An alternative reduced dose regimen of ticagrelor for neuroendovascular patients.

OBJECTIVE: There is a growing use of ticagrelor in patients undergoing neuroendovascular procedures, especially those who demonstrate clopidogrel resistance. While multiple dosages are studied in the cardiology literature, the optimal dose for patients with neurological pathology has yet to be established. Here, we describe a single center experience involving 39 patients who underwent neuroendovascular procedures that then received an adjusted lower dose of ticagrelor. METHODS: A retrospective chart review was performed between 2013 and 2017 for patients on dual anti-platelet therapy (DAPT) for either cervical or intracranial vascular pathologies, as well as stenting of the neurovasculature, including carotid arteries. Patients were placed on ticagrelor if their measured P2Y12 reaction units (PRU) responses to clopidogrel were outside the expected range in our center using the VerifyNow™ P2Y12 test. All patients were maintained on a dose of 45 mg twice daily except for one patient who received 22.5 mg twice daily. Responsiveness to ticagrelor were measured utilizing the VerifyNow™ P2Y12 test. RESULTS: The mean number of days for follow-up post treatment initiation was 532 days. A total of 39 patients were included in the analysis. Of these, 8 patients (21%) received implantation of intracranial stents (5 patients received pipeline embolization devices, 1 patient received stent-assisted coiling, and 2 patients received intracranial stents for atherosclerotic disease). Fourteen patients (35%) received carotid angioplasty and stenting. Seventeen patients (44%) did not receive permanent implantation of a stent. All patients on the lower dose ticagrelor of 45 mg twice daily achieved responsiveness (i.e., PRU < 194). Hemorrhagic transformation of ischemic stroke occurred in one patient (2.5%). No other hemorrhagic complications were encountered. No thromboembolic events were recorded aside from one patient (2.5%) with intracranial atherosclerotic disease who had an ischemic event. CONCLUSIONS: A lower dose of ticagrelor (45 mg twice daily) appears to be safe and effective in this small cohort of patients who are resistant to clopidogrel per P2Y12 testing and who have increased risk of ischemic or hemorrhagic strokes due to neurovascular pathologies and implants. Further randomized studies are required to confirm these findings.

Normal-Tension Glaucoma Complicated by a Giant Internal Carotid-Ophthalmic Artery Aneurysm.

Purpose. We describe a patient with normal tension glaucoma (NTG) of several years whose management was complicated by the presence of a giant internal carotid-ophthalmic artery aneurysm. Observations. A 72-year-old woman presented to our glaucoma clinic with accelerated deterioration of her vision in her left eye (OS) over a 1-month period. Her ophthalmic history was most notable for bilateral NTG diagnosed 3 years prior which had been treated with several laser trabeculoplasty OS and topical bimatoprost 0.01% eye drops in both eyes (OU). Upon evaluation, her visual acuity OS had worsened, and visual field (VF) testing showed extensive progressive losses temporally and pericentrally OS over a year with stable IOP measurements and no neurological complaints. Given her atypical NTG progression, she was referred for an urgent neurological evaluation which revealed an unruptured giant left internal carotid-ophthalmic aneurysm. Following the successful treatment of the aneurysm with platinum coils, she continued to demonstrate additional bilateral ophthalmic changes including further progression of VF loss and RNFL thinning OS > OD on follow-up. Conclusion and Importance. Overall, this report describes a unique complication in the management of a patient with chronic bilateral NTG in the form of a giant internal carotid-ophthalmic aneurysm. Moreover, it highlights the need for clinicians to maintain a degree of suspicion for compressive lesions of the optic nerve when presented with atypical progression of VFs and/or visual acuity loss in glaucomatous patients.

A triple bifurcation aneurysm model for evaluating complex endovascular therapies in dogs.

