Intracranial stenting of severe symptomatic intracranial stenosis: results of 100 consecutive patients

Safety and efficacy of stenting for symptomatic intracranial artery stenosis: a systematic reveiw and meta-analysis

Background: Stroke is currently the second-leading cause of death just behind ischaemic heart disease. Drug therapy is currently the standard of care for patients with symptomatic intracranial artery stenosis (sICAS). Stenting is an important treatment for the prevention and treatment of ischemic stroke. It has been suggested that vertebral artery stenting might reduce this risk, but operation-related complications limit the application of stenting in the treatment of ischemic stroke. The differences in the safety and efficacy of stenting combined with drugs and drugs alone in the treatment of sICAS are unclear. The aim of this study was to assess the impact of both treatment modalities on the prognosis of patients with sICAS through a systematic review and meta-analysis. Methods: The Chinese databases (CNKI, Wanfang, VIP, CBM, DUXIU) and English databases (Pubmed, Embase, Ovid_medline, Cochrane library, Web of science)were searched to identify all studies describing sICAS. The "Risk of Bias Assessment" tool and the "Jadad Scale" provided by the Cochrane Collaboration were used to evaluate the risk of bias and quality of the collected literature. The risk ratio (RR) and its 95% confidence interval (CI) were determined using Stata statistical software version 14.0. Results: A total of 11 studies were included, comprising a total of 1,915 patients. The combined results of the study showed no significant difference between the incidence of transient cerebral ischemia (TIA)and stroke in patients with sICAS treated with drugs in combination with stents versus drugs alone. The incidence of death or stroke, cerebral haemorrhage, disabling stroke or death was significantly higher in patients receiving stent-combined drug therapy versus drug therapy alone for sICAS. Conclusion: Studies suggest that stenting combined with medication for patients with sICAS may increase the incidence of death or stroke, cerebral haemorrhage, stroke or death, but has no significant effect on the incidence of TIA and stroke. The studies report inadequate and conflicting data and therefore the safety and efficacy of stenting for sICAS should be interpreted with caution. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022377090, identifier CRD42022377090.

Outpatient Day-Care Management of Unruptured Intracranial Aneurysm: A Retrospective Cohort Study

OBJECTIVE

This study aimed to assess the outcomes of outpatient day-care management of unruptured intracranial aneurysm (UIA), and to present the risks associated with different management strategies by comparing the outcomes and adverse events between outpatient day-care management and management with longer admission periods.

MATERIALS AND METHODS

This retrospective cohort study used prospectively registered data and was approved by a local institutional review board. We enrolled 956 UIAs from 811 consecutive patients (mean age ± standard deviation, 57 ± 10.7 years; male:female = 247:564) from 2017 to 2020. We compared the outcomes after embolization among the different admission-length groups (1, 2, and ≥ 3 days). The outcomes included pre- and post-modified Rankin Scale (mRS) scores and rates of adverse events, cure, recurrence, and reprocedure. Events were defined as any cerebrovascular problems, including minor and major stroke, death, or hemorrhage.

RESULTS

The mean admission period was 2 days, and 175 patients (191 aneurysms), 551 patients (664 aneurysms), and 85 patients (101 aneurysms) were discharged on the day of the procedure, day 2, and day 3 or later, respectively. During the mean 17-month follow-up period (range 6-53 months; 2757 patient years), no change in post-mRS was observed compared to pre-mRS in 99.6% of patients. Cure was achieved in 95.6% patients; minimal recurrence that did not require re-procedure occurred in 3.5% patients, and re-procedure was required in 2.3% (22 of 956) patients due to progressive enlargement of the recurrent sac during follow up (mean 17 months, range, 6-53 months). There were eight adverse events (0.8%), including five cerebrovascular (two major stroke, two minor strokes and one transient ischemic stroke), and three non-cerebrovascular events. Statistical comparison between groups with different admission lengths (1, 2, and ≥ 3 days) revealed no difference in the outcomes.

CONCLUSION

This study revealed no difference in outcomes and adverse events according to the admission period, and suggested that UIA could be managed by outpatient day-care embolization.

Preventive effects of ginseng against atherosclerosis and subsequent ischemic stroke: A randomized controlled trial (PEGASUS trial)

Background

Korean Red Ginseng (KRG) extract has been shown to have beneficial effects in patients with atherosclerosis, suggesting that KRG extract may be effective in preventing subsequent ischemic stroke in patients with severe atherosclerosis.

Methods

This double-blind, placebo-controlled trial randomized patients with severe atherosclerosis in major intracranial arteries or extracranial carotid artery, to ginseng group and placebo group. They were given two 500-mg KRG tablets or identical placebo tablets twice daily for 12 months according to randomization. The primary endpoint was the composite of cerebral ischemic stroke and transient ischemic attack during 12 months after randomization. The secondary endpoints were change in volumetric blood flow of the intracranial vessels and the incidence of newly developed asymptomatic ischemic lesions. Any adverse events were monitored.

Results

Fifty-eight patients were randomized from June 2016 to June 2017, 29 to ginseng and 29 to placebo, and 52 (28 and 24, respectively) completed the study. One patient in the placebo group, but none in the ginseng group, experienced ischemic symptoms (p = 0.46). Changes in volumetric blood flow and the presence of ischemic brain lesions did not differ significantly in the two groups, and none of these patients experienced adverse drug reactions.

Conclusion

Ginseng was well tolerated by patients with severe atherosclerosis, with these patients showing good compliance with ginseng dosing. Ginseng did not show significant effects compared with placebo, although none of the ginseng-treated patients experienced ischemic events. Long-term studies in larger patient populations are required to test the effect of ginseng.

Acute intracranial stenting with mechanical thrombectomy is safe and efficacious in patients diagnosed with underlying intracranial atherosclerotic disease

OBJECTIVE

To investigate whether significant differences exist in recanalization rates and primary outcomes between patients who undergo mechanical thrombectomy alone versus those who undergo mechanical thrombectomy with acute intracranial stenting.

METHODS

Through the utilization of a prospectively collected endovascular database at a comprehensive stroke center between 2012 and 2020, variables such as demographics, co-morbid conditions, symptomatic intracerebral hemorrhage, mortality rate at discharge, and good/poor outcomes in regard to modified thrombolysis in cerebral infarction score and modified Rankin Scale were examined. The outcomes between patients receiving acute intracranial stenting + mechanical thrombectomy and patients that underwent mechanical thrombectomy alone were compared.

RESULTS

There were a total of 420 acute ischemic stroke patients who met criteria for the study (average age 70.6 ± 13.01 years; 46.9% were women). Analysis of 46 patients from the acute stenting + mechanical thrombectomy group (average age 70.34 ± 13.75 years; 37.0% were women), and 374 patients from the mechanical thrombectomy alone group (average age 70.64 ± 12.92 years; 48.1% were women). Four patients (8.7%) in the acute stenting + mechanical thrombectomy group experienced intracerebral hemorrhage versus 45 patients (12.0%) in the mechanical thrombectomy alone group (p = 0.506); no significant increases were noted in the median length of stay (7 vs 8 days; p = 0.208), rates of modified thrombolysis in cerebral infarction 2B-3 recanalization (p = 0.758), or good modified Rankin Scale scores (p = 0.806).

CONCLUSION

Acute intracranial stenting in addition to mechanical thrombectomy was not associated with an increase in overall length of stay, intracerebral hemorrhage rates, or any change in discharge modified Rankin Scale. Further research is required to determine whether mechanical thrombectomy and acute intracranial stenting in acute ischemic stroke patients is unsafe.

Incidence and Risk Factors of In-Stent Restenosis for Symptomatic Intracranial Atherosclerotic Stenosis: A Systematic Review and Meta-Analysis

BACKGROUND

In-stent restenosis affects long-term outcome in patients with intracranial atherosclerotic stenosis.

PURPOSE

The aim of this meta-analysis was to evaluate the incidence and risk factors of in-stent restenosis.

DATA SOURCES

All literature that reported in-stent restenosis was searched on PubMed, Ovid EMBASE and Ovid MEDLINE data bases.

STUDY SELECTION

Original articles about stents for symptomatic intracranial atherosclerotic stenosis were selected.

DATA ANALYSIS

Meta-analysis was conducted to derive the pooled in-stent restenosis using a random-effects model. Meta-regression was performed to explore the risk factors predisposing to in-stent restenosis.

