Impact of intravenous thrombolysis and emergent carotid stenting on reperfusion and clinical outcomes in patients with acute stroke with tandem lesion treated with thrombectomy: a collaborative pooled analysis.

BACKGROUND AND PURPOSE: Tandem anterior circulation lesions in the setting of acute ischemic stroke (AIS) are a complex endovascular situation that has not been specifically addressed in trials. We determined the predictors of successful reperfusion and good clinical outcome at 90 days after mechanical thrombectomy (MT) in patients with AIS with tandem lesions in a pooled collaborative study. METHODS: This was a retrospective analysis of consecutive patients presenting to 18 comprehensive stroke centers with AIS due to tandem lesion of the anterior circulation who underwent MT. RESULTS: A total of 395 patients were included. Successful reperfusion (modified thrombolysis in cerebral infarction score 2b-3) was achieved in 76.7%. At 90 days, 52.2% achieved a good outcome (modified Rankin Scale score 0-2), 13.8% suffered a parenchymal hematoma and 13.2% were dead. Lower National Institutes of Health Stroke Scale score [odds ratio (OR), 1.26; 95% confidence intervals (CI), 1.07-1.48, P = 0.004], Alberta Stroke Program Early CT Score ≥7 (OR, 2.00; 95% CI, 1.07-3.43, P = 0.011), intravenous thrombolysis (OR, 1.47; 95% CI, 1.01-2.12, P = 0.042) and stenting of the extracranial carotid lesion (OR, 1.63; 95% CI, 1.04-2;53, P = 0.030) were independently associated with successful reperfusion. Lower age (OR, 1.58; 95% CI, 1.26-1.97, P < 0.001), absence of hypercholesterolemia (OR, 1.77; 95% CI, 1.10-2.84, P = 0.018), lower National Institutes of Health Stroke Scale scores (OR, 2.04; 95% CI, 1.53-2.72, P < 0.001), Alberta Stroke Program Early CT Score ≥7 (OR, 2.75; 95% CI, 1.24-6.10, P = 0.013) and proximal middle cerebral artery occlusion (OR, 1.59; 95% CI, 1.03-2.44, P = 0.035) independently predicted a good 90-day outcome. CONCLUSIONS: Intravenous thrombolysis and emergent stenting of the extracranial carotid lesion were predictors of a successful reperfusion after MT of patients with AIS with tandem lesion of the anterior circulation.

Predictors and impact of early cerebral infarction after aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Cerebral infarction is a frequent and serious complication of aneurysmal subarachnoid hemorrhage (SAH). This study aimed to identify independent predictors of the timing of cerebral infarction and clarify its impact on disease course and patients' outcome. METHODS: All consecutive patients with SAH admitted to our institution from January 2005 to December 2012 were analyzed. Serial computed tomography (CT) scans were evaluated for cerebral infarctions. Demographic, clinical, laboratory and radiological data of patients during hospitalization as well as clinical follow-ups 6 months after SAH were recorded. RESULTS: Of the 632 analyzed patients, 320 (51%) developed cerebral infarction on CT scans. 136 patients (21.5%) with early cerebral infarction (occurring within 3 days after SAH) had a significantly higher risk of unfavorable outcome than patients with late infarction [odds ratio (OR) 2.94; P = 0.008], a higher in-hospital mortality (OR 3.14; P = 0.0002) and poorer clinical outcome after 6 months (OR 0.54; P < 0.0001). The rates of decompressive craniectomy (OR 1.96, P = 0.0265), tracheostomy (OR 1.87, P = 0.0446), the duration of intensive care unit stay and mechanical ventilation were significantly higher in patients with early infarction. In multivariate analysis, Hunt and Hess grades 4 and 5 (OR 2.06, P = 0.008), Fisher grades 3 and 4 (OR 3.99, P = 0.014), sustained elevations of intracranial pressure >20 mmHg (OR 5.95, P < 0.0001) and early vasospasm on diagnostic angiograms (OR 3.01, P = 0.008) were predictors of early cerebral infarction. CONCLUSION: Early cerebral infarction after SAH is associated with severe clinical course and unfavorable outcome and can be reliably predicted by poor initial clinical condition, thick subarachnoid clot, early angiographic vasospasm and sustained elevations of intracranial pressure.

[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.

Understanding the metal-carbon interface in FePt catalyzed carbon nanotubes.