OBJECT: Animal aneurysm models are required for the study of the hemodynamics and pathophysiology of intracranial aneurysms in humans and so that experimental treatments can be tested prior to clinical trials. The authors developed a canine model that consistently produces up to three bifurcation aneurysms similar in morphological features and hemodynamics to human intracranial aneurysms. METHODS: In 10 mongrel dogs, a harvested segment of the external jugular vein was anastamosed to an external carotid artery (CA)-lingual artery bifurcation arteriotomy site to create a lateral bifurcation aneurysm. The surgery was repeated on the contralateral side in each animal to form a second lateral bifurcation aneurysm and, in five dogs, a CA-CA crossover anastomosis was also performed to create a terminal bifurcation aneurysm. Nineteen of 20 lateral bifurcation aneurysms were confirmed in 10 dogs by diagnostic angiography 7 to 14 days after surgery. Aneurysm fundus-to-neck ratios ranged from 1 to 2, depending on the size of the arteriotomy. The terminal bifurcation aneurysms were confirmed in all five dogs by diagnostic angiography 7 to 14 days after the procedure. The authors later tested endovascular techniques for embolizing the aneurysms. CONCLUSIONS: Three bifurcation aneurysms of sufficient size for endovascular access can be created in a reproducible fashion in the same animal. This model is useful for studying complex endovascular procedures in aneurysms that mimic the human condition and for testing new devices and techniques.

Frequency and management of recurrent stenosis after carotid artery stent implantation.

OBJECT: To determine the rate of hemodynamically significant recurrent carotid artery (CA) stenosis after stent-assisted angioplasty for CA occlusive disease, the authors analyzed Doppler ultrasonography data that had been prospectively collected between October 1998 and September 2002 for CA stent trials. METHODS: Patients included in the study participated in at least 6 months of follow-up review with serial Doppler studies or were found to have elevated in-stent velocities (> 300 cm/second) on postprocedure Doppler ultrasonograms. Hemodynamically significant (> or = 80%) recurrent stenosis was identified using the following Doppler criteria: peak in-stent systolic velocity at least 330 cm/second, peak in-stent diastolic velocity at least 130 cm/second, and peak internal carotid artery/common carotid artery velocity ratio at least 3.8. Follow-up studies were obtained at approximate fixed intervals of 1 day, 1 month, 6 months, and yearly. Angiography was performed in the event of recurrent symptoms, evidence of hemodynamically significant stenosis on Doppler ultrasonography, or both. Treatment was repeated because of symptoms, angiographic evidence of severe (> or = 80%) recurrent stenosis, or both of these. Stents were implanted in 142 vessels in 138 patients (all but five patients were considered high-risk surgical candidates and 25 patients were lost to follow-up review). For the remaining 112 patients (117 vessels), the mean duration of Doppler ultrasonography follow up was 16.42+/-10.58 months (range 4-54 months). Using one or more Doppler criteria, severe (> or = 80%) in-stent stenosis was detected in six patients (5%). Eight patients underwent repeated angiography. Six patients (three with symptoms) required repeated intervention (in four patients angioplasty alone; in one patient conventional angioplasty plus Cutting Balloon angioplasty; and in one patient stent-assisted angioplasty). CONCLUSIONS: In a subset of primarily high-risk surgical candidates treated with stent-assisted angioplasty, the rates of hemodynamically significant restenosis were comparable to surgical restenosis rates cited in previously published works. Treatment for recurrent stenosis incurred no instance of periprocedure neurological morbidity.

Recent advances in endoluminal revascularization for intracranial atherosclerotic disease.

More than 750,000 strokes occur annually in the United States. Of these, 8-10% are due to intracranial atherosclerosis. Less than 50% of patients with strokes from intracranial atherosclerosis will have a transient ischemic attack. For those patients with symptomatic intracranial atherosclerosis, the prognosis is poor; and the recent Warfarin-Aspirin Symptomatic Intracranial Stenosis (WASID) trial results have demonstrated the high risk of warfarin without clear benefit. Intracranial angioplasty and stenting is emerging as a viable and effective treatment alternative for patients with symptomatic intracranial stenosis. Advances in stent design, endovascular wires, and catheters and balloons are allowing endovascular surgeons to safely treat intracranial atherosclerosis. Wider clinical experience has led to refinement of patient selection and endoluminal techniques. Drug eluting-stents have the promise of decreasing the risk of restenosis. In this review, the most recent clinical, laboratory, and technical details for the treatment of intracranial angioplasty and stenting are discussed.

