Anatomic Snuffbox (Distal Radial Artery) and Radial Artery Access for Treatment of Intracranial Aneurysms with FDA-Approved Flow Diverters.

BACKGROUND AND PURPOSE: Transradial access for neurointerventional procedures has been proved a safer and more comfortable alternative to femoral artery access. We present our experience with transradial (distal radial/anatomic snuffbox and radial artery) access for treatment of intracranial aneurysms using all 3 FDA-approved flow diverters. MATERIALS AND METHODS: This was a high-volume, dual-center, retrospective analysis of each institution's data base between June 2018 and June 2020 and a collection of all patients treated with flow diversion via transradial access. Patient demographic information and procedural and radiographic data were obtained. RESULTS: Seventy-four patients were identified (64 female patients) with a mean age of 57.5 years with a total of 86 aneurysms. Most aneurysms were located in the anterior circulation (93%) and within the intracranial ICA (67.4%). The mean aneurysm size was 5.5 mm. Flow diverters placed included the Pipeline Embolization Device (Flex) (PED, n = 65), the Surpass Streamline Flow Diverter (n = 8), and the Flow-Redirection Endoluminal Device (FRED, n = 1). Transradial access was successful in all cases, but femoral crossover was required in 3 cases (4.1%) due to tortuous anatomy and inadequate support of the catheters in 2 cases and an inability to navigate to the target vessel in a patient with an aberrant right subclavian artery. All 71 other interventions were successfully performed via the transradial approach (95.9%). No access site complications were encountered. Asymptomatic radial artery occlusion was encountered in 1 case (3.7%). CONCLUSIONS: Flow diverters can be successfully placed via the transradial approach with high technical success, low access site complications, and a low femoral crossover rate.

Unilateral Nonvisualization of a Transverse Dural Sinus on Phase-Contrast MRV: Frequency and Differentiation from Sinus Thrombosis on Noncontrast MRI.

BACKGROUND AND PURPOSE: Unilateral decreased/nonvisualization of a transverse dural sinus on MRV poses a diagnostic dilemma when gadolinium administration is contraindicated. We determined the frequency of unilateral decreased/nonvisualization of the transverse dural sinus and the performance of pregadolinium MR imaging sequences in diagnosing transverse sinus thrombosis in the presence of unilateral decreased/nonvisualization on phase-contrast MRV. MATERIALS AND METHODS: We conducted a retrospective review of consecutive 3D phase-contrast MRV (VENC, 30 cm/s) and routine brain imaging (noncontrast sagittal T1, axial T2, FLAIR, DWI, GRE, and postgadolinium 3D-MPRAGE images) performed during a 3-year period for a total of 208 patients. Nonvisualization of a transverse dural sinus was defined as ≥50% nonvisualization of the transverse sinus caliber versus the contralateral side on MRV. Noncontrast imaging findings were considered abnormal when hyperintense signal was present on T2, FLAIR, T1, and DWI, and there were T2* blooming artifacts on GRE and DWI. Postgadolinium 3D-MPRAGE was used to confirm the diagnosis of transverse sinus thrombosis. RESULTS: Nonvisualization of a transverse dural sinus was observed in 72/208 (34.6%) patients on MRV; 56/72 (77.8%) were without transverse sinus thrombosis, and 16/72 (22.2%) patients had transverse dural sinus thrombosis. Nonvisualization of a transverse dural sinus was seen in 56/192 (29.2%) patients without transverse sinus thrombosis and 16/16 (100%) with transverse sinus thrombosis. Abnormal findings on DWI (transverse sinus hyperintense signal or T2* blooming artifact) are 93.8% sensitive and 100.0% specific for transverse sinus thrombosis. Other noncontrast MR imaging sequences ranged from 56.3%-68.8% sensitive and 91.1%-100.0% specific. CONCLUSIONS: Nonvisualization of a transverse dural sinus is a frequent phenomenon on phase-contrast MRV. DWI can be effectively used to exclude sinus thrombosis when nonvisualization of a transverse dural sinus is a diagnostic conundrum on phase-contrast MRV and contrast-enhanced studies are contraindicated.

Emergent Endovascular Management of Long-Segment and Flow-Limiting Carotid Artery Dissections in Acute Ischemic Stroke Intervention with Multiple Tandem Stents.