DATA SYNTHESIS

In total, 51 studies with 5043 patients were included. The pooled incidence rate of in-stent restenosis was 14.8% (95% CI, 11.9%-17.9%). Among the lesions with in-stent restenosis, 28.8% of them led to (95% CI, 22.0%-36.0%) related neurologic symptoms. The series in the United States had a higher in-stent restenosis rate (27.0%; 95% CI, 20.6%-33.9%) compared with those from Asia (13.6%; 95% CI, 10.3%-17.2%) and other regions as a whole (7.6%; 95% CI, 1.1%-18.1%) (P < .01). Multiregression analysis revealed that younger patient age was related to high in-stent restenosis rates (P = .019), and vertebrobasilar junction location (P = .010) and low residual stenosis (P = .018) were 2 independent risk factors for symptomatic in-stent restenosis rate.

LIMITATIONS

The heterogeneity of most outcomes was high.

CONCLUSIONS

Our study showed promising results of in-stent restenosis for symptomatic atherosclerotic stenosis. Studies are needed to further expatiate on the mechanisms by which younger patient age, vertebrobasilar junction location, and low residual stenosis could increase in-stent restenosis and symptomatic in-stent restenosis, respectively.

Peri-procedural stroke or death in stenting of symptomatic severe intracranial stenosis

BACKGROUND AND PURPOSE

There are limited data on predictors of 30-day stroke or death in patients with symptomatic intracranial atherosclerosis (sICAS) undergoing stenting. We aim to determine the factors associated with stroke or death at 30 days in the stenting arm of the SAMMPRIS trial.

METHODS

This is a post-hoc analysis of the SAMMPRIS trial including patients who underwent angioplasty/stenting. We compared patient-specific variables, lesion-specific variables, procedure-specific variables, and FDA-approved indications between patients with and without the primary outcome (stroke or death at 30 days). Logistic regression analyses were performed to evaluate associations with the primary outcome.

RESULTS

We identified 213 patients, 30 of whom (14.1%) met the primary outcome. Smoking status and lesion length were associated with the primary outcome: the odds of stroke or death for non-smokers versus smokers (adjusted OR 4.46, 95% CI 1.79 to 11.1, p=0.001) and for increasing lesion length in millimeters (adjusted OR 1.20, 95% CI 1.02 to 1.39, p=0.029). These had a modest predictive value: absence of smoking history (sensitivity 66.7%, specificity 65.4%) and lesion length (area under curve 0.606). Furthermore, event rates were not significantly different between patients with and without the FDA-approved indication for stenting (15.9% vs 12%, p=0.437).

CONCLUSION

In SAMMPRIS patients who underwent angioplasty/stenting, neither clinical and neuroimaging variables nor the FDA indication for stenting reliably predicted the primary outcome. Further work in identifying reliable biomarkers of stroke/death in patients with sICAS is needed before considering new clinical trials of stenting.

TRIAL REGISTRATION NUMBER

SAMMPRIS NCT00576693; Results.

Endovascular recanalization for symptomatic subacute and chronic intracranial large artery occlusion of the anterior circulation: initial experience and technical considerations

PURPOSE

This study aimed to report the clinical findings and initial clinical experience of endovascular recanalization for symptomatic subacute/chronic intracranial large artery occlusion (ILAO) of the anterior circulation.

METHODS

From October 2015 to December 2017, 13 patients with symptomatic subacute/chronic ILAO of the anterior circulation were enrolled in this study and underwent endovascular recanalization. We collected the initial procedural results, including the rate of successful recanalization and periprocedural complications, and data pertaining to angiographic and clinical follow-up.

RESULTS

Recanalization was successful in 11 of 13 patients (84.6%). Intraoperative complications occurred in four cases, including symptomatic distal embolism in three cases; one of which was simultaneously complicated with artery dissection. Intracerebral hemorrhage occurred in one case. Eleven patients underwent angiographic follow-up, and 12 patients underwent clinical follow-up. The results of the angiography follow-up (mean 6 ± 3.29 months) showed that in-stent restenosis occurred in one of the 11 successfully recanalized patients. However, the artery was occluded again in the patient who achieved thrombolysis in cerebral infarction (TICI) grade of 2a after treatment. Clinical follow-up (mean 5.8 ± 2.25 months) showed no recurrence of transient ischemic attack (TIA) or stroke in ten successfully recanalized cases. However, the patient who developed in-stent stenosis suffered TIA.

CONCLUSIONS

Endovascular recanalization for symptomatic subacute/chronic ILAO of anterior circulation is feasible, relatively safe, and efficacious in highly selected cases, improving patients' symptoms in the short-term. However, further larger scale pilot studies are needed to determine the efficacy and long-term outcome associated with this treatment.

Cigarette Smoking Preferentially Affects Intracranial Vessels in Young Males: A Propensity-Score Matching Analysis

Purpose

Cigarette smoking (CS) is one of the major risk factors of cerebral atherosclerotic disease, however, its level of contribution to extracranial and intracranial atherosclerotic stenosis (ECAS and ICAS) was not fully revealed yet. The purpose of our study was to assess the association of CS to cerebral atherosclerosis along with other risk factors.

Materials and Methods

All consecutive patients who were angiographically confirmed with severe symptomatic cerebral atherosclerotic disease between January 2002 and December 2012 were included in this study. Multivariate logistic regression analyses were performed to identify risk factors for ECAS and ICAS. Thereafter, CS group were compared to non-CS group in the entire study population and in a propensity-score matched population with two different age-subgroups.

Results

Of 1709 enrolled patients, 794 (46.5%) had extracranial (EC) lesions and the other 915 (53.5%) had intracranial (IC) lesions. CS group had more EC lesions (55.8% vs. 35.3%, P<0.001) whereas young age group (<50 years) had more IC lesion (84.5% vs. 47.6%, P<0.001). In multivariate analysis, seven variables including CS, male, old age, coronary heart disease, higher erythrocyte sedimentation rate, multiple lesions, and anterior lesion were independently associated with ECAS. In the propensity-score matched CS group had significant more EC lesion compared to non-CS group (65.7% vs. 47.9%) only in the old age subgroup.

Conclusion

In contrast to a significant association between CS and severe symptomatic ECAS shown in old population, young patients did not show this association and showed relatively higher preference of ICAS.

Efficiency of Air Bubble Removal in Preparation of Low-Profile Angioplasty Balloon Catheter: Bench-Top Comparison of Six Methods

Purpose

Complete removal of air bubbles from balloons for neurovascular angioplasty is cumbersome. We compared the preparation difficulty, air removal efficiency, and air collection pattern of six different balloon catheter preparation methods to propose a better preparation method for both initial and second balloon uses, especially for small-profile angioplasty balloon catheters.Materials and

Methods

A total of 18 neurovascular angioplasty balloon catheters with nominal diameters of 2 mm were prepared to test six different preparation methods: the instruction for use method (method A), simplified method using a syringe (method B) and four newly devised preparation methods using inflating devices (methods C–F). Serial radiographs were obtained while the balloons were gradually inflated. We measured the time for each preparation and the bubble number, analyzed their distribution in the balloon, and calculated the contrast filling ratio (contrast filling area/total balloon area) for initial and second ballooning. The whole process was repeated three times.

Results

The preparation time varied widely (11.5 seconds [method D] to 73.3 seconds [method A]). On initial inflation, the contrast filling ratio at 8 atm was the highest (100%) with methods A and F. On second inflation, the ratio was again highest with method A (99.5%), followed by method F (99.2%). Initial ballooning tended to show a uniform pattern of single bubble in the distal segment of the balloon; in contrast, second ballooning showed varying patterns in which the bubbles were multiple and randomly distributed.

Conclusion

None of the six methods were able to completely exclude air bubbles from the balloon catheters including the second ballooning; however, the method of repeating aspiration with high-volume inflating device (method F) could be a practical option considering the simplicity and efficiency of preparation.

[Imaging Parameter Optimization of Non-contrast Three-dimensional Time-of-flight Magnetic Resonance Angiography for Patients with Intracranial Stents Using a 1.5 T Magnetic Resonance Imaging System]

The imaging parameters of non-contrast three-dimensional time-of-flight magnetic resonance angiography (3D TOF-MRA) were optimized to improve the image quality for patients treated using stent-assisted coiling. A simulated blood flow phantom with three types of stents (Enterprise 2, Neuroform Atlas, and LVIS) was imaged by changing echo time (TE), band width (BW), flip angle (FA), and matrix (phase, frequency). The difference between the signal intensity in the simulated vessel and the background was measured at each imaging condition. The ratio of this difference with and without the stent was evaluated as the relative in-stent signal (RIS). In addition, the error ratio of the stent lumen diameter was assessed by comparing the full width at half maximum (FWHM) to that measured by 3D X-ray angiography. The RIS was higher in order of LVIS, Neuroform Atlas, and Enterprise 2 in all conditions. The RIS was higher in imaging conditions with short TE, narrow BW, high FA, and large phase matrix. The highest RIS was seen with a frequency matrix of 320 in the Enterprise 2 and 256 in the others. FWHM error ratio was smaller in the same order as the RIS. FWHM error ratio was smaller in imaging conditions with short TE, large frequency matrix (>384), large phase matrix (>224), and high FA (>20°). Imaging conditions of 3D TOF-MRA that were effective to improve the image quality for stent lumen evaluation were short TE and high spatial resolution.

