Use Of Pipeline Embolization Device Research Articles

Treatment of intracranial aneurysms with pipeline embolization device: a single-center experience.

Endovascular therapy is the primary treatment modality for intracranial aneurysms (IA). The objective of this study was to assess the effectiveness and safety of a pipeline embolization device (PED) for the treatment of IA. This retrospective study was conducted at a single center. Data were collected for all patients who underwent PED treatment at the Fourth Affiliated Hospital of Xinjiang Medical University between December 2018 and January 2022. Clinical characteristics, aneurysm-related characteristics, treatment details, and clinical and imaging outcomes were collected and analyzed. A total of 60 consecutive patients with 60 IAs were treated with a PED. The mean age of the participants was 61.8 years, with 53% being female. The average size of the aneurysms was 14.7 mm, with 54 located in the anterior circulation and six in the posterior circulation. The median last follow-up time was 13.0 months (range, 11-24 months). All patients underwent final digital subtraction angiography (DSA) for angiographic follow-up, and 50 aneurysms (83.3%) were completely occluded. The overall complication rate was 3.3%, and there were no reported mortalities. Among the 12 cases of ruptured aneurysms, all of which underwent adjunctive coil embolization, the complete occlusion rate was 91.7% with a complication rate of 16.6% [ischemic complication and modified Rankin scale (mRS) deteriorated]. In the 6 cases of posterior circulation aneurysms (2 in the basilar artery), 5 cases achieved complete occlusion and 1 case achieved near-complete occlusion, with no reported complications or mortality. The use of PEDs appears to be an effective treatment option for IA, demonstrating high occlusion rates and low complication rates. While the application of PEDs for the treatment of ruptured aneurysms did not increase the risk of secondary aneurysm rupture, caution is still warranted due to a higher complication rate. In the treatment of aneurysms of the vertebrobasilar artery using PEDs, this study achieved favorable efficacy outcomes without complications nor patient mortality. However, further studies are needed to validate these findings.

Safety and Outcomes of the Off-Label Treatment of Intracranial Aneurysms with Pipeline Embolization Device: A Systematic Review and Meta-analysis

Off-label use of pipeline embolization devices (PEDs) has been increasingly used for endovascular treatment of intracranial aneurysms. Numerous articles have highlighted the safety and effectiveness of PED placement from independent centers for both on- and off-label indications. There remains a paucity of information that considers overall safety and efficacy of off-label PED placement across the existing literature. Our objective is to systematically review the safety and occlusion outcomes of PED off-label use in intracranial aneurysm embolization. A systematic search of PubMed and Embase was performed to identify studies on off-label use of PED. The selected studies provided relevant information, including study characteristics, patient demographics, clinical outcomes, peri-procedural complications, and long-term outcomes, which were subjected to meta-analysis. Twelve studies met the inclusion and exclusion criteria. There were 747 patients and 791 aneurysms included for analysis. Among the patient, 69.2% were female, with an age range of 16 to 80 years. The overall incidence rates for ischemic and hemorrhagic complications were 7% (95% CI: 4%-10%) and 2% (95% CI: 0%-4%), respectively. The mortality rate was 1% (95% CI: 0%-4%). The occlusion rates of aneurysm at initial follow up and 1 year follow-up were 82% (95% CI: 72%-91%) and 81% (95%CI: 75%-86%), respectively. Meta-regression analysis indicated no correlation between occlusion rate and factors such as age, sex, aneurysm size, location, morphology, rupture, or history of treatment. Despite variations in results observed in single-center studies, this meta-analysis provides evidence supporting the safety and efficacy of PED off-label use.

