Primary stent therapy for symptomatic intracranial atherosclerotic stenosis: 1-year follow-up angiographic and midterm clinical outcomes

Perioperative dual antiplatelets management for ventriculoperitoneal shunt operation in patients with hydrocephalus after stent-assisted coil embolization of the ruptured intracranial aneurysm

OBJECTIVE

Ventriculoperitoneal shunt (VPS) surgery is sometimes necessary in patients who present with symptomatic hydrocephalus after undergoing stent-assisted coil embolization of ruptured intracranial aneurysms. However, there are no guidelines for the perioperative management of VPS using dual antiplatelet therapy (DAPT) and balancing between the thromboembolic and hemorrhagic complications. Studies regarding discontinuation of DAPT and its substitution with a less potent drug for reducing the risk of hemorrhage have been previously attempted; however, the sample size in these studies was small. This study investigates the safety and feasibility of ibuprofen bridging therapy with discontinuation of DAPT for five days in patients who have recently received a neurovascular stent and require VPS.

METHODS

Forty-one patients, who were administered DAPT after neurovascular stent placement and later underwent VPS, were retrospectively enrolled. Patients were divided into two groups based on the perioperative DAPT therapy: (1) Bridge: discontinuing DAPT and substituting it with ibuprofen 600 mg bid for five days, and (2) Continue: maintaining DAPT during surgery. The groups were compared and risk factors for hemorrhagic complication were investigated.

RESULTS

On comparison analysis, no ischemic complications were observed in both groups; however, hemorrhagic complications were significantly higher in the continue than in the bridge group (p = 0.004). On multivariate logistic regression analysis, "ibuprofen bridging" was identified as a significant factor negatively associated with hemorrhagic complications (p = 0.019).

CONCLUSION

"Ibuprofen bridging therapy with discontinuation of DAPT for 5 days" is a potential treatment strategy for patients having recently undergone neurovascular stent placement and are scheduled for VPS surgery.

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.

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.

Peri-stent aneurysm formation following a stent implant for stenotic intracranial vertebral artery dissection: a technical report of two cases successfully treated with coil embolization

INTRODUCTION

Although stenting for stenotic vertebral artery dissection (VAD) improves compromised blood flow, subsequent peri-stent aneurysm (PSA) formation is not well-known. We report two cases with PSA successfully treated with coil embolization.

METHODS

Three patients with stenotic intracranial VAD underwent endovascular angioplasty at our institution because they had acute infarction in posterior circulation territory and clinical evidence of hemodynamic insufficiency. In two of three patients balloon angioplasty at first session failed to relieve the stenosis, and a coronary stent was implanted. Angiography immediately after stenting showed no abnormality in case 1 and minimal slit-like projection at proximal portion of the stent in case 2.

RESULTS

Angiography obtained 16 months after the stenting revealed PSA in case 1. In case 2, angiography performed 3 months later showed that the projection at proximal portion enlarged and formed an aneurysm outside the stent. Because follow-up angiographies showed growth of the aneurysm in both cases, endovascular aneurysmal embolization was performed. We advanced a microcatheter into the aneurysm through the strut of existing stent and delivered detachable coils into the aneurysm lumen successfully in both cases. The post-procedural course was uneventful, and complete obliteration of aneurysm was confirmed on angiography in both cases.

CONCLUSION

Stenting for stenotic intracranial VAD may result in delayed PSA; therefore, follow-up angiographies would be necessary after stenting for stenotic intracranial arterial dissection. Coil embolization through the stent strut would be a solution for enlarging PSA.

Intracranial atheromatous disease treatment with the Wingspan stent system: evaluation of clinical, procedural outcome and restenosis rate in a single-center series of 21 consecutive patients with acute and mid-term results

BACKGROUND

Intracranial atherosclerosis may be the underlying pathology in up to 15% of ischemic strokes, but may account for about 40% of strokes in some populations. After an ischemic event determined by intracranial atherosclerosis, patients have a 12% annual risk of stroke recurrence, mostly during the first year.

OBJECTIVE

To evaluate procedural safety, clinical outcome and restenosis rate of Wingspan stent placement.

METHODS

Twenty-one caucasoid patients were enrolled. Target patients were affected by high-grade, symptomatic, intracranial atherosclerotic lesions, were on antithrombotic therapy and at high stroke risk. All patients were treated with the Wingspan stent system.

RESULTS

Technical success resulted 100%, with all target lesions being reduced to <50%. No stroke or death were observed at 30. The mean percent of stenosis was reduced from a middle value of 84% to a middle value of 17% after stent placement. Medium follow-up was 19.5months (range 6-36months). No stroke or death occurred in any patient. None of the patients presented a <50% stent patency rate at follow-up.