Percutaneous Transluminal Angioplasty with Stent Placement versus Best Medical Therapy Alone in Symptomatic Intracranial Arterial Stenosis: A Best Evidence Review

Intracranial arterial stenosis (ICAS) is a common cause of stroke, and the risk of ischemic stroke from a stenotic intracranial artery remains high despite best medical therapy (BMT). As a result, clinicians have increasingly turned to percutaneous transluminal angioplasty and stenting (PTAS) over the last decade as an alternative therapy in high-risk patients with symptomatic ICAS. In this review, we will critically analyze multiple clinical trials to assess the safety and efficacy of PTAS with BMT versus BMT alone. The Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial reported a higher rate of stroke or death within 30 days in the PTAS plus BMT group (14.7%) than the BMT only group (5.8%, p = 0.002). The rate of any stroke during the follow-up period (mean = 32 months) was higher in the PTAS plus BMT group (22.3%) than the BMT only group (14.1%, p = 0.03). The Vitesse Intracranial Stent Study for Ischemic Stroke Therapy (VISSIT) trial reported a higher rate of stroke or death within 30 days in the PTAS plus BMT cohort (24.1%) than the BMT only cohort (9.4%, p = 0.05). There was also a higher rate of hard transient ischemic attack (TIA) or stroke within one year in the PTAS plus BMT group (36.2%) than the BMT only group (15.1%, p = 0.02). The Vertebral Artery Ischaemia Stenting (VIST) trial reported the rate of any stroke during the follow-up period to be two events in 50 person-years in the PTAS plus BMT cohort versus four events in 45 person-years in the BMT only cohort, with a calculated hazard ratio of 0.47 (p = 0.39). Vertebral Artery Stenting Trial (VAST) reported a higher incidence of stroke, MI, or vascular death in the PTAS with BMT cohort (22%) than the BMT only cohort (0%). Tang et al. reported no significant difference in the incidence of vascular events at one year and three years between the PTAS plus BMT and BMT only cohorts. However, the distribution of vascular events was more concentrated in the first postoperative week in the PTAS plus BMT cohort (75% of all vascular events) versus the BMT only cohort (17%). Feng et al. reported a lower periprocedural complication rate (9.1%) with the Enterprise stent in comparison to the Wingspan and balloon-expandable stents used in the SAMMPRIS and VISSIT trials. We conclude that PTAS should not be employed as first-line treatment in patients with symptomatic ICAS. However, PTAS should be considered in symptomatic ICAS patients that are hemodynamically unstable or have repeatedly failed BMT, especially at sites with lower rates of perioperative complications than those reported here.

Endovascular Treatment of Intracranial Aneurysms Concomitant with Severe Adjacent Atherosclerotic Stenosis

PURPOSE

To investigate the effect and safety of endovascular treatment of intracranial aneurysms concomitant with severe adjacent atherosclerotic stenosis.

MATERIALS AND METHODS

Twenty-six patients with aneurysms and adjacent stenosis were prospectively enrolled. The characteristics of the aneurysm, parent artery, atherosclerotic stenosis and endovascular treatment methods were analyzed.

RESULTS

All aneurysms were successfully embolized (100%), with stent-assisted coiling in 14 (53.8%) cases, coiling alone in 10 (38.5%), double microcatheter coiling in 1 (3.8%), and balloon-assisted coiling in the remaining 1 (3.8%). Immediately after embolization, complete occlusion was achieved in 10 cases (38.5%), nearly complete occlusion in 6 (23.1%) and non-complete occlusion in 10 (38.5%). Ten aneurysms were type I and were managed with coiling alone in 8 cases and stent-assisted coiling in the remaining 2 cases, with complete occlusion achieved in 6 cases (60%), nearly complete in 2 (20%), and noncomplete in the other 2 (20%). Sixteen aneurysms were type II and treated with stent-assisted coiling in 12 cases (75%), single coiling in 2 (12.5%), double microcatheters in 1 (6.3%), and balloon-assisted coiling in the remaining aneurysm (6.3%). Aneurysm occlusion was complete in 4 cases (25%), nearly complete in 4 (25%), and noncomplete in the other 8 (50%). Clinical follow-up of 2 months to 5 years (mean 26 ± 11 months) demonstrated no rebleeding, with the modified Rankin scale score of 0-2 in 20 patients, 3 in 4, and 6 in the remaining 2.

CONCLUSIONS

Intracranial aneurysms concomitant with severe adjacent atherosclerotic stenosis can be successfully treated endovascularly, and careful evaluation of the characteristics of the aneurysm, parent artery, stenosis and collateral circulation can help reducing complications.

Angioplasty, Stenting and Other Potential Treatments of Atherosclerotic Stenosis of the Intracranial Arteries: Past, Present and Future

Although there is an intuitive appeal to treat symptomatic stenotic intracranial arteries with endovascular therapies such as angioplasty and stenting, current data from randomized trials show intensive medical therapy is far superior for preventing stroke. This is in large part due to the high risk of peri-procedural stroke from angioplasty and stenting. If angioplasty and stenting is to emerge as a proven treatment for intracranial stenosis, endovascular techniques will need to become much safer, identification of patients with intracranial stenosis who are at particularly high risk of stroke despite intensive medical therapy will need to be targeted, and well-designed randomized trials will be necessary to show endovascular therapy is superior to medical therapy in these high-risk patients.

Successful Treatment of Symptomatic Intracranial Carotid Artery Stenosis Using a 24-mm Long Bare Metal Coronary Stent

BACKGROUND

Intracranial arterial atherosclerosis represents a common cause of stroke. Despite aggressive and optimal medical management, many patients will unfortunately suffer additional cerebrovascular events. The role of endovascular intervention for intracranial atherosclerotic disease continues to be uncertain, particularly in regard to extensive, symptomatic stenosis.

CASE DESCRIPTION

We present a case of a 42-year-old man with a complex medical history who presented with recurrent ischemic stroke in the ipsilateral hemisphere despite optimal medical management. Given the length of stenosis and the luminal size of the intracranial cavernous and petrous segments of the internal carotid artery, we used a bare metal coronary stent (4.0 mm × 24 mm). This represents one of the longest stents deployed for intracranial disease reported in the literature.

CONCLUSIONS

This case illustrates that a long coronary stent might be successfully used to manage extensive intracranial lesions. We also review the efficacy of using 1 very long stent versus multiple overlapping stents, with reference to the coronary angiography literature.

The experiences of balloon-expandable stent in symptomatic stenosis of middle cerebral artery

Background

Stent placement for middle cerebral artery (MCA) stenosis remains a technical and clinical challenge. Our purpose was to assess the safety and feasibility of balloon-expandable stent (BES) for patients with symptomatic M1 stenosis of MCA, and to introduce our experience during the procedure.

Methods

In the study, we analyzed retrospectively 37 patients with M1 stenosis of the MCA ranged from 70 to 90 % in diameter reduction and refractory to medical therapy between January 2012 and January 2015. All the patients underwent angioplasty and stenting with BES, and followed up continuously.

Results

Thirty-five out of 37 patients were successfully followed up and available until now. The technical successful rate was 100 % for all the lesions. The complication rate was 0 during the procedure. Stroke occurred to one patient at 4th day after the procedure. There were two patients experiencing slight stroke after 8 months. Two patients were found re-stenosis >50 % without any symptom. The stroke rate of 12 months was 8.57 % (3/35).

Conclusions

Angioplasty associated with BES appears to be safe and feasible for the patients with symptomatic M1 stenosis of MCA. Our experiences about the BES may be valuable for decreasing the complication. However, further study is needed.

Outpatient Day-care Neuroangiography and Neurointervention of Unruptured Intracranial Aneurysms

Purpose

Day-care management of unruptured intracranial aneurysms can shorten hospital stay, reduce medical cost and improve outcome. We present the process, outcome and duration of hospital stay for the management of unruptured intracranial aneurysms via a neurointervention clinic in a single center during the past four years.

