Aspiration thrombectomy in clinical routine interventional stroke treatment : Is this the end of the stent retriever era?

PURPOSE: The aim of our study was the technical evaluation of a first pass approach of primary thrombus aspiration (AST) in patients with emergency large intracerebral vessel occlusions (ELVO) under routine clinical conditions. MATERIALS AND METHODS: We collected procedural and clinical data of 104 patients who underwent mechanical thrombectomy due to ELVO between June 2014 and January 2016 with intentional first-line thrombus aspiration. Procedures were conducted due to occlusions of the distal internal carotid artery, middle cerebral artery, anterior cerebral artery, basilar artery and posterior cerebral artery and were performed with the patient under either conscious sedation or general anesthesia. If the AST technique failed completely or to some extent, stent retriever-based thrombectomy (SRT) was performed. RESULTS: As a stand-alone method AST was successful in achieving TICI (Thrombolysis in Cerebral Infarction) score 2b or 3 results in 29 cases (27.8%). After additional use of SRT successful recanalization was achieved in a total of 95 cases (91.3%, p = 0.048). If AST was performed exclusively, median procedure time until TICI 2b/3 was 15 min, in cases of combined procedures 35 min (p = 0.001). Subarachnoid hemorrhage (SAH) after thrombectomy appeared only if additional SRT was performed (12.0%) and not in cases of AST maneuvers alone (p = 0.09). CONCLUSION: When used as a first pass attempt AST is a fast and safe approach for patients suffering from stroke due to ELVO. Nonetheless, early conversion to SRT is needed in most cases and leads to overall excellent procedural results with low complication rates.

Stent Retriever Thrombectomy in Patients Who Are Ineligible for Intravenous Thrombolysis: A Multicenter Retrospective Observational Study.

BACKGROUND AND PURPOSE: Intravenous thrombolysis with rtPA is the standard of care for patients with acute ischemic stroke within 4.5 hours after symptom onset. However, a considerable number of patients are ineligible for IV thrombolysis due to various contraindications. Recent studies have proved the superiority of mechanical thrombectomy for patients with large-vessel occlusions in combination with IV rtPA compared with IV rtPA alone. We aimed to demonstrate the efficacy of mechanical thrombectomy for patients who are ineligible for IV rtPA. MATERIALS AND METHODS: Patients from the stroke registries of 4 dedicated centers who were treated with mechanical thrombectomy from January 2010 to October 2014 were retrospectively evaluated. Inclusion criteria were the following: acute stroke due to proved large-artery occlusion, ineligibility for IV thrombolysis, and a timeframe of ≤4.5 hours between stroke and the start of mechanical thrombectomy. Recanalization success, periprocedural complications, clinical outcome, and hemorrhages were evaluated. RESULTS: One hundred thirty endovascular recanalization procedures were identified. The locations were the following: proximal ICA in 17 (13.1%), terminus ICA in 25 (19.2%), M1 segment in 77 (59.2%), and M2 segment in 11 (8.5%). TICI 2b/3 results were achieved in 101 (77.7%), and an mRS score of 0-2 in 47 patients (37.9%). There was a significant correlation between TICI 2b/3 results and good clinical outcomes (87.2% versus 6.8%; P = .048). A good clinical result was most frequent when recanalization was achieved within 4.5 hours (37/74 = 50% versus 10/50 = 20.0%; P = .001). Symptomatic hemorrhage occurred in 13.1% of patients; mortality was 24.2%. Periprocedural complications were recorded in 10 patients (7.7%). CONCLUSIONS: Mechanical thrombectomy can achieve good clinical outcomes in patients with acute large-artery occlusion ineligible for IV thrombolysis, in particular when recanalization is reached early.

The Impact of Histological Clot Composition in Embolic Stroke.

PURPOSE: Thrombus composition has been suggested to have a decisive impact on the outcome of patients treated by mechanical thrombectomy because of embolic stroke. The recent development of stent retrievers allows collection and, hence, histopathological analysis of fresh thrombus material. Against this background, the aim of this prospective study was to assess the impact of thrombus composition on mechanical recanalization, clinical outcome and stroke etiology. METHODS: Thirty-four patients suffering from acute ischemic stroke due to occlusion of the distal internal carotid artery/carotid-T, anterior cerebral artery, or middle cerebral arteries were mechanically recanalized, and thrombus material was obtained. Histological thrombus composition was compared with imaging, clinical, and neurointerventional data. RESULTS: The main findings were that a higher percentage of white blood cells (WBCs) in the thrombus was associated with (i) cardioembolic etiology, (ii) extended mechanical recanalization time, and (iii) less favorable recanalization (Thrombolysis in Cerebral Infarction score) and clinical outcome (National Institute of Health Stroke Scale). CONCLUSION: Our results suggest that thrombi with a high WBC fraction are related to more organized thrombi of cardioembolic origin associated with less favorable recanalization and clinical outcome in acute ischemic anterior circulation stroke. WBC-mediated immunological and coagulatory processes may play a key role in thrombus formation and pathogenesis of stroke warranting further investigation.

