bluuebunny/crossref_metadata_2025 huggingface dataset:
O-032 Current trends in endovascular management of traumatic cerebrovascular injury: Abstract O-032 Table 1
Authors: Kansagra A , English J , Sincic R , Hetts S
Published: July 2012

Purpose

The role of catheter angiography in diagnosis and management of traumatic cerebrovascular injury has evolved dramatically due to increased adoption of CT and MR angiography and continued refinement of endovascular techniques. The purpose of this study was to identify the modern spectrum of cerebrovascular injury encountered during catheter angiography in the setting of trauma and to examine current patterns of endovascular treatment.

Methods

Records of patients undergoing catheter angiography for traumatic craniocervical arterial injury over a 4-year period at a Level 1 trauma center and a quaternary referral center were retrospectively reviewed. Patients without known trauma mechanism were excluded. The sample comprised 100 separate arterial lesions distributed among 39 males and 13 females (mean age 36 years); all patients had antecedent CT or MRI. Injuries were classified according to mechanism, location, type, acuity, and endovascular treatment. Follow-up-imaging and clinical notes were reviewed to identify delayed complications.

Results

Of 100 arterial lesions, 81% were related to blunt force trauma. Distribution of lesions by location was 39% cervical, 42% intracranial, and 19% extracranial. The most common injuries were pseudoaneurysm (37%), fistula (29%), and dissection (19%). In total, 41% of lesions underwent endovascular treatment; endovascular treatment rate was 24/71 (34%) for lesions less than 14 days old and 17/29 (59%) for older injuries. Therapy involved coil embolization for 36 (88%) lesions; stents were used as part of treatment for only 8 (20%) lesions. There were a total of 3 (7.3%) immediate neurovascular complications (infarct, intracranial hemorrhage, iatrogenic dissection) resulting in 1 (2.4%) permanent neurologic deficit. No delayed neurovascular complications occurred over a mean period of follow-up of 4.9 months (range 0–30 months), regardless of whether endovascular therapy was undertaken.

Conclusion

Strategies for treatment of traumatic cerebrovascular injury continue to evolve. Our recent experience in a large cohort of patients suggests that a relatively high proportion of traumatic arterial lesions identified during catheter angiography are treated by endovascular means, with a low rate of immediate and delayed neurovascular complications.

Competing interests

None.

Abstract O-032 Table 1

Endovascular treatment based on injury type

Treatment typeDissectionThrombusPseudoaneurysmOcclusionTransectionFistulaAneurysm ruptureTotalUntreated172151420059Coil embolization0014157128Coil embolization (stent-assisted)00500005Liquid embolization00200002Coil and liquid embolization00100203Stent20010003Total1923739291100
O-006 Pain management of patients with fatigue fractures of the OS sacrum with balloon sacroplasty using different approaches
Authors: Andresen R , Radmer S , Kamusella P , Wissgott C , Banzer J , Schober H
Published: July 2012

Introduction

In elderly patients with reduced bone quality, insufficiency fractures of the OS sacrum are relatively common and are typically associated with intense, debilitating pain. The objective of our study was to determine the practicability of cement augmentation using a balloon catheter via individual approaches taking into consideration the complex anatomy of the sacrum and the course of the fracture, as well as the postinterventional determination of leakages and representation of the outcome pain.

Material and Methods

In 30 patients with severe osteoporosis (23 women with an average age of 72.4 years, seven men with an average age of 68.7 years), a sacral fracture was detected by CT and MRT. This fracture was unilateral in 17 women and bilateral in the other patients. In order to achieve a cement distribution longitudinally in relation to the fracture, the balloon catheter was inserted into the OS sacrum via a hollow needle either from caudal to cranial, from dorsal to ventral or from lateral transiliac to medial. The balloon catheter was then inflated and deflated 1–3 times along the fracture in the respective direction, and the hollow space created was then filled with PMMA cement using a low-pressure procedure. A conventional radiograph in two planes and a control CT were then performed. Pain intensity was determined pre-intervention, on the second day post-intervention and 6 and 12 months post-intervention, using a visual analogue scale.

Results

The balloon sacroplasty was performed successfully from a technical point of view in all patients. The radiographic and CT control showed sufficient cement distribution in the sacrum along the course of the fracture, whereby leakage could be ruled out. According to the visual analogue scale, the mean value for pain was 8.8 pre-intervention, there was a significant reduction in pain on the second postoperative day, with an average value of 2.7 (p<0.001), which was stable at 2.5 after 6 months and 2.3 after 12 months.

Discussion

Approaches that take into account the anatomy of the OS sacrum and the course of the sacral fracture enable reliable augmentation with an optimum amount of cement. This makes balloon sacroplasty an effective treatment that has few complications for rapid and significant pain relief in patients with a sacral fracture.

Competing interests

None.
O-007 Carotid stent cell design modified the periprocedural outcomes in the stenting arm of randomized trials of carotid revascularization: a meta-analysis: Abstract O-007 Figure 1
Authors: Almekhlafi M , Yavin D , Mitha A
Published: July 2012

Introduction

Trials describe a risk of stroke of about 6% following carotid artery stenting (CAS). Stent cell design has been implicated as a potential factor in these risks. The small free cell area between the struts of a closed-cell stent theoretically provides better scaffolding of the vessel wall and superior plaque stabilization compared to the larger uncovered gaps in open-cell stents. No comparison between stent designs, and their relative effects on clinical outcome compared with carotid endarterectomy, has yet been published in the literature.

