Hanel, Ricardó A.

Various endovascular intraarterial approaches are available for treating patients with acute ischemic stroke who present with severe neurological deficits. Three recent randomized trials—Interventional Management of Stroke (IMS) III, Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy (MR RESCUE), and Synthesis Expansion: A Randomized Controlled Trial on Intra-Arterial Versus Intravenous Thrombolysis in Acute Ischemic Stroke (SYNTHESIS Expansion)—evaluated the efficacy of endovascular treatment of acute ischemic stroke and, after failing to demonstrate any significant clinical benefit of endovascular therapies, raised concerns and questions in the medical community regarding the future of endovascular treatment for acute ischemic stroke. In this paper, the authors review the evolution of endovascular treatment strategies for the treatment of acute stroke and provide their interpretation of findings and potential limitations of the three recently published randomized trials. The authors discuss the advantage of stent-retriever technology over earlier endovascular approaches and review the current status and future directions of endovascular acute stroke studies based on lessons learned from previous trials.

Purpose To determine the rates of neurologic adverse events following Pipeline Embolic Device (PED) placement for intracranial aneurysm treatment. Methods A retrospective review of medical records was performed at 19 centres to identify consecutive intracranial aneurysms treated with the PED following regulatory approval for marketing the device in the given country. All patients in whom at least one PED was placed and in whom follow-up was available prior to IRB or ethics panel approval were enrolled. Three anatomic/size subgroups were defined, including 1) pre-PComm, internal carotid artery aneurysms 10mm or greater (“large ICA”), 2) ICA aneurysms >10mm and/or at/distal to the PComm region (“other anterior circulation”), and 3) posterior circulation aneurysms. “Primary safety events” included stroke, haemorrhage, parent artery stenosis, permanent cranial neuropathy, and spontaneous rupture of the target aneurysm. Severe safety events were defined as any event causing significant impairment of functioning causing the inability of the subject to carry out usual activities. Statistical analysis was performed using standard summary statistics; p-values comparing subgroups were computed using Pearson's chi-square test for discrete variables and analysis of variance for continuous variables. Results To date, 580 aneurysms, including 183 large ICA, 344 other anterior circulation, and 53 posterior circulation aneurysms have been treated and followed for a mean duration of 7.8 months (SD 7.3, range 0.1 - 40.8). 437 (76%) of 580 aneurysms were saccular and 80 (14%) were fusiform; 32 (5.5%) were classified as giant (<25mm diameter). 549 (93%) were unruptured. 241 (42%) were treated with multiple PEDs. Primary safety events were noted in 62 (12%) cases. Severe neurological events occurred in 35 (6.8%) cases, and occurred more frequently in posterior circulation aneurysms (7 (13%)) than in either large ICA or other anterior circulation aneurysms (15 (8.8%) and (13 (4.5%), respectively, p=.035). Major stroke occurred in 20 (3.9%) of 515 subjects (4.1%, 3.1%, and 7.5% in large ICA, other anterior circulation, and posterior circulation aneurysms, respectively, p=.31). Ipsilateral intracranial haemorrhage occurred in 12 (2.3%) subjects (3.5%, 1.7%, and 1.9% in large ICA, other anterior circulation, and posterior circulation aneurysms, respectively, p=.47). Spontaneous aneurysm rupture occurred in 3 (0.6%) aneurysms, all of which were giant, resulting in a 9% incidence of rupture in giant aneurysms. Mortality rate was 4.3% and was significantly higher for posterior circulation aneurysms (11.3%) as compared to anterior circulation aneurysms (3.5%, p=.019). Conclusions Preliminary data indicates that in approximately 7% of aneurysms treated with PED, substantial neurologic complications occurred, with rates of both severe neurologic events and mortality occurring significantly higher in the posterior as compared to the anterior circulation. Both ipsilateral haemorrhage and spontaneous aneurysm rupture were rare, with the latter event limited to giant aneurysms. Disclosures D. Kallmes: 1; C; MicroVention, Sequent, Benvenue, eV3. 2; C; General Electric, Codman, eV3. E. Boccardi: None. A. Bonafe: None. S. Cekirge: None. D. Fiorella: 2; C; Pipeline proctor, consultant, (<10K, EV3). R. Hanel: None. P. Jabbour: None. E. Levy: None. D. Lopes: 6; C; Receives compensation for training & proctoring for Pipeline devices. P. Lylyk: None. C. McDougall: None. A. Siddiqui: None. I. Szikora: None. H. Woo: None.