Safety and efficacy profile of off-label use of the Pipeline Embolization Device: A systematic review and meta-analysis

ObjectiveThe off-label utilization of the Pipeline Embolization Device (PED) is a common practice in numerous medical centers globally. Therefore, we conducted a systematic review and meta-analysis to evaluate the overall outcomes of this off-label usage of PEDs. MethodsPubMed, Web of Science, Ovid Medline, Ovid Embase, and Scopus were searched up to February 2023 using the Nested Knowledge platform to identify studies assessing the off-label use of PEDs. Any use of PED outside of the FDA-approved indication granted in 2018 is considered off-label use. Overall angiographic occlusion rates, ischemic and hemorrhagic complications, mortality, retreatment rates, and favorable clinic outcomes were included. Statistical analyses were performed to compare the overall outcome rates of anterior cerebral artery(ACA) vs. middle cerebral artery(MCA) and anterior vs posterior circulation subgroups. ResultsWe included 26 studies involving a total of 1,408 patients. The overall rate of complete occlusion was 80.3 % (95 % CI= 76.0–84.1). Subgroup analysis demonstrated a statistically significant difference in the rate of complete occlusion between anterior circulation (78.9 %) and posterior circulation (69.2 %) (p value=0.02). The rate of good clinical outcomes was 92.8 % (95 % CI= 88.8–95.4). The mortality rate was 1.4 % (95 % CI= 0.5–2.7). The overall rate of ischemic complications was 9.5 % (95 % CI= 7.7–11.6), with a comparable difference between anterior circulation (7.7 %) and posterior circulation (12.8 %) (p value=0.07). There was no statistically significant difference in MCA vs ACA subgroups in all parameters. ConclusionsOff-label use of PEDs can be a safe and effective treatment option for intracranial aneurysms. However, there is a need for more prospective, high-quality, non-industry-funded registry studies and randomized trials to test the efficacy and safety of off-label usage of PEDs and to expand its indications.

The off-label uses of pipeline embolization device for complex cerebral aneurysms: Mid-term follow-up in a single center.

To describe the off-label uses of pipeline embolization device for a variety of types of aneurysms including ruptured aneurysms, posterior circulation aneurysms, small aneurysms, distal aneurysms, and recurrent aneurysms. Clinical and angiographic data of patients who underwent pipeline embolization device treatment on off-label use at our center were retrospectively reviewed. For categorical variables, Fisher's exact test was used, and a two-sample Wilcoxon rank-sum test was used for patients' age to analyze the correlation with outcomes. In this study, 121 aneurysms in 107 patients received off-label pipeline embolization device treatments. The overall rate of complete aneurysm occlusion was 77.8% (28/36 in 35 patients) for posterior circulation aneurysms and 95.3% (81/85 in 72 patients) for anterior circulation aneurysms. The posterior circulation aneurysms have a lower rate of aneurysm occlusion (p = 0.0372). The small aneurysms have a higher rate of aneurysm occlusion (p = 0.0104). The patient's sex, age, and aneurismal size were associated with ischemic stroke complications (p = 0.0397, 0.0166, and 0.0178). In posterior circulation aneurysm patients, only two basilar apex aneurysms underwent pipeline embolization device treatment, both of whom died of thrombotic complications. There was no difference in mortality between posterior circulation aneurysm patients (8.6%, 3/35) and anterior circulation aneurysm patients (1.4%, 1/72) (p = 0.1015). Patients of older age have a higher risk of death rate (p = 0.0053). The off-label use of pipeline embolization device is often performed in clinical practice and can achieve efficacy in complex aneurysms. The off-label use of pipeline embolization device was found to carry an increased rate of mortality in older patients. Excluding basilar apex aneurysms, the pipeline embolization device is as safe as anterior circulation aneurysms in the treatment of posterior circulation aneurysms elsewhere.

The Pipeline Embolization Device: a decade of lessons learned in the treatment of posterior circulation aneurysms in a multicenter cohort.