Materials and Methods

This is an exploratory meta-analysis of randomized control trials (RCTs) comparing carotid endarterectomy (CEA) to CAS stratified by the stent cell design. A comprehensive literature search was conducted on major scholar search engines until July 2010. The primary outcome was a composite of the 30-day risk of stroke or death. A Mantel-Hansel random-effects model was used to calculate OR and 95% CIs.

Results

Nine RCTs (4949 patients) were included in the final analysis. Closed-cell stent design was used in 807 patients and open-cell stents in 1657 patients, while 2485 patients were treated with CEA. The primary outcome was significantly lower in the CEA arm compared to CAS using open-cell design arm (OR 1.84, 95% CI 1.23 to 2.75; p=0.003). However, there was no significant difference in the primary outcome between CEA and CAS using closed-cell design, although a trend favoring CEA was noted (OR 1.54; 95% CI 0.69 to 3.47; p=0.29), Abstract O-007 figure 1. If only the 30-day stroke rate was considered, the difference between CEA and CAS in the closed-cell stents is still non-significant (OR 2.92; 95% CI 0.52 to 16.21; p=0.22), compared to open-cell stents which continued to be inferior to CEA (OR 1.97; 95% CI 1.33 to 2.92; p=0.0007).

Abstract O-007 Figure 1

(A) Periprocedural stroke or death with CEA vsOpen-cell stents. (B) Periprocedural stroke or death with CEA vsClosed-cell stents.

Conclusion

In this meta-analysis of nine RCTs, CEA was not superior to CAS in trials using closed-cell stents. While these results may suggest better outcomes of CAS using the closed-cell stents, trials included in this analysis did not randomize patients to open- vs closed-cell stents. Furthermore, trials using the closed design recruited fewer patients than those using open-cell stents. Further assessment of a potential modification of CAS outcomes by stent design is underway with a meta-analysis of prospective CAS cohorts and registries to directly compare open- vs closed-cell stents.

Competing interests

None.
P-001 Outcome of the patients with ruptured basilar artery bifurcation aneurysm who underwent endovascular approach in acute phase—a single center experience
Authors: Lodi Y , Swrankar A , Sethi K , Gaylon D , Bajwa S
Published: July 2012

Background

Due to the presence of a high morbidity and mortality associated with surgical clipping, most of patients with basilar artery bifurcation (BA) aneurysm are offered endovascular therapy. Objective of our study is to report our technical and clinical outcomes of BA ruptured patients who underwent endovascular therapy.

Methods

Consecutive patients with the diagnosis of ruptured BA aneurysms who underwent endovascular repair of aneurysm from 2007 to 2011 were enrolled. Patient's demographics including presenting Hunt & Hess (H&H) grade, Fisher scale, and aneurysm's morphology, use of stent, intra-operative complications and radiographic outcome were measured. Additionally, a 90 days clinical outcome was measured using Glasgow Outcome Scale (GOS).

Results

20 patients with a mean age of 51±13 year underwent successful repair of the ruptured BA bifurcation aneurysms. Most of the patient were women (80%) and 75% of patients were active smoker. H&H I was present in 6 (30%), H&H II in 4 (20%), H&H III in 3 (15%), H&H IV in 6 (30%) and H&H V in 1 (5%) of patients. 10 patients with wide-necked aneurysms required stent-assisted coiling in the acute phase and were given oral loading doses of clopidogrel (300 mg) and aspirin (325 mg) at least 2 h prior to the stent deployment. There was no incidence of intra-operative or postoperative intracranial or systemic hemorrhages or thromboembolic event. Immediate complete (7) and near complete (9) obliteration was observed in 80% and subtotal in 4 (20%) of patients. 30 days good outcome (GOS 5 in 12, GOS 4 in four) was observed in 80% of patients including four of seven patients presented with poor grades (H&H IV & H&H V). Poor outcome (GOS 3) was observed in 4 (20%) of patients. When these patient were examined in 90 days; good outcome (GOS 5 in 14, GOS 4 in four) was observed in 90% including six of the seven patients who had presenting poor grades.

Conclusions

Endovascular techniques offer successful repair of ruptured BA aneurysms including those with wide neck and required stent-assisted coiling. Good outcome was observed in most of our patients including those with poor clinical grade. Poor H&H grade was not associated with poor long-time outcome in our series. Further study is required to evaluate the role of Hunt & Hess grade in BA aneurysm in a broader scale.

Competing interests

None.
P-015 Novel use of the pipeline embolization device for reperfusion of the middle cerebral artery post aneurysm clipping: Abstract P-015 Figure 1
Authors: Turner R , Turk A , Chaudry I , Nyberg E
Published: July 2012

Introduction

Surgical clipping of intracranial aneurysm can be complicated by clip encroachment of the parent artery. We present a case where symptomatic MCA stenosis occurring after clipping of a left carotid terminus aneurysm with reperfusion was restored using a Pipeline Embolization Device to buttress open the MCA.

