Sandra Narayanan

Endovascular therapy of acute ischemic stroke: Report of the Standards of Practice Committee of the Society of NeuroInterventional Surgery

Objective To summarize and classify the evidence for the use of endovascular techniques in the treatment of patients with acute ischemic stroke. Methods Recommendations previously published by the American Heart Association (AHA) (Guidelines for the early management of adults with ischemic stroke (Circulation 2007) and Scientific statement indications for the performance of intracranial endovascular neurointerventional procedures (Circulation 2009)) were vetted and used as a foundation for the current process. Building on this foundation, a critical review of the literature was performed to evaluate evidence supporting the endovascular treatment of acute ischemic stroke. The assessment was based on guidelines for evidence based medicine proposed by the Stroke Council of the AHA and the University of Oxford, Centre for Evidence Based Medicine (CEBM). Procedural safety, technical efficacy and impact on patient outcomes were specifically examined.

Head, neck, and brain tumor embolization guidelines

Background Management of vascular tumors of the head, neck, and brain is often complex and requires a multidisciplinary approach. Peri-operative embolization of vascular tumors may help to reduce intra-operative bleeding and operative times and have thus become an integral part of the management of these tumors. Advances in catheter and non-catheter based techniques in conjunction with the growing field of neurointerventional surgery is likely to expand the number of peri-operative embolizations performed. The goal of this article is to provide consensus reporting standards and guidelines for embolization treatment of vascular head, neck, and brain tumors. Summary This article was produced by a writing group comprised of members of the Society of Neurointerventional Surgery. A computerized literature search using the National Library of Medicine database (Pubmed) was conducted for relevant articles published between 1 January 1990 and 31 December 2010. The article summarizes the effectiveness and safety of peri-operative vascular tumor embolization. In addition, this document provides consensus definitions and reporting standards as well as guidelines not intended to represent the standard of care, but rather to provide uniformity in subsequent trials and studies involving embolization of vascular head and neck as well as brain tumors. Conclusions Peri-operative embolization of vascular head, neck, and brain tumors is an effective and safe adjuvant to surgical resection. Major complications reported in the literature are rare when these procedures are performed by operators with appropriate training and knowledge of the relevant vascular and surgical anatomy. These standards may help to standardize reporting and publication in future studies.

Retrievable stents, “stentrievers,” for endovascular acute ischemic stroke therapy

Endovascular therapy for acute ischemic stroke continues to evolve to improve both efficacy and safety. In the late 1990s, intra-arterial chemical thrombolysis with prourokinase was shown to be effective in achieving partial recanalization and improving clinical outcome, in comparison with intra-arterial heparin administration. However, this was at the expense of an increase in the rate of symptomatic intracranial hemorrhage to 10%. To improve the rate of recanalization, expand the time window, and reduce the risk of symptomatic intracranial hemorrhage, mechanical thrombectomy was introduced, with initial approval of the Merci clot retriever, a corkscrew-like device, and then more recently with approval of the Penumbra thromboaspiration system. Both devices are associated with a high rate of recanalization (total, partial, and complete). However, time to recanalization was on average 45 minutes, with a low rate of complete clot resolution, given that the majority of patients achieved only partial recanalization. More recently, retrievable stents have shown promise in reducing the time to recanalization, and they achieve a higher rate of complete clot resolution with improved feasibility. The retrievable stent can be opened within the clot to engage it within the stent struts, and subsequently it is retrieved by pulling it under flow arrest. The retrievable stents provide a new tool in the armamentarium of devices that can be used to achieve safe and timely clot removal. This review provides the historical evolution of endovascular therapy to use of stentreivers.

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. ### Osteoporotic vertebral fractures Osteoporosis 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 12 months.2 Most 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 6–8 weeks 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). However, conservative treatment for those with severe pain or limitation of function is not benign. It …

Invasive interventional management of post-hemorrhagic cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage

Current clinical practice standards are addressed for the invasive interventional management of post-hemorrhagic cerebral vasospasm (PHCV) in patients with aneurysmal subarachnoid hemorrhage. The conclusions, based on an assessment by the Standards Committee of the Society of Neurointerventional Surgery, included a critical review of the literature using guidelines for evidence based medicine proposed by the Stroke Council of the American Heart Association and the University of Oxford, Centre for Evidence Based Medicine. Specifically examined were the safety and efficacy of established invasive interventional therapies, including transluminal balloon angioplasty (TBA) and intra-arterial vasodilator infusion therapy (IAVT). The assessment shows that these invasive interventional therapies may be beneficial and may be considered for PHCV—that is, symptomatic with cerebral ischemia and refractory to maximal medical management. As outlined in this document, IAVT may be beneficial for the management of PHCV involving the proximal and/or distal intradural cerebral circulation. TBA may be beneficial for the management of PHCV that involves the proximal intradural cerebral circulation. The assessment shows that for the indications described above, TBA and IAVT are classified as Class IIb, Level B interventions according to the American Heart Association guidelines, and Level 4, Grade C interventions according to the University of Oxford Centre for Evidence Based Medicine guidelines.

Standard of practice: endovascular treatment of intracranial atherosclerosis.

