Prophylactic Dual Catheter Technique to Prevent Side Branch Snowplowing Complications during Angioplasty and Stenting

OBJECTIVE: Angioplasty and Stenting of intracranial atherosclerotic lesions have a higher complication rate and a large proportion of this is attributable to side branch arterial occlusion from forceful displacement of the atheroma into the ostia or snowplowing effect. This can result in severe disabilities when it result in small infarcts involving eloquent areas in the posterior circulation or the motor tracts. MATERIALS AND METHODS: We present a series of 6 cases utilizing a new dual catheter technique for maintaining the patency of at-risk vessels during angioplasty and stenting. There are several methods previously described to help reduce the incidence of stroke but because they do not have a physical presence in the ostia to protect it, they are unable to guarantee the patency of the vessel. RESULTS: All 6 patients underwent angioplasty and stenting with the technique. The patients were assessed for complications with post-procedure magnetic resonance imaging and no complications were found. CONCLUSION: In this preliminary series, the dual catheter technique appears to safe and effective in preventing occlusion of the adjacent branch arteries. This technique may facilitate the use of the Wingspan stent in the treatment of intracranial atherosclerotic stenotic segments by reducing the risk of peri-procedural stroke.

Changes of high-resolution magnetic resonance imaging before and after Wingspan stent in patients with intracranial large artery stenosis / 中国脑血管病杂志

Objective To evaluate the imaging changes of the arterial wall and lumen at the site of intracranial large artery lesions with high-resolution magnetic resonance imaging (HR-MRI) before and after Wingspan stent implantation.Methods From December 2013 to December 2014,9 patients with symptomatic intracranial arterial stenosis (stenosis rate:70%-99%) admitted to the Department of Interventional Neuroradiology,Xuanwu Hospital,Capital Medical University were enrolled retrospectively.The sites of the lesions included middle cerebral arteries,basilar artery,and intracranial segment of vertebral artery.Head 3D HR-MRI technique was used to analyze and compare the changes of the tube-wall enhancement areas in the lesion sites through image registration and matching.The consistency of stenosis rates measured by HR-MRI and DSA was compared through Pearson correlation analysis and Bland-Altman Plot.Results The success rate of technique was 100% without related complications.(1) After Wingspan stent implantation,the gadolinium enhancement in the vascular walls of the stenosis sites was decreased significantly compared with that before procedure.The area of enhancement decreased was 87±16% after stent implantation compared with before implantation,and the difference was statistically significant (t=2.325,P=0.049).(2) Before stent implantation,the mean stenosis rates of the HR-MRI and DSA measurements were 82±6% and 82±8% respectively,and the difference was not statistically significant (t=0.051,P=0.961);after procedure,the mean stenosis rates of HR-MRI and DSA measurements were 16±12% and 21±12% respectively,and the difference was not statistically significant (t=1.345,P=0.216).(3) The Pearson correlation coefficients of HR-MRI and DSA for stenosis rate measurement before and after stent implantation were 0.347 (P=0.361) and 0.545 (P=0.129) respectively.Bland-Altman statistical images showed that most of the data points were within the consistency limit (x-±1.96 s).Conclusions As an in vivo noninvasive imaging means,HR-MRI can be used to assess the changes of vascular walls of the lesion sites,the vascular lumen,and the original plaques after the intracranial stent release.It can also be used to evaluate the reconstruction of intracranial arterial walls.

Carotid artery stent angioplasty for treatment of internal carotid artery stenosis in the elderly: analysis on its efficacy and related factors of safety / 上海预防医学