Mathematical model of the rupture mechanism of intracranial saccular aneurysms through daughter aneurysm formation and growth.

OBJECTIVES: Daughter aneurysms have been strongly associated with saccular aneurysm rupture. We constructed a mathematical model to help explain this association as a possible hemodynamic mechanism for intracranial saccular aneurysm rupture. METHODS: Our model is based on the assumption that when an aneurysm reaches a state of imminent rupture, the weakest area of the aneurysm wall responds passively to a surge of intra-aneurysmal pressure by forming a daughter aneurysm that will be the site of the eventual rupture. The daughter and parent aneurysms were assumed to be spherical. Using mathematical modeling, the growth of the daughter aneurysm was observed. To obtain the change in tensile stress in the daughter aneurysm wall under constant pressure and changing geometry, the Law of Laplace was applied to the parent and the daughter aneurysms. RESULTS: The model reveals that the stress factor, i.e. tensile stress in the daughter aneurysm wall relative to the wall strength (rupture point), is dependent on two geometric parameters: the orifice factor (mu), which represents the relative size of the daughter aneurysm orifice radius to the parent aneurysm radius; and the aspect ratio (lambda), which represents the height-to-orifice ratio of the daughter aneurysm. As the daughter aneurysm develops, the stress factor first decreases to protect against rupture. Minimal stress is attained at an aspect ratio (lambda) of 0.577 regardless of the orifice factor. This is a relatively stable state. Further growth of the daughter aneurysm results in an increase of stress above the minimum, eventually leading to rupture at a stress factor of 1. A smaller orifice factor mu allows this aneurysm to grow to a higher aspect ratio lambda before rupture. DISCUSSION: Daughter aneurysm formation is a likely path to aneurysm rupture. The formation of a daughter aneurysm temporarily decreases the tensile stress within a parent aneurysm in which rupture is imminent, indicating a temporary protective role of daughter aneurysm development. Aneurysms harboring daughter aneurysms are at a more advanced stage of development, hence at a greater risk for rupture. The severity of the rupture risk can be estimated on the basis of daughter aneurysm geometry; aspect ratio lambda > 0.577 indicates a greater risk of rupture. Furthermore, daughter aneurysms with larger orifices are associated with a greater risk of rupture.

Contrast settling in cerebral aneurysm angiography.

During angiography, blood flow is visualized with a radiopaque contrast agent, which is denser than blood. In complex vasculature, such as cerebral saccular aneurysms, the density difference may produce an appreciable gravity effect, where the contrast material separates from blood and settles along the gravity direction. Although contrast settling has been occasionally reported before, the fluid mechanics behind it have not been explored. Furthermore, the severity of contrast settling in cerebral aneurysms varies significantly from case to case. Therefore, a better understanding of the physical principles behind this phenomenon is needed to evaluate contrast settling in clinical angiography. In this study, flow in two identical groups of sidewall aneurysm models with varying parent-vessel curvature was examined by angiography. Intravascular stents were deployed into one group of the models. To detect contrast settling, we used lateral view angiography. Time-intensity curves were analysed from the angiographic data, and a computational fluid dynamic analysis was conducted. Results showed that contrast settling was strongly related to the local flow dynamics. We used the Froude number, a ratio of flow inertia to gravity force, to characterize the significance of gravity force. An aneurysm with a larger vessel curvature experienced higher flow, which resulted in a larger Froude number and, thus, less gravitational settling. Addition of a stent reduced the aneurysmal flow, thereby increasing the contrast settling. We found that contrast settling resulted in an elevated washout tail in the time-intensity curve. However, this signature is not unique to contrast settling. To determine whether contrast settling is present, a lateral view should be obtained in addition to the anteroposterior (AP) view routinely used clinically so as to rule out contrast settling and hence to enable a valid time-intensity curve analysis of blood flow in the aneurysm.

Clinical and angiographic results of dilatation procedures for symptomatic intracranial atherosclerotic disease.