Case report

A 61-year-old African American underwent an orbito-zygomatic craniotomy of multiple aneurysms, including a 15 mm left carotid terminus aneurysm. After clip placement the left carotid terminus, ACA, and MCA origins were widely patent with a 2 mm dog ear remnant along the MCA (top figure) Abstract P-0015 figure 1. The anterior dome of the aneurysm was incised and showed no filling of the aneurysm. There was no vascular kinking or compromise of flow in the carotid terminus or MCA measured by intra-operative Doppler. Post-operatively the patient's neurological exam declined to somnolence, confusion and right-sided hemiparesis. CT/CTA/CTP demonstrated patency of the left carotid terminus and MCA, a small infarct in the left lentiform nuclei, and markedly increased mean transit time in the left MCA territory with preservation of the cerebral blood volume. Diagnostic angiography demonstrated a critical narrowing of the carotid terminus and MCA origin with delayed flow through the left MCA territory (bottom left figure) Abstract P-015 figure 1. There was no filling of the aneurysm, including the dog ear remnant noted at surgery. A 3.0×18 mm PED was advanced across the narrowing and deployed followed by intra-device angioplasty. Post PED and angioplasty angiography demonstrated improved caliber of the narrowed segment with markedly improved perfusion of the MCA territory (bottom right figure). The aneurysm remained completely occluded.

Abstract P-015 Figure 1

Discussion

Arterial stenosis due to an aneurysm clip traditionally required surgical re-positioning of the aneurysm clip. Endovascular options are limited due to poor radial resistive forces of neurovascular nitinol stents. However, cobalt chromium has a higher specific modulus than nitinol that makes it an attractive high stiffness, low weight material. As such, Pipeline should have a steeper loading curve and corresponding radial resistive force, than nitinol stents. In addition, the static friction at the points of intersection of the braided tines may also provide additional resistance to deflection.

Conclusion

Successful restoration of flow using Pipeline was achieved without complication.

Competing interests

R Turner: Microvention, Codman. ev3, Penumbra, Mindframe. A Turk: None. I Chaudry: None. E Nyberg: None.
P-016 Snare-Monorail technique during pipeline embolization of a large cavernous carotid aneurysm: a technique to overcome severe tortuosity
Authors: Turner R , Turk A , Chaudry I , Nyberg E
Published: July 2012

Introduction

Flow diversion is a treatment option for large and giant anterior circulation aneurysms, however tortuosity can preclude the ability to use this therapy.

Case presentation

A 59-year-old female presents with cavernous sinus syndrome of the right eye and a large cavernous carotid aneurysm. Just distal to the aneurysm were two 180° turns in the carotid artery. Attempts to navigate distal to the aneurysm with traditional 0.014′ microwires resulted in herniation of the microcatheters and wires into the aneurysm. Multiple attempts using various microwires, including a “buddy-wire” system failed to navigate and deliver the microcatheter to the carotid terminus. An 0.010′ microwire was navigated to the carotid terminus however did not offer enough support to navigate a microcatheter. A microvascular snare was navigated up the contralateral carotid and across the anterior communicating artery to the ipsilateral carotid artery. The microwire was ensnared at the carotid terminus, creating a rigid and supportive monorail (Abstract P-0016 figure 1). Over this system, a 0.026” microcatheter was navigated into position and two Pipeline devices were deployed across the neck of the aneurysm, successfully embolizing the aneurysm (Abstract P-0016 figure 2).

Abstract P-016 Figure 1Abstract P-016 Figure 2

Discussion

Treatment of large and giant aneurysms with flow divesion can be difficult due to tortuosity and the relative stiffness of the devices. By anchoring a microwire distally, a rigid monorail system can be created to deliver the catheters into position. The snare allows for entrapping and releasing the delivery devices as needed to complete the procedure.

Conclusion

Challenging cases require utilization of devices that are outside normal indications, however within the capabilities of the devices. Knowledge of these technics can allow for treatment of otherwise untreatable vascular diseases.

Competing interests

R Turner: Microvention, Codman. ev3, Penumbra, Mindframe. A Turk: None. I Chaudry: None. E Nyberg: None.
P-017 Radiation target delineation of micro brain arteriovenous malformations using high-resolution flat-detector cone-beam Computed Tomography (CBCT): Abstract P-017 Figure 1
Authors: van der Bom I , Wakhloo A , Kuhn A , Ding L , Goff D , Gounis M
Published: July 2012

Purpose

Radiation therapy has shown to be an effective treatment of brain arteriovenous malformations (bAVMs).1 2Target delineation is commonly performed on volumetric image data, such as MRI or CT data. However, the nidi of micro-AVMs may not be visualized adequately by these modalities due to their limited image resolution. In this report, we show a novel usage of high-resolution contrast-enhanced cone-beam computed tomography (CBCT) imaging and multi-modal image registration3for radiation target delineation of a micro-AVM, a technique previously suggested for larger AVMs.4

Case

A 42-year-old male presented with intraparenchymal hemorrhage in the mesencephalic tectum and left posterior thalamus. Conventional angiography revealed a left superior collicular AVM with a nidus of 3 mm. The AVM was successfully embolized but follow-up angiography examinations at 36 months demonstrated a small re-growth of the AVM (Abstract P-017 figure 1A). The patient was thus referred to radiosurgery. Thin slice contrast and non-contrast MRI acquired for target delineation did not show the AVM nidus. Therefore, the patient was transferred to the angiography suite for high resolution contrast-enhanced CBCT. Data was acquired using the angiography c-arm system with a reduced detector size of 22 cm. Contrast was injected with 2 ml/s for a total of 64 ml and a 2 sec delay) using a coupled power injector into the left vertebral artery with a 5Fr catheter. Volumetric CBCT data (FOV: 703 mm3, matrix: 0.143 mm3) was generated using a non-binned reconstruction algorithm. Lesion and nidus were visualized with CBCT. MRI, CT-simulator and CBCT data was then transferred to the radiation planning software and mutually co-registered. The nidus was delineated on CBCT data by an experienced neurointerventional radiologist for radiation therapy and dose/treatment plan was completed. Due to image registration, the target area could be directly transferred to MRI and CT data (Abstract P-0017 figure 1B). The patient received a total of 4 radiation sessions.