Objective To study the efficacy and safety of carotid artery stenting(CAS) in elderly patients with internal carotid artery stenosis and its related factors.Methods Between January 2012 and July 2014,a total of 152 patients(over 65 years of age)with carotid artery stenosis were enrolled in this study,of whom 79 patients received drug treatment (control group) and 73 patients received CAS (intervention group).The two groups were followed up for one year.The patients'' scores of mRS(the modified Rankin Scale) and NIHSS(the National Institute of Health Stroke Scale) were observed and compared in the curative effect between the two groups.By means of logistic regression were analyzed the related safety factors in CAS treatment for elderly patients over 65 with extracranial stenosis of internal carotid artery.Results Both the median mRS (P<0.01) and NIHSS(P<0.05) scores were lower in intervention group than those in control group at 3,6 and 12 months follow-up,respectively.Thirty days after CAS,there occurred transient ischemic attack (TIA) in intervention group,whose incidence was significantly lower than that in control group (P<0.05).However,there was no statistical significant difference found between the two groups in the incidence of serious adverse events including TIA,cerebral hemorrhage,cerebral infarction and death(P>0.05)at one year follow-up.And logistic regression analysis showed that the previous history of cerebral infarction,residual stenosis or combined un-interferential cerebral arterial stenosis were all independent predictors of serious adverse events including TIA,cerebral infarction,cerebral hemorrhage,re-stenosis and death (P<0.05).Conclusion CAS is a safe and effective procedure for old patients with internal carotid artery stenosis.A history of cerebral infarction,combined un-interferential cerebral arterial stenosis or residual stenosis after CAS were all risk factors,which need to be effectively controlled before CAS.

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.

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

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 or =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.

Comparison of Drug-eluting Coronary Stents, Bare Coronary Stents and Self-expanding Stents in Angioplasty of Middle Cerebral Artery Stenoses

OBJECTIVE: The purpose of this study is to investigate the results of treatment using stent-angioplasty for symptomatic middle cerebral arterial (MCA) stenosis and comparison of in-stent restenosis between drug-eluting stents (DES), bare metal coronary stents (BMS) and self-expanding stents (SES). MATERIALS AND METHODS: From Jan. 2007 to June. 2012, 34 patients (mean age +/- standard deviation: 62.9 +/- 13.6 years) with MCA stenosis were treated. Inclusion criteria were acute infarction or transient ischemic attacks (TIAs) and angiographically proven symptom related severe stenosis. Stents used for treatment were DES (n = 8), BMS (n = 13) and SES (n = 13). National Institutes of Health Stroke Scale (NIHSS) at admission was 2.5 +/- 3.1 and mean stenosis rate was 79.0 +/- 8.2%. Assessment of clinical and angiographic results was performed retrospectively. RESULTS: Among 34 patients, periprocedural complications occurred in four cases (11.8%), however, only two cases (6.0%) were symptomatic. All patients were followed clinically (mean follow-up period; 40.7 +/- 17.7 months) and 31 were followed angiographically (91.2%. 13.4 +/- 8.5 months). There was no occurrence of repeat stroke in all patients; however, mild TIAs related to restenosis occurred in three of 34 patients (8.8%). The mean NIHSS after stent-angioplasty was 1.7 +/- 2.9 and 0.8 +/- 1.1 at discharge. The modified Rankin score (mRS) at discharge was 0.5 +/- 0.9 and 0.3 +/- 0.8 at the last clinical follow-up. In-stent restenosis over 50% occurred in five of 31 angiographically followed cases (16.1%), however, all of these events occurred only in patients who were treated with BMS or SES. Restenosis rate was 0.0% in the DES group and 20.8% in the other group (p = 0.562); it did not differ between BMS and SES (2/11 18.2%, 3/13 23.1%, p = 1.000). CONCLUSION: Stent-angioplasty appears to be effective for symptomatic MCA stenosis. As for restenosis, in our study, DES was presumed to be more effective than BMS and SES; meanwhile, the results did not differ between the BMS and SES groups.