Any tip functionalization of carbon nanotubes, for which the relative orientation between their (metallic) catalyst particle and the nanotube axis is essential, requires a detailed knowledge of the nature of the internal interface between the particle and the outgrown tube. In the present work, this interface is characterized with atomic precision using state-of-the-art low-voltage aberration-corrected transmission electron microscopy in combination with molecular dynamics simulations for the case of hard-magnetically terminated carbon nanotubes. Our results indicate that the physical principle based upon which the interfacial metal facet is chosen is a reduction of the desorption energy for carbon.

Mechanical thrombectomy with the Penumbra recanalization device in acute ischemic stroke.

BACKGROUND AND PURPOSE: The aim of this study was to assess the clinical outcome of patients treated with the Penumbra system (PS) for acute ischemic stroke. A retrospective, monocentric matched-pair analysis in comparison with patients treated by intraarterial thrombolysis (IAT) with alteplase was designed for this purpose. METHODS: Twenty-two consecutive patients, (mean age 62), with acute ischemic stroke and National Institutes of Health Stroke Scale (NIHSS) scores ≥ 7 were treated with the PS. Twenty corresponding patients could be identified, treated with IAT. Matches were sought for initial NIHSS score and target vessels. Thrombolysis in myocardial infarction (TIMI) grades, mortality rates, NIHSS upon discharge, and modified Rankin scores (mRs) at 90 days were compared. RESULTS: A total of 32 vessels in 20 patients were treated in either arm of the study. Recanalization to TIMI 2/3 was successful in 25/32 (78%) of target vessels with the PS, and 17/32 (53%) of target vessels in the IAT group. Upon discharge, 2/20 patients treated with PS and 7/20 patients treated with IAT had a NIHSS score of 0 to 1 or an improvement greater or equal to 10-point on the NIHSS scale. All cause mortality at 90 days was 3/20 patients treated with PS, and 2/20 patients treated with IAT. Three out of twenty patients treated with PS and 7/20 patients treated with IAT had a mRS of ≤ 2 at 90 days. CONCLUSION: The Penumbra system is effective in re-opening occluded major arteries. Our data seems to indicate that not all patients benefit clinically from improved revascularization of occluded major arteries.

Interobserver Agreement in Scoring Angiographic Results of Basilar Artery Occlusion Stroke Therapy.

BACKGROUND AND PURPOSE: The modified TICI Infarction grading system is a metric currently used to evaluate angiographic results of thrombectomy for large-vessel occlusion in ischemic stroke. Originally designed for evaluating MCA territories, it is currently used for other vessel occlusions, including the posterior circulation. We postulate that the modified TICI use for the posterior circulation is not accurate due to the different vascular territories supplied by vertebrobasilar vasculature, making grading more complex. MATERIALS AND METHODS: We collected angiographic results from 30 patients who presented with acute posterior circulation occlusions between 2015 and 2018 and underwent thrombectomy in our institution. Eight observers were asked to evaluate the TICI scores before and after thrombectomy. The multirater statistics were computed using Fleiss κ analysis. Further data were collected regarding the potential brain territories at risk and the existence of atherosclerotic disease in the basilar artery. RESULTS: The overall agreement κ reached 0.277 (SD, 0.013), which suggests a "fair" agreement among the raters. On average, 45% of observers achieved a high accuracy in predicting brain areas at risk of ischemia. As for the existence of basilar atherosclerotic disease, a high agreement (defined as at least 5 of 6 observers) was seen in 20 of the 30 patients. CONCLUSIONS: Despite TICI being ubiquitous in stroke diagnostics, the high variability of posterior circulation TICI scores calls into question its use in these strokes. Other methods should be developed to assess recanalization in the posterior circulation.

Spontaneous thrombosis of a recurrent clipped intracranial aneurysm.

Spontaneous thrombosis of an intracranial aneurysm is a rare event. It is predominantly observed with aneurysms that are large and have relatively narrow necks. We report here a case of a 48-year-old woman presenting with subarachnoid hemorrhage (SAH) due to rupture of a 2-mm aneurysm of the anterior cerebral artery treated by microsurgical clipping. Six months after treatment of the aneurysm, the patient presented with severe headache. SAH was excluded, but computed tomographic angiography (CTA) revealed the recurrence of a large aneurysm (7 mm) that was confirmed by cerebral angiography (DSA). Endovascular treatment was scheduled for several days later, but DSA also revealed spontaneous occlusion of the recurrent aneurysm. On the control CTA performed one week later, the recurrent aneurysm had again reappeared, again confirmed by DSA, and was subsequently treated by coil embolization.