Abstract P-017 Figure 1

Discussion and Conclusion

Radiation target delineation of micro AVMs can be challenging with conventional 3D imaging techniques as their spatial resolution is relatively low for the application of visualization of the nidus. We were able to demonstrate the complementary value of high resolution contrast enhanced CBCT in radiation target delineation of a micro brain AVM. Multi-modal image registration of CBCT with MRI and CT-simulator has shown to be an effective method for radiation target delineation.

Competing interests

I van der Bom: None. A Wakhloo: Philips Healthcare. A Kuhn: None. L Ding: None. D Goff: None. M Gounis: None.

References

1.AJNR1995;16:299.

2.J Neurosurg2002;97:779–84.

3.vanderBom IMJ,et al. J NeuroIntervent Surg2011. In press.

4.Radvany MG,et al. J NeuroIntervent Surg2011. In press.
P-019 Mid-term results of single or multiple overlapping neuroform stents as monotherapy for treating supraclinoid carotid “blister-like” pseudoaneurysms
Authors: Spiotta A , Walsh K , Bhalla T , Hui F
Published: July 2012

Introduction

“Blister-like” pseudoaneurysms of the supraclinoid internal carotid artery have a malignant natural history and can be difficult to treat, both surgically and via endovascular techniques. These lesions often involve a long arterial segment and lack a defined saccular component that would safely accommodate the introduction of embolization coils. This report describes follow-up data from patients who underwent Neuroform stent reconstruction as monotherapy.

Methods

A retrospective review was performed on a prospectively maintained Neuroform stent database at our institution. Patients who had undergone stent reconstruction of supraclinoid ICA “blister-like” aneurysms were included. Long-term clinical and angiographic data was obtained and analyzed.

Results

Eight patients were identified (mean age 61.1 years; five female, three male) who underwent stent reconstruction using Neuroform stents; seven (87.5%) were treated in the ruptured setting. Three patients presented in Hunt and Hess (HH) grade 2, two in HH3, and one presented months after rupture, with no documented HH score. All patients underwent endovascular Neuroform stenting of their aneurysms. Initial angiographic results were as follows: complete occlusion (Raymond 1; n=3; 37.5%) and residual aneurysm (Raymond 3; n=5; 62.5%). There were no intraprocedural complications. There were no cases of re-bleeding. Clinical follow-up data (range 1–34 months; average 12.4 m) was obtained from all patients and angiographic follow-up data (range 1–28 months; average 10.9 m) was obtained from seven patients (87.5%). Follow-up angiographic results are as follows: complete occlusion (Raymond 1; n=6; 75%) and residual aneurysm (Raymond 3; n=2; 25%). Clinical outcomes are as follows: mRS of 0 (n=2; 25%), mRS of 1 (n=5; 62.5%) and mRS of 2 (n=1, 12.5%). No patients had mRS of 3 or greater. Two patients (25%) required retreatment, one required ICA sacrifice with STA-MCA bypass, and the other required emergent endovascular intervention with abciximab for stent thrombosis. Neither of these patients suffered permanent neurological deficits.

Conclusion

Endovascular stent reconstruction of supraclinoid ICA “blister-type” aneurysms using the Neuroform stent is an effective treatment option even in the setting of subarachnoid hemorrhage. Stent reconstruction prevents aneurysmal reruptures and is associated with favorable long-term clinical and angiographic outcomes.

Competing interests

A Spiotta: Integra, Hemedex. K Walsh: None. T Bhalla: None. F Hui: None.
P-024 Stress distribution after intracranial stent by realistic model
Authors: Fujimoto M , Shobayashi Y , Tateshima S , Vinters H , Viñuela F
Published: July 2012

There is no effective treatment for symptomatic intracranial atherosclerotic stenosis, which has an association with a high rate of recurrent stroke. Percutaneous transluminal angioplasty and stenting (PTAS) has been applied to the intracranial lesion, and only the WingspanTM Stent System (Stryker) was approved by the Food and Drug Administration (FDA) in 2005. However the high incidence of stoke or death (7%–14% at 6 months) and restenosis (25%–32%) have been viewed with suspicion and a randomized trial for intracranial symptomatic severe stenosis (SAMMPRIS Clinical Trial) revealed the superiority of aggressive medical treatments to PTAS. This first-generation intracranial stent can have still room for both procedural and technical improvement. We aimed to explore the cause of stroke complication after stenting in animal model and evaluated the biological response in the Wingspan stent by the fine element method (FEM). Simulation analysis using idealized model showed various stress distribution depended on stent geometries. Although idealized stent analysis has a limitation in its symmetry and uniformity, realistic artery model has been recognized to be essential to prove the correlation with pathobiological response. Some realistic simulation analysis concluded that higher radial stress concentration or non-uniform distribution of wall shear stress could lead to greater neointimal hyperplasia. In this report, we deployed the Wingspan stent at swine ascending pharyngeal artery, and simulated the several stress distribution including radial, circumferential and wall shear stress. We used a realistic arterial model to simulate the clinical situation. As for the radial stress, stress concentration at stent markers and the gradational augmentation of radial stress from proximal to distal were detected. The high wall shear stress gradient at distal stent segment, especially around the stent markers, was also marked. Actually, the excessive intimal hyperplasia was recognized around the distal stent. The radial stress and wall shear stress distribution can have an essential biological implication for intimal hyperplasia. These insights about stress concentration can help us, not only perform the optimal intracranial stenting, but also develop a new endovascular device in future.

