Advances in interventional neuroradiology 2006.
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Cerebrovascular Disorders↗
Biomedical subjects
Elad I Levy
Publications and source records attributed to Elad I Levy.
Perforator stroke following intracranial stenting: a sacrifice for the greater good?
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Blood Vessel Prosthesis↗
Self-expanding stent-assisted middle cerebral artery recanalization: technical note.
INTRODUCTION: Investigation into pharmacological and mechanical means of improving recanalization rates by intraarterial therapy has led to technological development. Angiographic recanalization has been associated with improvement in clinical outcome. A clot retriever has recently joined an imperfect armamentarium for intraarterial stroke therapy. In this report, we describe successful recanalization of an acute thrombotic occlusion of the inferior division of the middle cerebral artery (MCA) achieved with a self-expanding stent. METHODS: An 82-year-old woman with a history of coronary atherosclerosis and previous cerebellar hemorrhage presented with a National Institutes of Health Stroke Scale (NIHSS) score of 11. Perfusion computed tomography imaging showed a left MCA territory deficit. Diffusion-weighted magnetic resonance (MR) imaging revealed a small punctiform insular hyperintensity. Angiography documented occlusion of the inferior division of the left MCA (Thrombolysis in Myocardial Infarction or Thrombolysis in Cerebral Infarction, TIMI/TICI, grade 0). Intraarterial delivery of eptifibatide to the occlusion site failed to recanalize the vessel. Deployment of a self-expanding stent in the occluded segment resulted in complete revascularization of the distal vascular bed. RESULTS: Angiography performed on the next day confirmed patency of the stented vessel segment (TIMI/TICI 3). The patient was discharged 3 days after the procedure (NIHSS 3). MR angiography obtained 3 months after the procedure documented left MCA patency. CONCLUSION: This technique may have a role worthy of further investigation in acute stroke therapy.
Aged, 80 and over↗
Multimodal reperfusion therapy for acute ischemic stroke: factors predicting vessel recanalization.
BACKGROUND AND PURPOSE: Endovascular therapies using mechanical and pharmacological modalities for large vessel occlusions in acute stroke are rapidly evolving. Our aim was to determine whether one modality is associated with higher recanalization rates. METHODS: We retrospectively reviewed 168 consecutive patients treated with intra-arterial (IA) therapy for acute ischemic stroke between May 1999 and November 15, 2005. Demographic, clinical, radiographic, angiographic, and procedural notes were reviewed. Recanalization was defined as achieving thrombolysis in myocardial infarction 2 or 3 flow after intervention. A logistic regression model was constructed to determine independent predictors of successful recanalization. RESULTS: A total of 168 patients were reviewed with a mean age of 64+/-13 years and mean National Institutes of Health Stroke Scale score of 17+/-4. Recanalization was achieved in 106 (63%) patients. Independent predictors of recanalization include: the combination of IA thrombolytics and glycoprotein IIb/IIIa inhibitors (odds ratio [OR], 2.9 [95% CI, 1.04 to 6.7]; P<0.048), intracranial stent placement with angioplasty (OR, 4.8 [95% CI, 1.8 to 10.0]; P<0.001), or extracranial stent placement with angioplasty (OR, 4.2 [95% CI, 1.4 to 9.8]; P<0.014). Lesions at the terminus of the internal carotid artery were recalcitrant to revascularization (OR, 0.34 [95% CI, 0.16 to 0.73]; P value 0.006). CONCLUSIONS: Intracranial or extracranial stenting or combination therapy with IA thrombolytics and glycoprotein IIb/IIIa inhibitors in the setting of multimodal therapy is associated with successful recanalization in patients treated with multimodal endovascular reperfusion therapy for acute ischemic stroke.
Aged↗
Reversal of a 30-h fixed deficit with carotid angioplasty and stenting: technical note.
We describe the case of an 82-year-old man with a fixed neurological deficit of 30 h duration. A left hemispheric perfusion deficit was found on perfusion/diffusion imaging studies in conjunction with an ipsilateral carotid stenosis documented by cerebral angiography. Carotid angioplasty with stent placement was performed and resulted in dramatic clinical improvement. Carotid stenosis can cause acute hemodynamic hypoperfusion with a symptomatic reversible clinical deficit.