CONCLUSIONS

The short-term results and follow up analysis provide evidence demonstrating the safety of the Wingspan system when used in high-risk patient population. Due to concerns regarding long-term stent patency and ischemic events occurrence emerged from clinical trials such as the SAMMPRIS, intracranial angioplasty and stent with the Wingspan system should be considered only for high risk patients in which it may be considered the only viable therapeutic option.

Perioperative management of a neurosurgical patient requiring antiplatelet therapy

In patients who undergo neurovascular stent placement with postoperative dual antiplatelet therapy to prevent in-stent thrombosis, there is no protocol for balancing the risk of acute stent thrombosis and bleeding if urgent neurosurgical procedures are required. We detail perioperative management of dual antiplatelet therapy in a 66-year-old man with a dolichoectatic aneurysm of the basilar artery treated with a Pipeline stent. Postoperatively, the patient was placed on aspirin and clopidogrel to prevent in-stent thrombosis. One month after the procedure, his neurological status declined secondary to obstructive hydrocephalus. His condition necessitated urgent placement of a ventriculoperitoneal shunt, despite the dual antiplatelet therapy for the flow-diverting Pipeline stent. Aspirin and clopidogrel were discontinued seven days prior to the planned shunt placement. To minimize time off antiplatelet therapy, aspirin was immediately replaced with ibuprofen. Eptifibatide was then started three days prior to surgery. The ibuprofen/eptifibatide bridge was discontinued at midnight prior to surgery. Aspirin was restarted on the first postoperative day and clopidogrel was restarted on the second postoperative day. The patient tolerated shunt placement without excessive bleeding or hemorrhagic complications. During the remainder of his hospital course, no evidence of stent thrombosis or intracranial hemorrhage was noted. We conclude that management of antiplatelet prophylaxis for neurovascular stent thrombosis in patients requiring urgent neurosurgical procedures may be successfully achieved by bridging aspirin and clopidogrel with ibuprofen and eptifibatide in the preoperative period.

Stenting for the treatment of high-grade intracranial stenoses

To date, evidence to recommend endovascular treatment in patients with intracranial stenoses is lacking. Recently, the introduction of self-expanding stents (Wingspan Stent System) aroused considerable expectations in their employ for stroke prevention. We report a single-center experience of percutaneous transluminal angioplasty and stenting in a series of consecutive patients with intracranial stenoses and compare the safety and performance of balloon-mounted stents versus self-expanding stent systems (Wingspan). Thirty-four patients with 39 severe (>70%) intracranial stenoses were treated during a 6-year period. An independent stroke neurologist collected data about intra and periprocedural complications and short-term outcome. We considered as endpoint measures (1) any 30-day stroke or death (2) any major 30-day complication and (3) procedure technical success. Technical success was achieved in all patients. No vessel dissection or ruptures were observed. The 30-day stroke/death rate was 17.9%. Five ischemic strokes in the territory of treated vessels and two intracranial hemorrhages occurred respectively within 24 h and 5 days after endovascular treatment. Three (17.6%) patients of Wingspan treated group and four (18.2%) of the patients treated with different stent systems had unfavorable outcome. Our study confirms that endovascular treatment can be performed with a high technical success rate, even though the safety of these devices has still to be demonstrated.

COMPARISON BETWEEN PRIMARY ANGIOPLASTY AND STENT PLACEMENT FOR SYMPTOMATIC INTRACRANIAL ATHEROSCLEROTIC DISEASE

OBJECTIVE

To compare the short- and long-term rates of stroke-and/or-death associated with primary angioplasty alone and angioplasty with stent placement using a meta-analysis of published studies. Both primary angioplasty alone and angioplasty with stent placement have been proposed as treatment strategies for symptomatic intracranial atherosclerotic disease to reduce the risk of stroke-and/or-death with best medical treatment alone. However, it remains unclear which of these endovascular techniques offers the best risk reduction.

METHODS

We identified pertinent studies published between January 1980 and May 2008 using a search on PubMed and Cochrane libraries, supplemented by a review of bibliographies of selected publications. The incidences of stroke-and/or-death were estimated for each report and pooled for both angioplasty alone and angioplasty with stent placement at 1 month and 1 year postintervention and then compared using a random-effects model. The association of year of publication and 1-year incidence of stroke-and/or-death was analyzed with meta-regression.

