Flow diversion with the pipeline embolization device for patients with intracranial aneurysms and antiplatelet therapy: A systematic literature review

BackgroundIntracranial aneurysms located in the distal vessels are rare and remain a challenge to treat through surgical or endovascular interventions.ObjectiveTo describe a multicenter approach with flow diversion using the pipeline embolization device (PED) for treatment of distal intracranial aneurysms.MethodsCases of distal intracranial aneurysms defined as starting on or beyond the A2 anterior cerebral artery, M2 middle cerebral artery, and P2 posterior cerebral artery segments were included in the final analysis.Results65 patients with distal aneurysms treated with the PED were analyzed. Median aneurysm size at the largest diameter was 7.0 mm, 60% were of a saccular morphology, and 9/65 (13.8%) patients presented in the setting of acute rupture. Angiographic follow-up data were available for 53 patients, with a median follow-up time of 6 months: 44/53 (83%) aneurysms showed complete obliteration, 7/53 (13.2%) showed reduced filling, and 2/53 (3%) showed persistent filling. There was no association between patient characteristics, including aneurysm size (P=0.36), parent vessel diameter (P=0.27), location (P=0.81), morphology (P=0.63), ruptured status on admission (P=0.57), or evidence of angiographic occlusion at the end of the embolization procedure (P=0.49). Clinical outcome data were available for 60/65 patients: 95% (57/60) had good clinical outcome (modified Rankin Scale score of 0–2) at 3 months.ConclusionsThis large multicenter study of patients with A2, M2, and P2 distal aneurysms treated with the PED showed that flow diversion may be an effective treatment approach for this rare type of vascular pathology. The procedural compilation rate of 7.7% indicates the need for further studies as the flow diversion technology constantly evolves.

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Flow Diversion for Treatment of Intracranial Aneurysms in Pediatric Patients: Multicenter Case Series

Neurosurgery ◽

10.1093/neuros/nyz380 ◽

2019 ◽

Vol 87 (1) ◽

pp. 53-62

Author(s):

Jacob Cherian ◽

Visish Srinivasan ◽

Michael T Froehler ◽

Jonathan A Grossberg ◽

C Michael Cawley ◽

...

Keyword(s):

Clinical Outcomes ◽

Intracranial Aneurysms ◽

Case Series ◽

Flow Diversion ◽

Pipeline Embolization Device ◽

Patient Demographics ◽

Scale Scores ◽

Treatment Considerations ◽

Device Placement ◽

Aneurysm Occlusion

Abstract BACKGROUND Though the Pipeline Embolization Device (Medtronic) is approved for use in adults 22 yr and older, the high efficacy and long-term durability of the device is attractive for treatment of intracranial aneurysms in younger patients who often have aneurysms less amenable to traditional endovascular treatments. OBJECTIVE To report technical, angiographic, and clinical outcomes in patients aged 21 or below undergoing flow-diversion treatment for intracranial aneurysms. METHODS Retrospective review across 16 institutions identified 39 patients aged 21 or below undergoing 46 treatment sessions with Pipeline Embolization Device placement between 2012 and 2018. A total of 50 intracranial aneurysms were treated. Details regarding patient demographics, aneurysm characteristics, treatment considerations, clinical outcomes, and aneurysm occlusion were obtained and analyzed in a multicenter database. RESULTS A total of 70% of patients were male. Nonsaccular morphology was seen in half of identified aneurysms. Six aneurysms were giant, and five patients were treated acutely after ruptured presentation. Eight patients were younger than 10 yr of age. Complete aneurysm occlusion was seen in 74% of treated aneurysms. Three aneurysms (6%) were retreated. A total of 83% of patients had a modified Rankin Scale scores of ≤2 at last clinical follow-up. There were 2 early mortalities (4.3%) in the immediate postprocedure period because of rerupture of a treated ruptured aneurysm. No recanalization of a previously occluded aneurysm was observed. CONCLUSION Flow-diversion treatment is a safe and effective treatment for intracranial aneurysms in patients younger than 22 yr. Rates of complete aneurysm occlusion and adverse events are comparable for rates seen in older patients.

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Whole blood aggregometry prior to Pipeline embolization device treatment of intracranial aneurysms: defining an optimal platelet inhibition cutoff value for clopidogrel

Journal of Neurosurgery ◽

10.3171/2018.6.jns181044 ◽

2019 ◽

Vol 131 (5) ◽

pp. 1437-1444 ◽

Cited By ~ 1

Author(s):

Paul M. Foreman ◽

Alejandro Enriquez-Marulanda ◽

James H. Mooney ◽

Philip G. R. Schmalz ◽

Christoph J. Griessenauer ◽

...