BACKGROUND AND PURPOSE: Although most cervical dissections are managed medically, emergent endovascular treatment may become necessary in the presence of intracranial large-vessel occlusions, flow-limiting and long-segment dissections with impending occlusion, and/or hypoperfusion-related ischemia at risk of infarction. We investigated the role of emergent endovascular stenting of long-segment carotid dissections in the acute ischemic stroke setting. MATERIALS AND METHODS: We retrospectively studied long-segment carotid dissections requiring stent reconstruction with multiple tandem stents (≥3 stents) and presenting with acute (<12 hours) ischemic stroke symptoms (NIHSS score, ≥4). We analyzed patient demographics, vascular risk factors, clinical presentations, imaging/angiographic findings, technical procedures/complications, and clinical outcomes. RESULTS: Fifteen patients (mean age, 51.5 years) with acute ischemic stroke (mean NIHSS score, 15) underwent endovascular stent reconstruction for vessel and/or ischemic tissue salvage. All carotid dissections presented with >70% flow limiting stenosis and involved the distal cervical ICA with a minimum length of 3.5 cm. Carotid stent reconstruction was successful in all patients with no residual stenosis or flow limitation. Nine patients (60%) harbored intracranial occlusions, and 6 patients (40%) required intra-arterial thrombolysis/thrombectomy, achieving 100% TICI 2b-3 reperfusion. Two procedural complications were limited to thromboembolic infarcts from in-stent thrombus and asymptomatic hemorrhagic infarct transformation (7% morbidity, 0% mortality). Angiographic and ultrasound follow-up confirmed normal carotid caliber and stent patency, with 2 cases of <20% in-stent stenosis. Early clinical improvement resulted in a mean discharge NIHSS score of 6, and 9/15 (60%) patients achieved a 90-day mRS of ≤2. CONCLUSIONS: Emergent stent reconstruction of long-segment and flow-limiting carotid dissections in acute ischemic stroke intervention is safe and effective, with favorable clinical outcomes, allowing successful thrombectomy, vessel salvage, restoration of cerebral perfusion, and/or prevention of recurrent thromboembolic stroke.

MR imaging of myeloperoxidase activity in a model of the inflamed aneurysm wall.

BACKGROUND AND PURPOSE: Although myeloperoxidase activity in vivo can be visualized by using noninvasive imaging, successful clinical translation requires further optimization of the imaging approach. We report a motion-sensitized driven-equilibrium MR imaging approach for the detection of a myeloperoxidase activity-specific gadolinium-containing imaging agent in experimental aneurysm models, which compensates for irregular blood flow, enabling vascular wall imaging in the aneurysm. MATERIALS AND METHODS: A phantom was built from rotational angiography of a rabbit elastase aneurysm model and was connected to a cardiac pulse duplicator mimicking rabbit-specific flow conditions. A T1-weighted turbo spin-echo-based motion-sensitized driven-equilibrium pulse sequence was optimized in vitro, including the addition of fat suppression and the selection of the velocity-encoding gradient parameter. The optimized sequence was applied in vivo to rabbit aneurysm models with and without inflammation in the aneurysmal wall. Under each condition, the aneurysms were imaged before and after intravenous administration of the imaging agent. The signal-to-noise ratio of each MR imaging section through the aneurysm was calculated. RESULTS: The motion-sensitized driven-equilibrium sequence was optimized to reduce flow signal, enabling detection of the myeloperoxidase imaging agent in the phantom. The optimized imaging protocol in the rabbit model of saccular aneurysms revealed a significant increase in the change of SNR from pre- to post-contrast MR imaging in the inflamed aneurysms compared with naïve aneurysms and the adjacent carotid artery (P < .0001). CONCLUSIONS: A diagnostic MR imaging protocol was optimized for molecular imaging of a myeloperoxidase-specific molecular imaging agent in an animal model of inflamed brain aneurysms.

Complications during carotid artery stenting.

Carotid stenting has become a commonly used procedure for the treatment of carotid artery stenosis. Though equipment and techniques have improved tremendously over the recent 3 decades, complications do occur. It is important for carotid operators to be familiar with potential complications and adverse events. In this article complications and adverse events of carotid stenting including those that are related to the vascular access site, vessel spasm, dissection, perforation, thrombotic occlusion and hemodynamic instability and arrhythmias are reviewed. In addition, management strategies are discussed.

Vitamin B1 in the treatment of Wernicke's encephalopathy due to hyperemesis after gastroplasty.

Wernicke's encephalopathy (WE) is a severe brain disorder, first described in 1881, and is caused by a nutritional deficiency of thiamine (vitamin B1) found mostly in patients suffering from chronic alcoholism. In addition, WE can also complicate bariatric surgery if adequate vitamin supplementation is not insured. Without immediate treatment, the prognosis is poor and the mortality rate is high. Most patients present with atypical neurological symptoms, which hampers rapid diagnosis. We present a 40-year-old woman who underwent gastroplasty combined with gastric banding for severe obesity. She experienced repetitive vomiting and her diet was without vitamin supplementation. After three months she developed convergent strabismus, apathy and urinary incontinence, which was diagnosed as WE and treated as such. Six months later her recovery was incomplete, still showing gait difficulties and nystagmus. We aim to show that adequate vitamin supplementation in patients undergoing gastroplasty is necessary, especially considering the risk of permanent neurological deficits.

Simple measurement of aneurysm residual after treatment: the SMART scale for evaluation of intracranial aneurysms treated with flow diverters.