The Pipeline Embolization Device (PED) has prompted a paradigm shift in the approach to posterior circulation aneurysms. The year 2021 marks a decade since FDA approval of this flow diverter, and during this time operators have adapted to its off-label uses. The authors examined whether case selection, practice trends, and patient outcomes have changed over this 10-year period. This study is a retrospective review of consecutive posterior circulation aneurysms managed with the PED at four academic institutions in the US between January 1, 2011, and January 1, 2021. Factors related to case selection, rates of aneurysm occlusion, or complications were identified and evaluated. Angiographic outcomes as well as thromboembolic and hemorrhagic complications were investigated. This study included 117 patients (median age 60 years). At a median follow-up of 12 months, adequate occlusion (> 90%) was attained in 73.2% of aneurysms. Aneurysm occlusion rates were similar over the study interval. Thromboembolic and hemorrhagic complications were reported in 12.0% and 6.0% of the procedures, respectively. There was a nonsignificant trend toward a decline in the rate of thromboembolic (14.1% in 2011-2015 vs 9.4% in 2016-2021, p = 0.443) and hemorrhagic (9.4% in 2011-2015 vs 1.9% in 2016-2021, p = 0.089) complications. The authors observed a trend toward a decline in the rate of thromboembolic and hemorrhagic complications with improved operator experience in using the PED for posterior circulation aneurysms. The use of single-device PED flow diversion significantly increased, as did the tendency to treat smaller aneurysms and observe large unruptured fusiform/dolichoectatic lesions. These findings reflect changes attributable to evolving judgment with maturing experience in PED use.

Comparative study of on-label versus off-label treatment of intracranial aneurysms with the Pipeline embolization device.

The Pipeline embolization device (PED) is widely used for the treatment of intracranial aneurysms, including in off-label applications. In this work, the authors compared the real-world efficacy and safety of PED use in on-label and off-label aneurysm treatments. Clinical and angiographic data of patients who underwent PED placement at a high-volume academic medical center were retrospectively obtained. Treatments were classified as on-label if they fell within the applications approved by the United States Food and Drug Administration as of 2021. Recorded outcomes included aneurysm occlusion, procedural complications, ischemic events, in-stent stenosis, intracranial hemorrhage, postprocedural functional status, and death. In total, 416 aneurysms in 330 patients were treated with PED, comprising 256 aneurysms that received on-label treatments and 160 that received off-label treatments. The overall rate of complete aneurysm occlusion was 76.4% for on-label aneurysms and 75.6% for off-label aneurysms (p = 0.898). The risk of ischemic stroke in patients who underwent off-label treatments was 15.2%, which was higher than the 4.2% rate in patients who underwent on-label treatment (p = 0.003). All other clinical complications, procedural complications, and long-term functional status were comparable between the on-label and off-label groups. In real-world practice, off-label use of PED is common and can achieve similar efficacy as on-label use. However, in aggregate, off-label use was found to carry an increased rate of ischemic complications. With judicious attention to safety and individual patient characteristics, these results highlight the scale and general feasibility of off-label PED use by experts.

Rupture of an adjacent cerebral aneurysm following the deployment of a Pipeline embolization device: illustrative case.

BACKGROUNDAlthough the Pipeline embolization device (PED) is effective for intracranial aneurysm treatment, its impact on the surrounding vascular structure is unknown.OBSERVATIONSA 71-year-old woman was incidentally found to have a simultaneous large posterior communicating artery aneurysm and an ipsilateral small anterior choroidal artery aneurysm. She underwent flow diversion therapy for both aneurysms with a PED, but the distal shortening of the PED after deployment led to the exposure of the anterior choroidal artery aneurysm. Follow-up angiography revealed complete obliteration of the posterior communicating artery aneurysm, but the anterior choroidal artery aneurysm remained. Three years after the endovascular surgery, the patient experienced a subarachnoid hemorrhage due to the rupture of the anterior choroidal artery aneurysm. Retrospective analysis of angiographic images revealed a change in the vascular geometry surrounding the ruptured aneurysm after PED deployment; this was further accompanied by an increase in the flow velocity inside the aneurysm.LESSONSBecause PED use might induce the adverse effects on the adjacent uncovered aneurysm by changing the vascular geometry and hemodynamic stress, a cautious therapeutic strategy, such as proper placement of the stent and using a longer and appropriate-sized PED, should be chosen when deploying the PED.

Safety and Efficacy of the Off-Label Use of Pipeline Embolization Device Based on the 2018 Food and Drug Administration-Approved Indications for Intracranial Aneurysms: A Single-Center Retrospective Cohort Study.