Aged, 80 and over↗
Advancements in carotid stenting leading to reductions in perioperative morbidity among patients 80 years and older.
OBJECTIVE: Patients 80 years and older are generally considered to be at an increased risk for stroke and death from carotid endarterectomy. High-risk status often qualifies them for entry into a carotid angioplasty and stenting (CAS) trial. The aim of this study is to report periprocedure (0-30 d) morbidity and mortality among elderly patients undergoing CAS with and without distal embolic protection in an intention-to-treat analysis. METHODS: A retrospective review was performed to evaluate the medical records and imaging studies of patients 80 years or older who underwent attempted CAS procedures with and without distal embolic protection between June 1996 and February 2004. RESULTS: Ages of the 75 patients identified in our review ranged from 80 to 91 years (average 83.1 yr); 41 were men. Internal carotid artery stenosis ranged from 60 to 95% (mean 78.3%). Forty-two patients had symptoms (transient ischemic attack, 29; stroke, 13), and 33 patients were asymptomatic. Total event rates were major stroke, 4% (3 patients); minor stroke, 6.7% (5 patients); death, 4% (3 patients). Rates in the unprotected group (35 patients) were major stroke, 8.6% (3 patients); minor stroke, 5.7% (2 patients); major stroke/death, 14.3% (5 patients). Rates in the protected group (40 patients) were major stroke, 0; minor stroke, 7.5% (3 patients); major stroke/death, 0; (P < 0.05). CONCLUSION: These results suggest that elderly patients undergoing CAS with adjunctive distal embolic protection are at a lower risk of periprocedure adverse events. Routine clopidogrel use, smaller hardware profile, patient selection, and increased experience likely contributed to these results.
Aged, 80 and over↗
Acute M2 bifurcation stenting for cerebral infarction: lessons learned from the heart: technical case report.
OBJECTIVE AND IMPORTANCE: Acute ischemic stroke is the third leading cause of death in the United States. For patients with NIHSS scores >10 and evaluated within 6 hours, intra-arterial thrombolysis is the treatment of choice. The Merci retriever (Concentric Medical Inc., Mountain View, CA) and IV TPA are currently the only FDA-approved treatments for acute ischemic stroke. For patients who do not meet the criteria for TPA administration and/or in whom the Merci device fails, options are limited. Intracranial stenting for acute ischemic stroke after failed thrombolysis is now possible because of improved delivery systems and appropriately sized stents. CLINICAL PRESENTATION: A 26-year-old woman presented with an NIHSS score of 11 (right-sided hemiparesis and mixed aphasia) 4 hours from the time of symptom onset. CT perfusion demonstrated increased time to peak in the entire left hemisphere; conventional angiography demonstrated a left M1 occlusion. INTERVENTION: After crossing the occlusion with a microcatheter, reteplase (2 units) was administered into the clot. Mechanical thrombolysis was then attempted, without restoration of flow. Two 3 x 12-mm coronary stents were placed from the M1 into the superior and inferior divisions, respectively, with complete restoration of flow (TIMI 3). Within 72 hours, the patient had an NIHSS score of 1, with a small infarction in the external capsule. CONCLUSION: Novel stroke interventions need to be developed for patients with acute ischemic stroke in whom traditional interventions fail. We present (to our knowledge) the first case of successful revascularization of an acute M1 occlusion accomplished with placement of two coronary stents.
Adult↗
Stent-assisted intracranial recanalization for acute stroke: early results.
