Complex Cerebral Aneurysms Research Articles

頭蓋内血行再建を安全確実に行うための原則と工夫

Introduction: Although improvements in endovascular treatment have decreased the frequency of bypass surgery, cerebral vascular reconstructions are still important. Many critical points are required to achieve a reliable bypass patency. We describe our experience and techniques for bypass surgery, especially focusing on the superficial temporal artery to middle cerebral artery (STA-MCA) bypass.Materials and methods: Over a period of 5 years, STA-MCA bypass was performed for 42 patients with atherosclerotic internal carotid artery or middle cerebral artery occlusion, or hemodynamic ischemia; 35 patients with moyamoya disease; and 97 patients with complex cerebral aneurysms. Mean occlusion time, bypass patency, hyperperfusion, ischemic complication, and postoperative delayed wound healing were assessed.Results: Within 42 ischemic cases, the mean occlusion time of the STA-MCA procedure was 20 minutes 16 seconds. No ischemic complications due to temporal occlusion occurred. Acute bypass occlusion (occlusion within 2 weeks after operation) occurred in 1 case of STA-MCA for moyamoya disease and 1 case of STA-MCA bypass for a patient with ischemic occlusion. Perioperative ischemic stroke was observed in 4 patients with ischemic occlusion and 1 patient with moyamoya disease.Conclusion: To perform a safe and reliable vascular reconstruction, off-the-job training, a bloodless operative field, selection of an appropriate donor and recipient artery, use of the “fish mouth” method for trimming the donor artery, and an intima-to-intima everting suture are necessary.

Predictive modeling and in vivo assessment of cerebral blood flow in the management of complex cerebral aneurysms

Cerebral aneurysms are weakened blood vessel dilatations that can result in spontaneous, devastating hemorrhage events. Aneurysm treatment aims to reduce hemorrhage events, and strategies for complex aneurysms often require surgical bypass or endovascular stenting for blood flow diversion. Interventions that divert blood flow from their normal circulation patterns have the potential to result in unintentional ischemia. Recent developments in computational modeling and in vivo assessment of hemodynamics for cerebral aneurysm treatment have entered into clinical practice. Herein, we review how these techniques are currently utilized to improve risk stratification and treatment planning.

Pipeline Embolization Device with or without Adjunctive Coil Embolization: Analysis of Complications from the IntrePED Registry.

Flow diversion to treat cerebral aneurysms has revolutionized neurointerventional surgery. Because the addition of coils potentially increases the time and complexity of endovascular procedures, we sought to determine whether adjunctive coil use is associated with an increase in complications. Patients in the International Retrospective Study of Pipeline Embolization Device registry were divided into those treated with the Pipeline Embolization Device alone (n = 689 patients; n = 797 aneurysms; mean aneurysm size, 10.3 ± 7.6 mm) versus those treated with the Pipeline Embolization Device and concurrent coil embolization (n = 104 patients; n = 109 aneurysms; mean aneurysm size, 13.6 ± 7.8 mm). Patient demographics and aneurysm characteristics were examined. Rates of neurologic morbidity and mortality were compared between groups. The Pipeline Embolization Device with versus without coiling required a significantly longer procedure time (135.8 ± 63.9 versus 96.7 ± 46.2 min; P < .0001) and resulted in higher neurological morbidity (12.5% versus 7.8%; P = .13). These data suggest that either strategy represents an acceptable risk profile in the treatment of complex cerebral aneurysms and warrants further investigation.

Surgical Treatment of Complex Cerebral Aneurysms Using Interposition Short Vein Graft.