Clinical and Angiographic Outcomes of Wingspan Stent Placement for Treatment of Symptomatic Intracranial Stenosis: Single Center Experience with 19 Cases

OBJECTIVE: The limitations of medical management of symptomatic intracranial arterial stenosis (ICS) have prompted development of new strategies, including endovascular treatment. However, stenting of symptomatic ICS remains investigational. Here, we have reported and analyzed a series of 19 endovascular procedures involving placement of a Wingspan stent. METHODS: We conducted a retrospective review of a series of ICS in which patients were treated with percutaneous transarterial balloon angioplasty and stent placement (PTAS). Patients included in the study were diagnosed as symptomatic ICS between May 2010 and September 2011. RESULTS: Nineteen patients (median age, 65 years; 12 males, seven women) were treated with the Wingspan stent system for symptomatic ICS ranging from 50% to 99%. The technical success rate was 100%. The location of ICS included the internal carotid (n = 5; 1 petrous, 3 cavernous, and 1 clinoid segments), vertebral (n = 1; V4 segment), basilar (n = 1), and middle cerebral (n = 12; 9 M1, 3 M2) arteries. There was no occurrence of procedure-related mortality. Periprocedural morbidity occurred in two cases (10.5%), including carotid-cavernous fistula (n = 1) and subarachnoid hemorrhage (n = 1). No ipsilateral stroke was recorded beyond 30 days during a mean follow-up period of 13.2 months (range 9-19 months). Restenosis (> 50%) was observed in one patient (6.3%), who was asymptomatic, on follow-up imaging. CONCLUSION: Wingspan stent for symptomatic ICS can be performed with a high rate of technical success and acceptable periprocedural morbidity rates. Our initial experience indicates that this procedure represents a viable treatment option for this patient population.

An update on interventional revascularization therapy of intracranial arterial steno-occlusive diseases

Intracranial arterial stenosis (ICAS) has been recognized as one of the major causes of ischemic stroke especially in Asian countries including Korea. There have been some arguments on the optimal management strategy over this condition. The purpose of this review is to briefly summarize its clinical significance and the current status of neurointerventional revascularization treatment. The mechanisms of stroke in ICAS are hemodynamic insufficiency, artery-to-artery embolism, athero-thrombosis, or branch artery occlusion. The first-line treatment of symptomatic ICAS is medical treatment. Balloon angioplasty followed by stent placement can be performed to improve perfusion abnormality and elimination of future embolic sources. However, a recent randomized trial on stent vs. medical management failed to show any benefit of angioplasty/stenting. Endovascular therapy is now reserved only for high-risk symptomatic cases refractory to the best medical management. High-resolution magnetic resonance imaging may help provide a better understanding of the disease and patient selection for the optimal treatment modality. Improvement of the device is mandatory to facilitate procedure safety and efficacy. The role of strict medical management which, includes risk factor modification in ICAS, has become critical. Patient outcomes could be improved if we could provide safer and efficacious technology and procedural techniques for intracranial angioplasty and stenting, especially in selected high-risk patients.

Current Status and Future Prospect of Endovascular Neurosurgery

Recently, due to the evolution of technology, the field of neurosurgery is receiving spotlight. In particular endovascular neurosurgery has gained a great interest along with the advancement of the modern neurosurgery. The most remarkable advances were made in embolization of the cerebral aneurysms, arteriovenous malformations and intracranial stenosis during the past 10 years. These advances will further change the role of neurosurgeons in treating cerebrovascular disease. Because interventional neuroradiologists have performed most of procedures in the past, neurosurgeons have been deprived of chances to learn endovascular procedure. This article discusses the development of technological aspect of endovascular neurosurgery in chronological order. By understanding the history and current status of the endovascular surgery, the future of neurosurgery will be promising.

Guideline for Intracranial Stenting of Symptomatic Intracranial Artery Stenosis: Preliminary Report / 신경중재치료의학

The annual stroke and death rate in symptomatic patients with intracranial atherosclerotic stenosis has been published as high as 20% or even more. According to the studies of the Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) and Extracranial-intracranial bypass surgery did not prove to be effective for prevention of stroke or improvement of prognosis of intracranial atherosclerotic stenosis. Increasing experience of angioplasty and stenting in intracranial atherosclerotic stenosis and technological advances during the past two decades have led the current results of complication rates as low as 10% with success rates of up to 90% and significant low recurrence rate of stroke after endovascular treatment of intracranial atherosclerotic stenosis. Growing evidence supports the endovascular treatment to be a primary method of treatment of intracranial atherosclerotic stenosis. This has engendered the need for the treatment guideline of the procedure such as indication, procedure's protocol, evaluating uniform methods of the results. In 2006, the Guideline Research Group in the Korean Society of Interventional Neuroradiology had conferences to provide the guideline and came to propose this preliminary result in this paper. The indication is symptomatic patients with 50-70% stenosis or patients having progressively aggravating stenosis. The procedure interval being as short as possible from the symptom onset would result in better outcome. In terms of treatment method, previous reports showed that both balloon angioplasty and stenting were good for success rate, complication rate and effectiveness for preventing stroke but the balloon angioplasty had more risk of dissection and more frequency of re-procedure than stenting. We also proposed reporting guideline at the periods of pre and post-procedure and mid and long-term follow-up.