The pipeline embolization device (PED; ev3/Covidien) has proven safe and effective for treating selected intracranial aneurysms. This device's versatility and popularity have driven increased interest in expanding the latest 2018 Food and Drug Administration-approved indications. To compare "off-label" and "on-label" PED treatment. Retrospective analysis of aneurysms treated with PED at a single center from 2013 to 2019. Comparisons were made based on the 2018 Food and Drug Administration-approved indications. A total of 492 treated aneurysms were included (65.2% on-label and 34.8% off-label). Aneurysm complete and near-complete occlusion rate was nonsignificantly lower in the off-label group (80.9% vs 85.7%; P = .19). Off-label treatment had higher rate of poor functional outcomes (modified Rankin Scale [mRS] >2: 10.3% vs 3.5%; P = .002). Although pretreatment mRS was already higher in the off-label group (5.3% vs 0.3%; P < .001) and there were no differences in mRS worsening during follow-up (5.5% vs 2.9%; P = .15). We also found a trend to a higher rate of intracranial hemorrhagic complications in the off-label group (4.7% vs 1.6%; P = .05), but there were no differences in hemorrhages requiring surgical intervention (1.8% vs 1.3%; P = .65). There were no differences in retreatment, thromboembolic complications, and mortality rates. Off-label PED treatment may be considered for select aneurysms, which are challenging to treat with other techniques. These cases have similar complete and near-complete occlusion rates compared with on-label cases. There are, however, higher risks of poor functional outcomes despite similar rates of thromboembolic and hemorrhagic complications. This is partly explained by the significantly higher pretreatment mRS score in the off-label group.

400 Safety and Efficacy of the Off-label Use of Pipeline Embolization Device Based on the 2018 FDA Approved Indications for Intracranial Aneurysms: A Single Center Retrospective Cohort Study

INTRODUCTION: The Pipeline embolization device (PED) has proven to be safe and effective for treating selected intracranial aneurysms. The versatility and the popularity of this device have driven increased interest in expanding the latest 2018 FDA-approved indications. METHODS: Retrospective analysis of aneurysms treated with PED at a single center from 2013-2019 was performed. Comparisons were made based on the compliance to the 2018 FDA-approved indications. Univariate comparisons and longitudinal analysis were performed. RESULTS: A total of 492 treated aneurysms were included, from which 65.2% were considered on-label and 34.8% off-label. Aneurysm complete and near-complete occlusion rate was non-significantly lower in the off-label group (80.9% vs 85.7%; p=0.19). Off-label treatment had higher rate of poor functional outcomes defined as modified Rankin scale &gt; 2 (10.3% vs 3.5%; p=0.002). Although baseline pre-treatment mRS was already higher in the off-label group (10.3% vs 3.5%; p&lt;0.001). There were no differences in retreatment, thromboembolic complications, intracranial hemorrhagic complications, and mortality rates. CONCLUSION: Off-label treatment with PED may be considered for select aneurysms, which are challenging to treat with other techniques (clipping, coiling, etc.). These cases have similar complete and near-complete occlusion rates compared to on-label cases. There are, however, potential higher risks of poor functional outcomes.

Pipeline embolization of cerebral aneurysms in pediatric patients: combined systematic review of patient-level data and multicenter retrospective review.

Cerebral aneurysms in the pediatric population are rare and optimal treatment strategies are not as well characterized as in adults. The Pipeline embolization device (PED) is an endoluminal flow diverter that is commonly used to treat aneurysms in adults, but experience with this device in children is limited. The authors sought to further characterize PED use and outcomes in this specific population by performing both a systematic review of patient-level data from studies reporting the use of the PED to treat pediatric aneurysms and a retrospective review of their experience. A systematic review of the PubMed, Embase, and Scopus databases was performed to identify studies reporting the use of the PED in pediatric patients (age ≤ 18 years). Disaggregated data regarding demographics, aneurysm characteristics, treatment, and outcomes were collected. Retrospective data from the authors' two institutions were also included. Thirty studies comprising patient-level data on 43 pediatric patients with 47 aneurysms were identified. An additional 9 patients with 9 aneurysms were included from the authors' institutions for a total of 52 patients with 56 aneurysms. The mean patient age was 11.1 years. Presentations included aneurysm rupture (17.3%) and symptomatic mass effect (23.1%). Aneurysms were located in the anterior circulation in 55.4% of cases, and 73.2% were described as nonsaccular. Imaging follow-up was available for 89.3% with a mean follow-up of 13.3 months. Aneurysm occlusion was reported in 75%, with 1 case each (1.8%) demonstrating significant in-stent stenosis and parent vessel occlusion. Clinical follow-up was reported in 90.4% with a mean follow-up of 14.7 months. Good functional outcomes (modified Rankin Scale score of 0-1 or Glasgow Outcome Scale score of 5) were reported in 65.4% of the total population. Two major complications were reported, including 1 death. Despite substantial differences in aneurysm location and type between published pediatric and adult patient populations treated with the PED, the use of the PED in the pediatric population appears to be safe. While the short-term effectiveness is also similar to that of adults, additional studies are needed to further characterize the long-term outcomes and better define the use of this device in pediatric patients.