BACKGROUND AND PURPOSE: The authors determined the technical success and the clinical and angiographic results of angioplasty and/or stent placement for intracranial atherosclerotic disease (ICAD) at a tertiary-care referral hospital. METHODS: Angiographic and clinical outcomes occurring within the 1-month follow-up interval were recorded. Patients were followed up for a mean period of 20.5 +/- 9.2 months, and a neurovascular imaging study was performed in 18 of the 21 patients alive after a mean period of 19.7 +/- 9.2 months. Stroke-free survival and ipsilateral stroke-prevention rates were estimated using Kaplan Meier analyses. RESULTS: Twenty-four patients (mean age = 61.0 +/- 13.5 years; 15 were men) underwent 30 procedures for treatment of ICAD. The procedures included angioplasty (n = 18) and attempted primary stent placement (n = 14). In 2 procedures, angioplasty was performed in the same session after unsuccessful stent placement. There was immediate stenosis reduction (mean +/- SD) from 84% +/- 17% to 27% +/- 21%. The overall 1-month composite rate of major stroke, death, and major bleeding complications was 7% for the 30 procedures. Overall stroke-free survival at 36 months was estimated as 79% (95% confidence interval, 57%-91%), and the ipsilateral stroke-prevention rate was estimated to be 87% (95% confidence interval, 65%-95%). Among the 15 patients who underwent repeat angiography, restenosis requiring second intervention was observed in 1 patient. No restenosis could be identified in 3 patients who underwent computed tomographic or magnetic resonance angiography. CONCLUSION: This single-center study demonstrates the feasibility and effectiveness (for secondary stroke prevention) of angioplasty and/or stent placement for treatment of ICAD.

Perforation of external carotid artery branch arteries during endoluminal carotid revascularization procedures: consequences and management.

The purpose of this article is to describe several inadvertent perforations of external carotid artery branches that occurred in our laboratory during planned carotid artery stenting procedures. When known, the mechanism of the perforation is described. The treatment of these complications is discussed, along with a more general discussion of potential embolic materials. Perforation of branch arteries within the external carotid artery territory during planned carotid revascularization is an uncommon but potentially life-threatening complication. This complication can occur as a result of wire or catheter placement into these vessels. Early recognition of the perforation, prompt treatment of the bleeding, and control of the patient's airway are necessary to avoid a potentially catastrophic outcome.

Toward clinical equipoise: the current case for carotid angioplasty and stent placement.

Recent advances in carotid artery (CA) stent placement procedures have propelled this technology into the forefront of treatment options for both symptomatic and asymptomatic patients with CA stenosis. Until recently, endarterectomy was the only surgical option for patients with CA occlusive disease. For high-risk surgical candidates, periprocedural stroke rates remained unacceptable and were significantly higher than those associated with the natural history of the disease. Advances in stent technology and improvements in antiplatelet and antithrombotic regimens, in conjunction with distal protection devices, have significantly lowered the risk of periprocedural complications for high-risk surgical candidates requiring CA revascularization. In this paper the authors review data gleaned from the important recent CA stent trials and address questions concerning the safety, efficacy, and durability of stent-assisted angioplasty for extracranial CA occlusive disease. Additionally, they review the role of noninvasive imaging modalities for the diagnosis and surveillance of CA disease in these high-risk patients.

Stent placement for the treatment of nonsaccular aneurysms of the vertebrobasilar system.

Vertebrobasilar nonsaccular aneurysms represent a small subset of intracranial aneurysms and usually are among the most challenging to be treated. The aim of this article was to review the literature and summarize the experience in the treatment of these lesions with endovascular approaches. The method of stent implantation as it is performed at the authors' institution, including options available for vertebral artery access, is described. Practitioners involved in the treatment of these lesions should be aware of the potential application of intravascular stent placement as well as the associated postprocedure risks and potential complications.

Isolated and borderline isolated systolic hypertension relative to long-term risk and type of stroke: a 20-year follow-up of the national health and nutrition survey.