The pREset Stent Retriever for Endovascular Treatment of Stroke Caused by MCA Occlusion: Safety and Clinical Outcome.

PURPOSE: The purpose of this study was to analyze the safety and efficacy of the pREset device, a stent retriever system, for endovascular mechanical thrombectomy (MT) in acute ischemic stroke (AIS) after middle cerebral artery (MCA) occlusion. METHODS: Retrospectively, 48 consecutive patients (mean age ± standard deviation, 71.0 ± 11.9 years; 24 women) treated for acute MCA occlusion using pREset solely or in combination with other MT devices were identified. Recanalization success was evaluated using the modified thrombolysis in cerebral infarction score (TICI), and complications were detected by 24-h follow-up computed tomography or magnetic resonance imaging. MCA anatomy was assessed in angiograms. Clinical outcome was evaluated with National Institutes of Health Stroke Scale (NIHSS) score at admission and discharge, and modified Rankin scale (mRS) score at discharge and follow-up. RESULTS: Successful recanalization (TICI 2b/3) was achieved in 39 patients (81.3 %). Rate of procedure-related complications was 8.3 %. In four patients, a subarachnoid hemorrhage occurred (8.3 %), and parenchymal hematoma was detected in four patients (8.3 %). None of those events was associated with clinical deterioration. MCA curvature significantly influenced recanalization success (P < 0.005). Successful recanalization correlated significantly with lower NIHSS scores and favorable clinical outcome (mRS score 0-2) at discharge (P < 0.05). Mortality within 90 days was significantly lower in patients with TICI 2b/3 (P < 0.005). CONCLUSIONS: High recanalization rates, low complication rates, and a significantly improved outcome after successful recanalization strongly suggest that MT with pREset is an adequate therapy for AIS after MCA occlusion. Vessel curvature is a significant determining factor for recanalization success.

Single-Layer WEBs: Intrasaccular Flow Disrupters for Aneurysm Treatment­Feasibility Results from a European Study.

BACKGROUND AND PURPOSE: The safety and efficiency of the dual-layer Woven EndoBridge (WEB) device has already been published. However, this international multicenter study sought to evaluate the safety of single-layer devices, which are the newest generation of the WEB intrasaccular flow-disrupter family. They have been designed to offer smaller-sized devices with a lower profile to optimize navigability and delivery, which may, in turn, broaden their range of use. MATERIALS AND METHODS: Data from all consecutive patients treated with a single-layer WEB device, in 10 European centers from June 2013 to May 2014 were included. Clinical presentations, technical details, intra- and perioperative complications, and outcomes at discharge were recorded. Clinical and angiographic data at last follow-up were also analyzed when available. RESULTS: Ninety patients with 98 WEB-treated aneurysms were included in this study. In 93 cases (95%), WEB placement was possible. Complete occlusion at the end of the procedure was obtained in 26 instances (26%). Additional treatment during the procedure (coiling and/or stent placement) was necessary in 12 cases (12.7%). Procedure-related complications occurred in 13 cases, leading to permanent neurologic deficits in 4 patients (4.4%). Early vascular imaging follow-up data were available for 44 patients (57%), with an average time interval of 3.3 months. Treatment-related morbidity and mortality rates at last follow-up were 2.2% and 1.1%, respectively. CONCLUSIONS: In this study, the feasibility and safety of the single-layer WEB device was comparable with that of the double-layer. However, further studies are needed to evaluate long-term efficacies.