Multiple pipeline embolization devices improves aneurysm occlusion without increasing morbidity: A single center experience of 140 cases

IntroductionRates of aneurysm occlusion with the pipeline embolization device (PED) has varied widely in the literature from 55.7% to 93.3% at 6 months, which may reflect a difference in technique including sizing and number of devices used. Methods140 cases at our institution were retrospectively reviewed, and aneurysms treated with a single PED vs. multiple were compared. ResultsComplete aneurysm occlusion was achieved in 86.9% at 6 months, 91.8% at 1 year, and 97.6% at longest follow-up. Retreatment with an additional device was required in 7 (5.1%). Major and minor complication rate within 30 days was 1.4% and 5.0%, and at greater than 30 days was 0.8% and 3.1%.Patients treated with multiple PEDs had significantly higher rates of aneurysm occlusion at 6 months (92.9% vs. 75.6%, p = 0.017) and 12 months (98.4% vs. 81.1%, p = 0.014), with no difference in complications. The two groups were similar aside from a higher number of ophthalmic and paraophthalmic aneurysms treated with multiple PEDs (23.4% vs. 6.5%, p = 0.004; and 35.1% vs. 17.4%, p = 0.020), and more posterior communicating artery and recurrent aneurysms treated with a single PED (28.3% vs. 3.2%, p = 0.001; 23.9% vs. 8.5%, p = 0.031). The use of multiple PEDs was found to be an independent predictor of aneurysm occlusion in a multivariate analysis (p = 0.015). ConclusionsThe use of multiple PEDs for intracranial aneurysms leads to significantly higher occlusion rates without added morbidity. This benefit is particularly appropriate for ophthalmic segment aneurysms, while more distal segments with eloquent perforating branches should be managed with caution.

Effect of aneurysm morphologic parameters on occlusion rates following pipeline embolization

ObjectiveTreatment failures with the use of Pipeline Embolization Device (PED) continue to be observed in up to 18% of patients in large case series. Adjunctive coiling and layering of multiple devices have been shown to improve occlusion rates; however, the optimal treatment strategy with the use of PED has not been established. The purpose of this study is to identify morphological characteristics predictive of treatment failure after PED. Patient and methodsA case control design was used to evaluate the association of aneurysm morphologic parameters with failure after PED placement. Retrospective analysis of patients undergoing PED for elective aneurysm treatment between 2014 and 2017 was performed. Patients who underwent PED placement with at least 12 months follow-up using conventional cerebral angiography were included for further review. Results84 patients met inclusion criteria for further analysis. ten patients (11.9%) experienced treatment failure defined by retained flow within the aneurysm and of those eight patients (9.5%) required additional retreatment. On multivariate analysis decreasing aspect ratio and increasing neck width were significant parameters that predicted treatment failure. ConclusionAneurysms with small aspect ratio and large neck width may be more likely to experience treatment failure after PED embolization. This subset of aneurysms may therefore benefit from adjunctive coiling to improve occlusion rates. Future prospective studies are needed to validate these findings.

Aneurysm Remnants after Flow Diversion: Clinical and Angiographic Outcomes.

