Abstract 138: Perfusion Imaging of Intracranial Atherosclerotic Disease in SAMMPRIS

Background: Noninvasive perfusion imaging with CT (CTP) or MRI (PWI) provides key physiologic data regarding hemodynamics of intracranial atherosclerotic disease (ICAD). Parameters of delayed perfusion such as Tmax, time to peak (TTP), mean transit time (MTT) and cerebral blood volume (CBV) or flow (CBF) may disclose important mechanisms of stroke in ICAD. We analyzed CTP and PWI acquired in SAMMPRIS to identify the principal perfusion patterns, correlation with conventional angiography and potential links with clinical outcome.

Methods: CTP and PWI were identified in the SAMMPRIS imaging archive. Perfusion datasets were processed with Olea Sphere® to yield Tmax, TTP, MTT, CBV and CBF maps graded by 2 expert readers to identify markers of decreased, normal, or increased perfusion in the symptomatic territory. The resultant multiparametric perfusion patterns were correlated with clinical and angiographic variables, using Fisher’s exact test and Kaplan-Meier methods followed by log-rank tests.

Results: Perfusion imaging was available in 59 subjects at baseline and 42 at follow-up. Baseline perfusion included Tmax (decreased in 2, normal in 18, increased in 39); TTP (decreased in 2, normal in 18, increased in 39); MTT (decreased in 2, normal in 27, increased in 30); CBV (decreased in 5, normal in 42, increased in 12); CBF (decreased in 7, normal in 48, increased in 4). The baseline Tmax increases in 66% of subjects were associated with the combined (TICI and collaterals) diminished angiographic flow patterns (p=0.016) and with increased 30-day SIT (p=0.015). Baseline CBV changes were associated with stroke as a qualifying event (p=0.007), NIHSS (p=0.039), presenting symptoms of hypoperfusion (p=0.071), severity of stenosis (p=0.015), and angiographic flow patterns (p=0.009). Follow-up CTP or PWI revealed similar patterns to baseline, although delay maps normalized in patients after stenting.

Conclusions: Noninvasive perfusion imaging with CT or MRI discloses delayed flow caused by ICAD, often compensated by autoregulatory vasodilation (increased CBV) to maintain CBF in the downstream territory. Perfusion imaging parameters may reflect angiographic collateral flow patterns in ICAD, warranting further investigation as predictors of stroke risk.

A Multicenter Study of Stent-Assisted Coiling of Cerebral Aneurysms With a Y Configuration

BACKGROUND:

Stent-assisted coiling with 2 stents in a Y configuration is a technique for coiling complex wide-neck bifurcation aneurysms.

OBJECTIVE:

We sought to provide long-term clinical and angiographic outcomes with Y-stent coiling, which are not currently established.

METHODS:

Seven centers provided deidentified, retrospective data on all consecutive patients who underwent stent-assisted coiling for an intracranial aneurysm with a Y-stent configuration.

RESULTS:

Forty-five patients underwent treatment by Y-stent coiling. Their mean age was 57.9 years. Most aneurysms were basilar apex (87%), and 89% of aneurysms were unruptured. Mean size was 9.9 mm. Most aneurysms were treated with 1 open-cell and 1 closed-cell stent (51%), with 29% treated with open-open stents and 16% treated with 2 closed-cell stents. Initial aneurysm occlusion was excellent (84% in Raymond grade I or II). Procedural complications occurred in 11% of patients. Mean clinical follow-up was 7.8 months, and 93% of patients had a modified Rankin Scale score of 0 to 2 at last follow-up. Mean angiographic follow-up was 9.8 months, and 92% of patients had Raymond grade I or II occlusion on follow-up imaging. Of those patients with initial Raymond grade III occlusion and follow-up imaging, all but 1 patient progressed to a better occlusion grade (83%; P < .05). Three aneurysms required retreatment because of recanalization (10%). There was no difference in initial or follow-up angiographic occlusion, clinical outcomes, incidence of aneurysm retreatment, or in-stent stenosis among open-open, open-closed, or closed-closed stent groups.

CONCLUSION:

In a large multicenter series of Y-stent coiling for bifurcation aneurysms, there were low complication rates and excellent clinical and angiographic outcomes.