Background Acetazolamide induces cerebral vasodilatation and may be used to measure cerebrovascular reserve in patients with cerebral arteriopathy. While acetazolamide is known to induce transient neurologic deficits as a result of “steal phenomenon,” prolonged deficits have rarely been described. Methods Retrospective, single-centre case review from 2011 to 2012. Results We describe 3 patients ages 41, 60 and 65 years (2 women; 1 man) who developed prolonged neurological deterioration following administration of acetazolamide in the acute phase following presentation for evaluation of cerebrovascular reserve. Two patients presented with hemispheric ischaemic symptoms; one presented with headache and parietal convexity subarachnoid haemorrhage. One patient had extensive intracranial vascular disease consistent with a moyamoya-like syndrome with left middle cerebral artery (MCA) occlusion and severe left supraclinoid internal carotid artery (ICA) stenosis. Another had 50% left MCA stenosis as well as > 70% stenosis of the left ICA. She failed medical therapy, L CAS, L MCA angioplasty, and left EC-IC bypass. A third patient had occlusion of the right ICA and severe left ICA stenosis. In every case, acetazolamide challenge was carried out in the acute phase following presentation. All three patients developed significant prolonged worsening of neurologic deficits following the administration of acetazolamide (1 g). Patients received aggressive intravenous hydration. Two of the patients regained pre-acetazolamide neurological status within 18 hours. The third patient recovered several days after emergency left carotid artery stenting. Imaging studies (CT in 2 cases; MRI in 1) did not reveal interval haemorrhage or additional ischaemic changes in any case. Conclusion Administration of acetazolamide has the potential to induce decline in neurological function after administration in the acute phase and may be persistent for several hours or days. A steal phenomenon is a possible mechanism. The combination of severe extracranial and intracranial vascular disease may predispose to prolonged deficits and may be a contraindication to diagnostic use of acetazolamide. Disclosures R. Tawk: None. B. Eidelman: None. R. Hanel: None. J. Meschia: None. K. Barrett: None.

Object Near-infrared spectroscopy (NIRS) offers noninvasive bedside measurement of direct regional cerebral arteriovenous (mixed) brain oxygenation. To validate the accuracy of this monitoring technique, the authors analyzed the statistical correlation of NIRS and CT perfusion with respect to regional cerebral blood flow (CBF) measurements. Methods The authors retrospectively reviewed all cases in which NIRS measurements were obtained at a single, academic neurointensive care unit from February 2008 to June 2011 in which CT perfusion was performed at the same time as NIRS data was collected. Regions of interest were obtained 2.5 cm below the NIRS bifrontal scalp probe on CT perfusion with an average volume between 2 and 4 ml, with mean CBF values used for purposes of analysis. Linear regression analysis was performed for NIRS and CBF values. Results The study included 8 patients (2 men, 6 women), 6 of whom suffered subarachnoid hemorrhage, 1 ischemic stroke, and 1 intracerebral hemorrhage and brain edema. Mean CBF measured by CT perfusion was 61 ml/100 g/min for the left side and 60 ml/100 g/min for the right side, while mean NIRS values were 75 on the right and 74 on the left. Linear regression analysis demonstrated a statistically significant probability value (p < 0.0001) comparing NIRS frontal oximetry and CT perfusion–obtained CBF values. Conclusions The authors demonstrated a linear correlation for frontal NIRS cerebral oxygenation measurements compared with regional CBF on CT perfusion imaging. Thus, frontal NIRS cerebral oxygenation measurement may serve as a useful, noninvasive, bedside intensive care unit monitoring tool to assess brain oxygenation in a direct manner.

Incidental findings pose considerable management dilemmas for the treating physician and psychological burden for the respective patient. With an aging population, more patients will be diagnosed with asymptomatic internal carotid artery stenosis. Patients will have to be counseled with regard to treatment options according to their individual risk profile and according to professionals' knowledge of evidence-based data derived from large randomized control trials. Treatment consensus has long been lacking for patients with asymptomatic carotid artery stenosis prior to any randomized controlled trials. Additionally, an individual's risk profile may be hard to assess according to knowledge gained from randomized controlled trials. Moreover, while earlier studies compared carotid endarterectomy and medical therapy, in the past years, a new therapeutic modality, carotid artery angioplasty and stenting, has emerged as a possible alternative. This has been evaluated in a recent randomized controlled trial, the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST), which compared carotid endarterectomy with angioplasty and stenting in both symptomatic and asymptomatic patients. The following review summarizes current knowledge of the natural history, diagnosis, and treatment strategies to counsel patients with asymptomatic carotid artery stenosis.