Flow diversion is an established method to treat complex intracranial aneurysms. The natural history of flow-diversion treatment failure resulting in aneurysm remnants is not well-defined. We aimed to delineate the clinical and angiographic features of this entity. Review of a prospectively maintained Pipeline Embolization Device data base from inception to October 2017 was performed for aneurysms that demonstrated residual filling on follow-up imaging. Procedural and follow-up clinical details were recorded. Independent, blinded, angiographic assessment of occlusion was performed on the basis of the O'Kelly-Marotta scale. Aggregated outcomes were analyzed using the Fisher exact and Mann-Whitney U tests for categoric and continuous variables, respectively (statistical significance, α = .05). During the study period, 283 sequential patients were treated; 87% (246/283) were women. The median patient age was 55 years (interquartile range, 47-65 years). Six-month follow-up imaging was available in 83.7% (237/283) of patients, which showed 62.4% (148/237) complete occlusion (class D, O'Kelly-Marotta grading scale). Adjunctive coiling (P = .06), on-label Pipeline Embolization Device use (P = .04), and multiple device constructs (P = .02) had higher rates of complete occlusion at 6 months. Aneurysm remnants were identified in 25 cases on long-term follow-up imaging (median, 16 months; interquartile range, 12-24 months). No patient with an aneurysm remnant after flow diversion presented with delayed rupture or other clinical sequelae, with a median clinical follow-up of 31 months (interquartile range, 23-33 months). Aneurysm remnants after flow diversion are infrequent with minimal clinical impact. When appropriate, the presence of overlapping devices and possibly adjunctive coiling may result in higher rates of complete occlusion.

Evaluation of Radiological Features of the Posterior Communicating Artery and Their Impact on Efficacy of Saccular Aneurysm Treatment with the Pipeline Embolization Device: A Case Series Study

Posterior communicating artery segment aneurysms are one of the most frequent intracranial aneurysms. Currently, limited data have described the use of the pipeline embolization device (PED) in these aneurysms. We conducted a multicenter retrospective review of 3 prospectively collected databases of patients treated with the PED from January 2013 to December 2017. The primary objective was to assess the efficacy and safety of the PED in the treatment of saccular posterior communicating artery (PComA) aneurysms. We also assessed the effect of anatomical variations on the angiographic and clinical outcomes, including the presence of fetal PComA, vessel origin relationship to the aneurysm, and patency after PED placement. We identified 57 patients with 60 saccular aneurysms; Their mean age was 60.5 years, and 49 were female (86.0%). A total of 55 aneurysms (91.7%) were unruptured. The median imaging follow-up duration was 8.5 months. Complete occlusion at the last imaging follow-up study was 84.0%. At the last follow-up examination, 94.5% of patients had a modified Rankin scale score of ≤2. The presence of fetal PComA, origin type, and patency during follow-up did have a significant effect on aneurysm occlusion (P= 0.61, P= 0.40, and P= 0.14, respectively). PED use for treatment of PComA aneurysms resulted in acceptable occlusion rates. The present study did not find that fetal PComA, its origin, or its patency during follow-up had an effect on aneurysm occlusion.

Safety and Efficacy of the Pipeline Embolization Device Use in the Outside Circle of Willis Located Intracranial Aneurysms: A Single-Center Experience

Background: The use of Pipeline Embolization Device (PED) is approved by the US Food and Drug Administration (FDA) to treat aneurysms located between the petrous and superior hypophyseal segments of the internal carotid artery. The purpose of this study is to evaluate the feasibility and efficacy of treating aneurysms outside the FDA approved anatomical locations. Furthermore, we analyze the safety of our antiplatelet protocol. Methods: Data on all patients treated with PED at our center from March 2015 to December 2017 were reviewed. Only patients with aneurysms treated with PED as off label use were included. Procedural complications and long-term functional outcome measured by modified Rankin Scale (mRS) were recorded. Tirofiban maintenance infusion was administered intravenously after PED deployment. None of the patients had platelet function testing. Results: A total of 36 patients harboring 36 aneurysms were included in the study. Mean age was 58.2 years ±14.6. Nineteen were women (52.8%) and most aneurysms were unruptured (80.6%). There were no intraoperative complications. Five patients experienced postoperative complications – 4 ischemic strokes and one groin hematoma. None led to any significant disability at follow-up. Thirty-one patients (86.1%) achieved an mRS of 0–2 at follow-up. A Raymond-Roy classification of 1 was achieved in 78.9% of patients. Conclusion: The use of PED to treat aneurysms located outside the circle of Willis is feasible and effective. Our novel antiplatelet protocol did not require platelet function assay testing and did not lead to a higher rate of thrombo-embolic events compared to what has been previously reported.