Physical factors effecting cerebral aneurysm pathophysiology

Many factors that are either blood-, wall-, or hemodynamics-borne have been associated with the initiation, growth, and rupture of intracranial aneurysms. The distribution of cerebral aneurysms around the bifurcations of the circle of Willis has provided the impetus for numerous studies trying to link hemodynamic factors (flow impingement, pressure, and/or wall shear stress) to aneurysm pathophysiology. The focus of this review is to provide a broad overview of such hemodynamic associations as well as the subsumed aspects of vascular anatomy and wall structure. Hemodynamic factors seem to be correlated to the distribution of aneurysms on the intracranial arterial tree and complex, slow flow patterns seem to be associated with aneurysm growth and rupture. However, both the prevalence of aneurysms in the general population and the incidence of ruptures in the aneurysm population are extremely low. This suggests that hemodynamic factors and purely mechanical explanations by themselves may serve as necessary, but never as necessary and sufficient conditions of this disease's causation. The ultimate cause is not yet known, but it is likely an additive or multiplicative effect of a handful of biochemical and biomechanical factors.

Pipeline for uncoilable or failed aneurysms: results from a multicenter clinical trial

PURPOSE

To evaluate the safety and effectiveness of the Pipeline Embolization Device (PED; ev3/Covidien, Irvine, Calif) in the treatment of complex intracranial aneurysms.

MATERIALS AND METHODS

The Pipeline for Uncoilable or Failed Aneurysms is a multicenter, prospective, interventional, single-arm trial of PED for the treatment of uncoilable or failed aneurysms of the internal carotid artery. Institutional review board approval of the HIPAA-compliant study protocol was obtained from each center. After providing informed consent, 108 patients with recently unruptured large and giant wide-necked aneurysms were enrolled in the study. The primary effectiveness endpoint was angiographic evaluation that demonstrated complete aneurysm occlusion and absence of major stenosis at 180 days. The primary safety endpoint was occurrence of major ipsilateral stroke or neurologic death at 180 days.

RESULTS

PED placement was technically successful in 107 of 108 patients (99.1%). Mean aneurysm size was 18.2 mm; 22 aneurysms (20.4%) were giant (>25 mm). Of the 106 aneurysms, 78 met the study's primary effectiveness endpoint (73.6%; 95% posterior probability interval: 64.4%-81.0%). Six of the 107 patients in the safety cohort experienced a major ipsilateral stroke or neurologic death (5.6%; 95% posterior probability interval: 2.6%-11.7%).

CONCLUSION

PED offers a reasonably safe and effective treatment of large or giant intracranial internal carotid artery aneurysms, demonstrated by high rates of complete aneurysm occlusion and low rates of adverse neurologic events; even in aneurysms failing previous alternative treatments.

Abstract 156: SAMMPRIS Angiography Discloses Hemodynamic Effects of Intracranial Stenosis: Computational Fluid Dynamics of Fractional Flow

Background: Pressure gradients across an intracranial stenosis, or fractional flow (FF), may identify the hemodynamic significance of symptomatic lesions. Computational fluid dynamic (CFD) simulations on 3D morphology of such lesions can calculate these pressure gradients and model effects of systemic physiology interacting with these lesions, such as hypotension and induced hypertension. We studied SAMMPRIS angiography to calculate FF across symptomatic intracranial stenoses and modeled the downstream effect of systemic blood pressure (BP) fluctuations.

Methods: Conventional angiography of symptomatic intracranial stenoses in the SAMMPRIS trial was converted from biplanar images to a 3D geometric mesh. CFD simulations were conducted with Ansys CFX on a Cray supercomputer to calculate FF derived from distal/proximal pressure gradients for each of 3 inflow conditions: normal BP (120/80 mm Hg), hypotension (90/60 mm Hg) and hypertension (180/120 mm Hg). Abnormal FF was defined as ≤ 0.8 during diastole to define hemodynamic significance of a stenosis.

Results: 407 patients with 70-99% symptomatic stenosis had conventional angiography with biplanar views available for 3D reconstruction in 249, and CFD simulations in 188 (25 VA, 45 BA, 32 ICA, 86 MCA). Under simulated normal inflow conditions (120/80 mm Hg), only 76/188 (40%) cases had low FF.