Materials and Methods

We analyzed 403 patients who were referred to Neurointervention Clinic at Asan Medical Center for aneurysm evaluation between January 1, 2011 and December 31, 2014. There were 141 (41%) diagnostic catheter angiographies, 202 (59%) neurointerventional procedures and 2 (0.6%) neurointerventional procedures followed by operation. We analyzed the process, outcome of angiography or neurointervention, and duration of hospital stay.

Results

There was no aneurysm in 58 patients who were reported as having an aneurysm in MRA or CTA (14 %). Among 345 patients with aneurysm, there were 283 patients with a single aneurysm (82%) and 62 patients with multiple aneurysms (n=62, 18%). Aneurysm coiling was performed in 202 patients (59%), surgical clipping in 14 patients (4%), coiling followed by clipping in 2 patients (0.6%) and no intervention was required in 127 patients (37%). The hospital stay for diagnostic angiography was less than 6 hours and the mean duration of hospital stay was 2.1 days for neurointervention. There were 4 procedure-related adverse events (2%) including 3 minor and 1 major ischemic strokes.

Conclusion

Our study revealed that day-care management of unruptured intracranial aneurysms could be performed without an additional risk. It could enable rapid patient flow, shorten hospital stay and thus reduce hospital costs.

Spectral Imaging for Intracranial Stents and Stent Lumen

Introduction

Application of computed tomography for monitoring intracranial stents is limited because of stent-related artifacts. Our purpose was to evaluate the effect of gemstone spectral imaging on the intracranial stent and stent lumen.

Materials and Methods

In vitro, we scanned Enterprise stent phantom and a stent–cheese complex using the gemstone spectral imaging protocol. Follow-up gemstone spectral images of 15 consecutive patients with placement of Enterprise from January 2013 to September 2014 were also retrospectively reviewed. We used 70-keV, 140-keV, iodine (water), iodine (calcium), and iodine (hydroxyapatite) images to evaluate their effect on the intracranial stent and stent lumen. Two regions of interest were individually placed in stent lumen and adjacent brain tissue. Contrast-to-noise ratio was measured to determine image quality. The maximal diameter of stent markers was also measured to evaluate stent-related artifact. Two radiologists independently graded the visibility of the lumen at the maker location by using a 4-point scale. The mean of grading score, contrast/noise ratio and maximal diameter of stent markers were compared among all modes. All results were analyzed by SPSS version 20.

Results

In vitro, iodine (water) images decreased metallic artifact of stent makers to the greatest degree. The most areas of cheese were observed on iodine (water) images. In vivo, iodine (water) images had the smallest average diameter of stent markers (0.33 ± 0.17mm; P < .05) and showed the highest mean grading score (2.94 ± 0.94; P < .05) and contrast/noise ratio of in-stent lumen (160.03 ±37.79; P < .05) among all the modes.

Conclusion

Iodine (water) images can help reduce stent-related artifacts of Enterprise and enhance contrast of in-stent lumen. Spectral imaging may be considered a noninvasive modality for following-up patients with in-stent stenosis.

Undersized angioplasty and stenting of symptomatic intracranial tight stenosis with Enterprise: Evaluation of clinical and vascular outcome

BACKGROUND

Severe intracranial arterial stenosis results in more than 10% incidence of stroke and transient ischemic attack. Using undersized angioplasty with off-label closed-cell Enterprise stent may be a feasible alternative option for treating patients with intracranial atherosclerotic disease who fail dual-antiplatelet medical therapy. The results of the authors' study are presented in this paper.

MATERIALS AND METHODS

Between January 2013 and July 2014, 24 symptomatic patients with a total of 30 intracranial arterial stenotic lesions refractory to medical therapy, who underwent undersized angioplasty and Enterprise stenting, were retrospectively reviewed in the authors' institution. The results evaluated include technical success rate, clinical outcome measured as modified Rankin Scale at presentation and follow-up, peri-procedural morbidity within 30 days and 1 year, and follow-up vessel patency.

RESULTS

Stent deployment was successfully achieved in all stenotic lesions (30/30). Mean pre-stent and post-stent diameter residual stenosis was 81% and 18%, respectively. The peri-procedural complication rate during 30 days after stenting was 10% per lesion (3/30), including intracranial hemorrhage, in-stent thrombosis and ischemic stroke. No further thromboembolic event or complication occurred in any patient more than 30 days after stenting. Modified Rankin scale ≤ 2 was observed in 64% and 83% of patients at initial presentation and follow-up (mean 15.8 months), respectively. Imaging follow-up was available in 17 of 24 patients (70.8%) and 20 of 30 treated lesions (66.6%) with a mean follow-up period of 15.4 months. Only one asymptomatic in-stent restenosis occurred in 20 available lesions (5.0%).

CONCLUSION

This preliminary study suggests that using undersized angioplasty and Enterprise stenting may effectively treat high-degree symptomatic intracranial arterial stenosis with favorable clinical and angiographic outcome.

Percutaneous transluminal angioplasty and stenting for severe stenosis of the intracranial extradural internal carotid artery causing transient ischemic attack or minor stroke

The purpose of this study is to assess the technical feasibility and clinical efficacy of percutaneous transluminal angioplasty and stenting (PTAS) for symptomatic stenosis of the intracranial extradural (petrous and cavernous) internal carotid artery (ICA).Review of medical records identified 26 consecutive patients who underwent PTAS using a balloon-expandable coronary stent (n = 15, 57.7%) or a Wingspan self-expandable stent (n = 11, 42.3%) for treatment of severe stenosis (>70%) involving the intracranial extradural ICA. The inclusion criteria were transient ischemic attack with an ABCD(2) score of ≥3 (n = 12, 46.2%) or minor stroke with an NIHSS score of ≤4 (n = 14, 53.8%). Technical success rates, complications, and angiographic and clinical outcomes were analyzed retrospectively.PTAS was technically successful in all patients. The mean stenosis ratio decreased from 77.1% to 10.0% immediately after PTAS. The overall incidence of procedural complications was 23.1%, and the postoperative permanent morbidity/mortality rate was 7.7%. A total of 22 patients were tracked over an average period of 29.9 months. During the observation period, 20 patients (90.9%) had no further cerebrovascular events and stroke recurrence occurred in two patients (9.1%), resulting in an annual stroke risk of 3.7%. Two cases (11.1%) of significant in-stent restenosis (>50%) were found on follow-up angiography (n = 18).PTAS for severe stenosis (>70%) involving the intracranial extradural ICA showed a good technical feasibility and favorable clinical outcome in patients with transient ischemic attack or minor stroke.

Intra-arterial DynaCT angiography: an alternative tool to assess the patency of intracranial stent lumen

OBJECTIVE

The aim of this retrospective study was to assess the clinical utility of intra-arterial DynaCT angiographic imaging for the evaluation of intracranial stent patency.

METHODS

Between July 2011 and May 2014, 35 patients with symptomatic intracranial atherosclerotic stenosis (ICAS) were treated with percutaneous transluminal angioplasty and stents. All were evaluated with intra-arterial DynaCT angiographic imaging during the operations and follow-up. All images were further processed with three different kernels (sharp, normal, or smooth).

RESULTS

Thirty-six stents were implanted into the parent arteries. DynaCT provided "good" quality images (median score of 2 or 3 on a 5-point scale) with minimal artifact interference as rated by observers blind to treatment history and other imaging results. The median subjective visibility score was highest (3) using the sharp kernel.

CONCLUSIONS

DynaCT with sharp kernel image processing achieved good visualization of luminal patency following intracranial stents.

Primary angioplasty for symptomatic atherosclerotic middle cerebral artery stenosis

Objective

The objective of this study is to evaluate the clinical and angiographic outcomes after primary balloon angioplasty in patients with symptomatic middle cerebral artery (MCA, M1 segment) stenosis refractory to medical therapy.

Materials and Methods

Eleven patients with intracranial stenosis were treated with primary balloon angioplasty. All patients had MCA stenosis with recurrent transient ischemic attack (TIA). The indication for balloon angioplasty was patients with significant MCA stenosis: 1) age older than 18 years with recurrent or progressive TIA or infarction despite optimal medical therapy, including anti-coagulation, dual anti-platelet, and anti-lipid medication; 2) previous ischemic events or asymptomatic severe stenosis (more than 50%) with poor collateral cerebral circulation, or diminished cerebral perfusion on single photon emission computed tomography before and after administration of the intravenous dosage of acetazolamide.