Cerebral revascularization strategies may become necessary in select patients who present with challenging cerebral aneurysms. In this study, we present the techniques of a moderate-flow extra-intracranial bypass using a short interposition vein graft and concurrent aneurysm management. The short interposition vein graft was used for the reconstruction of complex cerebral aneurysms in nine patients. In eight of them, the superficial temporal artery (STA) main trunk was used as a donor site for the anastomosis of a short interposition vein graft, and an extracranial vertebral artery (VA) was used in one case. The vein grafts were implanted into the M2 of the middle cerebral artery (MCA) for the adjunctive treatment of internal carotid artery (ICA) aneurysms in three patients, into the A3 of the anterior cerebral artery (ACA) in one patient, into the P2 of the posterior cerebral artery (PCA) for the adjunctive treatment of complex PCA aneurysms in three patients, into the P3 of the PCA for the adjunctive treatment of a basilar artery (BA) trunk giant aneurysm in 1 patient, and into the postero-inferior cerebellar artery (PICA) for the adjunctive treatment of the VA dissecting aneurysm in one patient. All of the bypasses were patent. Intraoperative flow measurements confirmed a moderate flow-carrying capacity of the short interposition short vein graft (30-70 ml; mean: 43 ml/min). The STA main trunk to proximal MCA/PCA bypass and the extracranial VA to PICA bypass using short interposition vein grafts can provide sufficient blood flow and may be a reasonable alternative to the conventional EC-IC bypass/high-flow bypass.

Minimum Transpetrosal Retrolabyrinthine Approach for Revascularization of Posterior Cerebral Artery: Operative Nuance.

Revascularization of the posterior cerebral artery (PCA) can be essential for treating complex cerebral aneurysms in the posterior circulation, and it is considered technically challenging. To help decrease the difficulty of this technique, we developed the minimum transpetrosal approach (MTPA). The technical nuances of the MTPA were innovated by cadaver head dissections and an actual clinical case. Four sides of the formalin-fixed cadaver heads were used to investigate if the posterior cerebral artery could be exposed with this minimum retraction of the temporal lobe in the subtemporal approach and the MTPA. By using the MTPA, 1 patient harboring a ruptured PCA aneurysm underwent superficial temporal artery-PCA anastomosis followed by isolation of the aneurysm. In the cadaver head dissections, we noticed that the PCAs were difficult to expose with gentle retraction of the temporal lobe in the subtemporal approach. By performing an additional retrolabyrinthine mastoidectomy, performed as the MTPA, all 4 PCAs were easily exposed in the 4 wide surgical fields. The maximum widths of the surgical fields above and below the PCA could be successfully measured in 2 cases, which were 13.3 mm and 11.2 mm, respectively (mean, 12.3 mm). Additionally, in the actual live surgery using MTPA, the PCAs were relative easy to expose with a surgical field wide enough to perform PCA bypass, which was performed without complication. The MTPA may be the most favorable approach for PCA bypass that can be performed easily with minimal temporal lobe retraction.

Assisted coiling using LEO Baby or LVIS Jr stents: Report of six cases.

Endovascular treatment of broad-neck, complex cerebral aneurysms is a challenging issue. Placement of a stent over the aneurysm neck and secondary coil embolization prevents coil migration and allows dense packing of the coils. Another challenge is represented by distal aneurysms situated in small vessels. In these cases, the use of little stents, which we are going call ministents, could be a good decision. These low-profile intracranial ministents can be deployed into arteries with diameters between 1.5 and 3.10 mm and delivered through microcatheters with an internal diameter of 0.0165 inches, which allows easier navigation in small-sized, delicate vessels. We present six cases of wide-neck aneurysms, with small parental arteries less than 2.5 mm using a low-profile ministent system (LEO Baby and LVIS Jr) plus coil embolization. We retrospectively reviewed patients in whom LEO Baby or LVIS Jr stent was used for the treatment of intracranial aneurysms. Five aneurysms were treated during 2013-2014 in our service using the LEO Baby stent and one aneurysm using LVIS Jr. Stent-assisted coil embolization was performed using the jailing technique in all cases. Clinical and angiographic findings, procedural data, and follow-up are reported. Six consecutive patients were included in this study. Four patients presented with subarachnoid hemorrhage in the subacute-chronic phase and two patients had unruptured aneurysms. Two of the six aneurysms were located at branches of the sylvian artery, one at the basilar artery, two at the anterior communicating artery, and one at the P1-P2 artery. The procedures were successful. Six-month control digital subtraction angiograms were obtained in all cases; they demonstrated complete occlusion of the aneurysms in all instances. All patients had good clinical outcomes on follow-up, as measured with the Glasgow Outcome Scale and Modified Rankin Scale. The results of this small study show that the LEO Baby and LVIS Jr ministents could be safe and efficient for endovascular treatment of intracranial broad-neck aneurysms situated in small arteries.