During simulated hypertension, FF improved to normal in 10/188 (5%) cases. Simulated hypotension caused FF to worsen from normal in 12/188 (6%) cases. Other hemodynamic parameters including shear stress could also be calculated and visually depicted in all cases.

Conclusions: CFD and hemodynamic modeling of FF can be retrospectively performed after 3D conversion of biplanar angiogram views. FF estimates predict that only 40% of severe (70-99%) symptomatic intracranial stenoses are hemodynamically significant. Systemic BP fluctuations can be modeled during phases of the cardiac cycle to show downstream flow changes.

IN VITRO QUANTIFICATION OF THE SIZE DISTRIBUTION OF INTRASACCULAR VOIDS LEFT AFTER ENDOVASCULAR COILING OF CEREBRAL ANEURYSMS

PURPOSE

Endovascular coiling of cerebral aneurysms remains limited by coil compaction and associated recanalization. Recent coil designs which effect higher packing densities may be far from optimal because hemodynamic forces causing compaction are not well understood since detailed data regarding the location and distribution of coil masses are unavailable. We present an in vitro methodology to characterize coil masses deployed within aneurysms by quantifying intra-aneurysmal void spaces.

METHODS

Eight identical aneurysms were packed with coils by both balloon- and stent-assist techniques. The samples were embedded, sequentially sectioned and imaged. Empty spaces between the coils were numerically filled with circles (2D) in the planar images and with spheres (3D) in the three-dimensional composite images. The 2D and 3D void size histograms were analyzed for local variations and by fitting theoretical probability distribution functions.

RESULTS

Balloon-assist packing densities (31±2%) were lower (p=0.04) than the stent-assist group (40±7%). The maximum and average 2D and 3D void sizes were higher (p=0.03 to 0.05) in the balloon-assist group as compared to the stent-assist group. None of the void size histograms were normally distributed; theoretical probability distribution fits suggest that the histograms are most probably exponentially distributed with decay constants of 6-10 mm. Significant (p<=0.001 to p=0.03) spatial trends were noted with the void sizes but correlation coefficients were generally low (absolute r<=0.35).

CONCLUSION

The methodology we present can provide valuable input data for numerical calculations of hemodynamic forces impinging on intra-aneurysmal coil masses and be used to compare and optimize coil configurations as well as coiling techniques.

Abstract 1900: Collateral Circulation and Hemodynamics of Severe Intracranial Atherosclerosis: Angiography and Clinical Correlates at Baseline in the SAMMPRIS Trial

Background: Severe intracranial atherosclerosis, in excess of 70% luminal stenosis, is an established cause of recurrent stroke. Collateral circulation and the hemodynamic effects of such stenoses, however, may further delineate such risk. We conducted angiographic analyses in the SAMMPRIS trial to correlate the degree of collaterals and hemodynamic effects of such stenoses with baseline clinical and imaging characteristics of enrolled subjects.

Methods: Baseline angiography of SAMMPRIS subjects was submitted for blinded review to grade collaterals with the ASITN/SIR scale and antegrade flow across the lesion with TICI. Hemodynamic effect was defined as any flow reduction (a partial TICI score). The association of these angiographic scores (dichotomized as none/partial versus complete collaterals and partial versus complete TICI) and baseline demographic, clinical and imaging variables were evaluated using chi-square tests for percentages and independent group t-tests for means.

Results: 424/451 subjects enrolled in SAMMPRIS had baseline angiography available for review, with adequate information to score collaterals in 376 cases. Complete collaterals were noted in 117 (31%). Hemodynamic effects (partial TICI scores) were noted in only 188 (50%) of these lesions, which were all in excess of 70% luminal stenosis. Mean lesion length (n=184, from stenting arm) did not differ between the two categories of either collaterals or hemodynamic impairment. Mean percent stenosis was higher for patients with complete collaterals (none/partial, mean 73.7%; complete, 77.4%; p<0.001) and hemodynamic impairment was more common (p<0.001). More robust collaterals (complete versus none/partial) were associated with patients who at baseline were younger (mean age 58.0 versus 61.5 years; p=0.009), had higher serum HDL (40.0 versus 37.7 mg /dL, p=0.035), participated in moderate exercise (43.1 versus 27.9%, p=0.004) and did not smoke (79.5 versus 69.4%, p=0.042). Previously reported associations with collateral circulation (diabetes, statins, presence of infarction on CT or MRI) were inapparent. These relationships of collaterals with hemodynamic impairment and other baseline variables were established across all anatomical distributions of intracranial stenosis.