BACKGROUND AND PURPOSE: Although the short-term risks of stroke and types of stroke associated with isolated systolic hypertension (ISH) and borderline isolated systolic hypertension (BISH) have been described, the long-term effects of these hypertensive conditions, particularly in younger individuals, are unclear. We performed this study to evaluate the long-term risks of stroke, type of stroke, and predictors of stroke associated with ISH and BISH and how this risk compares with that for persons with diastolic hypertension and normotension. METHODS: We used the 20-year follow-up data for 12 344 adults aged 25 to 74 years who participated in the First National Health and Nutrition Examination Survey Follow-Up Study to determine the aforementioned risks. Blood pressure (BP) measurements of the participants were obtained during baseline evaluation. ISH was defined as systolic BP >/=160 mm Hg and diastolic BP <90 mm Hg. BISH was defined as systolic BP between 140 and 159 mm Hg and diastolic BP <90 mm Hg. Diastolic hypertension was defined as a diastolic BP >/=90 mm Hg. Normotension was defined as systolic BP <140 mm Hg and diastolic BP <90 mm Hg. Incidence of stroke overall and incidence of ischemic stroke and intracerebral hemorrhage were determined from a review of hospital records and death certificates. Relative risk (RR) of stroke and stroke type in association with each hypertensive category was determined by Cox proportional hazards analysis after adjustment for potential confounding variables. RESULTS: Among the 12 344 participants, hypertension was categorized as ISH (n=493), BISH (n=1241), and diastolic hypertension (n=3954). Normotension was observed in 6656 persons. After adjustment for differences in age, sex, education, serum cholesterol level, body mass index, diabetes mellitus, and cigarette smoking, a significantly higher RR for all strokes was observed in participants with ISH (RR, 2.7; 95% CI, 2.0 to 3.4) and BISH (RR, 1.4; 95% CI, 1.1 to 1.8) than those with normotension. The risk was significantly higher for ischemic stroke or intracerebral hemorrhage in persons with ISH and BISH. Among the 1734 persons with either ISH or BISH, the risk of stroke was independently associated with older age, diabetes mellitus, and systolic BP >/=180 mm Hg. CONCLUSIONS: Increased risks for stroke, ischemic stroke, and intracerebral hemorrhage were observed in patients with BISH, similar to those associated with ISH and diastolic hypertension. Future clinical trials are required to evaluate the effect of antihypertensive treatment in younger patients with BISH and ISH.

Site-specific thromboembolism: a novel animal model for stroke.

BACKGROUND AND PURPOSE: To develop a technique for site-specific placement of a thrombus of predetermined volume in an animal model for the purpose of evaluating methods of intravascular thrombolysis and clot retrieval. METHODS: Six swine were subjected to thrombus injection bilaterally in the ascending pharyngeal artery (APA). Each animal underwent transfemoral angiography while under general anesthesia. A nondetachable balloon catheter and a 3-French microcatheter were then advanced into the common carotid artery through a 7-French guide catheter. With the microcatheter in the proximal APA and the balloon inflated proximally, a bolus of preformed thrombus composed of 0.9 mL of autologous blood and 0.1 mL of bovine thrombin (200 IU/mL) was injected through the microcatheter while local flow arrest was maintained for 15 min. The balloon was deflated and removed. The occluded arteries were observed by serial angiography for 3 hr and then resected for gross examination and hematoxylin and eosin staining. RESULTS: Each APA was occluded angiographically and did not recanalize during the 3-hr observation period. Persistent, proximal progression of thrombus to the superior thyroid artery origin occurred in three animals. Gross inspection revealed that the resected arteries contained thrombus in the proximal APA but not in the common carotid artery. Histologic examination revealed organized thrombus, without evidence of intimal injury. CONCLUSION: Our model provides a simple, reliable method for site-specific injection of a thrombus of predetermined volume. Site-specific placement is important for evaluation of the efficacy of thrombolytic agents and techniques. Angiographic evidence of brain revascularization can be used to grade revascularization and clot volume. The ability to specifically localize and estimate clot volume makes our model well suited for the evaluation and comparison of thrombolytic agents and endovascular techniques.

Follow-up of stented carotid arteries by Doppler ultrasound.