[Imaging of subarachnoid hemorrhage]. / Imagerie de l'hémorragie sous-arachnoïdienne.

Even if acute subarachnoid hemorrhage (SAH) accounts for only 5% of strokes, its diagnosis is very important because its clinical consequences can be tragic. Recent technological advances in medical imaging have improved diagnostic and therapeutic management of patients with SAH. Nonenhanced CT of the head is the initial imaging modality in suspected SAH for the detection of ruptured intracranial aneurysms. Digital subtraction angiography (DSA) remains the reference exam. Multidetector row CT angiography may potentially replace DSA in the emergency setting, as it provides image data that allows evaluating aneurysmal morphology, the neck size or the visualization of vessels in the vicinity of the aneurysm. For SAH unrelated to aneurysm rupture (15% of cases), MRI and MRA can be added to the diagnostic work-up in order to exclude other differential diagnoses such as venous thrombosis or angiitis. Finally, transcranial color-coded duplex sonography, CT, or MRI are used in clinical practice in order to detect aggravating factors of SAH like hydrocephalus or vasospasm.

Treatment decision in ruptured intracranial aneurysms: comparison between multi-detector row CT angiography and digital subtraction angiography.

OBJECTIVE: The aim of this study was to determine the accuracy of multi-detector row computed tomography angiography (CTA) for the triage of patients with acutely ruptured aneurysms, and to assess how therapeutic decisions based on this method compared with digital subtraction angiography (DSA). METHODS: Twenty-seven consecutive patients with acute subarachnoid hemorrhage were included, and underwent both CTA and DSA. CTA was performed on a 16-detector row CT scanner with a 0.75-mm collimation and a 0.558-beam pitch. Two readers reviewed the CTA data, and two different readers reviewed the DSA data. Aneurysm characteristics were recorded and treatment by surgical clipping or endovascular coil embolization was proposed. RESULTS: A total of 24 aneurysms were identified on DSA in 21 patients. Sensitivity and specificity for CTA were 100% and 83%, respectively, on a per-aneurysm-basis. The correlation between DSA and CTA for the determination of sac and neck sizes was very good (r=0.92, and r=0.95, respectively, P<0.0001). Sensitivity and specificity for the detection of arterial branches incorporated into the aneurysmal sac or neck were 50% and 100%, respectively. In three aneurysms, readers judged CTA inappropriate for triage, because peri-aneurysmal branches were not properly visualized. Overall agreement between CTA and DSA regarding the therapeutic decision between surgical clipping and endovascular coil embolization in 24 aneurysms was good (kappa=0.76). CONCLUSION: Multi-detector row CTA provides accurate anatomic information for aneurysm location as well as sac and neck sizes; however, the technique appears to have a low sensitivity in detecting branches incorporated into the aneurysmal sac.

Surgical views from three-dimensional digital subtraction angiography for the planning of aneurysm surgery.

AIM: To develop a semi-automatic protocol helping to present directly and quickly three-dimensional digital subtraction angiography (3D-DSA) data in an orientation that reproduces exactly the neurosurgeon's intraoperative view. METHOD: Post-processing of 3D-DSA data (volume-rendering) was performed on an Integris workstation (Philips, Best); surgical views were obtained by visualization of the patient's head through a frontopterional approach: the 3D volume was turned 135 degrees in the sagittal plane (around the X axis) and rotated by 45 degrees and 60 degrees in the coronal plane (around the Y axis). The protocol was evaluated on a consecutive series of nine patients who had ruptured or asymptomatic anterior circulation aneurysms requiring surgical treatment. Frontopterional views of angiographic 3D data were compared with intraoperative views. RESULTS: The proposed semi-automatic algorithm is simple, fast and reproducible, and displays the 3D data in an orientation identical to the intraoperative views. The surgical anatomy of the anterior communicating artery was best reproduced with a coronal rotation of 60 degrees , with a coronal rotation of 45 degrees for the other aneurysm locations. In each case, the surgical reconstructions allowed a more accurate analysis of the vascular anatomy around the aneurysm, and facilitated pre- and perioperative planning. CONCLUSION: The present protocol displays angiographic 3D data in a projection that exactly reproduces the vascular anatomy through a frontopterional approach. It may help neurosurgeons to better anticipate any potential difficulties during access and clip-positioning arising due to the specific vascular anatomy of a given patient.