Conclusions: Severe intracranial atherosclerotic lesions are not always associated with hemodynamic effects. Collateral circulation may also frequently compensate for severe stenosis, with more robust collaterals in younger and healthier individuals.

Abstract 124: Collaterals Determine Risk of Early Territorial Stroke and Hemorrhage in the SAMMPRIS Trial

Background: The degree of collateral circulation is a powerful risk factor for recurrent stroke in the setting of medical therapy for symptomatic intracranial atherosclerosis. The impact of collaterals on the short-term risk for stroke in patients treated by stenting or intensive medical therapies is not known. We systematically evaluated baseline angiographic features of collateral circulation and antegrade flow across intracranial stenoses in randomized subjects of the multicenter SAMMPRIS trial and correlated these to their 30-day risk of ischemic stroke.

Methods: Digital review of baseline angiograms in SAMMPRIS was conducted to score ASITN/SIR collateral grade and TICI antegrade flow, blind to other data. Dichotomized collateral and TICI scores (none/partial versus complete) were analyzed independently and in combinations with trial endpoints of territorial ischemic stroke or stroke in territory (SIT) and intracranial hemorrhage (ICH) within 30 days in the intensive medical and stenting arms of the study. Log-rank tests with follow-up time censored at 30 days were used in the analysis.

Results: Collaterals could be assessed on 376/424 baseline angiography studies available for digital imaging review for the 451 randomized subjects in SAMMPRIS (186 medical, 190 stenting). Early territorial stroke (SIT) occurred in 6/186 (3.2%) subjects in the medical arm and 20/190 (10.5%) after stenting. SIT was not associated with TICI in either arm, whereas collaterals exerted a potent protective influence in medical (p=0.067) and stented (p=0.004) cases, with 0/66 (0%) SIT in the medical arm and 0/51 (0%) SIT in the stented arm when collaterals were complete. SIT in medical cases was associated with partial TICI/partial collaterals (5/25 (20.0%)) versus complete TICI/partial collaterals (1/95 (1.1%)) and partial TICI/complete collaterals (0/66 (0%)), p<0.001. SIT in stented cases was associated with partial TICI/partial collaterals (11/46 (23.9%)) versus complete TICI/partial collaterals (9/93 (9.7%)) and partial TICI/complete collaterals (0/51 (0%)), p<0.001. ICH within 30 days occurred in 0/186 (0%) subjects randomized to medical therapy. In the stenting arm, early ICH occurred in 8/190 (4.2%) and was associated with TICI (p=0.036) and collaterals (p=0.077). Overall, early ICH after stenting was associated with partial TICI/partial collaterals (7/46 (15.2%)) versus complete TICI/partial collaterals (1/93 (1.1%)) and partial TICI/complete collaterals (0/51 (0%)), p<0.001.

Conclusions: Patients with impaired collateral flow associated with severe intracranial stenosis had the highest risk for stroke within 30 days, both with intensive medical therapy and as a complication of angioplasty and stenting.

Midterm clinical and angiographic follow-up for the first Food and Drug Administration-approved prospective, Single-Arm Trial of Primary Stenting for Stroke: SARIS (Stent-Assisted Recanalization for Acute Ischemic Stroke)

BACKGROUND

Although early data demonstrate encouraging angiographic results following intracranial stent deployment for acute ischemic stroke, longer-term follow-up is necessary to evaluate the clinical outcomes, as well as the durability of angiographic results.

OBJECTIVE

We report 6-month clinical and radiologic follow-up data of the 20 patients prospectively enrolled in the Stent-Assisted Recanalization in acute Ischemic Stroke (SARIS) trial.

METHODS

Twenty patients were prospectively enrolled to receive self-expanding intra-arterial stents as first-line therapy for acute ischemic stroke treatment. Patients were scheduled for follow-up 6-months after treatment for clinical evaluation (modified Rankin Scale [mRS] score obtained by a trained certified research nurse/nurse practitioner) and repeat cerebral angiography. Angiographic interpretation was performed by an independent adjudicator.

