Seon-Kyu Lee

Aspiration Thrombectomy After Intravenous Alteplase Versus Intravenous Alteplase Alone

Background and Purpose— Thrombectomy, primarily with stent retrievers with or without adjunctive aspiration, provided clinical benefit across multiple prospective randomized trials. Whether this benefit is exclusive to stent retrievers is unclear. Methods— THERAPY (The Randomized, Concurrent Controlled Trial to Assess the Penumbra System’s Safety and Effectiveness in the Treatment of Acute Stroke; NCT01429350) was an international, multicenter, prospective, randomized (1:1), open label, blinded end point evaluation, concurrent controlled clinical trial of aspiration thrombectomy after intravenous alteplase (IAT) administration compared with intravenous-alteplase alone in patients with large vessel ischemic stroke because of a thrombus length of ≥8 mm. The primary efficacy end point was the percent of patients achieving independence at 90 days (modified Rankin Scale score, 0–2; intention-to-treat analysis). The primary safety end point was the rate of severe adverse events (SAEs) by 90 days (as treated analysis). Patients were randomized 1:1 across 36 centers in 2 countries (United States and Germany). Results— Enrollment was halted after 108 (55 IAT and 53 intravenous) patients (of 692 planned) because of external evidence of the added benefit of endovascular therapy to intravenous-alteplase alone. Functional independence was achieved in 38% IAT and 30% intravenous intention-to-treat groups (P=0.52). Intention-to-treat ordinal modified Rankin Scale odds ratio was 1.76 (95% confidence interval, 0.86–3.59; P=0.12) in favor of IAT. Secondary efficacy analyses all demonstrated a consistent direction of effect toward benefit of IAT. No differences in symptomatic intracranial hemorrhage rates (9.3% IAT versus 9.7% intravenous, P=1.0) or 90-day mortality (IAT: 12% versus intravenous: 23.9%, P=0.18) were observed. Conclusions— THERAPY did not achieve its primary end point in this underpowered sample. Directions of effect for all prespecified outcomes were both internally and externally consistent toward benefit. It is possible that an alternate method of thrombectomy, primary aspiration, will benefit selected patients harboring large vessel occlusions. Further study on this topic is indicated. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01429350.

Diagnostic value of peritumoral minimum apparent diffusion coefficient for differentiation of glioblastoma multiforme from solitary metastatic lesions.

OBJECTIVEnIn glioblastoma multiforme, the peritumoral region may be infiltrated with malignant cells in addition to vasogenic edema, whereas in a metastatic deposit, the peritumoral areas comprise predominantly vasogenic edema. The purpose of this study was to determine whether the minimum apparent diffusion coefficient (ADC) can be used to differentiate glioblastoma from solitary metastasis on the basis of cellularity levels in the enhancing tumor and in the peritumoral region.nnnMATERIALS AND METHODSnSeventy-three patients underwent conventional MRI and diffusion-weighted imaging (DWI) before undergoing treatment. The minimum ADC was measured in the enhancing tumor, peritumoral region, and contralateral normal white matter. To determine whether there was a statistical difference between metastasis and glioblastoma, we analyzed patient age and sex, minimum ADC value, and ADC ratio of the two groups. A receiver operating characteristic (ROC) curve analysis was used to determine the cutoff value of the minimum ADC that had the best combination of sensitivity and specificity for distinguishing between glioblastoma and metastasis.nnnRESULTSnThe mean minimum ADC values and mean ADC ratios in the peritumoral regions of glioblastomas were significantly higher than those in metastases. However, the mean minimum ADC values and mean ADC ratios in enhancing tumors showed no statistically significant difference between the two groups. According to ROC curve analysis, a cutoff value of 1.302 × 10(-3) mm(2)/s for the minimum peritumoral ADC value generated the best combination of sensitivity (82.9%) and specificity (78.9%) for distinguishing between glioblastoma and metastasis.nnnCONCLUSIONnAlthough the characteristics of solitary metastasis and glioblastoma multiforme may be similar on conventional MRI, DWI can offer diagnostic information to distinguish between the tumors.