Results

The median age of patients was 53 years (range 44-79). The technical success rate was 100%. Mean pretreatment stenosis degree was 83.63 ± 9.53% and 29.1 ± 15.4% before and after angioplasty, respectively. Procedural-related complications occurred in four of 11 patients (36%), but none of the patients had permanent neurological deficit. All patients were available for an average follow-up period of 19.4 ± 5.1 months. One patient had a stroke in the territory of angioplasty at two months after angioplasty. The stroke free survival rate at 30 days and 12 months was 100% and 91%, respectively. Restenosis over 50% was observed in three of 11 patients (27%); all were asymptomatic.

Conclusion

Intracranial angioplasty for symptomatic MCA stenosis refractory to medical therapy can be a treatment option to reduce the risk of further TIA or stroke.

Solving the Issue of Restenosis After Stenting of Intracranial Stenoses: Experience with Two Thin-Strut Drug-Eluting Stents (DES)-Taxus Element™ and Resolute Integrity™

PURPOSE

Thin-strut, flexible DES are suitable for intracranial stenting and may improve long-term vessel patency. The purpose of this study was to report our experience with two new-generation DES for the treatment of intracranial atherosclerotic disease.

PATIENTS AND METHODS

We retrospectively reviewed all patients treated with Taxus Element™ or Resolute Integrity™ stent for an intracranial atherosclerotic stenosis between March 2011 and August 2013. Technical success was defined as the ability to deploy the device at the desired location and reduce the degree of stenosis below 50 %. All procedure-related strokes were recorded. Control angiography was scheduled after 6 weeks, 3, 6, and 12 months and yearly thereafter. A luminal narrowing ≥50 % was regarded as a restenosis. Stroke recurrence in the territory of the treated artery was reported.

RESULTS

In the defined period we treated 101 patients harboring 117 intracranial stenoses. The procedure was successful in 100 (85.5 %) lesions. Procedure-related strokes occurred in 10 (9.9 %) patients with a permanent morbidity in 3 (3.0 %). Follow-up angiography was available for 83 of 100 (83.0 %) successfully treated lesions with an average of 355 days (IQR 153-482 days). Three (3.6 %) asymptomatic restenoses were detected. All occurred after treatment with Resolute Integrity™, none after Taxus Element™ (p = 0.059). New strokes in the territory of the treated artery were encountered in 2 (2.6 %) occasions.

CONCLUSION

Thin-strut DES improve long-term patency and reduce the risk of subsequent stroke. Differences between devices may exist. Feasibility is comparable to bare-metal balloon-mounted stents and procedure-related strokes occurred within the expected range.

Research on intracranial atherosclerosis from the East and west: why are the results different?

Intracranial atherosclerosis (ICAS) is a major cause of stroke worldwide and is more common in Asians than Caucasians. The study results from the East and West are generally similar, but notable differences exist. For example, studies from the East have reported that ICAS is associated with young age, whereas ICAS seems to be associated with old age in the West. Studies from the East have strongly suggested that mild ICAS associated with branch occlusion is one of the main causes of single subcortical infarction, whereas this aspect has not been considered in stroke classification systems developed in the West. While clopidogrel is commonly used in patients with large artery disease in the West, cilostazol has been more extensively studied and commonly used in ICAS patients in the East. A randomized controlled study from the West reported negative results regarding the efficacy of stenting in ICAS patients due largely to a relatively high rate of periprocedural adverse events, whereas research papers from the East have reported a relatively lower rate of complications. Studies to narrow these East-West gaps should be performed, including risk factor studies using homogenous ethnic populations, studies investigating appropriate classification systems, drug trials in different ethnic populations, and rigorous high standard randomized controlled studies on the efficacy of stenting in Eastern populations.

Balloons in endovascular neurosurgery: history and current applications

The use of balloons in the field of neurosurgery is currently an essential part of our clinical practice. The field has evolved over the last 40 years since Serbinenko used balloons to test the feasibility of occluding cervical vessels for intracranial pathologies. Since that time, indications have expanded to include sacrificing cervical and intracranial vessels with detachable balloons, supporting the coil mass in wide-necked aneurysms (balloon remodeling technique), and performing intracranial and cervical angioplasty for atherosclerotic disease, as well as an adjunct to treat arteriovenous malformations. With the rapid expansion of endovascular technologies, it appears that the indications and uses for balloons will continue to expand. In this article, we review the history of balloons, the initial applications, the types of balloons available, and the current applications available for endovascular neurosurgeons.

A Study Design to Evaluate Association between Smoking and Intracranial Atherosclerotic Stenosis

Purpose

Smoking is a well known risk factor for stroke. The cerebral arteries may be uniquely susceptible to the atherosclerotic effects of smoking, such that it has a different risk profile for stroke compared with other atherosclerosis risk factors. It remains uncertain whether smoking is associated specifically with intracranial (IC) or extracranial (EC) atherosclerotic cerebrovascular disease. The aim of this study design will be to evaluate the association between smoking and severe IC stenosis, adjusting for other atherosclerosis risk factors, particularly age distribution.

Study design

This is a retrospective cohort study design. Participants are patients (n=1714) with severe atherosclerotic stenosis undergoing cerebral catheter angiography because of stroke or transient ischaemic attack. All atherosclerotic steno-occlusive lesions are described in terms of location (anterior versus posterior circulation, IC versus EC, or intradural versus extradural). The atherosclerotic or stroke risk factors for analysis include age, gender, smoking history, number of lesions (single versus multiple), cardiac disease, diabetes mellitus, hypertension, family history, dyslipidemia, history of previous stroke, alcohol intake, metabolic syndrome and body mass index. Statistical analysis includes univariate analysis followed by multivariate logistic regression. The relationship between IC atherosclerotic stenosis and smoking will be assessed. Differences in risk factor distribution is analysed according to age at intervals of 10 years. Significant risk factors associated with IC atherosclerotic stenosis will also be assessed by multivariate logistic regression analysis.

Summary

This is an analytical study design that intends to measure the association between IC or EC atherosclerotic stenosis and smoking and other risk factors. We anticipate that it will have the power to detect any relationship between smoking and IC atherosclerotic lesions especially in younger patients.

Reviving Intracranial Angioplasty and Stenting "SAMMPRIS and beyond"

We review the methods and results of Stenting and Aggressive Medical Management for Preventing Recurrent Stroke (SAMMPRIS) and provide a critical review of its strengths and limitations. In SAMMPRIS, the aggressive medical treatment arm (AMT arm) did substantially better than the Wingspan Stenting plus aggressive medical management arm (WS+ arm). Complications in the first 30 days post intervention led to the disparity between treatment arms. A major contribution of SAMMPRIS was the added value that AMT and lifestyle change may provide, when compared to a precursor trial, Warfarin–Aspirin Symptomatic Intracranial Disease (WASID), designed to prevent stroke in persons with high-grade symptomatic intracranial occlusive disease, however, the results of neither of these two trials have ever been reproduced. On the other hand, we argue that technical limitations of the Wingspan stent system (WS System) and lack of an angioplasty only intervention arm may have led to a premature launch of the trial and early termination of the study. Future randomized trials with different devices and modified patient selection criteria are warranted.

The case for angioplasty in patients with symptomatic intracranial atherosclerosis

Intracranial atherosclerotic disease (ICAD) is likely the most common cause of stroke worldwide and remains highly morbid even with highly monitored medical therapy. Recent results of the SAMMPRIS trial, which randomized patients to stenting plus aggressive medical management versus aggressive medical management alone have shown that additional treatment of intracranial atherosclerotic lesions with the Wingspan stent is inferior to aggressive medical management alone. In light of these results, there has been renewed interest in angioplasty alone to treat symptomatic ICAD. This article will briefly review the natural history of ICAD and discuss the possible future for endovascular treatment of ICAD with primary intracranial angioplasty in appropriately selected patients.

Stenting of symptomatic intracranial stenosis using balloon mounted coronary stents: a single center experience

OBJECTIVE

Intracranial atherosclerotic disease is the cause of up to 10% of ischemic strokes and transient ischemic attacks. Intracranial stenting with off-label balloon mounted coronary stents (BMCS) may be a viable alternative for patients with symptomatic intracranial stenosis who fail best medical therapy.

DESIGN

Between December 2005 and June 2012, 42 symptomatic intracranial stenoses were treated with a BMCS after failing medical management. Procedural records, clinical outcomes, and imaging follow-up were reviewed. Outcome measurements included technical success rate, morbidity and mortality, long term stent patency, and clinical outcomes, as measured by the modified Rankin Scale.