開頭・血管内手術を利用した複合脳動脈瘤手術

開頭・血管内手術を利用した複合脳動脈瘤手術

Adenosine-induced transient asystole.

Cerebral aneurysms are an important health issue in the United States, and the mortality rate following aneurysm rupture, or SAH, remains high. The treatment of these aneurysms uses endovascular options which include coil placement, stent assistant coiling and, recently, flow diversion. However, microsurgical clipping remains an option in those aneurysms not suited for endovascular therapy. These are often the more complicated aneurysms such as in large, giant aneurysms or deep-seated aneurysms. Circumferential visualization of the aneurysm, parent vessels, branches, perforators, and other neurovascular structures is important to prevent residual aneurysms or strokes from vessel or perforator occlusion. Decompression of the aneurysm sac is often required and we believe that adenosine-induced transient asystole should be an important option for clipping of complex cerebral aneurysms.

Contrast-enhanced time-resolved MRA for follow-up of intracranial aneurysms treated with the pipeline embolization device.

Endovascular reconstruction and flow diversion by using the Pipeline Embolization Device is an effective treatment for complex cerebral aneurysms. Accurate noninvasive alternatives to DSA for follow-up after Pipeline Embolization Device treatment are desirable. This study evaluated the accuracy of contrast-enhanced time-resolved MRA for this purpose, hypothesizing that contrast-enhanced time-resolved MRA will be comparable with DSA and superior to 3D-TOF MRA. During a 24-month period, 37 Pipeline Embolization Device-treated intracranial aneurysms in 26 patients underwent initial follow-up by using 3D-TOF MRA, contrast-enhanced time-resolved MRA, and DSA. MRA was performed on a 1.5T unit by using 3D-TOF and time-resolved imaging of contrast kinetics. All patients underwent DSA a median of 0 days (range, 0-68) after MRA. Studies were evaluated for aneurysm occlusion, quality of visualization of the reconstructed artery, and measurable luminal diameter of the Pipeline Embolization Device, with DSA used as the reference standard. The sensitivity, specificity, and positive and negative predictive values of contrast-enhanced time-resolved MRA relative to DSA for posttreatment aneurysm occlusion were 96%, 85%, 92%, and 92%. Contrast-enhanced time-resolved MRA demonstrated superior quality of visualization (P = .0001) and a higher measurable luminal diameter (P = .0001) of the reconstructed artery compared with 3D-TOF MRA but no significant difference compared with DSA. Contrast-enhanced time-resolved MRA underestimated the luminal diameter of the reconstructed artery by 0.965 ± 0.497 mm (27% ± 13%) relative to DSA. Contrast-enhanced time-resolved MRA is a reliable noninvasive method for monitoring intracranial aneurysms following flow diversion and vessel reconstruction by using the Pipeline Embolization Device.

Preliminary experiences of "Waffle cone" technique for the treatment of intracranial aneurysm

To explore the preliminary experiences of "Waffle cone" technique for the treatment of intracranial aneurysm. Retrospective data analyses were performed for patients with intracranial aneurysms embolized by the "Waffle cone" technique from stent-assisted coiling at our hospital from December 2010 to November 2012. Six patients used the "Waffle cone" technique from 138 stent-assisted coiling. All had complex wide-neck bifurcation cerebral aneurysms. And the angles between parental artery and distal vessels were acute. Six rupture aneurysms were at the terminus of basilar artery (BA) (n = 2), right anterior communicating artery (AcomA) (n = 3) and trifurcation middle cerebral artery (MCA) (n = 1). All stents were of Solitaire with specification 4×15 mm (ev3, USA) .Four patients had Raymond classification Class I while another 2 Class II. No perioperative complication occurred. The average follow-up period was 6 months. This technique is safe, time-saving, simple and effective for complex, wide-necked bifurcation aneurysms with acute angles between parental artery and distal vessels.Long-term follow-ups are needed to further evaluate its efficacy.