Competing interests

None.
P-026 Post-treatment ASPECT area analysis for revascularization effects in the interventional management of stroke (IMS) I/II vs solitaire studies
Authors: Shivashankar R , Tomsick T , Carrozzella J , Investigators I
Published: July 2012

Background

Pretreatment baseline ASPECT score is used as a useful predictor of clinical outcome in acute ischemic stroke revascularization; post-treatment ASPECT analysis has not been used to analyze revascularization effects. We hypothesize assessment of post-treatment ASPECT areas may give information on differences between revascularization effects and clinical outcome in competing revascularization studies.

Purpose

To examine differences in post-treatment ASPECT regions affected in the Interventional Management of Stroke (IMS) I/II vs Solitaire Studies.

Methods

24-hr. CT/MR of subjects from the Solitaire Study and from IMS I/II with ICA-T, M1, or M2 occlusion treatment was reviewed. We recorded the degree of revascularization and post-treatment ASPECT areas affected. The cohort was divided into two categories based on site of arterial occlusive lesion (AOL) as Group A (ICA-T or M1 proximal to lenticulostriates) and Group B (M1 or M2 distal to lenticulostriates). The affected ASPECT regions for both groups were then compared for the two studies.

Results

96 subjects from Solitaire Study (67 Group A, 29 Group B) and 68 from IMSI/II (36 Group A, 32 Group B) with index AOL had complete imaging available for review. Abstract P-0026 figure 1 and 2 displays ASPECT areas for both groups in both studies. Incidence of basal ganglia involvement was similar in both studies, and was frequently found in subjects with AOL beyond the striate arteries. IMS subjects had more peripheral cortex zones affected compared to Solitaire subjects in both groups A and B (p=0.01). Patients in IMSI/II also had more frequent involvement of insular cortex compared to Solitaire subjects in both groups A and B (p<0.001).

Abstract P-026 Figure 1Abstract P-026 Figure 2

Conclusion

In AOL beyond the origin of lenticulostriate arteries, involvement of basal ganglia may indicate initial deep small vessel occlusion, or early recanalization prior to arteriography. Greater involvement of peripheral cortex and insula in IMS may be an effect of less complete or delayed revascularization, or increased distal emboli (poorer reperfusion). Better preservation of distal tissue following more rapid and complete revascularization with Solitaire is hypothesized.Solitaire Revascularization was not associated with increased basal ganglia ischemia, as might be anticipated due to compression during stent deployment or microembolism during clot retrieval. Other clinical and imaging factors affecting infarct volume will be discussed.

Competing interests

None.
P-027 Review of penumbra system trials: low rate of embolization of previously uninvolved territory of the brain using the penumbra system in acute ischemic stroke treatment: Abstract P-027 Table 1
Authors: Baxter B
Published: July 2012

Introduction/Purpose

Early and safe revascularization of the primary occlusion correlates with favorable clinical outcome in acute ischemic stroke treatment. One factor in assessing safety of mechanical thrombectomy devices is embolization to a previously uninvolved or new territory (ENT). The Penumbra System is an embolectomy device specifically designed to remove thrombus in acute ischemic stroke through two mechanisms: aspiration and extraction. The purpose of this study is to examine the rate of ENT in the three published Penumbra System trials.

Materials and Methods

Three papers reporting results of the Penumbra System trials were analyzed for ENT procedure-related adverse events and total number of cases.

Results

Our analysis of the Penumbra System ENT adverse event rate in the three Penumbra trials is summarized below. In the three studies, which included a total of 303 patients, only one incident of ENT was observed.

Conclusion

The unintentional embolization of new territory during mechanical thrombectomy can close collateral flow that is vital to preserving the penumbra. An assessment of the results from three Penumbra trials demonstrates a low rate of ENT of <0.5% using the Penumbra System in treatment for acute ischemic stroke. Aspirating immediately proximal to the thrombus ensures capture of clot at the site of occlusion into a catheter, which may reduce the potential for ENT. Combined with a revascularization rate of 86%, the experience in the three papers shows the ability of the Penumbra System to safely and effectively revascularize the site of primary occlusion.

Competing interests

B Baxter: Stryker Neurovascular, EV3, Penumbra, Rapid Medical, Reverse Medical, Codman, Silk Road.

Abstract P-027 Table 1

Summary of analysis of the penumbra system ENT adverse event rate in the three penumbra trials

# of ENT# CasesENT Rate, %Phase 1 study0210Pivotal study11250.8POST study01570Total13030.33
P-030 Impact of point-of-care platelet function testing by VerifyNow on periprocedural antiplatelet therapy in neuroendovascular stenting
Authors: Noorian A , Gupta R , Chester K Wyatt , Faggard J , Gershon R , Nogueira R
Published: July 2012

Background

Proper platelet inhibition is essential for prevention of thromboembolic complications in patients undergoing stent placement.

