalization was 103 min. A modified Rankin Scale (mRS) score of ≤ 2 was achieved in 32.6% at the time of discharge. CONCLUSION: Endovascular therapy of patients with tandem occlusion in the anterior circulation with emergency extracranial stenting and intracranial mechanical thrombectomy appears to be safe and may lead to a satisfactory angiographic result and clinical outcome.