OBJECTIVE: In patients who are not candidates for intravenous tissue plasminogen activator, intra-arterial (IA) therapy is an alternative. Current recanalization rates are 50 to 60% for IA thrombolysis. Stent-assisted recanalization in the setting of acute stroke after failed thrombolysis may improve recanalization rates. METHODS: A retrospective analysis was performed of 19 patients treated at two institutions between July 2001 and March, 2005 with intracranial stenting of a vessel resistant to standard thrombolytic techniques. Demographics, clinical, and radiographic presentation and outcomes were studied. RESULTS: Thirteen men and six women with a median baseline National Institutes of Health Stroke Scale (NIHSS) score of 16 (range, 15-22) were included. Eight lesions were located at the internal carotid artery terminus, seven in the M1/M2 segment, and four in the basilar artery. Average time-to-treatment was 210 +/- 160 minutes. Overall recanalization rate (Thrombolysis in Cerebral Infarction Grade 2 or 3) was 79%. There were six deaths: five due to progression of stroke and withdrawal of care at the family's request and one as the result of a delayed carotid injury after tracheostomy. One postoperative asymptomatic intracranial hemorrhage occurred without adverse affect on outcome. Median discharge NIHSS score of surviving patients was 5 (range, 2.5-11.5). Lesions at the internal carotid artery terminus (P < 0.009), older age (P < 0.003), and higher baseline NIHSS score (P < 0.009) were significant negative outcome predictors, as measured by >3 modified Rankin scale score at discharge. CONCLUSION: Stent-assisted recanalization for acute stroke resulting from intracranial thrombotic occlusion is associated with a high recanalization rate and low intracranial hemorrhage rate. These initial results suggest that stenting may be an option for recalcitrant cerebral arterial occlusions.
Adult↗
Surgical decompression and coil removal for the recovery of vision after coiling and proximal occlusion of a clinoidal segment aneurysm: technical case report.
OBJECTIVE: We present the case of a patient with continued deterioration of vision after endovascular treatment of an unruptured clinoidal segment aneurysm. In conjunction with a review of the literature, the findings in this case highlight the need for further refinements in our understanding of pathophysiological changes induced by coiling of cerebral aneurysms, especially those in aneurysms producing signs and symptoms relating to mass effect. CLINICAL PRESENTATION: The patient is a 45-year-old man who presented with progressive vision loss. Imaging studies revealed a large, clinoidal segment aneurysm. The patient continued to experience progressive vision loss despite treatment with endovascular coiling, proximal occlusion, and high-dose steroid medication. INTERVENTION: The patient underwent a craniotomy for decompression of the optic nerve and for salvage of vision. Clipping of the distal vessel was performed, and the coil mass was removed. The patient experienced marked improvement of central vision after the surgical procedure. CONCLUSION: Although endovascular treatment of aneurysms protects most patients from aneurysm rupture, this case illustrates the fact that coiling, followed by proximal occlusion, might fail to alleviate symptoms related to mass effect. Our experience in this case suggests that early surgical decompression may be indicated for patients presenting with progressive visual deterioration.
Carotid Artery Diseases↗
Intravascular ultrasound for intracranial angioplasty and stent placement: technical case report.
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.
Aged↗
Use of heparin-coated stents in neurovascular interventional procedures: preliminary experience with 10 patients.
OBJECTIVE: Currently, there is minimal published data on the use of heparin-coated stents in the neurovasculature; however, these stents have a proven clinical record in the treatment of coronary disease. This article details our experience with the safety and technical aspects of stent deployment in the first 10 patients who had heparin-coated stents placed in the intracranial and cervical vasculature and the preliminary follow-up in most cases. METHODS: We retrospectively reviewed the clinical history, intra- and periprocedural data, and imaging for the patients who received heparin-coated stents in the cervical and intracranial vasculature for cerebrovascular disease between October 2002 and October 2003. RESULTS: Thirteen heparin-coated stents were placed in 10 patients. Seven out of the 10 patients had heparin-coated stents placed in the posterior circulation; the remaining three patients had stents placed in the anterior circulation. Four patients had stents placed intracranially. There was no acute or subacute in-stent thrombosis and no procedure-related complications. Follow-up was performed on most patients, with no clinical symptoms attributable to restenosis in any patient. CONCLUSION: This small series suggests that heparin-coated stents are safe for use in the treatment of cervical and intracranial atherosclerotic disease. Longer-term follow-up is needed to study the heparin coating effect on in-stent restenosis rates and to assess the long-term durability and clinical efficacy of this stent. The use of drug-coated stents in the cerebrovascular circulation is an area that warrants further investigation.