RESULTS

At 6 months, the mRS score was ≤3 in 60% of patients (n = 12) and was ≤2 in 55% of patients (n = 11). Mortality at the 6-month follow-up was 35% (n = 7). Follow-up angiography was performed for 85% (11 of 13) of surviving patients. All patients undergoing angiographic follow-up demonstrated Thrombolysis in Myocardial Infarction 3 flow on digital subtraction angiography or stent patency on computed tomographic angiography. None of the patients demonstrated evidence of in-stent stenosis (≥50% vessel narrowing).

CONCLUSION

The midterm angiographic and clinical results following intracranial stent deployment for acute ischemic stroke are encouraging. Further study of primary stent-for-stroke treatment is warranted.

Delayed Thrombosis or Stenosis Following Enterprise-Assisted Stent-Coiling: Is It Safe? Midterm Results of the Interstate Collaboration of Enterprise Stent Coiling

BACKGROUND:

Stent-assisted coiling of intracranial aneurysms with self-expanding stents has widened the applicability of neuroendovascular therapies to those aneurysms previously considered “uncoilable” because of poor morphology. The Enterprise Vascular Reconstruction Device and Delivery System (Cordis) has demonstrated promising initial short-term results. However, the rates of delayed in-stent stenosis or thrombosis are not known.

OBJECTIVE:

To report midterm results of the Enterprise stent system.

METHODS:

A 10-center registry was created to provide a large volume of data on the safety and efficacy of the Enterprise stent system. Pooled data were compiled for consecutive patients undergoing Enterprise stent-assisted coiling at each institution. Available follow-up data were evaluated for the incidence of in-stent stenosis, thrombosis, and aneurysm occlusion.

RESULTS:

In total, 213 patients (176 females) with 219 aneurysms were treated with the Enterprise stent. One hundred ten patients had undergone delayed angiography (≥30 days from stent placement, mean follow-up 174.6 days). Forty percent of patients demonstrated total occlusion with 88% having ≥90% aneurysm occlusion. Six percent of patients had delayed (&gt;30 days) angiographic findings, of which 3% demonstrated significant (≥50%) in-stent stenosis or occlusion. Seven delayed thrombotic events occurred (3%), along with 2 additional immediate periprocedural events. All 7 delayed events were concomitant to cessation of double-antiplatelet therapy.

CONCLUSION:

Midterm occlusion rates are excellent, and stenosis and thrombosis rates are comparable to other available neurovascular stents. Interruption of antiplatelet therapy appears to be a factor in those developing delayed stenosis or thrombosis.

U.S. Wingspan Registry: 12-month follow-up results

BACKGROUND AND PURPOSE

The purpose of this study is to present 12-month follow-up results for a series of patients undergoing percutaneous transluminal angioplasty and stenting with the Gateway-Wingspan stenting system (Boston Scientific) for the treatment of symptomatic intracranial atherostenosis.

METHODS

Clinical and angiographic follow-up results were recorded for patients from 5 participating institutions. Primary end points were stroke or death within 30 days of the stenting procedure or ipsilateral stroke after 30 days.

RESULTS

During a 21-month study period, 158 patients with 168 intracranial atherostenotic lesions (50% to 99%) were treated with the Gateway-Wingspan system. The average follow-up duration was 14.2 months with 143 patients having at least 3 months of clinical follow-up and 110 having at least 12 months. The cumulative rate of the primary end point was 15.7% for all patients and 13.9% for patients with high-grade (70% to 99%) stenosis. Of 13 ipsilateral strokes occurring after 30 days, 3 resulted in death. Of these strokes, 76.9% (10 of 13) occurred within the first 6 months of the stenting procedure and no events were recorded after 12 months. An additional 9 patients experienced ipsilateral transient ischemic attack after 30 days. Most postprocedural events (86%) could be attributed to interruption of antiplatelet medications (n=6), in-stent restenosis (n=12), or both (n=1). In 3 patients, the events were of uncertain etiology.

CONCLUSIONS

After successful Wingspan percutaneous transluminal angioplasty and stenting, some patients continued to experience ipsilateral ischemic events. Most of these ischemic events occurred within 6 months of the procedure and were associated with the interruption of antiplatelet therapy or in-stent restenosis.