Amaurosis Fugax Associated with Stenosis of the Intracranial Internal Carotid Artery: Successful Restoration of Ophthalmic Artery Flow by Stent Placement

Two patients presented with amaurosis fugax(AMF), despite treatment with antiplatelet drugs and anticoagulants due to previous transient ischemic attacks. Angiography demonstrated severe stenosis in the cavernous and petrous internal carotid artery(ICA) respectively, with reduced flow in the ophthalmic artery(OA). Endovascular stent placement in both patients resulted in normalization of the vessel lumen of the stenotic vessel segments. In addition, complete restoration of OA flow was noted immediately after stenting. Both patients showed no further episode of AMF over a follow-up period of 38 and 23 months respectively. Our clinical and angiographic findings suggest that hemodynamic insufficiency in retinal vasculature caused by a stenosis of the cavernous or petrous ICA can be treated successfully by endovascular stent.

Endovascular Stent-Assisted Angioplasty of Symptomatic Intracranial Stenosis / 国际脑血管病杂志

The application of intracranial stent-assisted angioplasty has been in controversy.In recent years, the development novel stents, preoperative evaluation, and accumulation of periprocedural management experiences have significantly improved the success rate of this operation.The incidence of complications has decreased significantly. However, the efficacy and safety of intracranial stent-assisted angioplasty are still lack of support from prospective multicenter studies.This article reviews the recent advances in this field.

Intracranial Atherosclerosis: Incidence, Diagnosis and Treatment

Intracranial atherosclerosis is considered a cause of approximately 8% of all strokes in the western society. However, its frequency is much higher in Asian countries. In our hospital-based study, among the patients who had angiographic abnormalities, the frequency of intracranial atherosclerosis was approximately 70% far exceeding that of extratracranial atherosclerosis. Symptomatic atherosclerotic diseases were most often found in the middle cerebral artery. Generally, it has been shown that obesity and hyperlipidemia are related to extracranial diseases while advance hypertension is associated with intracranial diseases. However, these results have not always been replicated, and certain genetic factors may be related with the ethnic differences in the location of atherosclerosis. Recent studies using diffusion weighted MRI showed that the main mechanisms of stroke in patients with intracranial atherosclerosis are the branch occlusion, artery to artery embolism and both. The intracranial stenosis, especially symptomatic one, is not a static condition and may progress or regress in a relatively short period of time. Progressive stenosis of intracranial arteries is clearly related to the development of ischemic events. The annual risk of stroke relevant to the stenosed intracranial vessel is approximately 8%. In retrospective studies including ASID, anticoagulation was found to be superior to aspirin in reducing the stroke events. However, a recent prospective study failed to confirm the superiority of anticoagulation over aspirin in patients with intracranial stenosis. Moreover, anticoagulation resulted in excessive central nervous system bleeding as compared to aspirin. Because aspirin alone seems to be insufficient in the prevention of progression of intracranial stenosis, a combination of antiplatelets has been tried. Recently, we found that a combination of aspirin + cilostazol was superior to aspirin monotherapy in the prevention of progression of symptomatic intracranial stenosis. However, further studies are required to find out the best combination of antiplatelets for symptomatic intracranial stenosis. The effect of other atheroma stabilizers such as statins should also be properly evaluated. Angioplasty/stent is another important option for the relatively severe intracranial stenosis. According to previous studies, immediate success rate has reached up to 90%. If patients are carefully selected, and procedures done by experienced hand, angioplasty/stent can be of benefit especially in relatively young patients with proximal, short-segment, severe symptomatic stenosis. However, this procedure is not without complications or long-term re-stenosis. Further studies are required to elucidate the best therapeutic strategy in patients with intracranial atherosclerosis.