The Venous Distension Sign: A Diagnostic Sign of Intracranial Hypotension at MR Imaging of the Brain

BACKGROUND AND PURPOSE: Patients with intracranial hypotension (IH) demonstrate intracranial venous enlargement with a characteristic change in contour of the transverse sinus seen on routine T1-weighted sagittal imaging. In IH, the inferior margin of the midportion of the dominant transverse sinus acquires a distended convex appearance; we have termed this the venous distension sign (VDS). This is distinct from the normal appearance of this segment, which usually has a slightly concave or straight lower margin. This sign is introduced, and its performance as a test for the presence of this disease is evaluated. MATERIALS AND METHODS: The transverse sinuses on T1-weighted sagittal imaging of 15 patients with IH and 15 control patients were independently assessed in a blinded fashion by 3 readers for the presence of a VDS. A present or absent VDS was determined for each patient by each reader, and a consensus result for each patient was determined by unanimity or majority rule. RESULTS: Using the VDS, the readers correctly identified 93% (14 of 15) of the IH patients and similarly 93% (14 of 15) of the control patients. There was a high rate of agreement among the readers for the interpretation of the VDS (multirater κ = 0.82). The overall sensitivity of the VDS for the diagnosis of intracranial hypotension was 94%. Specificity was also 94%. CONCLUSION: The VDS appears to be an accurate test for the presence or absence of IH and may be helpful in the evaluation of these patients.

Clinical and angiographic long-term follow-up of completely coiled intracranial aneurysms using endovascular technique.

OBJECTnThe anatomical evolution and clinical outcome of completely coiled intracranial aneurysms after endovascular embolization have rarely been studied separately. From their prospective database, the authors reviewed follow-up angiography and clinical outcome of 87 patients whose aneurysms were designated as 100% obliterated on immediate postembolization angiography.nnnMETHODSnNinety-one aneurysms (56 ruptured and 35 unruptured) in 87 patients were included in this study. Clinical outcome was evaluated using the Glasgow Outcome Scale. Follow-up angiographic findings were assessed and categorized as 1 of the following: no recanalization, recanalization with a neck remnant, or recanalization with a body remnant. For statistical analysis, the recanalization rate was correlated with: clinical presentation; the largest aneurysm diameter, aneurysm neck size, and dome-to-neck ratio; aneurysm location; and use of special techniques such as usage of a surface modified coil, balloon remodeling technique, or stent.nnnRESULTSnAt the latest clinical evaluation (mean 34.3 months), 81 (93.1%) of the 87 patients (91 aneurysms) had good clinical outcomes (Glasgow Outcome Scale Score 5). The procedure-related morbidity rate (permanent neurological deficit) was 2.3% (2 of 87), and there were no procedure-related deaths. On the latest follow-up angiography (mean 26.4 months), the recanalization rate was 26.4% (24 of 91 aneurysms): 16 (17.6%) with neck remnants and 8 (8.8%) with body remnants. The neck size of the recanalized aneurysms was statistically significantly larger than that of the nonrecanalized aneurysms (p = 0.006), and aneurysms with wide necks (> or = 4 mm) had a higher recanalization rate than those with a narrow neck (< 4 mm) (p = 0.002). There was no bleeding after endovascular treatment during the follow-up period.nnnCONCLUSIONSnCompletely coiled aneurysms after endovascular embolization demonstrated good clinical outcome, and there was no bleeding episode after endovascular treatment; however, there was a relatively high recanalization rate.

Embolectomy for stroke with emergent large vessel occlusion (ELVO): report of the Standards and Guidelines Committee of the Society of NeuroInterventional Surgery

Stroke is the leading cause of adult disability in North America and is the fifth most common cause of death.1 ,2 The natural history of patients with acute ischemic stroke and occlusion of a major intracranial vessel such as the internal carotid artery (ICA), middle cerebral artery (MCA), or basilar artery is dismal, with high rates of mortality and low rates of disability-free survival.3 ,4 We introduce the term ‘Emergent Large Vessel Occlusion (ELVO)’ to describe this clinical scenario.nnAmong acute ischemic stroke, ELVO accounts for the greatest proportion of patients with long-term disability. For the past two decades the use of endovascular therapy has been performed in many centers across the world. The therapies have spanned from infusion of thrombolytic agents5 ,6 to mechanical embolectomy with the introduction of first-generation devices,7 ,8 aspiration-based embolectomy techniques,9 ,10 and the use of stent-retriever based procedures.11 ,12 However, these embolectomy trials were single-arm trials demonstrating safety of the procedure and technique or superiority over another, without direct comparison with standard medical therapy alone.nnIn the past 3u2005years, several major trials have been published comparing endovascular therapy with standard medical therapy alone. The purpose of this document is to summarize the results of these trials and synthesize the level of evidence supporting the use of embolectomy in patients with ELVO.nnThis document was prepared by the Standards and Guidelines Committee of the Society of NeuroInterventional Surgery, a multidisciplinary society representing the leaders in the field of endovascular therapy for neurovascular disease. The strength of the evidence supporting each recommendation was summarized using a scale previously described by the American Heart Association.nn### Role of intravenous thrombolysisnnIn 1996 the FDA approved the use of recombinant tissue plasminogen activator (tPA) for the treatment of acute ischemic stroke …