Novel Use of Pipeline Stent Device After Inadvertent Microcatheter Rupture During Arteriovenous Fistula Embolization

Onyx, a liquid embolic agent, is the mainstay of embolization treatment of arteriovenous malformation or arteriovenous fistula. Microcatheter retention in an embolic cast is a well-known complication. Rupture of catheter with spillage of onyx is a rare phenomenon but can lead to potential occlusion of the parent vessel. We describe a case in which a patient with ruptured arteriovenous fistula experienced rupture of a microcatheter at the proximal part and spillage of onyx on embolization. A Pipeline embolization device (PED) was successfully deployed, and onyx was jailed between the catheter and vessel wall at the third segment of the vertebral artery (V3 segment). A balloon angioplasty helped to complete the opening of the stent. The procedure was uneventful, and the patient recovered well. Follow-up angiogram revealed patency of posterior circulation. The 6-month follow-up angiogram revealed a patent stent. Microcatheter rupture and spillage of onyx during embolization of arteriovenous malformation/arteriovenous fistula is a potential complication, and management should be individualized. The unique close cell design of the PED was successfully used to avoid a potentially life-threatening occlusion of the vertebrobasilar system. To the best of our knowledge, we report for the first time this novel use of PED.

Outcomes After Off-Label Use of the Pipeline Embolization Device for Intracranial Aneurysms: A Multicenter Cohort Study

To examine outcomes of Pipeline embolization device (PED) use for treatment of intracranial aneurysms outside of U.S. Food and Drug Administration-approved indications. Data from patients with aneurysms treated with off-label use of PED were pooled from 4 centers in a retrospective multicenter cohort study. Primary endpoints were decline in modified Rankin Scale score by at least 1 point and angiographic aneurysm occlusion at follow-up. The study cohort comprised 109 patients. Mean aneurysm size was 8.4 ± 7.4 mm, 20.2% of aneurysms were located in the posterior circulation, and 11.9% of aneurysms were ruptured. The most common reasons for off-label use were aneurysm size (50.5%), aneurysm location (25.7%), and both size and location (10.1%). Mean follow-up was 9 months. Complete occlusion was achieved in 82.5% of cases at last angiographic follow-up. Modified Rankin Scale score decline was found in 18.8% of cases. On univariate analysis, age, aneurysm size, aneurysm morphology, aneurysm location, reason for off-label use, and rupture status were not associated with clinical decline or aneurysm occlusion on angiography. On multivariate analysis, treatment of a ruptured aneurysm with PED was found to be an independent predictor of postoperative decline in modified Rankin Scale score, and size as the only reason for off-label PED use was found to be an independent predictor of complete occlusion on final angiography. Off-label use of PED has a reasonable risk-to-benefit profile for appropriately selected aneurysms. Posterior circulation location and fusiform morphology do not appear to be associated with worse clinical or angiographic outcomes.

Outcome Analysis of the Flow Diversion with Pipeline Embolization Device for the Surgical Treatment of Unruptured Large and Giant Paraclinoid Carotid Aneurysms