Object Acute revascularization has been associated with improved stroke outcomes. The Prolyse in Acute Cerebral Thromboembolism (PROACT II) trial achieved recanalization rates of 66%. The Multi Mechanical Embolus Removal in Cerebral Ischemia (Multi MERCI) trial achieved recanalization in 70% of patients. However, these interventional tools are not always successful. The Enterprise vascular reconstruction device was recently introduced for treatment of cerebral aneurysms previously untreatable with endovascular techniques. The authors evaluated a multicenter experience using this stent as a salvage revascularization tool for acute stroke treatment. Methods Four medical centers participated in a retrospective review of endovascularly treated patients with acute stroke for cases treated with the Enterprise stent after routine interventions had been unsuccessful. Data collected included preprocedure information, intraprocedure findings, and outcomes. Results Twenty patients with acute stroke (mean age 61.6 ± 22 years) were treated with the Enterprise stent. Ten patients received intravenous recombinant tissue plasminogen activator before catheter intervention, without improvement. Intraarterial interventions attempted unsuccessfully before Enterprise deployment included the Merci retriever (12 patients), angioplasty (7 patients), glycoprotein IIb–IIIa inhibitor administration (12 patients), intraarterial nitroglycerin (1 patient), Wingspan stent deployment (3 patients), and Xpert stent deployment (1 patient). The mean preintervention National Institutes of Health Stroke Scale (NIHSS) score was 17 ± 6 (median 17). All patients presented with a Thrombolysis in Myocardial Infarction (TIMI) score of 0 or 1. Revascularization was achieved in all patients (75% with a TIMI score of 3, 25% with a TIMI score of 2). Improvement (≥ 4 points on the NIHSS) was documented in 75% of patients. Mean NIHSS improvement from intervention to discharge was 8 ± 7 points (median 9 points). Conclusions These preliminary data suggest a potential benefit to the use of the Enterprise stent when routine intervention methods fail.

✓The authors report the successful staged stenting and coil embolization of a large vertebral artery–posterior inferior cerebellar artery (VA-PICA) aneurysm using the contralateral VA for access. A 67-year-old woman presented with a large ruptured VA-PICA aneurysm. Initial attempts to stent the wide-necked aneurysm from the ipsilateral side failed, so coil embolization of the dome was performed. During a second endovascular session, the aneurysm neck was successfully stented from the contralateral VA into the PICA. Six weeks later, coils were inserted into the aneurysm from the ipsilateral side. The coil result was stable at the 3-month follow-up examination.

Abstract OBJECTIVE: Intravascular ultrasound (IVUS) imaging has been used extensively in coronary artery interventions and has provided invaluable information for the understanding and treatment of coronary arterial disease. We present here the first description, to our knowledge, of IVUS-guided intracranial arterial interventions in the clinical setting. CLINICAL PRESENTATION: Two patients underwent intracranial angioplasty and stent placement with the assistance of IVUS for the evaluation of their lesions. One patient underwent stenting to treat an occlusive dissection of the left internal carotid artery that occurred during arteriovenous malformation embolization. Another patient underwent angioplasty and stenting for high-grade restenosis of a basilar artery atherosclerotic lesion. RESULTS: Both patients underwent successful revascularization procedures. The patient with the dissection had a small intraventricular and parenchymal hemorrhage documented by computed tomography 4 hours after treatment, but did not develop hydrocephalus or further hemorrhage. Both patients did well clinically and had no permanent neurological deficits. IVUS provided important information in terms of lesion evaluation, stent selection, and stent placement in each case. CONCLUSION: IVUS of the intracranial circulation may assist the performance of intracranial angioplasty and stenting. It provides useful information that can affect clinical decisions. It may prove to be a valuable tool in clinical use and enhance our understanding of vascular disease of the intracranial circulation, as it has in the coronary circulation.