RESULTS

The technical success rate was 98% (41 of 42 lesions). Morbidity within the first 30 days was 7.1% (three of 42 lesions). Overall morbidity, including both periprocedural and long term evaluation, was 9.5% (four of 42 lesions). There were no deaths. Follow-up imaging was available for 30 stents (71%) with an average follow-up time of 35.1 months. Restenosis (>50%) and retreatment were observed in 20% and 10% of cases, respectively. Clinical evaluation by a neurologist ≥ 30 days postprocedure was available in 40 of 42 cases (95%) with an average of 32.1 months. At presentation, 55% of patients had a modified Rankin Scale (mRS) score of ≤ 2. At follow-up, 74% of patients were found to have an mRS score of ≤ 2.

CONCLUSIONS

This study suggests that BMCS may benefit patients with symptomatic intracranial stenosis who experience stroke or transient ischemic attack in spite of best medical therapy.

Potential for the use of the Solitaire stent for recanalization of middle cerebral artery occlusion without a susceptibility vessel sign

BACKGROUND AND PURPOSE

Absence of the MCA susceptibility vessel sign (negative MCA susceptibility vessel sign) on gradient recalled-echo MR imaging in acute stroke is commonly associated with in situ stenosis and thrombotic occlusion. We evaluated the effectiveness and safety of the Solitaire stent as the first-line device for the recanalization of MCA occlusion with a negative MCA susceptibility vessel sign.

MATERIALS AND METHODS

Thirty-eight consecutive patients presenting with acute ischemic stroke due to MCA occlusion were treated by using the Solitaire AB stent alone or combined with thrombolytic drugs. Among these patients, 11 (7 men and 4 women; median age, 70 years; range, 49-89 years) who underwent multimodal stroke MR imaging before the endovascular procedure and had no MCA susceptibility vessel sign on the initial gradient recalled-echo MR imaging were included in this study. The primary end point was the recanalization of the occluded artery evaluated by the arterial occlusive lesion score. Clinical outcome was assessed at discharge and 90 days, as was the degree of residual MCA stenosis or reocclusion.

RESULTS

Successful recanalization (arterial occlusive lesion score ≥ II) without balloon angioplasty was obtained in 9 patients (81.8%). Six patients (54.5%) had an mRS score of ≤2 at 90 days. After a median of 147 days, no patient showed reocclusion on follow-up imaging. There were no symptomatic intracerebral hemorrhages.

CONCLUSIONS

The Solitaire stent is a feasible tool as the first-line device for multimodal endovascular recanalization therapy in acute ischemic stroke with a negative MCA susceptibility vessel sign. It has a good rate of successful and complete recanalization and is a fast yet safe procedure.

The outcome and efficacy of recanalization in patients with acute internal carotid artery occlusion

BACKGROUND AND PURPOSE

Acute occlusion of the ICA is often associated with poor outcomes and severe neurologic deficits. This study was conducted to evaluate outcome of the occluded ICA and efficacy of recanalization under protective flow arrest.

MATERIALS AND METHODS

Fifty consecutive patients who underwent endovascular treatment for acute ICA occlusion were identified from the prospectively collected data base. We assessed NIHSSo, occlusion type (cardioembolism vs atherosclerosis), occlusion level (supraclinoid-terminal, petrocavernous, or bulb-cervical), recanalization degree (TICI), and efficacy of recanalization (protective flow arrest vs nonprotection) leading to better outcome.

RESULTS

Successful recanalization (TICI ≥ 2) was obtained in 90% of patients and good recovery (mRS ≤ 2) in 60% of patients. Good outcome was related to National Institutes of Health Stroke Scale score on admission (P < .001), TICI (P < .007), occlusion type (P = .022), and occlusion level (P = .038). Poor initial patient status, less recanalization, cardioembolism, and supraclinoid-terminal occlusion were associated with poor prognosis. Application of protective flow arrest led to better outcome in the distal ICA segment than in the bulb-cervical segment.

CONCLUSIONS

In addition to the initial patient status and successful recanalization, the occlusion level or type of the occluded ICA could affect clinical outcome. In this study, treatment benefits of protective flow arrest were accentuated in patients with ICA occlusion above the bulb-cervical segment.

Intracranial stenting for severe symptomatic stenosis: self-expandable versus balloon-expandable stents

Intracranial atherosclerosis against optimal medical treatment requires reperfusion therapy to improve the clinical outcome. We compared outcomes between self-expandable stent (SES) and/or balloon-expandable stent (BES) and present the potential advantages of using each stent. During the same time frame before and after Wingspan introduction to our institute, 115 consecutive patients underwent intracranial stenting for symptomatic severe intracranial stenosis against optimal medical treatment using BES alone (n = 71) vs. BES or SES (n = 44). We analyzed 15 factors including outcome related to an adverse event (AE), modified Rankin Scale (mRS) and restenosis at six months and retrospectively compared the potential advantages of using each stent. BES or SES groups had a significantly lower AE rate (2.3%) than the BES only group (14%) (P = 0.049) revealing mRS of ≤ 2 in all patients at six months compared to 93% of the patients in the BES group. Analysis of BES or SES subgroups revealed that BES was associated with less residual stenosis after stenting than SES (18 vs. 32%; P < 0.001). Both SES and BES can improve the clinical outcome of intracranial stenting especially with a selective choice of SES or BES. Further study is needed to analyse the difference in long-term outcome and the restenosis rate between SES and BES.

A single center experience of stenting in symptomatic intracranial atherosclerosis

Atherosclerotic intracranial arterial stenosis is an important cause of stroke that is increasingly being treated with percutaneous transluminal angioplasty and stenting (PTAS) to prevent recurrent stroke. However, PTAS has been compared with medical management in a randomized trial (SAMMPRIS), where aggressive medical management was superior to PTAS with the use of the Wingspan stent system, however in our experience we have had good results and have experienced no complications with this therapy. In a retrospective, single-center study we enrolled seven consecutive patients with a symptomatic angiographically proven atherosclerotic intracranial arterial stenosis of the anterior and posterior circulation. All cases received adjuvant therapy (aspirin and clopidogrel or ticlopidine) before and after deployment of the device. The procedures were performed with the patient under general anesthesia. We use the Wingspan stent system. The occlusion site was middle cerebral artery (MCA) in three patients, proximal internal carotid artery (ICA) in one patient and vertebrobasilar artery in three patients. Primary interventional successful revascularization was achieved in all cases. Four patients had no residual stenosis, and the other three had 20%, 30% and 40% residual stenosis (Table 1). All patients showed a clinical improvement after stent deployment. No peri-interventional events or neurologic complications occurred directly related to the technique. Patency rate was 100% at the last examination in six cases, one case had a pre-occlusive stenosis, requiring angioplasty. No patients died during the follow-up period, and 100% of patients showed good functional outcome at three months (modified Rankin Scale score ≤ 2). Although the SAMMPRIS study showed that aggressive medical management was superior to PTAS, our results suggest that intracranial stenting is safe and effective, probably due to an extraordinary selection of candidates and to an exquisite technique.

Advances in imaging of intracranial atherosclerotic disease and implications for treatment

OPINION STATEMENT

Intracranial atherosclerotic disease (ICAD) is one of the most common causes of ischemic stroke worldwide and is associated with a high risk of recurrent stroke despite aggressive therapy. ICAD may lead to cerebral ischemia through a variety of mechanisms, the interactions of which are largely unknown. The use of endovascular therapy for the prevention of stroke related to severe ICAD has been studied but was associated with a higher risk of recurrent stroke and death in the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) study. With advances in diagnostic testing, it may be possible to better delineate the specific mechanism of stroke from ICAD and identify those patients at higher risk for recurrent ischemia. There may be a subset of patients less responsive to medical interventions, such as those with hemodynamic failure as opposed to those with perforator syndromes, who would benefit from medical plaque stabilization or safer endovascular approaches such as angioplasty alone. These will need to be tested in future clinical trials. Overall, symptomatic ICAD remains a high risk condition with suboptimal treatment options.

Disappeared pulsatile tinnitus related to petrous segment stenosis of the ICA after relief of the stenosis by stenting

Pulsatile tinnitus may result from turbulent flow within the internal carotid artery (ICA). Atherosclerotic carotid stenosis is a rare but well-known cause of pulsatile tinnitus. The classical treatment was endarterectomy or ligation for proximal ICA disease or stenting for distal ICA lesions. Endovascular techniques offer new ways to treat atherosclerotic vascular stenosis lesions. We describe two cases of pulsatile tinnitus caused by stenosis within the petrous segment of the ICA and treated by stent-assisted angioplasty.

Computational modeling with fluid-structure interaction of the severe m1 stenosis before and after stenting

PURPOSE

Image-based computational models with fluid-structure interaction (FSI) can be used to perform plaque mechanical analysis in intracranial artery stenosis. We described a process in FSI study applied to symptomatic severe intracranial (M1) stenosis before and after stenting.