Adult↗
Safety and pharmacokinetics of sirolimus-eluting stents in the canine cerebral vasculature: 180 day assessment.
OBJECTIVE: We evaluated local and systemic pharmacokinetics and pharmacodynamics of sirolimus-eluting stents (SES) in canine cerebral vessels. METHODS: SES (1.5 x 8 mm, 79 microg/479 microg sirolimus) and control stents (1.5 x 8 mm stainless steel with or without polymer) were implanted in canine basilar and ventral spinal arteries. Animals were sacrificed for local pharmacokinetic (36 animals at 1, 3, 8, 30, 90, 180 days) and pharmacodynamic (60 animals at 3, 30, 90, 180 days) assessment. RESULTS: Postrecovery adverse clinical events were not serious, requiring no unscheduled treatment. Histologically, brain and spinal cord sections revealed scattered microinfarcts and minimal gliosis consistent with postprocedure changes in all four stent-treatment groups. All stented vessels at all time points demonstrated good luminal patency with low injury and inflammation scores and no thrombosis of either stented or branch arteries. Endothelialization was complete in all stent groups by 30 days. Intimal smooth muscle cell scores were reduced in both SES groups at 30, 90, and 180 days. Systemic sirolimus levels peaked between 1 and 7 hours postimplant (maximum concentration, 1.2 +/- 1.47, 79 microg; 4.5 +/- 1.23 ng/ml, 479 microg), then declined rapidly to 1 ng/ml or less by 96 hours. Peak local tissue sirolimus levels were 41.5 ng/mg (79 microg) and 65 ng/mg (479 microg). CONCLUSION: SES in canine cerebral vessels were associated with good luminal patency to 180 days, with complete endothelialization and no evidence of acute thrombosis. This model has shown that SES deployed within the brain do not cause neurotoxicity during a 180-day time course, even when exaggerated doses are used. The findings support the contention that SES are safe to use and maintain patency in cerebral vessels.
Animals↗
Current concepts in the management of intracranial atherosclerotic disease.
Medically refractory, symptomatic intracranial atherosclerotic disease has a poor prognosis. Based on the results of the Warfarin-Aspirin Symptomatic Intracranial Disease study, the risk of ipsilateral stroke at 1.8 years is between 13 and 14% in patients with symptomatic intracranial atherosclerosis. Synergistic advances in intracranial angioplasty and stenting, modern neuroimaging techniques, and periprocedural and postprocedural antithrombotic regimens are creating new models for the diagnosis and successful endovascular treatment of intracranial stenosis. In this article, the most recent clinical developments and concepts for the diagnosis and endovascular treatment of intracranial atherosclerotic disease are discussed.
Angioplasty↗
Giant cerebral aneurysms: endovascular challenges.
OBJECTIVE: Giant (>or=25 mm in diameter) cerebral aneurysms have a poor natural history, with high risks of subarachnoid hemorrhage or progressive disability or death caused by mass effect or stroke. Surgical treatment may be effective but carries a high burden of morbidity and mortality. Thus, attempts at endovascular solutions to these complex lesions have been developed to offer therapy at reduced risk. METHODS: The authors reviewed their clinical experience and the current body of literature concerning giant cerebral aneurysms and present their perspective on the current state of the art in endovascular therapy for these aneurysms. A variety of techniques are described that can be used in an attempt to provide a solution to the wide variety of clinical dilemmas associated with the management of these difficult lesions. Preprocedural planning and periprocedural considerations are discussed briefly. The use of intracranial balloons and stents are described in conjunction with the use of detachable platinum coils. The developing concept of using stents alone to treat aneurysms is discussed. Alternative methods of treating giant aneurysms are discussed. RESULTS: Current endovascular approaches, when properly selected and applied, can provide lower-risk therapies than conventional microsurgical approaches for patients harboring giant cerebral aneurysms. However, endovascular approaches do not, at present, provide results that are as durable as current surgical techniques for giant cerebral aneurysms. CONCLUSION: Treatment of giant cerebral aneurysms via endovascular therapeutics requires the interventionist to possess an extensive armamentarium. Meticulous preprocedure evaluation, patient selection, and execution of the treatment plan enable safe and effective management. Current therapies do not provide an ideal solution for every patient, so one must consider creative and evolving solutions to these difficult clinical challenges. The procedural morbidity of open surgery versus the decreased durability of current endovascular techniques must be assessed carefully.