Platelet function inhibitors and platelet function testing in neurointerventional procedures

Over the past decade there has been a growing use of intracranial stents for the treatment of both ischemic and hemorrhagic cerebrovascular disease, including stents to assist in the remodeling of the neck of aneurysms as well as the use of flow diverting devices for aneurysm treatment. With this increase in stent usage has come a growing need for the neurointerventional (NI) community to understand the pharmacology of medications used for modifying platelet function, as well as the testing methodologies available. Platelet function testing in NI procedures remains controversial. While pre-procedural antiplatelet assays might lead to a reduced rate of thromboembolic complications, little evidence exists to support this as a standard of care practice. Despite the routine use of dual antiplatelet therapy (DAT) with aspirin and a P2Y12 receptor antagonist (such as clopidogrel, prasugrel, or ticagrelor) in most neuroembolization procedures necessitating intraluminal reconstruction devices, thromboembolic complications are still encountered.1–3 Moreover, DAT carries the risk of hemorrhagic complications, with intracerebral hemorrhage (ICH) being the most potentially devastating.4 ,5nnLight transmission aggregometry (LTA) is the gold standard to test for platelet reactivity, but it is usually expensive and may not be easily obtainable at many centers. This has led to the development of point-of-care assays, such as the VerifyNow (Accumetrics, San Diego, California, USA), which correlates strongly with LTA and can reliably measure the degree of P2Y12 receptor inhibition.6–9 VerifyNow results are reported in P2Y12 reaction units (PRUs), with a lower PRU value corresponding to a higher level of P2Y12 receptor inhibition and, presumably, a lower probability of platelet aggregation, and a higher PRU value corresponding to a lower level of P2Y12 receptor inhibition and, hence, a higher chance of platelet activation and aggregation.nnWhile aspirin resistance is perhaps less common, clopidogrel resistance may be more challenging as …

Vertebral augmentation: report of the Standards and Guidelines Committee of the Society of NeuroInterventional Surgery

Vertebroplasty and kyphoplasty are minimally invasive image-guided procedures that involve the injection of cement (typically polymethylmethacrylate (PMMA)) into a vertebral body. Kyphoplasty involves inflation of a balloon tamp to create a cavity within the vertebral body into which cement is subsequently injected. The majority of these vertebral augmentation procedures are performed to relieve back pain from osteoporotic or cancer-related vertebral compression fractures and to reinforce the vertebral body with neoplasm or vascular tumor. The primary goal of vertebroplasty and kyphoplasty is to reduce back pain and to improve patients functional status, and the secondary goal is stabilization of a vertebra weakened by fracture or neoplasia.nn### Osteoporotic vertebral fracturesnnOsteoporosis is a common disease that causes significant morbidity and incurs a significant healthcare cost to the community. The major osteoporotic fractures involve the hip, vertebra, proximal humerus and distal forearm; the lifetime osteoporotic fracture risk at age 50 is approximately one in two women and one in five men.1 The lifetime incidence of symptomatic osteoporotic vertebral fractures in women at age 50 is estimated at 10–15%1; once a vertebral fracture occurs, there is a 20% risk of another vertebral fracture within 12u2005months.2nnMost osteoporotic vertebral compression fractures are asymptomatic or result in minimal pain; only a third of vertebral fractures result in medical attention.3 Conservative medical therapy is therefore appropriate for the vast majority of vertebral compression fractures since most acute back pain symptoms are mild and subside over a period of 6–8u2005weeks as the fracture heals. The goals of conservative therapy are pain reduction (with analgesics and/or bed rest), improvement in functional status (with orthotic devices and physical therapy) and prevention of future fractures (with vitamin D, calcium supplementation and antiresorptive agents).nnHowever, conservative treatment for those with severe pain or limitation of function is not benign. It …

Standard and Guidelines: Intracranial Dural Arteriovenous Shunts.