Stent-assisted coiling in acutely ruptured intracranial aneurysms: a qualitative, systematic review of the literature

BACKGROUND AND PURPOSE

The use of stents for treatment of morphologically unfavorable, acutely ruptured aneurysms is avoided by most operators because of concerns about the risk of using dual antiplatelet therapy in the setting of acute SAH. Our aim was to review the literature regarding stent-assisted coil embolization of acutely ruptured intracranial aneurysms to determine the safety and efficacy of this treatment option.

MATERIALS AND METHODS

Articles including ≥5 patients with ruptured aneurysms who were treated acutely with stent-assisted coiling or uncovered stent placement alone were identified. Data on clinical presentation, technical success, surgical crossover, intracranial complications, and clinical outcome were evaluated.

RESULTS

A total of 17 articles were identified reporting 339 patients who met inclusion criteria. Among 212 patients with available data, technical success was noted in 198 (93%) patients. Three hundred twenty-six (96%) of 339 patients received both heparin during the procedure and dual-antiplatelet therapy during or immediately postprocedure. One hundred thirty (63%) of 207 aneurysms were completely occluded. Six (2%) of 339 patients required surgical crossover, usually for failure in stent placement or for intraprocedural aneurysm rupture. Clinically significant intracranial hemorrhagic complications occurred in 27 (8%) of 339 patients, including 9 (10%) of 90 patients known to have EVDs who had ventricular drain-related hemorrhages. Clinically significant thromboembolic events occurred in 16 (6%) of 288 patients. Sixty-seven percent of patients had favorable clinical outcomes, 14% had poor outcomes, and 19% died.

CONCLUSIONS

Stent-assisted coiling in ruptured aneurysms can be performed with high degrees of technical success, but adverse events appear more common and clinical outcomes are likely worse than those achieved without stent assistance. Thromboembolic complications appear reasonably well-controlled. Reported EVD-related hemorrhagic complications were uncommon, though the total number of EVDs placed was unknown.

Prediction of adverse outcomes by blood glucose level after endovascular therapy for acute ischemic stroke

OBJECT

The authors evaluated the prognostic significance of blood glucose level at admission (BGA) and change in blood glucose at 48 hours from the baseline value (CG48) in nondiabetic and diabetic patients before and after endovascular therapy for acute ischemic stroke (AIS).

METHODS

The BGA and CG48 data were analyzed in 614 patients with AIS who received endovascular therapy at 7 US centers between 2006 and 2009. Data reviewed included demographics, stroke risk factors, diabetic status, National Institutes of Health Stroke Scale (NIHSS) score at presentation, recanalization grade, intracranial hemorrhage (ICH) rate, and 90-day outcomes (mortality rate and modified Rankin Scale score of 3-6 [defined as poor outcome]). Variables with p values < 0.2 in univariate analysis were included in a binary logistic regression model for independent predictors of 90-day outcomes.

RESULTS

The mean patient age was 67.3 years, the median NIHSS score was 16, and 27% of patients had diabetes. In nondiabetic patients, BGA ≥ 116 mg/dl (≥ 6.4 mmol/L) and failure of glucose level to drop > 30 mg/dl (> 1.7 mmol/L) from the admission value were both significant predictors of 90-day poor outcome and death (p < 0.001). In patients with diabetes, BGA ≥ 116 mg/dl (≥ 6.4 mmol/L) was an independent predictor of poor outcome (p = 0.001). The CG48 was not a predictor of outcome in diabetic patients. A simplified 6-point scale including BGA, Thrombolysis in Myocardial Infarction (TIMI) Grade 2-3 Reperfusion, Age, presentation NIHSS score, CG48, and symptomatic ICH (BRANCH) corresponded with poor outcomes at 90 days; the area under the curve value was > 0.79.

CONCLUSIONS

Failure of blood glucose values to decrease in the first 48 hours after AIS intervention correlated with poor 90-day outcomes in nondiabetic patients. The BRANCH scale shows promise as a simple prognostication tool after endovascular therapy for AIS, and it merits prospective validation.

First Food and Drug Administration-approved prospective trial of primary intracranial stenting for acute stroke: SARIS (stent-assisted recanalization in acute ischemic stroke)

BACKGROUND AND PURPOSE

Acute revascularization is associated with improved outcomes in ischemic stroke patients. However, it is unclear which method of intraarterial intervention, if any, is ideal. Numerous case series and cardiac literature parallels suggest that acute stenting may yield high revascularization levels with low associated morbidity. We therefore conducted a Food and Drug Administration-approved prospective pilot trial to evaluate the safety of intracranial stenting for acute ischemic stroke.