Objective

The aim of this study was to analyze the impact of VerifyNow® assay (VNA) on the management of periprocedural antiplatelet therapy in cerebrovascular stenting.

Design/Methods

Consecutive patients were retrospectively categorized in three groups: elective (Clopidogrel+aspirin (C+A)≥7 days), urgent (C+A for 12–72 h including clopidogrel bolus),and emergent (no previous C+A, intra-procedural abciximab and postprocedural C+A) stenting groups. Clopidogrel resistance (CR) and hypersensitivity (CH) were defined as <20% and >80% platelet inhibition measured by VNA, respectively.

Results

A total of 72 consecutive patients undergoing cerebrovascular stenting were included in the analysis. Twenty-three patients (age 64±14; 65% male) underwent elective stenting to treat symptomatic atherosclerotic lesions. The rates of CR and CH were 26% and 13%, respectively. Three of the six CR patients were treated with abciximab to achieve platelet inhibition. In one of the patients with CH (96% inhibition), stenting procedure was aborted. There were no hemorrhagic or ischemic complications. Twenty patients (age 60±12; male, 75%) underwent urgent stenting to treat symptomatic atherosclerotic lesions (n=18), medically refractory carotid dissection (n=1), and carotid pseudoaneurysm due to a gunshot wound (n=1). The rates of CR and CH were 60% (12/20) and 5% (1/20), respectively. Nine of the twelve CR patients were treated with abciximab to achieve an average 42%±14% platelet inhibition (range, 22%–52%). There were two hemorrhagic (gastrointestinal bleeding and spontaneous intracranial hemorrhage) with no ischemic events in the CR group. The patient with CH had a spontaneous fatal ICH in the unaffected cerebral hemisphere. Twenty-nine patients (age, 65±15; male, 50%) underwent emergent stenting all presenting with acute ischemic stroke. None of these patients were on chronic outpatient C+A therapy. Two received boluses of Clopidogrel before the procedure. The remaining patients received intra-procedural intravenous abciximab (3–13 mg) to achieve 29%–94% platelet inhibition. There was one intracranial and one systemic hemorrhage with no ischemic events.

Conclusions

Our results suggest the applicability of VNA in assuring adequate platelet inhibition. Future studies are needed to manage CR and CH optimally to prevent thrombosis or hemorrhage.

Competing interests

A Noorian: None. R Gupta: Concentric Medical, Codman Neurovascular, CoAxia, and Rapid Medical. K Wyatt Chester: None. J Faggard: None. R Gershon: None. R Nogueira: Concentric Medical, ev3 Neurovascular, CoAxia, and Rapid Medical.
P-033 Aneurysm embolization treatment efficiency: comparing the penumbra coil 400TM system to conventional coils
Authors: Patel A , Kamath A , Polykarpou M , Mascitelli J , Patel A , Moyle H
Published: July 2012

Purpose

The Penumbra Coil 400 System (PC 400) are the newly introduced platinum coils designed specifically to enhance filling efficiency by increasing coil diameter. Reported herein are the results of a comparison study to assess the PC 400's filling advantage in the treatment of cerebral aneurysms as compared to conventional embolic coils (Controls). Particular focus was put on the extent to which the larger diameter affects acute packing density, embolization time and the aneurysm occlusion at 6 months post-treatment.

Methods

This was a single center, retrospective case-review of 111 aneurysm cases treated in 110 patients by the PC 400 (N=16) or Controls (N=95). The aneurysm and procedural characteristics listed below were evaluated. Aneurysm volume and packing density were calculated using AngioCalc (http://www.angiocalc.com), an open source aneurysm calculator endorsed by the manufacturers of the currently available coil systems. Aneurysm occlusion was graded using investigator reported Raymond Scale classification immediately post-procedure, and at 6 (±2) months when patient follow-up was available. The data was then evaluated for statistical significance.

Results

PC 400 (N=16)Controls (N=95)Mean age (yrs)5856 (N=94)Location: ICA/P Comm./A Comm. ACA/MCA/Other (%)50/31.3/12.5/6.2/036.9/21.1/26.3/9.5/6.2Aneurysm volume (mean) (cc)204.3*154.5Ruptured (%)43.857.9# Coils used (mean)3.95.5Coil length (mean) (cm)36.346.8Stent assisted coiling (%)37.528.4Procedure time (mean)(min)46.758.8Packing density (mean) (%)36.2**27.5PC 400 (N=7)Controls (N=44)Follow-up (mean/median) (mos)6.2/7.06.2/6.0Raymond scale-class I occlusion†: approx. 6 months post treatment (%)85.761.4Raymond scale-class I occlusion1Comparison to immediate post-treatment: better/same/worse (%)57.1/42.9/036.4/52.2/11.4

*p<0.05, **p<0.005 (non-parametric wilcoxon ranked test).

†Classifications from Royet al. Stroke2001;32:1998–2004.

Conclusion

Aneurysm embolization with PC 400 achieved statistically significant greater packing density compared with conventional coils. This was achieved with less procedure time and less total number of coils despite statistically significant greater aneurysm volume. For patient follow-up, the seven PC 400 cases had a greater percentage of Class I Raymond Scale occlusion compared to the controls with available data at 6 months. Our data confirms that when compared to conventional coils, the PC 400 is indeed more efficient in the embolization of cerebral aneurysm, without affecting accessibility or safety.