Revascularization and pediatric aneurysm surgery.

Aneurysms are relatively rare in the pediatric population and tend to include a greater proportion of large and giant lesions. A subset of these large and giant aneurysms are not amenable to direct surgical clipping and require complex treatment strategies and revascularization techniques. There are limited data available on the management of these lesions in the pediatric population. This study was undertaken to evaluate the outcome of treatment of large and giant aneurysms that required microsurgical revascularization and vessel sacrifice in this population. The authors retrospectively identified all cases in which pediatric patients (age < 18 years) with aneurysms were treated using cerebral revascularization in combination with other treatment modalities at their institution between 1989 and 2013. The authors identified 27 consecutive patients (19 male and 8 female) with 29 aneurysms. The mean age of the patients at the time of treatment was 11.5 years (median 13 years, range 1-17 years). Five patients presented with subarachnoid hemorrhage, 11 with symptoms related to mass effect, 2 with stroke, and 3 with seizures; in 6 cases, the aneurysms were incidental findings. Aneurysms were located along the internal carotid artery (n = 7), posterior cerebral artery (PCA) (n = 2), anterior cerebral artery (n = 2), middle cerebral artery (MCA) (n = 14), basilar artery (n = 2), vertebral artery (n = 1), and at the vertebrobasilar junction (n = 1). Thirteen were giant aneurysms (45%). The majority of the aneurysms were fusiform (n = 19, 66%), followed by saccular (n = 10, 34%). Three cases were previously treated using microsurgery (n = 2) or an endovascular procedure (n = 1). A total of 28 revascularization procedures were performed, including superficial temporal artery (STA) to MCA (n = 6), STA to PCA (n = 1), occipital artery to PCA (n = 1), extracranial-intracranial (EC-IC) bypass using radial artery graft (n = 3), EC-IC using a saphenous vein graft (n = 7), STA onlay (n = 3), end-to-end anastomosis (n = 1), and in situ bypasses (n = 6). Perioperative stroke occurred in 4 patients, but only one remained dependent (Glasgow Outcome Scale [GOS] score 3). At a mean clinical follow-up of 46 months (median 14 months, range 1-232 months), 26 patients had a good outcome (GOS score 4 or 5). There were no deaths. Five patients had documented occlusion of the bypass graft. The majority of aneurysms (n = 24) were obliterated at last follow-up. There was a single case of a residual aneurysm and one case of recurrence. Angiographic follow-up was unavailable in 3 cases. Cerebral revascularization remains an essential tool in the treatment of complex cerebral aneurysms in children.

False-negative indocyanine green videoangiography among complex unruptured middle cerebral artery aneurysms: The importance of further aneurysm inspection

Successful surgical treatment of cerebral aneurysms requires complete occlusion of the aneurysm lumen while maintaining patency of the adjacent branching and perforating arteries. Intraoperative flow assessment allows aneurysm clip repositioning in the event these requirements are not met, avoiding the risk of postoperative rehemorrhage or infarction. A number of modalities have been proposed for primarily intraoperative qualitative blood flow assessment, including microdoppler ultrasonography, intraoperative digital subtraction angiography (DSA), and more recently noninvasive fluorescent angiography including indocyanine green (ICG) fluorescent imaging. Puncture of the aneurysm dome to exclude aneurysm sac filling may also assess the efficacy of clip placement. Although a high concordance between ICG and DSA has been reported, there remains an important subset of aneurysms for which negative ICG study may erroneously suggest aneurysm occlusion. A high-risk situation for such a false-negative study is an atherosclerotic middle cerebral artery (MCA) aneurysm in which vessel wall plaque interferes with the ICG signal. Furthermore, a decreased flow within the aneurysm may not allow enough emission light for detection under the current technology. In this report, we describe our experience with cases of MCA aneurysms with false-negative ICG-VA studies requiring clip adjustment for optimal surgical treatment and discuss two illustrative cases of MCA aneurysms with intraoperative fluorescence studies that were falsely negative, requiring puncture of the aneurysm to correctly identify incomplete aneurysm occlusion.