METHODS

Eligibility criteria included presentation <or=8 hours after stroke onset, age 18 years or older, National Institutes of Health Stroke Scale score >or=8, angiographic demonstration of focal intracerebral artery occlusion <or=14 mm, and either contraindication to intravenous tissue plasminogen activator or failure to improve 1 hour after intravenous tissue plasminogen activator administration. Exclusion criteria included known hemorrhagic diathesis or coagulopathy, platelet count <100 000, intracranial hemorrhage, blood glucose level of <51 mg/100 mL, or CT perfusion imaging demonstrating more than one-third at-risk territory with nonsalvageable brain (low cerebral blood volume). Data are presented as mean+/-SD.

RESULTS

Twenty patients were enrolled (mean age, 63+/-18 years;14 women). Mean presenting National Institutes of Health Stroke Scale was 14+/-3.8 (median 13). Presenting thrombolysis in myocardial infarction score was 0 (85% of patients) or 1 (15%). Recanalization to thrombolysis in myocardial infarction score of 3 (60% of patients) or 2 (40% of patients; P<0.0001) was achieved. One (5%) symptomatic and 2 (10%) asymptomatic intracranial hemorrhages occurred. At 1-month follow-up, a modified Rankin scale score of <or=3 was achieved in 12 of 20(60%) patients and a modified Rankin scale score of <or=1 was achieved in 9 of 20 (45%) patients.

CONCLUSIONS

This Food and Drug Administration-approved prospective study suggests primary intracranial stenting for acute stroke may be a valuable addition to the stroke treatment armamentarium.

Treatment of intracranial aneurysms with the Enterprise stent: a multicenter registry

OBJECT

The development of self-expanding stents dedicated to intracranial use has significantly widened the applicability of endovascular therapy to many intracranial aneurysms that would otherwise have been untreatable by endovascular techniques. Recent Food and Drug Administration approval of the Enterprise Vascular Reconstruction Device and Delivery System (Cordis) has added a new option for self-expanding stent-assisted intracranial aneurysm coiling.

METHODS

The authors established a collaborative registry across multiple institutions to rapidly provide largevolume results regarding initial experience in using the Enterprise in real-world practice. Ten institutions (University at Buffalo, Thomas Jefferson University, University of Florida, Cleveland Clinic, Northwestern University, West Virginia University, University of Puerto Rico, Albany Medical Center Hospital, the Neurological Institute of Savannah, and the Barrow Neurological Institute) have provided consecutive data regarding their initial experience with the Enterprise.

RESULTS

In total, 141 patients (119 women) with 142 aneurysms underwent 143 attempted stent deployments. The use of Enterprise assistance with aneurysm coiling was associated with a 76% rate of > or = 90% occlusion. An inability to navigate or deploy the stent was experienced in 3% of cases, as well as a 2% occurrence of inaccurate deployment. Procedural data demonstrated a 6% temporary morbidity, 2.8% permanent morbidity, and 2% mortality (0.8% unruptured, 12% ruptured).

CONCLUSIONS

The authors report initial results of the largest series to date in using the Enterprise for intracranial aneurysm treatment. The Enterprise is associated with a high rate of successful navigation and low occurrence of inaccurate stent deployment. The overall morbidity and mortality rates were low; however, caution should be exercised when considering Enterprise deployment in patients with subarachnoid hemorrhage as the authors' experience demonstrated a high rate of associated hemorrhagic complications leading to death.

Target lesion revascularization after wingspan: assessment of safety and durability

BACKGROUND AND PURPOSE

In-stent restenosis (ISR) occurs in approximately one-third of patients after the percutaneous transluminal angioplasty and stenting of intracranial atherosclerotic lesions with the Wingspan system. We review our experience with target lesion revascularization (TLR) for ISR after Wingspan treatment.

METHODS

Clinical and angiographic follow-up results were recorded for all patients from 5 participating institutions in our US Wingspan Registry. ISR was defined as >50% stenosis within or immediately adjacent (within 5 mm) to the implanted stent and >20% absolute luminal loss.