Competing interests

A Patel: Penumbra, Inc. A Kamath: None. M Polykarpou: None. J Mascitelli: None. A Patel: None. H Moyle: None.
P-039 Changes in a neuroendovascular practice after introduction of flow diverters
Authors: Cloft H , Lanzino G , Crobeddu E , Kallmes D
Published: July 2012

Introduction

Flow diversion represents a major paradigm shift in the treatment of unruptured intracranial aneurysms. The potential impact of this technique on coil utilization and adjunctive techniques such as balloon-assisted and stent-assisted coiling is unknown. In this study, we assessed the effect of introduction of flow diversion devices on coil and adjunctive techniques utilization. We also performed a matched-pair analysis to assess the efficacy of flow diverters compared to traditional endovascular treatment of unruptured paraclinoid aneurysms.

Methods

Retrospective review of consecutive patients with unruptured aneurysms treated at our Institution comparing two groups: (Group 1, patients treated in the 2-year interval preceding introduction of the Pipeline Embolization Device (PED) and Group 2 (patients treated during the 2-year interval following introduction in our practice of the PED. For the matched-pair analysis, 21 eligible patients with 22 paraclinoid aneurysms treated with the PED were matched to historical controls with an aneurysm of similar size and location.

Results

Mean aneurysm diameter was 8.7±6.3 mm in Group 1 and 8.5±6.1 mm in Group 2 (p=0.79). There were no significant differences in the location of the aneurysms between the two groups suggesting that changes in referral pattern were not responsible for the observed changes in practice patterns. PED therapy was employed in 38 (21.7%) of 175 aneurysms in Group 2. The proportion of stent-assisted procedures was significantly less in Group 2 as compared to Group 1 (6.9% vs 14.7%, respectively, p=0.04), as was the proportion of patients undergoing parent artery sacrifice (0.6% vs 3.9% respectively, p=0.046). The mean and the median number of coils utilized per aneurysm were 5.4±3.6 and 5 (range 1–18) for Group 1 and 3.2±3.2 and 3 (range 0–19) for Group 2 (p≤0.0001). The pair-matched analysis demonstrated a significant difference in the rate of complete occlusion favoring PED at radiological follow-up (77.3% in the PED vs 45.4% in the control group, p=0.03). Complications rates were similar between the two groups.

Conclusion

Flow diversion represents a disruptive technology. More than one fifth of unruptured aneurysms at our institution were treated with PED after introduction of this technology, resulting in marked decreases in coil and stent utilization. Flow diverters achieve a much higher rate of complete angiographic obliteration when compared to other standard endovascular techniques in the treatment of internal carotid artery aneurysms. In this series, this higher angiographic obliteration rate did not occur at the expenses of an increased rate of complications.

Competing interests

H Cloft: Cordis Endovascular. G Lanzino: Educational support from ev3 and Synthes. E Crobeddu: None. D Kallmes: ev3, Micrus, MicroVention, Penumbra, Sequent, NFocus.
P-040 A comparison between particulate and Onyx embolization for devascularization of Juvenile angiofibromas prior to surgical resection
Authors: Gemmete J , Gao M , Pandey A , Chaudhary N , Sullivan S , McKean E , Marentette L
Published: July 2012

Introduction

Juvenile nasopharyngeal angiofibroma is a locally invasive tumor in adolescent males. Surgical resection is the treatment of choice, but the tumor's extensive vascular involvement necessitates preoperative embolization. In this retrospective cohort, we compare the effectiveness of a novel liquid embolic agent, Onyx (ethylene vinyl alcohol copolymer), to traditional particulate embolic agents in reducing estimated blood loss (EBL) during surgical resection of Juvenile nasopharyngeal angiofibroma.

Methods

We included 46 consecutive resections since 1995 for which preoperative embolization was either particulate (n=39) or Onyx only (n=7), and for which age at operation, date of operation, length of hospital stay, Fisch grade of tumor, resection approach, EBL during resection, and fluids during resection were available. In a subset of 26 resections, OR time was available.

Results

The mean EBL for the Onyx group was 658.6±858.7 ml and the mean EBL for the particulate group was 1348.6±932.2 ml (one tailed Student t test p=0.043). The mean units packed red blood cells (PRBCs) used in the Onyx group 0.29±0.76 units (p=0.003) and the mean PRBCs used in the particulate cohort was 1.56±2.01. The relationship between embolization type, EBL and embolization type, PRBCs remained significant in the subset of patients with Fisch grade=III (Onyx n=4, particulate n=18, EBL p=0.001 and PRBCs p=0.045), and other Fisch categories did not have enough patients for a statistical analysis. The relationship between embolization type and EBL remained significant after correcting for age at operation (p=0.033). The proportion of resections for which an endoscopic approach was used was significantly higher in the Onyx group than the particulate group (71.4% and 20.5%; p=0.009), and this was also significant in the subset of patients with Fisch grade=III (p=0.040).

Conclusion

Existing reports suggest that Onyx embolization decreases intraoperative EBL. Our study supports this result and also shows a reduction in units PRBC used intraoperatively. Although further studies are needed, Onyx appears to facilitate a less challenging surgical resection relative to traditional particulate embolization.