OBJECTIVE: Blood flow velocity (BFV) in the carotid artery is altered by stent placement. The significance of these alterations is unknown. In our experience, both standard BFV criteria for stenosis and customized criteria recommended by other authors have led to high rates of false-positive studies. We reviewed our experience with Doppler ultrasonography immediately after extracranial carotid artery stent placement to define criteria for restenosis by BFV. METHODS: Complete carotid angiograms and BFV results were available for 114 patients treated between January 1998 and December 1999. Angiographic images obtained immediately after stent placement and at follow-up were measured for residual or recurrent stenosis by a blinded reviewer according to the North American Symptomatic Carotid Endarterectomy Trial method. Results of BFV studies obtained within 1 week of stent placement were interpreted by using two standard criteria (A, peak in-stent systolic velocity greater than 125 cm/s; B, internal carotid artery-to-common carotid artery ratio greater than 3.0) and two customized criteria (C, peak in-stent velocity greater than 170 cm/s; D, internal carotid artery-to-common carotid artery ratio greater than 2.0). The results of follow-up angiography and the most recent Doppler study were compared for nine patients. RESULTS: On the basis of an examination of Doppler studies obtained immediately after stent placement, 36 patients met Criterion A for stenosis according to measured BFV (corresponding mean angiographic stenosis, 14.73 +/- 18.45%), 3 patients met Criterion B (mean stenosis, 1.67 +/- 2.89%), 8 patients met Criterion C (mean stenosis, 12.61 +/- 13.18%), and 14 met Criterion D (mean stenosis, 7.98 +/- 21.74%). No patient with Doppler criteria for significant stenosis had more than 50% residual stenosis. Three of nine patients who underwent follow-up angiography had stenosis of 50% or more; of these three patients, two underwent second angioplasty procedures. The peak in-stent systolic velocity or internal carotid artery-to-common carotid artery BFV ratio for each of the three patients with restenosis, but not for the six other patients, had increased by more than 80% since the immediate post-stenting Doppler study. CONCLUSION: Strict BFV criteria for restenosis after carotid artery stenting are less reliable than change in BFV over time. An immediate post-stenting Doppler study must be obtained to serve as a reference value for future follow-up evaluation.

Apoptosis as a form of cell death in intracerebral hemorrhage.

OBJECTIVE: The goals of this study were to identify and quantify the presence of programmed cell death (apoptosis) in intracerebral hemorrhage (ICH) among human subjects. Recent evidence from laboratory models suggests that cell death in the perihematoma region may involve apoptosis. METHODS: Retrospective clinical and histological analyses were performed for patients with spontaneous ICH who underwent surgical evacuation. Quantification of apoptotic cells was performed in sections obtained from the perihematoma region from 12 patients with ICH and stained with the terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick-end labeling method. Necrosis was identified on the basis of morphological criteria, using hematoxylin and eosin staining. RESULTS: Evidence of apoptosis was present in surgical specimens obtained from 10 of the 12 patients. The mean number of apoptotic cells in the perihematoma region in each patient specimen was 38% (range, 0-90%). For five patients, more than one-half of the total cells observed were apoptotic. Apoptosis was observed in specimens obtained within 1 day, 2 days, and 5 days after the onset of symptoms. No terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick-end labeling-positive cells were observed in specimens from the two patients with cerebellar hematomas. The mean proportion of necrotic cells in the perihematoma region in each patient specimen was 25% (range, 0-100%). There was a prominent excess of apoptotic cells, in comparison with necrotic cells, for 6 of the 12 patients who underwent hematoma evacuation. For five other patients, similar proportions of apoptotic and necrotic cells were observed. Necrosis was the predominant finding for only one patient, who underwent late surgical evacuation on Day 5. CONCLUSION: These observations suggest that apoptosis represents a prominent form of cell death associated with ICH in the perihematoma region. Further studies are required to define the mediators of apoptosis in ICH.

Fate of branch arteries after intracranial stenting.