The Curved MCA: Influence of Vessel Anatomy on Recanalization Results of Mechanical Thrombectomy after Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Vessel anatomy is assumed to influence results of endovascular mechanical thrombectomy using stent retrievers. The purpose of this study was to analyze the influence of vessel curvature on recanalization results in patients with acute ischemic stroke caused by large-vessel occlusion. MATERIALS AND METHODS: In 159 patients (70 ± 12.8 years of age; 79 women) treated for acute ischemic stroke after carotid T and/or MCA occlusion by using stent retrievers, the following angles were measured in standard anteroposterior angiograms to describe vessel anatomy: first, between the terminal ICA segment and the most downward curved M1 segment conterminous to the proximal face of the thrombus (ICA/M1 angle); second, between the most proximal M1 segment and the segment immediately conterminous to the thrombus (M1/M1 angle); and additionally, in patients with distal M1/proximal M2 occlusion, the angle of the last curvature proximal of the thrombus (M1/M2 angle). Angles of patients with-versus-without successful recanalization were compared. RESULTS: Patients without successful recanalization (TICI 0-2a) showed significantly larger ICA/M1 angles (mean, 110°± 23.8° versus 69°± 28.7°, P < .001) and significantly larger M1/M1 angles (56°± 29.2° versus 29°± 26.6°, P = .001) than patients with successful recanalization (TICI 2b/3). In patients without successful recanalization after a distal M1 or proximal M2 occlusion, the M1/M2 angle was significantly larger than that in patients with successful recanalization (117° ± 34.3° versus 67° ± 29.5°, P = .006). CONCLUSIONS: This retrospective analysis showed that mechanical thrombectomy in the anterior circulation was significantly less often successful in patients with large vessel angles. Therefore, vessel curvature significantly influences the results of mechanical thrombectomy with stent retrievers for treatment of acute ischemic stroke. Further work is needed to understand the underlying causality.

Fate of the penumbra after mechanical thrombectomy.

BACKGROUND AND PURPOSE: In acute stroke, CTP is often used to visualize the endangered brain areas, including the ischemic core and the penumbra. Our goal was to assess the evolution of the infarct after mechanical thrombectomy and to analyze the interventional factors determining the fate of the penumbra. MATERIALS AND METHODS: All patients receiving mechanical thrombectomy in the anterior circulation and receiving CTP beforehand were identified. The infarct volume was specified. The clinical parameters, outcome, and interventional results were correlated with the CTP and the final infarct size. RESULTS: In total, 73 patients were included. After mechanical thrombectomy, 78.1% reached a TICI score of 3/2b. The final infarct volume was significantly smaller, with a TICI score of 3/2b compared with less sufficient recanalization (19.60 ± 3 cm(3) versus 38.1 ± 9 cm(3); P < .001). After TICI 3/2b recanalization, 81% ± 5.2% of the potential infarct size (calculated as the sum of infarct core and penumbra) could be rescued. In patients with TICI scores of 2a or worse, only 39 ± 28.3 were salvaged (P < .001). The Alberta Stroke Program Early CT Score after successful recanalization TICI score of 3/2b resulted in a decline of 1.9 ± 1.4 compared with the significantly higher degradation score of 3.7 ± 1.7 after recanalization, with a TICI score of 2a or worse. A recanalization TICI score of 3/2b resulted in an NIHSS improvement of 7.3 ± 0.8 NIHSS points, whereas a poorer recanalization improved on the NIHSS by only 2.5 ± 1.5 points (P < .01). CONCLUSIONS: Mechanical thrombectomy is a potent method to rescue large areas of penumbra in acute stroke.

Stent angioplasty of intracranial stenosis: single center experience of 54 cases.