RESULTS

After applying our selection criteria, we included 69 studies (33 primary angioplasty-alone studies [1027 patients] and 36 studies of angioplasty with stent placement [1291 patients]) in the analysis. There were a total of 91 stroke-and/or-deaths reported in the angioplasty-alone–treated group (8.9%; 95% confidence interval [CI], 7.1%–10.6%), compared with 104 stroke-and/or-deaths in the angioplasty-with-stent–treated group (8.1%; 95% CI, 6.6%–9.5%) during a 1-month period (relative risk [RR], 1.1; P = 0.48). The pooled incidence of 1-year stroke-and/or-death in patients treated with angioplasty alone was 19.7% (95% CI, 16.6%–23.5%), compared with 14.2% (95% CI, 11.9%–16.9%) in the angioplasty-with-stent–treated patients (RR, 1.39; P = 0.009). The incidence of technical success was 79.8% (95% CI, 74.7%–84.8%) in the angioplasty-alone group and 95% (95% CI, 93.4%–96.6%) in the angioplasty-with-stent–treated group (RR, 0.84; P &lt; 0.0001). The pooled restenosis rate was 14.2% (95% CI, 11.8–16.6%) in the angioplasty-alone group, as compared with 11.1% (95% CI, 9.2%–13.0%) in the angioplasty-with-stent–treated group (RR, 1.28; P = 0.04). There was no effect of the publication year of the studies on the risk of stroke-and/or-death.

CONCLUSION

Risk of 1-year stroke-and/or-death and rate of angiographic restenosis may be lower in symptomatic intracranial atherosclerosis patients treated by angioplasty with stent placement compared with patients treated by angioplasty alone.

Risk factors associated with major cerebrovascular complications after intracranial stenting

BACKGROUND

There are limited data on the relationship between patient and site characteristics and clinical outcomes after intracranial stenting.

METHODS

We performed a multivariable analysis that correlated patient and site characteristics with the occurrence of the primary endpoint (any stroke or death within 30 days of stenting or stroke in the territory of the stented artery beyond 30 days) in 160 patients enrolled in this stenting registry. All patients presented with an ischemic stroke, TIA, or other cerebral ischemic event (e.g., vertebrobasilar insufficiency) in the territory of a suspected 50-99% stenosis of a major intracranial artery while on antithrombotic therapy.

RESULTS

Cerebral angiography confirmed that 99% (158/160) of patients had a 50-99% stenosis. In multivariable analysis, the primary endpoint was associated with posterior circulation stenosis (vs anterior circulation) (hazard ratio [HR] 3.4, 95% confidence interval [CI] 1.2-9.3, p = 0.018), stenting at low enrollment sites (< 10 patients each) (vs high enrollment site) (HR 2.8, 95% CI 1.1-7.6, p = 0.038), < or = 10 days from qualifying event to stenting (vs > or = 10 days) (HR 2.7, 95% CI 1.0-7.8, p = 0.058), and stroke as a qualifying event (vs TIA/other) (HR 3.2, 95% CI 0.9-11.2, p = 0.064). There was no significant difference in the primary endpoint based on age, gender, race, or percent stenosis (50-69% vs 70-99%).

CONCLUSIONS

Major cerebrovascular complications after intracranial stenting may be associated with posterior circulation stenosis, low volume sites, stenting soon after a qualifying event, and stroke as the qualifying event. These factors will need to be monitored in future trials of intracranial stenting.

The NIH registry on use of the Wingspan stent for symptomatic 70-99% intracranial arterial stenosis

BACKGROUND

The Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) trial showed that patients with symptomatic 70% to 99% intracranial arterial stenosis are at particularly high risk of ipsilateral stroke on medical therapy: 18% at 1 year (95% CI = 3% to 24%). The Wingspan intracranial stent is another therapeutic option but there are limited data on the technical success of stenting and outcome of patients with 70% to 99% stenosis treated with a Wingspan stent.

METHODS

Sixteen medical centers enrolled consecutive patients treated with a Wingspan stent in this registry between November 2005 and October 2006. Data on stenting indication, severity of stenosis, technical success (stent placement across the target lesion with <50% residual stenosis), follow-up angiography, and outcome were collected.

RESULTS

A total of 129 patients with symptomatic 70% to 99% intracranial stenosis were enrolled. The technical success rate was 96.7%. The mean pre and post-stent stenoses were 82% and 20%. The frequency of any stroke, intracerebral hemorrhage, or death within 30 days or ipsilateral stroke beyond 30 days was 14.0% at 6 months (95% CI = 8.7% to 22.1%). The frequency of >or=50% restenosis on follow-up angiography was 13/52 (25%).

CONCLUSION

The use of a Wingspan stent in patients with severe intracranial stenosis is relatively safe with high rate of technical success with moderately high rate of restenosis. Comparison of the event rates in high-risk patients in Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) vs this registry do not rule out either that stenting could be associated with a substantial relative risk reduction (e.g., 50%) or has no advantage compared with medical therapy. A randomized trial comparing stenting with medical therapy is needed.