MATERIALS AND METHODS

Reconstructed 3D angiography in STL format was transferred to Magics for smoothing of vessel surface and trimming of branch vessels and to HyperMesh for generating tetra volume mesh from triangular surface-meshed 3D angiogram. Computational analysis of blood flow in the blood vessels was performed using the commercial finite element software ADINA Ver 8.5. The distribution of wall shear stress (WSS), peak velocity and pressure was analyzed before and after intracranial stenting.

RESULTS

The wall shear stress distributions from Computational fluid dynamics (CFD) simulation with rigid wall assumption as well as FSI simulation before and after stenting could be compared. The difference of WSS between rigid wall and compliant wall model both in pre- and post-stent case is only minor except at the stenosis region. These WSS values were greatly reduced after stenting to 15~20 Pa at systole and 3~5 Pa at end-diastole in CFD simulation, which are similar in FSI simulations.

CONCLUSION

Our study revealed that FSI simulation before and after intracranial stenting was feasible despite of limited vessel wall dimension and could reveal change of WSS as well as flow velocity and wall pressure.

Long-term Outcomes of Drug-eluting Stents in Symptomatic Intracranial Stenosis

Purpose

The use of drug-eluting stent (DES) to treat intracranial stenosis has shown short-term success. However, there are no reports regarding the long-term results of DES. We present the long-term clinical outcome after DES stenting for symptomatic severe intracranial stenosis.

Materials and Methods

Our study included a consecutive series of 11 patients who underwent intracranial stenting using DES between March and July, 2006, during the time when bare metal stents were not available at our medical institution. The mean patient age was 59 years. Lesion location was the middle cerebral artery in five patients, the intradural vertebral artery in three, the basilar artery in one, the vertebrobasilar junction in one, and the cavernous internal cerebral artery in one patient. We evaluated the technical success, defined as reduction of residual stenosis ≤30% in the target lesion) as well as the clinical and imaging outcomes as long as 75 months following the procedure. In addition to a cerebral angiogram (n = 2), follow-up study was obtained by CT angiography (n = 6) or intracranial Doppler imaging (n = 2) during a mean time of 55 months after the procedure (range, 24 to 73 months). Three patients refused imaging follow-up and accepted only clinical follow-up. The mean clinical follow-up period was 67 months (range, 47-75 months).

Results

Stenting in all patients was technically successful and without periprocedural complications. There was thrombus formation during the procedure in one patient who experienced no further complications. There were no new neurological events during the mean follow-up period of 5.6 years. No patients were found to have restenosis ≥50% at during the mean follow-up period of 55 months. One patient died of a sudden heart attack 59 months following the procedure which was regarded as unrelated to the cerebral lesion.

Conclusion

Our study demonstrates that DES shows long-term stability and safety, and results in good clinical outcomes with a low rate of restenosis.

Factors affecting pre- and post-stenting computed tomography perfusion in patients with middle cerebral artery stenosis

The aim of this study was to investigate the factors affecting pre- and post-stenting head computed tomography perfusion (CTP) in patients with middle cerebral artery stenosis. A total of 25 patients with severe middle cerebral artery stenosis were enrolled. CTP was performed prior to and following stenting. Scores were allocated to the time-to-peak (TTP) parameter of CTP using the Alberta stroke program early computed tomography scoring (ASPECTS) scale. The factors possibly affecting pre- and post-stenting CTP were analyzed. All the patients exhibited markedly prolonged TTP on the affected side prior to stenting, compared with the healthy side. Following surgery, the TTP was improved in all patients. The preoperative ASPECTS score was negatively correlated with the degree of middle cerebral artery stenosis with a correlation coefficient of −5.78. The preoperative vascular stenosis rate was positively correlated with the improvement degree of the ASPECTS score with a correlation coefficient of 1.137 (P=0.001). TTP is a sensitive parameter for evaluating the effect of stenting on middle cerebral artery stenosis. TTP prior to and following stenting may be quantitatively assessed using the ASPECTS scale. Patients with serious stenosis and/or good collateral circulation are able to benefit more from stenting.

A Comparison of Stent Implant versus Medical Treatment for Severe Symptomatic Intracranial Stenosis: A Controlled Clinical Trial

Background

Atherosclerotic stenosis of the major intracranial arteries is the most common cause of ischemic stroke. There are limited treatments for severe intracranial stenosis, and stent placement versus medical treatment remains controversial. The aim of this study was to compare functional outcomes of these two modalities in patients with severe symptomatic intracranial stenosis.

Methods

At a single center, between 2008 and 2011, patients with angiographically demonstrated severe (70–90%) symptomatic intracranial atherosclerosis were divided into two groups: group A, which received only medical treatment, and group B, which underwent endovascular stent implant treatment. The severity and location of the stenosis was determined by digital subtraction angiography and the Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) trial criteria in all patients. The exclusion criteria were: specific causes other than atherosclerosis, such as artery dissection, fibromuscular dysplasia, vasculitis, radiation and intracranial hemorrhage, focal neurological deficit that did not correlate to internal carotid artery or middle cerebral artery stenosis. All procedures were done under light anesthesia. Technical success was defined as the reduction of stenosis to <30% with complete enveloping of the lesion after the procedure. Early and late adverse events and functional outcomes were compared between the groups using the modified Rankin Scale (mRS).

Results

Overall, 63 patients (29 in group A and 34 in group B) were evaluated and followed for a mean period of 15.22 months (range 6–25). The technical success rate was 97% in a total of 34 stents in 34 patients. There was no difference between the early (within 30 days) adverse event rates of the two groups. The median follow-up duration for the stent implant patients was 15 months (range 6–25), and for the medically treated cohort it was 14 months (range 8–25). The re-stenosis rate was 5.8% and the total number of late (>30 days) adverse events, including stroke, myocardial infarction and death, was 1 (2.9%) and 6 (20.7%) in the stent implant and medical groups, respectively (p = 0.042). The stent implant group had significantly better favorable functional outcomes according to the mRS than the medical group (93.9 vs. 63.0%). The cumulative secondary adverse event-free survival was significantly lower in the stent implant group.

Conclusion

Stent implants can be considered more durable and safe for patients with symptomatic severe stenosis of the internal carotid artery or middle cerebral artery, despite optimal medical therapy. Randomized, multicenter trials are required to confirm these results.

Acute intracranial in-stent thrombosis after angioplasty of middle cerebral artery symptomatic stenosis: a case report

INTRODUCTION

Intracranial atherosclerotic disease is one of the major risk factors of ischemic stroke. Percutaneous transluminal angioplasty with stent deployment may be effective for the treatment of symptomatic intracranial stenosis, however its value is yet to be determined. High possibility of serious periprocedural complications, such as acute in-stent thrombosis or stroke, narrows the current recommendations for this treatment to patients with high-grade stenosis (>70%), and to experienced neurointerventional centers.

CASE REPORT

We present a 44-year-old male with symptomatic high-grade stenosis of the M1 segment of left middle cerebral artery, treated with percutaneous transluminal angioplasty with stenting. The procedure was complicated with acute in-stent thrombosis treated with intra-arterial thrombolysis, which resulted in a nondisabling stroke.

CONCLUSIONS

The procedure-related stroke in this patient was probably caused by middle cerebral artery perforator ostium occlusion with balloon predilatation and transient in-stent thrombosis related to insufficient antiplatelet pretreatment. Exhausted cerebrovascular reserve due to long-lasting high-grade intracranial stenosis should also be considered as a factor contributing to ischemic complications.

Mechanism of procedural failure related to wingspan

PURPOSE

Wingspan is the only FDA approved self-expanding stent for intracranial artery and known to have better delivery compared to balloon expandable stent. However, some delivery failure has been reported but incidence and mechanism of the failure have not been completely elucidated. We present the cause and mechanism of Wingspan deployment failure experienced in our Institute.

MATERIALS AND METHODS

We experienced deployment failure in seven patients (8.8%) out of 80 patients who underwent Wingspan stenting since 2007. Mean age of the patients was 62 (range 47~78) and male to female ratio was 6:1. We evaluated the cause and mechanism why the deployment was not successful and how we could manage it subsequently.

RESULTS

WE CATEGORIZED FAILURES OCCURRED IN SEVEN PATIENTS INTO THREE CATEGORIES: delivery failure (n = 3), deployment failure of stent (n = 3), retrieval failure of dual tapered (olive) tip of the inner body through the deployed the stent (n = 1). The technical failure in using Wingspan stent (delivery, deployment and retrieval failures) are related to tortuousness of the proximal (n =4) as well as distal (n =1) cerebral vessels to the stenotic lesion and bulky profile of the olive tip (n =2).