OBJECTIVE: One concern with respect to stent procedures performed to treat patients with intracranial lesions is the fate of normal major arterial branches after stents are placed across them. Because most of these lesions occur at vessel bifurcations or at branch points, a normal major branch often arises near the lesion and may be difficult to avoid during stent positioning. The aim of this article is to describe the angiographic outcome of intracranial major branch arteries crossed by a stent in the intracranial circulation. METHODS: We examined the immediate postprocedural cerebral angiograms of the 40 patients who underwent intracranial stenting at the University at Buffalo, Buffalo, NY, between June 1998 and April 2000. In each of 10 patients, the stent was placed across a normal major branch artery. Stents were used to treat aneurysms in seven patients and intracranial stenosis in three patients. The latest cerebral angiogram available was reviewed, and the patency of the major branch arteries was evaluated. RESULTS: The angiographic follow-up period ranged from 4 days to 35 months (mean follow-up, 10 mo). Each of the 10 major branch arteries was patent. No infarcts were associated with the territory of the major branch arteries crossed by the stents, and no patient experienced a related episode of clinical ischemia. Four patients died as a result of causes unrelated to the stenting procedure. The histology of a middle cerebral artery stent that was placed across a lenticulostriate perforator is presented. CONCLUSION: The flexible, low-profile stents used in this study had no angiographically or clinically apparent effect on the major intracranial branches across which they were placed.

Transradial stenting of the cervical internal carotid artery: technical case report.

OBJECTIVE AND IMPORTANCE: We describe a case of endoluminal stent placement for a cervical internal carotid artery stenosis in which percutaneous access was obtained via the radial artery. CLINICAL PRESENTATION: A 69-year-old man with known disease of the carotid, peripheral, and coronary arteries as well as chronic obstructive pulmonary disease presented for endoluminal revascularization of a severe, progressive right internal carotid artery stenosis. TECHNIQUE: Transfemoral access was complicated by the previous placement of a synthetic graft as the result of a previous right-to-left iliofemoral artery bypass procedure and an aortoiliac occlusion. A transradial approach was successfully attempted, and a Precise stent (Cordis Endovascular, Miami Lakes, FL) was successfully placed through a 6-French guide sheath. CONCLUSION: The transradial approach is becoming an increasingly viable alternative route for stent placement in patients with contraindicated or complicated femoral access routes. As devices become increasingly more pliable and smaller, the transradial route will be used with increasing frequency in this select patient population for stenting of both the cervical and intracranial circulation.

Evolution of neuroendovascular intervention: a review of advancement in device technology.

Neuroendovascular surgery is a rapidly evolving field. Each year, numerous improvements are made in the endovascular surgeon's armamentarium. This evolution in technology, which is occurring at a dizzying pace, addresses many of the current limitations of neuroendovascular approaches. The potential to improve the outcomes of our patients is tremendous, particularly because one of the most common and most devastating neurological disorders, ischemic stroke, remains largely untreated. This article presents several of the new technologies that are currently being investigated or are under development and have the potential to lead to major advances in endovascular approaches for the treatment of intracranial and extracranial diseases.

Brainstem infarction after delayed thrombosis of a stented vertebral artery fusiform aneurysm: case report.

OBJECTIVE AND IMPORTANCE: Recent technological advances have provided clinicians with stents that can be navigated throughout the tortuous proximal vessels of the posterior intracranial circulation. There have been few reports of fusiform and wide-necked aneurysms treated with stents. Of the known risks involved in stent placement in the intracranial circulation, delayed stent thrombosis has not been well described. CLINICAL PRESENTATION: A 34-year-old man who experienced the sudden onset of a severe headache with increasing lethargy was found on computed tomographic imaging to have a subarachnoid hemorrhage. Angiography revealed a left vertebral artery fusiform aneurysm that incorporated the posteroinferior cerebellar artery origin. INTERVENTION: A low-porosity Magic Wallstent (Boston Scientific, Natick, MA) was placed in the left vertebral artery across the aneurysm and the origin of the posteroinferior cerebellar artery. Angiography performed 9 days later revealed significant reduction in filling of the aneurysm. The patient returned 3 months after stent placement with severe neurological deterioration from a brainstem infarction caused by complete thrombotic occlusion of the left vertebral artery at the stented segment of the vessel. CONCLUSION: Stenting of fusiform aneurysms has provided an alternative to surgical clipping or parent vessel reconstruction. With the increasing frequency of intracranial stent placement for various cerebrovascular disease entities, we must become aware of potential complications associated with these procedures. Such awareness may influence decision-making processes regarding treatment and follow-up care.