Background: Both the high frequency of recurrence of large or giant paraclinoid aneurysms (PA) of the internal carotid artery and the occurrence of intra- and postoperative complications, leading to unsatisfactory results of surgical treatment of this group of patients, make the stated problem urgent. Flow-diverter embolization devices are actively used in many large international neurosurgical centers for the treatment of cerebral aneurysms of different morphology, size, and localization. Currently, there are very few reports on the effectiveness of the use of flow diverting stents in the surgical treatment of large and giant PA of the internal carotid artery. The results of these studies are controversial and largely contradictory. Aim: Outcome analysis of the use of Pipeline embolization device (PED) for the surgical treatment of large and giant carotid PA. Methods: The study enrolled 37 patients (25 women, 12 men; mean age 51.7±10.7 years) who were divided into those treated with the PED alone versus those treated with the PED and concurrent coil embolization. The average follow-up period was 19.7±3.8 months. Results: In 56.7% of cases, PA caused the development of an insignificant neurological deficit (Modified Rankin Scale 1−2). In 18.9% of patients, PA provoked a gross neurologic deficit (MRS 3−5). 24.3% of patients with PA did not have any clinical-neurological manifestations. After the surgery, neurologic status improved in 32.4% of patients, remained the same — in 45.9% of cases, and the degree of neurologic deficit increased in 21.6%. PED procedure was performed in 70.2% of patients. In 29.7% of cases, the dislocation of large or giant PA of the internal carotid artery from the systemic blood stream was performed using PED and concurrent coil embolization. At the indicated period of patient observation, complete occlusion of large and giant carotid PA was achieved in 75.6% of cases, almost complete and partial occlusion — in 24.3%. The incidence of thromboembolic and hemorrhagic complications was 10.8% and 8.1%, respectively. Mortality rate among patients was 2.7%. Conclusions: The use of PED is an effective method for occluding large or giant PA of the internal carotid artery. Nevertheless, this method of endovascular treatment of PA is associated with a high complication incidence.

Short-term results following treatment of unruptured intracranial aneurysms with Pipeline embolization device

Objective To present preliminary experience and short-term safety and efficacy of pipeline embolization device (PED) for endovascular treatment of unruptured intracranial aneurysms. Methods A retrospective analysis of clinical data and short-term safety and efficacy was conducted on 42 patients who underwent endovascular treatment with PED at Neurosurgery Department of Xuanwu Hospital, Capital Medical University, from October 2014 to June 2016. Results A total of 42 patients with 44 intracranial aneurysms were treated with 49 PEDs during the study period. Retention of contrast agent in the aneurysm cavity was detected by immediate postoperative radiography for 42 aneurysms and contrast agent could still be observed following surgery in 2 other cases. Four patients had procedural complications. A total of 32 aneurysms of 31 patients were followed up for 2-12(mean: 6.6±1.9) months. Majority of the aneurysms (24/32, 75%) showed angiographic evidence of complete obliteration and 6 aneurysms (6/32, 19%) demonstrated angiographic evidence of near complete obliteration. Conclusion It is suggested that use of PED may offer a safe and effective strategy for treatment of unruptured intracranial aneurysms. Larger prospective studies are needed to confirm those observations. Key words: Intracranial aneurysm; Embolization, therapeutic; Pipeline embolization device; Flow diversion

Pipeline Embolization Device in Treatment of 50 Unruptured Large and Giant Aneurysms

Treatment of large (≥20 mm) and giant (≥25 mm) intracranial aneurysms is challenging and can be associated with a high rate of morbidity and mortality. The Pipeline Embolization Device (PED) has been used effectively for the treatment of intracranial aneurysms achieving a high rate of complete occlusion. However, its safety and efficacy in treatment of large and giant aneurysms has not been evaluated fully. A retrospective analysis of consecutive aneurysms treated with PED between 2009 and 2016 at 3 academic institutions within the United States was performed. Large (≥20 mm) and giant aneurysms (≥25 mm) were selected for evaluation of occlusion and complication rates following treatment with PED. A total of 50 large and giant aneurysms were individually treated using PED. Aneurysms were fusiform (74%) or saccular (26%) in morphology. PED alone was used for treating 78% of the aneurysms, whereas PED with adjunctive coiling was used for treating 22%. The median length of angiographic follow-up was 13 months (mean follow up 20.4 months). At last follow-up, complete or near-complete occlusion (90-100%) was achieved in 76.9% of aneurysms. Symptomatic thromboembolic complications were encountered in 12% of procedures and symptomatic hemorrhagic complications in 8%. The use of PED for the treatment of large and giant intracranial aneurysms is associated with good occlusion rates, but also a greater complication rate compared to aneurysms of smaller size. There was no significant difference in occlusion rate based on aneurysm shape or size, number of PEDs placed, or adjunctive coiling.