Background Symptomatic intracranial atherosclerotic disease (ICAD) worldwide represents one of the most prevalent causes of stroke. When severe, studies show that it has a very high risk for recurrent stroke, highlighting the need for effective preventative strategies. The mainstay of treatment has been medical therapy and is of critical importance in all patients with this disease. Endovascular therapy is also a possible therapeutic option but much remains to be defined in terms of best techniques and patient selection. This guideline will serve as recommendations for diagnosis and endovascular treatment of patients with ICAD. Methods A literature review was performed to extract published literature regarding ICAD, published from 2000 to 2011. Evidence was evaluated and classified according to American Heart Association (AHA)/American Stroke Association standard. Recommendations are made based on available evidence assessed by the Standards Committee of the Society of NeuroInterventional Surgery. The assessment was based on guidelines for evidence based medicine proposed by the American Academy of Neurology (AAN), the Stroke Council of the AHA and the University of Oxford, Centre for Evidence Based Medicine (CEBM). Results 59 publications were identified. The SAMMPRIS study is the only prospective, randomized, controlled trial available and is given an AHA level B designation, AAN class II and CEBM level 1b. The Stenting of Symptomatic Atherosclerotic Lesions in the Vertebral or Intracranial arteries (SSYLVIA) trial was a prospective, non-randomized study with the outcome assessment made by a non-operator study neurologist, allowing an AHA level B, AAN class III and CEBM level 2. The remaining studies were uncontrolled or did not have objective outcome measurement, and are thus classified as AHA level C, AAN class IV and CEBM level 4. Conclusion Medical management with combination aspirin and clopidogrel for 3 months and aggressive risk factor modification is the firstline therapy for patients with symptomatic ICAD. Endovascular angioplasty with or without stenting is a possible therapeutic option for selected patients with symptomatic ICAD. Further studies are necessary to define appropriate patient selection and the best therapeutic approach for various subsets of patients.

Society of NeuroInterventional Surgery Standards of Practice: general considerations

This is the first in a set of documents intended to standardize techniques, procedures, and practices in the field of endovascular surgical neuroradiology. Standards are meant to define core practices for peer review, comparison, and improvement. Standards and guidelines also form the basic dialogue, reporting, and recommendations for ongoing practices and future development.

Safety and efficacy of intracranial stenting for acute ischemic stroke beyond 8 h of symptom onset

Objective To report our experience with stent supported intracranial recanalization for acute ischemic stroke beyond 8 h of symptoms onset. Background Acute ischemic stroke (AIS) therapy is often limited to an 8 h window using mechanical means. However, recent reports have shown delayed recanalization beyond 8 h might be a viable option in a subset of patients. Methods A retrospective review was performed of our AIS database for patients who underwent stent supported intracranial recanalization beyond 8 h of symptom onset. Clinical and angiographic data were reviewed. Outcome was measured using modified Rankin Scale (mRS) scores at 30 and 90 days. Results 12 patients (11 men and one woman) underwent delayed stenting for AIS. Mean age was 49 years (range 37–73) and mean National Institutes of Health Stroke Scale was 17 (range 8–29, median 15). Mean time from stroke onset to intervention was 66.1 h (range 10–168 h, median 46 h). 10 patients presented with a Thrombolysis in Myocardial Infarction (TIMI) score of 0 and the remaining two had a TIMI of 1. Recanalized vessels included: left middle cerebral artery (n=6), basilar trunk (n=2), vertebrobasilar junction (n=3) and internal carotid artery (ICA)-T (n=1). Four patients had prior attempts of embolectomy/thrombolysis using mechanical and chemical means. Stents used included: six balloon mounted stents, five Wingspan and one Enterprise self-expanding intracranial stent. Recanalization, defined as a TIMI score of 2 or more, was achieved in 11 patients. Two patients (17%) had intracranial hemorrhage. Thirty day mRS of ≤3 was achieved in six patients (50%). Seven patients (58%) had a 90 day mRS of ≤2. Conclusion Stent supported intracranial recanalization is a safe and feasible approach in a selective group of patients presenting with acute ischemic stroke beyond 8 h of symptom onset.

Arrival by ambulance is associated with acute stroke intervention in young adults

BACKGROUND AND PURPOSE Timely intervention in young stroke patients minimizes long term disability. We hypothesized that arrival to the emergency department by ambulance would be associated with increased rate of stroke intervention with intravenous t-PA or intra arterial procedures. METHODS Charts of 77 patients aged 15-49 years diagnosed with ischemic stroke were analyzed. Data was collected on demographics, arrival to emergency department by ambulance, whether initial hospital at presentation was a Primary Stroke Center, and intervention by intravenous t-PA or intra arterial procedures. Data was analyzed by Fishers exact test, and significant variables were included in multivariable analysis. RESULTS Arrival by ambulance was significantly associated with acute stroke intervention in young adults (p=0.016). Gender and Primary Stroke Center certification did not make a difference in patients getting stroke intervention. CONCLUSION Young adults with stroke symptoms were more likely to receive acute stroke intervention if they arrived by ambulance. Larger multi-center studies should address whether Primary Stroke Centers are more likely to provide either IV thrombolysis or interventional therapies in young patients with acute ischemic stroke.

Endovascular management of intracranial dural arteriovenous fistulas.

Classification, pathophysiology, and endovascular treatment of intracranial dural arteriovenous fistulas are discussed. Risk for neurologic deterioration is based on the presence and extent of cortical venous reflux. Previous endovascular techniques relied heavily on transvenous coil embolization. Recent advances in endovascular materials have facilitated the treatment and cure of many of these lesions via transarterial approaches. Penetration of liquid embolic agent into the nidus and foot of the draining vein is crucial for long-term angiographic cure.