RESULTS

To date, 36 patients in the registry have experienced ISR after percutaneous transluminal angioplasty and stenting with Wingspan. Of these patients, 29 (80.6%) have undergone TLR with either angioplasty alone (n=26) or angioplasty with restenting (n=3). Restenting was performed for in-stent dissections that occurred after the initial angioplasty. Of the 29 patients undergoing TLR, 9 required >/=1 interventions for recurrent ISR, for a total of 42 interventions. One major complication, a postprocedural reperfusion hemorrhage, was encountered in the periprocedural period (2.4% per procedure; 3.5% per patient). Angiographic follow-up is available for 22 of 29 patients after TLR. Eleven of 22 (50%) demonstrated recurrent ISR at follow-up angiography. Nine patients have undergone multiple retreatments (2 retreatments, n=6; 3 retreatments, n=2; 4 retreatments, n=1) for recurrent ISR. Nine of 11 recurrent ISR lesions were located within the anterior circulation. The mean age for patients with recurrent anterior circulation ISR was 57.9 years (vs 81 years for posterior circulation ISR).

CONCLUSIONS

TLR can be performed for the treatment of intracranial Wingspan ISR with a relatively high degree of safety. However, the TLR results are not durable in approximately 50% of patients, and multiple revascularization procedures may be required in this subgroup.

Magnetic resonance angiographic imaging follow-up of treated intracranial aneurysms

Conventional catheter-based angiography, magnetic resonance imaging/angiography, and computed tomographic angiography are all techniques routinely practiced for the diagnosis of aneurysms. With regard to the evaluation of treated aneurysms, each of these imaging modalities has inherent advantages and disadvantages. This review was aimed to provide a better understanding of the optimal application and interpretation of the available imaging modalities for the assessment of treated cerebral aneurysms.

ANGIOGRAPHIC PATTERNS OF WINGSPAN IN-STENT RESTENOSIS

OBJECTIVE

A classification system developed to characterize in-stent restenosis (ISR) after coronary percutaneous transluminal angioplasty with stenting was modified and applied to describe the appearance and distribution of ISR occurring after Wingspan (Boston Scientific, Fremont, CA) intracranial percutaneous transluminal angioplasty with stenting.

METHODS

A prospective, intention-to-treat, multicenter registry of Wingspan treatment for symptomatic intracranial atherosclerotic disease was maintained. Clinical and angiographic follow-up results were recorded. ISR was defined as greater than 50% stenosis within or immediately adjacent (within 5 mm) to the implanted stent(s) and greater than 20% absolute luminal loss. ISR lesions were classified by angiographic pattern, location, and severity in comparison with the original lesion treated.

RESULTS

Imaging follow-up (3–15.5 months) was available for 127 intracranial stenotic lesions treated with Wingspan percutaneous transluminal angioplasty with stenting. Forty-one lesions (32.3%) developed either ISR (n = 36 [28.3%]) or complete stent occlusion (n = 5 [3.9%]) after treatment. When restenotic lesions were characterized using the modified classification system, 25 of 41 (61.0%) were focal lesions involving less than 50% of the length of the stented segment: three were Type IA (focal stenosis involving one end of the stent), 21 were Type IB (focal intrastent stenosis involving a segment completely contained within the stent), and one was Type IC (multiple noncontiguous focal stenoses). Eleven lesions (26.8%) demonstrated diffuse stenosis (&gt;50% of the length of the stented segment): nine were Type II with diffuse intrastent stenosis (completely contained within the stent) and two were Type III with proliferative ISR (extending beyond the stented segment). Five stents were completely occluded at follow-up (Type IV). Of the 36 ISR lesions, 16 were less severe or no worse than the original lesion with respect to severity of stenosis or length of the segment involved; 20 lesions were more severe than the original lesion with respect to the segment length involved (n = 5), actual stenosis severity (n = 6), or both (n = 9). Nine of 10 supraclinoid internal carotid artery ISR lesions and nine of 13 middle cerebral artery ISR lesions were more severe than the original lesion.

CONCLUSION

Wingspan ISR typically occurs as a focal lesion. In more than half of ISR cases, the ISR lesion was more extensive than the original lesion treated in terms of lesion length or stenosis severity. Supraclinoid internal carotid artery and middle cerebral artery lesions have a propensity to develop more severe posttreatment stenosis.