Blood Vessel Prosthesis↗
Cervical carotid revascularization: the case for carotid angioplasty with stenting.
Carotid artery angioplasty with or without stent placement has evolved as an alternative to carotid endarterectomy, particularly for those patients in whom carotid endarterectomy is associated with a higher risk of complications. This article summarizes the selection criteria for participation in and the results of several carotid intervention trials, reviews the relative indications and limitations for both surgical and endovascular revascularization approaches, and describes the technique for and results associated with carotid stenting. The discussion is presented from the vantage of neurosurgeons who are experienced in both revascularization approaches.
Angioplasty↗
Workforce needs for endovascular neurosurgery.
During the past decade, endovascular techniques and clinical experience have matured to the point that all or a significant part of the treatment of acute ischemic stroke, cerebral aneurysms, brachiocephalic occlusive disease, and arteriovenous fistulae or malformations is performed in angiography suites by neuroradiologists, vascular surgeons, peripheral interventionists, cardiologists, neurologists, and neurosurgeons worldwide. With improvements in technology and lower morbidity rates, the scope of endovascular techniques will only increase. Currently, in the United States alone, this amounts to a volume of more than 500,000 patients annually. Neurosurgeons currently provide only a small portion of the care of these patients. The workforce needs for endovascular surgeons in neurosurgery will be determined by the patients, the willingness of neurosurgeons to embrace endovascular techniques, and the broad scope of cerebrovascular disorders that can be treated.
Career Mobility↗
Endovascular management of acute symptomatic intracranial arterial occlusion.
OBJECTIVE: Acute ischemic stroke has reached epidemic proportions in the United States, affecting approximately 700,000 people annually. With the recent technological advancements in endovascular devices, clinicians now have tools capable of recanalizing acute intracranial occlusions. The combination of pharmacological thrombolysis and mechanical clot perturbation may result in increased rates of angiographic recanalization, which may lead to improvement in patient outcomes after acute stroke. METHODS: In this article, the various intra-arterial pharmacological and mechanical therapies used by interventionists to treat acute stroke are described. Strategies for using combinations of these therapies are discussed, as are preliminary radiographic and clinical outcomes. Techniques for complex mechanical stroke interventions are discussed in detail. RESULTS: Several advances in endovascular stroke technologies are becoming increasingly available. CONCLUSION: With proper patient selection, these therapies may lead to increased recanalization rates and better patient outcomes.
Acute Disease↗
A model system for mapping vascular responses to complex hemodynamics at arterial bifurcations in vivo.
OBJECTIVE: Cerebral aneurysms are preferentially located at arterial bifurcation apices with complex hemodynamics. To understand disease mechanisms associated with aneurysm initiation, we attempted to establish a causal relationship between local hemodynamics and vascular responses. METHODS: Arterial bifurcations were surgically created from native common carotid arteries in two dogs, angiographically imaged 2 weeks and 2 months later, and then excised. We characterized local morphological changes in response to specifically manipulated hemodynamics. Computational fluid dynamics simulations were performed on the in vivo images and results mapped onto histological images. RESULTS: Local flow conditions, such as high wall shear stress and high wall shear stress gradient, were found to be associated with vascular changes, including an intimal pad in the flow impingement region and a "groove" bearing the characteristics of an early aneurysm. CONCLUSION: This novel method of histohemodynamic micromapping reveals a direct correlation between an altered hemodynamic microenvironment and vascular responses consistent with aneurysm development.
Animals↗