PURPOSE: The aim of the study was to retrospectively evaluate the safety and efficacy of stent angioplasty of symptomatic intracranial stenosis in a single center experience. MATERIALS AND METHODS: Between November 2006 and September 2009 a total of 54 stent angioplasties were performed in 49 patients and of these 46 were done for symptomatic intracranial high-grade (>70%) stenoses and 8 for complete vessel occlusions in acute stroke. All elective treatments were carried out with patients under antithrombotic/anticoagulant medication. Self-expandable stents were used in 42 cases and balloon-expandable stents in 12 cases. RESULTS: Stent angioplasty was successful in 53 out of 54 cases (98%). Periprocedural complications occurred in 6 patients, including 2 dissections, 1 contrast-mediated toxic reaction and 1 thromboembolic event with transient neurological deficits but did not cause permanent neurological deficits, in any of the cases. Adverse events within 30 days after intervention occurred in 11 of the 49 patients (20.4%) of which 4 were scheduled patients (8.3%) and 7 were treated for acute stroke with complete vessel occlusions (87.5%). Overall there were 9 cases of restenosis (7 out of 9>90% stenoses and 2 complete vessel occlusions), 5 out of 9 were asymptomatic, 4 out of 9 had a transient ischemic attack and 1 developed a major stroke. Two complete in-stent thromboses were seen in acute stroke patients with initial complete occlusion within 24 h after recanalization. One restenosis and one complete occlusion occurred under double antiplatelet medication, 4 out of 9 restenoses occurred under aspisol medication and 3 out of 9 after antiplatelet medication was discontinued. In 2 out of 9 restenoses, balloon-expandable stents had been used, the remaining 7 had been treated with self-expanding stents, 5 out of 9 restenoses were treated by balloon-angioplasty alone, in 3 out of 9 an additional stent had to be placed and 1 asymptomatic occlusion was left untreated. CONCLUSIONS: The results demonstrate the technical feasibility and satisfactory success rates of stent angioplasty in intracranial atherosclerotic stenoses. The procedural success rate was 98% and the overall rate of adverse events was 20.4%. The rate of adverse events was high in unstable patients (87.5%) treated without antiplatelet premedication, especially in the setting of an acute stroke. In stable patients the rate of adverse events was much lower (8.3%). Future development of dedicated stents and a better understanding of factors that predispose to restenosis may help to further decrease the rate of periprocedural and postprocedural adverse events thus helping to improve both short-term and long-term outcome after intracranial stent angioplasty.

[Preoperative mapping of speech-eloquent areas with functional magnetic resonance imaging (fMRI): comparison of different task designs]. / Präoperatives Mapping der Sprachareale mittels funktioneller Magnetresonanztomographie (fMRT) bei Patienten mit Hirntumoren: Ein Paradigmenvergleich.

PURPOSE: Functional magnetic resonance imaging (fMRI) is a well-established, non-invasive method for pre-operative mapping of speech-eloquent areas. This investigation tests three simple paradigms to evaluate speech lateralisation and visualisation of speech-eloquent areas. MATERIALS AND METHODS: 14 healthy volunteers and 16 brain tumour patients were given three tasks: to enumerate months in the correct order (EM), to generate verbs fitting to a given noun (GV) and to generate words fitting to a given alphabetic character (GW). We used a blocked design with 80 measurements which consisted of 4 intervals of speech activation alternating with relaxation periods. The data were analysed on the basis of the general linear model using Brainvoyager(R). The activated clusters in the inferior frontal (Broca) and the posterior temporal (Wernicke) cortex were analysed and the laterality indices calculated. RESULTS: In both groups the paradigms GV and GW activated the Broca's area very robustly. Visualisation of the Wernicke's area was best achieved by the paradigm GV. The paradigm EM did not reliably stimulate either the frontal or the temporal cortex. Frontal lateralisation was best determined by GW and GV, temporal lateralisation by GV. CONCLUSION: The paradigms GV and GW visualise two essential aspects of speech processing: semantic word processing and word production. In a clinical setting with brain tumour patients, both, GV and GW can be used to visualise frontal and temporal speech areas, and to determine speech dominance.

Minor tumour shrinkage in nonfunctioning pituitary adenomas by long-term treatment with the dopamine agonist cabergoline.

OBJECTIVE: The purpose of this study was to define safety and efficacy of medical therapy in the treatment of nonfunctioning pituitary tumours. DESIGN: We studied thirteen patients with a clinically nonfunctioning pituitary macroadenoma for response to cabergoline treatment for 1 year. Twelve/13 patients were already operated and had residual or recurrent tumours. METHODS: We determined the outcome of treatment by visual perimetry, computed tumour size measurement in MRI and hormonal response (changes in pituitary function, reduction of alpha-subunit). RESULTS: Seven/13 patients on cabergoline had a tumour shrinkage above 10% of the initial tumour volume. In 4 patients, this tumour shrinkage was correlated to an increasing distance of the tumour to the optic chiasm. Only 2/9 patients with visual field defects before therapy showed improvements in visual acuity under cabergoline. No significant side effects of the therapeutical regimens were observed. Neither LH and/or FSH expression in the tumour cells nor the reduction of the alpha-subunit serum levels by medical therapy was correlated to tumour shrinkage. CONCLUSION: Given that these patients had advanced disease which makes it difficult to find significant therapeutic effects, medical therapy with potent dopamine agonists such as cabergoline may evolve as a novel therapeutic option in a subgroup of patients with clinically nonfunctioning tumours declining operation and radiotherapy.