Intracranial Atherosclerosis: Incidence, Diagnosis and Treatment

Intracranial atherosclerosis is considered a cause of approximately 8% of all strokes in the western society. However, its frequency is much higher in Asian countries. In our hospital-based study, among the patients who had angiographic abnormalities, the frequency of intracranial atherosclerosis was approximately 70% far exceeding that of extratracranial atherosclerosis. Symptomatic atherosclerotic diseases were most often found in the middle cerebral artery. Generally, it has been shown that obesity and hyperlipidemia are related to extracranial diseases while advance hypertension is associated with intracranial diseases. However, these results have not always been replicated, and certain genetic factors may be related with the ethnic differences in the location of atherosclerosis. Recent studies using diffusion weighted MRI showed that the main mechanisms of stroke in patients with intracranial atherosclerosis are the branch occlusion, artery to artery embolism and both. The intracranial stenosis, especially symptomatic one, is not a static condition and may progress or regress in a relatively short period of time. Progressive stenosis of intracranial arteries is clearly related to the development of ischemic events. The annual risk of stroke relevant to the stenosed intracranial vessel is approximately 8%. In retrospective studies including ASID, anticoagulation was found to be superior to aspirin in reducing the stroke events. However, a recent prospective study failed to confirm the superiority of anticoagulation over aspirin in patients with intracranial stenosis. Moreover, anticoagulation resulted in excessive central nervous system bleeding as compared to aspirin. Because aspirin alone seems to be insufficient in the prevention of progression of intracranial stenosis, a combination of antiplatelets has been tried. Recently, we found that a combination of aspirin + cilostazol was superior to aspirin monotherapy in the prevention of progression of symptomatic intracranial stenosis. However, further studies are required to find out the best combination of antiplatelets for symptomatic intracranial stenosis. The effect of other atheroma stabilizers such as statins should also be properly evaluated. Angioplasty/stent is another important option for the relatively severe intracranial stenosis. According to previous studies, immediate success rate has reached up to 90%. If patients are carefully selected, and procedures done by experienced hand, angioplasty/stent can be of benefit especially in relatively young patients with proximal, short-segment, severe symptomatic stenosis. However, this procedure is not without complications or long-term re-stenosis. Further studies are required to elucidate the best therapeutic strategy in patients with intracranial atherosclerosis.

Association of Metabolic Syndrome and C-reactive Protein Levels with Intracranial Atherosclerotic Stroke

BACKGROUND: The risk factors for intracranial atherosclerosis are unclear but may differ from those for other stroke subtypes. Here, we investigated whether metabolic syndrome, an emerging risk factor for cardiovascular disease, is associated with intracranial atherosclerotic stroke. METHODS: Using the Adults Treatment Panel III criteria, we evaluated the components of metabolic syndrome in 439 patients with ischemic stroke or transient ischemic attacks. The prevalence of metabolic syndrome within each stroke subtype was determined, and the association between intracranial atherosclerosis and metabolic syndrome was evaluated. RESULTS: Metabolic syndrome was observed more frequently in patients with intracranial atherosclerosis than in those with other types of stroke (P=0.003). In a multiple regression analysis, metabolic syndrome, but not conventional risk factors, was independently associated with intracranial atherosclerosis (P=0.016). By contrast, the serum level of C-reactive protein was correlated negatively with the presence of intracranial atherosclerosis. Intracranial atherosclerosis was most prevalent in patients with metabolic syndrome and low levels of C-reactive protein (P=0.024). CONCLUSIONS: Our results indicate that metabolic syndrome is a strong independent risk factor for intracranial atherosclerotic stroke. Therefore, treatment of metabolic abnormalities may be an important prevention strategy for intracranial atherosclerotic stroke.