The clinical diagnosis and treatment of blood-blister-like cerebral aneurysms in supra-clinoid segment of internal carotid artery

To study the clinical characteristics, surgical principles and treatment options of blood-blister-like cerebral aneurysms in supra-clinoid segment of internal carotid artery. Twelve blood-blister-like aneurysms were retrospectively studied including 4 open-surgery cases and 8 endovascular-treated cases from November 2008 to December 2012. Patients comprised 8 female and 4 male patients, whose mean age was 46.6 (range 38-56) years. Eleven patients presented with severe headache as the primary symptom, and 1 patient was found with aneurysm incidentally. Preoperative Hunt-Hess graded 0 in 1 patient, graded I in 5 patients, graded II in 4 patients, and graded III in 2 patients. By DSA examinations, 4 blood-blister-like aneurysms located in anterior wall and 8 in medial-anterior wall of supra-clinoid segment of internal carotid artery. Open surgical treatment included direct clipping, trapping, or wrapping and interventional treatment included stent-assisted coiling or simple stent placement. Intra-operative electroencephalogram and somatosensory evoked potentials monitoring was regularly used. Microvascular Doppler ultrasonography and indocyanine green videoangiography were used to assess blood flow in parent and branch vessels. The patients were followed up at 6 months by CT angiography (CTA) examination in outpatient clinic. For 4 open surgeries, 2 aneurysms were directly clipped, 1 was trapped and 1 was wrapped. The patient underwent trapping paralyzed postoperatively. For endovascular treatment, 6 patients were coiled assisted with stents and 2 patients were treated with simple stent placement. All the patients were followed with a mean follow-up time of 16 months (range, 6-61 months). At 6 months follow-up, 3 out of 4 surgical treated patients had good outcome and 1 was moderately severe disabled by modified Rankin scale; 1 patient underwent wrapping recurred and was transferred to endovascular treatment. Of the 6 patients treated with stent-assisted coiling, 4 patients were recurrent and coil replacements were performed. Two patients with simple stent placement had no recurrences. Blood-blister-like aneurysm is a special type of complex cerebral aneurysm. Comprehensive understanding of blood-blister-like aneurysm is the key to successful treatment.Open surgery is difficult procedure with high risk and complications while stent-assisted coiling has a high recurrent rate. To date, neither is the safe and effective treatment option.

Adaptive grid generation in a patient-specific cerebral aneurysm

Adapting grid density to flow behavior provides the advantage of increasing solution accuracy while decreasing the number of grid elements in the simulation domain, therefore reducing the computational time. One method for grid adaptation requires successive refinement of grid density based on observed solution behavior until the numerical errors between successive grids are negligible. However, such an approach is time consuming and it is often neglected by the researchers. We present a technique to calculate the grid size distribution of an adaptive grid for computational fluid dynamics (CFD) simulations in a complex cerebral aneurysm geometry based on the kinematic curvature and torsion calculated from the velocity field. The relationship between the kinematic characteristics of the flow and the element size of the adaptive grid leads to a mathematical equation to calculate the grid size in different regions of the flow. The adaptive grid density is obtained such that it captures the more complex details of the flow with locally smaller grid size, while less complex flow characteristics are calculated on locally larger grid size. The current study shows that kinematic curvature and torsion calculated from the velocity field in a cerebral aneurysm can be used to find the locations of complex flow where the computational grid needs to be refined in order to obtain an accurate solution. We found that the complexity of the flow can be adequately described by velocity and vorticity and the angle between the two vectors. For example, inside the aneurysm bleb, at the bifurcation, and at the major arterial turns the element size in the lumen needs to be less than 10% of the artery radius, while at the boundary layer, the element size should be smaller than 1% of the artery radius, for accurate results within a 0.5% relative approximation error. This technique of quantifying flow complexity and adaptive remeshing has the potential to improve results accuracy and reduce computational time for patient-specific hemodynamics simulations, which are used to help assess the likelihood of aneurysm rupture using CFD calculated flow patterns.