Competing interests

None.
P-046 Correlation between recanalization rate and good clinical outcome in acute ischemic stroke, a meta-analysis
Authors: Nourollahzadeh E , Kass-Hout O , Mokin M , Aliotta R , Synder K , Siddiqui A , Levy E , Kass-Hout T
Published: July 2012

Background

Early recanalization is strongly associated with improved functional outcomes and reduced mortality in acute ischemic stroke (AIS). This is the rationale that stands behind the use of intravenous (IV) or intra-arterial (IA) thrombolytics and the growing list of mechanical thrombectomy devices. There has been multiple small sized studies that have reported this positive association, however, we are lacking a recent review compilation demonstrating this.

Methods

Data were collected through Medline search. We analyzed all articles published between the years 2002 and 2011 comparing various clinical outcomes including modified Rankin Scale (mRS) at 90 days, symptomatic intracranial hemorrhage, and mortality rate between non-revascularized and revascularized groups in the setting of AIS therapy. Search key words included recanalization, reperfusion, thrombolysis, thrombectomy, modified rankin scale, in combination with ischemic stroke and cerebral ischemia.

Results

73 studies reporting recanalization rate on 4390 patients were analyzed. Recanalization rate through various intervention approaches were extracted (IV thrombolytic 32%, IA 58%, mechanical thrombectomy 89%, and combined thrombolytic/mechanical 91%). Correlation between clinical outcomes and different revascularization therapies, location of the occlusion and the time from symptom onset to revascularization was only stratified in 68 studies. Patients with successful revascularization defined as Thrombolysis In Myocardial Infarction of 2–3 had a better functional clinical outcome compared to non-revascularized group (Pooled OR 6.01; 95% CI 4.87 to 7.18). Mortality rate was reduced in patients that were revascularized (Pooled OR 0.32; 95% CI 0.18 to 0.41). Symptomatic intracranial hemorrhage rate were reduced for the non-revascularized group, however it was not significant (p=0.31).

Conclusion

This meta-analysis further supports the positive correlation between revascularization rate and good functional outcome and reduced mortality rate in AIS.

Competing interests

E Nourollahzadeh: None. O Kass-Hout: None. M Mokin: None. R Aliotta: None. K Synder: Toshiba and ev3. A Siddiqui: NINDS 1R01NS064592-01A1, University at Buffalo. Shurtleff, Inc., Concentric Medical, ev3/Covidien Vascular Therapies, GuidePoint Global Consulting, Penumbra. Codman & Shurtleff, Inc., Genentech. Hotspur, Intratech Medical, StimSox, Valor Medical. Abbott Vascular, an Emergency Medicine Conference, Neocure Group LLC, Genentech, American Association of Neurological Surgeons. E Levy: Codman & Shurtleff, Inc, ev3/Covidien Vascular Therapies, Boston Scientific, TheraSyn Sensors, Inc., Medical Ltd., Mynx/Access Closure. Boston Scientific. T Kass-Hout: Genentech.
P-047 Aneurismal thrombosis post coil introduction in a rat aneurysm model: correlation of MRI findings with histopathology
Authors: Elias A , Zhang C , Pandey A , Guoua X , Gemmete J , Chaudhary N
Published: July 2012

Introduction

MRI plays a significant role in the post embolization follow-up of patients who have undergone coil embolization of cerebral aneurysms. We have utilized a rat aneurysm model to study the aneurysm healing process. Based on the extrapolation of signal characteristics of endovascular thrombus in humans, we have determined that gradient echo sequences (T2* weighted images) would be the optimal method to quantify amount of endoluminal thrombus. We aim to correlate the MRI findings with histopathological findings in this experimental rat aneurysm model.

Methods

This experimental aneurysm study in a rat model was approved by the University Committee on Use and Care of Animals. Male Sprague Dawley rats were anesthetized with transperitoneal injection of 50–60 mg/kg pentobarbital. In each animal an artificial aneurysm was created by permanent ligation of the rat external carotid artery (ECA) 5 mm from the carotid bifurcation (ECA blind pouch aneurysm). Subsequently a 5 mm coil segment was inserted into this aneurysm by an arteriotomy and then a ligature was placed proximal to the arteriotomy. Five rat aneurysms were treated with platinum coils and five others were treated with hydrocoils. 14 days post-treatment, animals underwent MRI analysis of the treated aneurysms as well as being sacrificed for histopathological analysis. The volume of the thrombus formation was calculated by measuring the maximal area (ROI) of blooming artifact × slice thickness (mm)/matrix (256) using NIH Image J software version 1.43U. The histological specimens were studied under high-field microscope and thrombus formation was demarcated following staining. Measurements were performed on the MR images and histological specimens independently in a blinded fashion. The measured values on MRI and histological sections were then analyzed using the Pearson correlation coefficient (PCC) by SPSS V.15.0.

Results

Our results demonstrate a significant correlation between the extent of luminal thrombus formation on histology and signal characteristics on T2* GRE MRI sequences when the rats were treated with bare platinum coils PCC=0.987 (p=0.002). The hydrogel coated coils did not show MR correlation with area of thrombus formation PCC=0.344 (p=0.571).

Conclusion

We report the first correlation extent of luminal thrombus formation on histology with signal characteristics on T2* GRE MRI sequences in a rat aneurysm model. Our hypothesis of direct correlation between the above mentioned variables holds true in the bare platinum coil group and not in the hydrocoil group. Such positive correlation could allow for non-invasive evaluation of treated experimental aneurysm models.

Competing interests

None.