CONCLUSION

The technical failure in using Wingspan stent (delivery, deployment and retrieval failures) are related to tortuousness of the proximal as well as distal cerebral vessels to the stenotic lesion and bulky profile of the olive tip. To avoid device-related complication, complete understanding of the stent design is mandatory before using the stent.

High resolution MR imaging in patients with symptomatic middle cerebral artery stenosis

PURPOSE

High resolution magnetic resonance imaging (HRMRI) has been used as an imaging modality to depict the intracranial artery wall. The aim of this study was to compare images of the vessel wall between symptomatic and asymptomatic atherosclerotic plaques of the middle cerebral artery (MCA) using HRMRI.

MATERIALS AND METHODS

From September 2009 to August 2010 we prospectively screened consecutive patients for MCA stenosis using time-of-flight (TOF) MR angiography. We studied 14 patients with symptomatic MCA stenosis and 16 patients with asymptomatic MCA stenosis. The HRMRI protocol included three different scans: T1-, T2-, and proton density (PD)-weighted black blood MRI. The cross-sectional images of the MCA wall on HRMRI were compared between the two groups based on the degree of stenosis, remodeling ratio, outward or inward remodeling, plaque signal intensity, plaque surface irregularity, and presence of an intact inner wall.

RESULTS

The degree of MCA stenosis and the ratio of plaque thickening to patent lumen in the symptomatic group were significantly higher than in the asymptomatic group. Outward remodeling of the stenotic area in symptomatic group was significantly higher than that seen in the asymptomatic group, and the reverse was true for inward remodeling of the stenotic area (it was significantly higher in the asymptomatic group compared to the symptomatic group). T2- and PD-weighted high signal foci, eccentric wall thickening, and plaque volume in the stenotic area were all similar between the two groups.

CONCLUSIONS

HRMRI has the potential to distinguish between atherosclerotic plaques in symptomatic and asymptomatic MCA stenoses.

Evaluation of middle cerebral artery stents using multidetector row CT angiography in vivo study: comparison of the three different kernels

BACKGROUND

There are very few reports assessing middle cerebral artery (MCA) stents using multidetector computed tomography (MDCT).

PURPOSE

To assess MCA stents using multidetector CT angiography (CTA) in vivo evaluation: the differences in the CTA results according to the three different kernels.

MATERIAL AND METHODS

We retrospectively evaluated 27 MCA stents from 26 patients who underwent CTA with 16- and 64-slice MDCT after percutaneous transluminal angioplasty and stenting (PTAS). By CTA, using medium-smooth kernel (B30), medium-sharp kernel (B50), and sharp kernel (B60), the lumen diameter, artificial luminal narrowing (ALN), and subjective visibility score of the stented vessels were evaluated. The subjective visibility score ranged from 1 (poor quality) to 5 (excellent) using a five-point scale.

RESULTS

There were excellent inter-observer agreements for the lumen diameter measurements (P < 0.001). The mean diameter of the stented vessels was 2.10 ± 0.31 mm on digital subtraction angiography (DSA), 0.93 ± 0.20 mm on CTA using B30, 1.18 ± 0.27 mm on CTA using B50, and 1.29 ± 0.29 mm on CTA using B60. The mean ALN was 55.7 ± 6.0% on CTA using B30, 43.8 ± 7.5% on CTA using B50, and 38.7 ± 8.3% on CTA using B60. CTA with higher kernels had a smaller ALN than images with smaller kernels. The median subjective visibility score on the CTA using B50 was 3, which was higher than for the other kernels. The differences in the lumen diameter, ALN, and the subjective visibility score of the stented vessels on CTA using the three different kernels was statistically significant (P < 0.001).

CONCLUSION

The sharp kernel was better to assess the lumen diameter and ALN, but was inferior to the medium-sharp kernel for in-stent evaluation due to high image-to-noise. CTA with medium-sharp kernel showed good lumen visibility and acceptable ALN for MCA stents. This could therefore be a non-invasive, readily applicable clinical method for assessing MCA stent patency after stent placement.

Balloon-expandable stent placement in patients with immediate reocclusion after initial successful thrombolysis of acute middle cerebral arterial obstruction

We present the results of our approach for treating 12 consecutive cases of acute middle cerebral artery (MCA) stroke by performing balloon-expandable stent (BES) placement after immediate reocclusion due to the underlying stenosis after intra-arterial thrombolysis (IAT). We retrospectively reviewed the clinical outcomes of 12 patients with acute MCA stroke who underwent recanalization by BES placement in an underlying stenosis after IAT. The time to treatment, urokinase dose, duration of the procedure, recanalization rates and symptomatic hemorrhage were analyzed. Clinical outcome measures were assessed on admission and at discharge (the National Institutes of Health stroke scores [NIHSS]) as well as three months after treatment (modified Rankin scales [mRS]). The median NIHSS score on admission was 8.6. Four patients received IV rtPA. The median time from symptom onset to IAT was 236 minutes and the median duration of IAT was 62 minutes. The median dose of urokinase was 140,000 units. Initial recanalization after stent deployment (thrombolysis in cerebral ischemia attack grade of II or III) was achieved in all patients. Two patients died in the hospital due to aspiration pneumonia during medical management. In two patients, in-stent reocclusion occurred within 48 hours after stent deployment. At discharge, the median NIHSS score in ten patients (including the patients with reobstruction) was 2.4. The three-month outcome was excellent (mRS, 0-1) in eight patients. In this study, BES deployment was safe and effective in patients with an immediately reoccluded MCA after successful IAT.

Outpatient (Same-day care) Neuroangiography and Neurointervention

Purpose

There have been few reports regarding same-day discharge following uncomplicated procedures such as cerebral angiography and neurointervention. We present same-day experience with cerebral angiography and neurointervention during the past three years.

Materials and Methods

Four hundred and fifty-three patients underwent cerebral angiography or neurointervention at Asan Medical Center between January 2009 and December 2011. Of these patients, 249 (55%) underwent diagnostic catheter cerebral angiography and 204 patients (45%) underwent neurointerventional procedures as same-day procedures. We analyzed any complications, the modified patient-care process, the yearly trend in patient increases, disease categories, and the additional duration of admission for these procedures.

Results

The number of overall patients increased by an average of 51% annually. The disease categories included aneurysm (51%), atherosclerosis (11%) and arteriovenous malformation (10%), etc. for which the patient underwent angiography, and aneurysm (42%), venous malformation (28%), and arteriovenous malformation (17%), etc. for which patients underwent neurointervention. Same-day care patients were admitted to the intermediary care unit in the angiosuite. Neurointervention patients were sent to the neurology intensive unit after the procedure. The same-day care patients stayed in angiosuite for six hours following the transfemoral procedure. The mean admission duration for neurointervention was 2.4 days. There were no reported complications for the same-day care procedures.

Conclusion

Our study revealed an increasing tendency toward same-day care for patients who require angiography and neurointervention. Further studies will be required to better define the cost-minimization effects of outpatient practice as well as the patient perception of this fast-tracking method. We propose that outpatient angiography and neurointervention will undoubtedly continue to increase over the next decade.

Usefulness of stent implantation for treatment of intracranial atherosclerotic stenoses

Purpose

We evaluated the usefulness of intracranial stent implantation for treating patients with atherosclerotic stenosis and with recurrent, ischemic, neurological symptoms despite having undergone medical therapy.

Materials and Methods

Between March 2004 and April 2010, we attempted intracranial, stent-assisted angioplasty in 77 patients with 85 lesions (anterior circulation 73 cases, posterior circulation 12 cases) and who had ischemic neurological symptoms with more than 50% major cerebral artery stenosis. We analyzed the results regarding the technical success rate, complication rate, and restenosis rate during the mean 29.4 month follow-up period.

Results

Intracranial stent implantation was successfully performed in 74 cases (87.1%). In nine cases among the 11, failed cases, stent implantation failure was due to the tortuosity of the target vessel. One patient experienced middle cerebral artery rupture during the procedure, and we embolized the vessel using a microcoil. Five patients developed cerebral infarction in three weeks after the procedure, three of whom improved using conservative management, although the other, two patients expired. The mean number of residual stenoses decreased from 72.3% to 14.7%. Three patients demonstrated significant in-stent restenosis, i.e. more than 50%, during the follow-up period.

Conclusion

As stent-assisted angioplasty in intracranial, atherosclerotic stenosis is effective and relatively safe, it can be considered as an alternative treatment for patients with recurrent, ischemic, neurologic symptoms despite having undergone medical therapy.