O-010 The Barrow Neurological Institute Experience with the Pipeline Embolisation Device: Results in the First 100 Patients Treated after FDA Approval

Aims and ObjectivesThe Pipeline Embolisation Device (PED) was recently approved in the United States (US) for the treatment of wide-necked anterior circulation aneurysms. Studies in both the US and Europe...

Pediatric bypasses for aneurysms and skull base tumors: short- and long-term outcomes

Object Cerebral bypass is a useful microsurgical technique for the treatment of unclippable aneurysms and invasive skull base tumors. The authors present the largest reported series of cerebrovascular bypasses in the pediatric population. They describe the short- and long-term clinical and radiographic outcomes of extracranial-intracranial and local bypasses performed for complex cerebral aneurysms and recurrent, invasive, and malignant skull base tumors in pediatric patients. Methods A consecutive series of 17 pediatric patients who underwent revascularization were analyzed retrospectively for indications, graft patency, and neurological outcomes. Results The mean age was 12 years (median 11 years, range 4–17 years), and there were 7 boys (41%) and 10 girls (59%). A total of 18 bypasses were performed in 17 patients and included 10 aneurysm cases (55.5%) and 8 tumor cases (45%). Of these 18 bypasses, there were 11 (61.1%) extracranial-intracranial bypasses (10 saphenous vein grafts [90%] and 1 radial artery graft [10%]), 1 side-to-side anastomosis (5.5%), 2 intracranial reimplants (11.1%), and 4 interposition bypass grafts (22.2%; 2 radial artery grafts, 1 saphenous vein graft, and 1 lingual artery graft). The mean clinical follow-up was 40.5 months (median 24 months, range 3–197 months). The mean radiographic follow-up was 40 months (median 15 months, range 9–197 months). Eighty-two percent of patients (14 of 17) achieved a modified Rankin Scale score between 0 and 2; however, 2 patients died of disease progression during long-term follow-up. The short-term (0- to 3-month) graft patency rate was 100%. Two patients had graft stenosis (11.7%) and underwent graft revisions. Two patients (11.1%) with giant middle cerebral artery aneurysms (&gt; 25 mm) had strokes postoperatively but recovered without a persistent neurological deficit. One patient observed for 197 months showed a stable dysplastic change at the end of the graft. The long-term graft patency was 100% with a mean follow-up of 40 months. There were 2 deaths in the cohort during follow-up; both patients died of malignant tumors (osteogenic sarcoma and chondrosarcoma). Conclusions The authors conclude that in properly selected cases, bypasses can be safely performed in patients with aneurysms and skull base tumors. The bypasses remained patent over long periods of time despite the growth of the patients.

Initial experience with implantation of novel dual layer flow-diverter device FRED.

Flow-diverting stents can help treat complex and wide-necked cerebral aneurysms. The aim of the study was to evaluate initial experiences related to the safety and effectiveness of eight aneurysms treated with a new dual layer coverage designed flow-diverter device. In 2012 Fred flow-diverter devices were used to treat 8 unruptured wide neck (dome-neck ratio ≤ 1.5) and sidewall aneurysms in 6 patients. All aneurysms were located in the anterior circulation on the internal carotid artery (ICA). In 4 larger aneurysms (> 10 mm) one 3D coil in association with Fred was used to reduce potential incidence of postoperative subarachnoid haemorrhage (SAH). Dual antiplatelet therapy was administered before the procedure and continued for 3 months after it. Clinical parameters, aneurysm features and 3-month follow-up angiograms are presented. All 6 patients with 8 aneurysms were successfully stented with the Fred flow-diverter device and were discharged in generally good condition on dual-antiplatelet therapy. No complications were related to the procedure. In 5 cases digital subtraction angiography (DSA) control examination was performed after 3 months, showing complete occlusion of the aneurysms with patency of the parent artery. In 1 case thrombosis of the Fred occurred but without any clinical consequences because of cross-flow from the other side. Use of the Fred flow-diverter device was efficacious in all 8 treated cerebral aneurysms. The system seems to be promising as a flow diverter with certain characteristics, which allow for easy delivery and implantation. Further clinical evaluation with a larger group of patients is needed.