Intracranial dural arteriovenous shunts (DAVS), also known as dural arteriovenous fistulas or dural arteriovenous malformations, are abnormal connections between dural (and occasionally pial) arteries and the veno vasora within the dura mater, comprising the walls of the dural sinuses, the leptomeningeal (bridging) veins, or the transosseous emissary veins within or adjacent to the dura mater. DAVS are rare, accounting for about 5–15% of intracranial vascular malformations.1 ,2 Although incompletely understood, DAVS are thought to be acquired lesions3 resulting from dural sinus or cortical venous thrombosis, possibly precipitated by hormonal changes, hypercoagulability states, trauma, or a combination of these factors.4–6 The clinical implications of intracranial DAVS are directly associated with its venous drainage pattern. For example, intracranial DAVS can cause either intracranial hemorrhages or non-hemorrhagic neurologic events such as regional or global venous congestive encephalopathy.nnThe aims of this document are (1) to review existing knowledge about the natural history, diagnostic methodology, and treatment modalities/techniques for DAVS; and (2) to provide recommendations on management strategies for intracranial DAVS using evidence-based medicine approaches when possible but, of necessity, relying frequently on expert opinion concerning this rare disease. Recommendations follow the American College of Cardiology/American Heart Association (ACC/AHA) Classification of Recommendation/Level of Evidence (COR/LOE) and the definition of classes and levels of evidence used in the AHA/American Stroke Association (AHA/ASA) recommendations (tables 1 and 2).nnView this table:nnTablexa01 nACC/AHA Classification of Recommendations and Level of Evidence (COR/LOE)nnnnView this table:nnTablexa02 nDefinition of classes and levels of evidence used in AHA/ASA recommendationsnnnnGiven the rarity of DAVS and the challenge of diagnosing them with non-invasive tools, the natural history of intracranial DAVS is not completely understood. There are few data on the progressive enlarge of DAVS over time with respect to recruitment or enlargement of arterial feeders or appearance of de novo fistulas over time. …

Post-thrombectomy management of the ELVO patient: Guidelines from the Society of NeuroInterventional Surgery

Recent trials have proven the benefits of endovascular treatment for patients with stroke from emergent large vessel occlusions (ELVOs).1–5 Optimal management of these patients involves attention to pre-procedural, intra-procedural, and post-procedural elements. However, many of the ideal treatment approaches following endovascular stroke therapy remain controversial. This document synthesizes current recommendations from the best available evidence to provide guidance in the post-procedural management of a patient undergoing stroke thrombectomy.nnThis document was constructed by the Standards and Guidelines Committee of the Society for NeuroInterventional Surgery, a multidisciplinary committee composed of practitioners with backgrounds including neuroradiology, vascular neurosurgery, stroke neurology, and neurocritical care. We reviewed electronic databases for publications related to the management of acute stroke patients post-procedure, using both broad and narrow search terms. We subsequently evaluated those results for papers with randomized clinical results, which were given the highest priority. The remaining papers were assessed on the basis of individual methodology, and recommendations were made based on the data available. In the absence of supporting adequate clinical trial evidence, the committee made consensus recommendations. Each recommendation is graded, where possible, with a level of evidence utilizing the American Heart Association/American Stroke Association grading system.6 This document represents one of a continuum related to acute stroke intervention, including other documents on prehospital management, training standards for thrombectomy, and management of ELVO patients.7–9 nn### Post-thrombectomy care environmentnnELVO patients require careful monitoring in a stroke unit or intensive care unit. Stroke units provide dedicated, specialized, multidisciplinary inpatient care for ELVO patients. Patients treated in this environment are more likely to survive, regain independence, and return home than those receiving less organized service.10 Stroke units are characterized by protocolxa0guided care, adherence to guidelines, and coordination of care provided by various services.11–14 Furthermore, a dedicated stroke unit is preferable to a mobile consultative …

Standards of practice and reporting standards for carotid artery angioplasty and stenting

Every year almost 800u2005000 people in the USA suffer a new or recurrent stroke, and stroke is the third leading cause of death with over 140u2005000 deaths in the USA in 1995.1 Additionally, stroke is a leading cause of long-term disability with an estimated cost of