Keyword(s):

Antiplatelet Therapy ◽

Whole Blood ◽

Intracranial Aneurysms ◽

Characteristic Curve ◽

Laboratory Data ◽

Thromboembolic Complications ◽

Optimal Cutoff ◽

Pipeline Embolization Device ◽

Cutoff Value ◽

Whole Blood Aggregometry

OBJECTIVEDual antiplatelet therapy is required for the treatment of intracranial aneurysms with the Pipeline embolization device (PED). Platelet function testing (PFT) is often used to assess the efficacy of the antiplatelet regimen prior to PED placement. The optimal impedance values for whole blood aggregometry in this setting have not been defined.METHODSA retrospective review of a prospectively maintained database was performed for the years 2011–2015 to identify patients with intracranial aneurysms treated with the PED who underwent pretreatment PFT using whole blood aggregometry. Antiplatelet therapy was not altered based on PFT results; all patients remained on standard doses of aspirin and clopidogrel. Clinical, radiographic, and laboratory data were analyzed to identify the optimal cutoff impedance value for clopidogrel responsiveness using the receiver operating characteristic curve and Youden’s index.RESULTSForty-nine patients underwent 53 endovascular procedures for the treatment of 76 aneurysms using the PED. The majority of these aneurysms were located in the anterior circulation (90.8%) and affected the internal carotid artery (89.5%). Patients in 30 procedures (56.6%) were identified as clopidogrel responders based on the manufacturer cutoff value (< 6 Ω). Thromboembolic complications occurred in 13 (24.5%) procedures; patients in 6 (11.3%) cases were symptomatic and those in 3 (5.7%) cases had ischemic strokes. Eleven of the 13 (84.6%) thromboembolic complications occurred in clopidogrel nonresponders. An impedance value of ≥ 6 Ω was independently associated with thromboembolic complications. The optimal electrical impedance value was identified as ≥ 6 Ω (sensitivity 84.6%, specificity 70.0%, area under the curve 0.77) for identifying clopidogrel nonresponders.CONCLUSIONSThromboembolic complications are more common following PED placement in patients who do not respond adequately to clopidogrel. Clopidogrel nonresponders can be identified using pretreatment whole blood aggregometry. The optimal cutoff value to categorize a patient as a clopidogrel nonresponder when using whole blood aggregometry is ≥ 6 Ω.

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Effect of antiplatelet therapy on thromboembolism after flow diversion with the Pipeline Embolization Device

Journal of Neurosurgery ◽

10.3171/2013.7.jns122178 ◽

2013 ◽

Vol 119 (6) ◽

pp. 1603-1610 ◽

Cited By ~ 42

Author(s):

Robert S. Heller ◽

Venkata Dandamudi ◽

Michael Lanfranchi ◽

Adel M. Malek

Keyword(s):

Antiplatelet Therapy ◽

Intracranial Aneurysms ◽

Univariate Analysis ◽

Platelet Inhibition ◽

Pipeline Embolization Device ◽

Diffusion Weighted ◽

Aneurysm Size ◽

Platelet Aggregometry ◽

Significant Difference ◽

Residual Activation

Object Flow-diverting stents offer a novel treatment approach to intracranial aneurysms. Data regarding the incidence of acute procedure-related thromboembolic complications following deployment of the Pipeline Embolization Device (PED) remain scant. The authors sought to determine the rate of embolic events in a bid to identify potential risk factors and assess the role of platelet inhibition. Methods Data in all patients receiving a PED for treatment of an intracranial aneurysm were prospectively maintained in a database. Diffusion-weighted 3-T MRI was performed within 24 hours of PED deployment. The incident rate of procedural embolism was established, and univariate analysis was then performed to determine any associations of embolic events with measured variables. The degree of platelet inhibition in response to aspirin and clopidogrel was evaluated by challenging the platelet samples with arachidonic acid and adenosine diphosphate, respectively, and then performing formal light transmission platelet aggregometry. Results Twenty-three patients with 26 aneurysms were eligible for inclusion in the study. Thirty-one PEDs were deployed in 25 procedures. All ischemic lesions detected on diffusion-weighted 3-T MRI were identified as embolic based on their location and distribution, with none appearing to be due to perforator artery occlusion. Procedural embolic events were found in the target parent vessel territory in 13 (52%) of 25 procedures, with no patients harboring lesions contralateral to the deployed PED. The number of embolic events per procedure ranged from 3 to 16, with a mean of 5.4. There was no significant difference between cases with and without procedural embolism in platelet inhibition by aspirin (mean 15% vs 12% residual activation; p = 0.28), platelet inhibition by clopidogrel (mean 41% vs 41% residual activation; p = 0.98), or intraprocedural heparin-induced anticoagulation (mean activated clotting time 235 seconds vs 237 seconds; p = 0.81). By multivariate analysis, the authors identified larger aneurysm size (p = 0.03) as the single variable significantly associated with procedural embolism. There was no significant relationship between aneurysm size and the number of embolic events (p = 0.32) or the total burden of the embolism lesion area (p = 0.53). Conclusions Acute embolism following use of the PED for treatment of intracranial aneurysms is more common than hypothesized. The only identifiable risk factor for embolism appears to be greater aneurysm size, perhaps indicating significant disturbed flow across the aneurysm neck with ingress and egress through the PED struts. The strength of antiplatelet therapy, as measured by residual platelet aggregation, did not appear to be associated with cases of procedural embolism. Further work is needed to determine the implications of these findings and whether anticoagulation regimens can be altered to lower the rate of complications following PED deployment.

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