Assisted techniques for the endovascular treatment of complex or atypical cerebral aneurysms

In the last ten years, the endovascular approach to the management of cerebral aneurysms has gone from being an alternative to surgery to being the first-choice technique in the vast majority of cases. The continuous development of new assisted techniques and of new materials for embolization has multiplied its therapeutic possibilities, so that safe and efficacious endovascular treatment is now possible for aneurysms that would have required surgery only a few years ago. These continuous technological advances require the professionals who treat patients with cerebral aneurysms to achieve a high degree of specialization and to keep up to date through continuous training. In this article, we review some of the most widely used assisted techniques in the endovascular treatment of cerebral aneurysms, discussing their main indications, their advantages over conventional embolization techniques, and their possible limitations.

The use of flow diverter stents in the management of traumatic vertebral artery dissections

Flow diverters constitute a new generation of flexible self-expanding stent-like devices with a high metal-surface area coverage, specifically designed for the endovascular management of complex cerebral aneurysms. Recently, other potential applications for these devices in the field of occlusive cerebrovascular disease have been described. In vertebral artery dissections causing occlusion associated with a burden of extensive clots, we have found that the reduced porosity of the diverter mesh serves as an effective barrier to in-stent clot protrusion and distal embolization. We describe the novel use of a flow diverter for the management of an occlusive traumatic vertebral artery dissection. Diverter implantation allowed subsequent angioplasty.

Abstract WMP27: Prevalence of Non-responsiveness to Antiplatelet Therapy in Patients Undergoing Treatment of Cerebral Aneurysms Utilizing Flow Diversion with the Pipeline Embolization Device

Introduction: Flow-diversion has emerged as a novel treatment for complex cerebral aneurysms. Although preliminary reports suggest flow-diverting devices are safe and effective, the risk of thromboembolic and hemorrhagic complications must be balanced with the added risk of dual antiplatelet therapy. Although the prevalence of antiplatelet therapy non-responsiveness (NR) has been associated with adverse cardiac events in patients with acute coronary syndrome (ACS), it has has not been studied in patients treated with these devices. Methods: All patients received clopidogrel 75mg and aspirin 325mg prior to modified light transmittance platelet aggregometry (LTA) using 4 agonists (ADP 5 and 20 uM, arachidonic acid (ACA), and U46619 ). NR was defined as a maximum amplitude (MA) &gt; 60% with ADP 20uM and 40% with ADP 5uM for clopidogrel and a MA &gt;20% with ACA for aspirin. Patients were also assessed for known drug interactions. Chi-square or Fisher’s exact tests were used for univariate analyses, and logistic regression was used to identify potential predictors of NR. Results: 79 patients with 98 cerebral aneurysms were treated with the pipeline embolization device (PED). The prevalence of clopidogrel and aspirin NR was 27.6% and 30.3%, respectively. In univariate and multivariate analyses, age, gender, race, presence of drug interactions, history of hypertension, diabetes, ischemic stroke, subarachnoid hemorrhage and smoking were not significant predictors of NR. Conclusions: In our cohort, the prevalence of clopidogrel and aspirin NR was high and similar to that reported in ACS patients. As a result of the rate of NR, patients were evaluated by a virtual antiplatelet clinic and patients with suboptimal LTA results underwent modification of a drug interaction, received double doses of clopidogrel and/or aspirin, or were transitioned to an alternative P2Y12 inhibitor (prasugrel or ticagrelor). The mechanisms underlying antiplatelet NR remain to be further explored to minimize the risk of hemorrhagic complications if more potent antiplatelet therapy is required.