BACKGROUND: Primary endovascular reconstruction with flow diversion represents a fundamental paradigm shift in the technique of endovascular aneurysm treatment. Unlike coil embolization, often there remains residual post-procedural filling within the aneurysm with flow diverters, the curative reconstruction presumably occurring over a period of weeks. Thus, conventional grading scales for post-procedural aneurysm occlusion and recanalization are inadequate. The aim of this paper is to propose a new angiographic grading scale that addresses this fundamentally new treatment option. METHOD: A five-point grading scale describes the location of residual flow within the aneurysm in the venous phase [grade 1: patent aneurysm with diffuse inflow; grade 2: residual filling of the aneurysm dome (saccular) or wall (fusiform); grade 3: only residual neck (saccular) or only intra-aneurysmal filling with former boundaries covered (fusiform); grade 4: complete occlusion]. FINDINGS: Grade 0 represents any aneurysm, regardless of occlusion rate with early phase, coherent inflow jet. Intra-aneurysmal flow stagnation is categorized into: (a) none, (b) capillary phase, and (c) venous phase. Prevailing parent vessel hemodynamics with in-stent stenosis (ISS) are divided into none (ISS0), mild (ISS1), moderate (ISS2), severe (ISS3), and total (ISS4) occlusion. The proposed grading scales allow assessment of the hemodynamic consequences of stent placement on endosaccular in-flow, stasis, and location of stasis as well as parent vessel hemodynamics. CONCLUSIONS: Further studies need to show the applicability and possible predictive value of this new grading scale on the efficacy of the stent in promoting intra-aneurysmal flow stagnation, thus creating the potential to harmonize the results of future papers. This may help to optimize treatment and future device design.

Comparison of stent free cell area and cerebral lesions after unprotected carotid artery stent placement.

OBJECTIVE: This study evaluates the correlation between closed, semi-closed and open-cell stent design and the association between stent type and clinical outcome as well as magnetic resonance imaging (MRI) findings. DESIGN: A total of 194 patients who underwent unprotected carotid artery stenting (CAS) as well as diffusion-weighted magnetic resonance imaging (DW-MRI) before and after intervention were retrospectively reviewed. MATERIALS AND METHODS: Three stent designs were studied: closed cell, semi-closed cell and open cell. Spearman's Rho test was performed between the stent free cell area and the number and area of ischaemic lesions found after intervention. Adverse events were evaluated. RESULTS: There was no significant difference in clinical outcome between the three stent groups (Zilver, Cook Europe, Denmark; Smart, Codman, MA; and Wallstent, Stryker, MN, USA). A significant correlation was found between the stent free cell area and the number and area of new ischaemic lesions on DW-MRI (P = 0.023). There were significantly fewer new lesions with an open-cell design (Zilver; 12.76 mm(2) free cell area) than with a closed-cell design (Wallstent; 1.08 mm(2) free cell area). CONCLUSIONS: Open-cell stent was related to a lower number and area of silent cerebral ischaemic lesions after unprotected CAS. However, clinical outcome, measured by incidence of adverse events and clinical neurologic assessment, was not significantly different between patients with different stent designs.

Controversies around carotid stenting.

In the last 10 years, CAS became an important alternative to surgery. However, many of the trials regarding stroke prevention had controversial requirements regarding the endovascular approach, leading to questionable conclusions. This review critically addresses results from previous randomized studies on efficacy and safety of the first established therapy for carotid artery stenosis, carotid endarterectomy (CEA) compared to the challenger, carotid artery stenting (CAS), as a newer and less invasive endovascular technique.

First description of posterior reversible encephalopathy syndrome as a complication of glycerolnitrate patch following open cardiac surgery.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) affects predominantly the parietal and occipital lobes. Frequent clinical features are epileptic seizure, altered mental status and visual disturbances. CLINICAL PRESENTATION: We present the first case of a patient with pericarditis and mitral valve insufficiency, who developed PRES after application of a glycerolnitrate patch day three post-operatively and whose neurological deficits improved within 2 days after withdrawal of patch therapy. CONCLUSION: The precise pathomechanism of PRES is unknown. The lower sympathetic innervation of the posterior circulation may be one explanation for its particular vulnerability to vasodilatation caused by glycerolnitrate.

Endovascular stroke treatment today.

The purpose of this study was to review current treatment options in acute ischemic stroke, focusing on the latest advances in the field of mechanical recanalization. These devices recently made available for endovascular intracranial thrombectomy show great potential in acute stroke treatments. Compelling evidence of their recanalization efficacy comes from current mechanical embolectomy trials. In addition to allowing an extension of the therapeutic time window, mechanical recanalization devices can be used without adjuvant thrombolytic therapy, thus diminishing the intracranial bleeding risk. Therefore, these devices are particularly suitable in patients in whom thrombolytic therapy is contraindicated. IV and IA thrombolysis and bridging therapy are viable options in acute stroke treatment. Mechanical recanalization devices can potentially have a clinically relevant impact in the interventional treatment of stroke, but at the present time, a randomized study would be beneficial.