Off-label uses of the Pipeline embolization device: a review of the literature

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

ObjectiveTo 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.MethodsClinical 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.ResultsIn 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).ConclusionsThe 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.

Pipeline versus non-pipeline flow diverter treatment for M1 aneurysms: A systematic review and meta-analysis

BackgroundThe flow diversion treatment of aneurysms located distal to the Circle of Willis has recently increased in frequency. We conducted a systematic review and meta-analysis of the clinical and radiological outcomes of flow diverter (FD) embolization in treating M1 aneurysms.MethodsPubMed, Web of Science, Ovid Medline, Ovid Embase, and Scopus were searched up to May 2024 using the Nested Knowledge platform. We included studies assessing the long-term clinical and radiological outcomes for M1 aneurysms. Results of FDs classified as Pipeline Embolization Devices (PED) versus other types of FDs. Angiographic occlusion rates, ischemic and hemorrhagic complications, and favorable clinic outcomes were included. All data were analyzed using R software version 4.2.2.ResultsThirteen studies with 112 total patients (58 patients for PED and 54 patients for other FD devices) were included in our meta-analysis. The overall adequate (complete + near-complete) occlusion rates were 85.1%. The complete occlusion rate was higher with PED than with other FD devices (72.9% PED and 41.6% for non-PED FDs, respectively, p-value <.01). The ischemic complications were 9.9% and 9.0% for the PED and non-PED groups, respectively (p-value = .89). The overall modified Rankin Scale 0-2 was 100% for the non-PED and 97.1% for the PED group (p-value = .51). In-stent stenosis rate was 7.5% for PED devices compared to 2.6% in the non-PED group (p-value = .35).ConclusionsThis relatively small meta-analysis showed high rates of adequate and complete occlusion in FD treatment of M1 segment aneurysms, with favorable safety profiles. PEDs were associated with higher rates of complete aneurysm occlusion compared to other types of FDs.

The endovascular treatment strategies of cerebrovascular injuries in traumatic brain injury

Vasculature injury occurs rarely in traumatic brain injury but increases lifetime risk of ischemic or hemorrhage stroke. The diverse and nonspecific clinical manifestations make the diagnosis and treatment of these injuries highly challenging. With advancements in device design, endovascular treatments have become widely adopted, playing an increasingly vital role in the management of vascular diseases. The purpose of this review is to introduce and summarize endovascular treatments of traumatic cerebrovascular injury and other related pathological states after traumatic brain injury. Given the innovations of neuroendovascular devices and improvements in the techniques over the past decade, this review will outline several recent advancements in endovascular treatment strategies for cerebrovascular pathologies. Popularizing more treatment options to clinicians will benefit in dealing with a variety of clinical scenarios and reduce the overall morbidity of traumatic cerebrovascular injury.

Off-label use of the pipeline embolization device for reconstruction of the extracranial internal carotid artery

Background

Internal carotid artery dissection (ICD) is a common cause of cerebral ischemia in adults. Medical management has been the standard of care; however, endovascular internal carotid artery (ICA) reconstruction has certain indications. The pipeline™ embolization device (PED) is a flow-diverting (low porosity), self-expanding, braided platinum and nickel-cobalt chromium alloy stent and is indicated for wide neck or large aneurysms of the ICA from the petrous to the superior hypophyseal segments. The flexible nature of PED stents, with their high wall coverage, makes them amenable as stents for reconstructing arterial dissections diagnosed in the tortuous segments of the extracranial ICA. We present our experience using PEDs for ICA reconstruction in cases of distal cervical or petrous segment dissection or dissecting aneurysms and review the literature on this contemporary indication of flow diverter devices.

Methods

This study was a retrospective review of patients with ICD or dissecting aneurysms who underwent endovascular reconstruction at our center using PED stent implants. Patients were selected based on pre-morbid modified Rankin Scores ≤1a and National Institutes of Health Stroke Scale (NIHSS) ≥3 and radiologic data consistent with ICA dissection.

Results

Eight patients with a mean age of 55.6 years (range: 31-82 years) and median NIHSS score of 8 (Interquartile range IQR: 2.75-16) who underwent off-label PED surgery were analyzed and are illustrated in this short series. The technical success rate was 100%, with all cases achieving reperfusions of thrombolysis in cerebral infarction grades ≥2b.

Conclusion

In our series of patients with distal cervical or petrous segment ICD or dissecting aneurysms, we found the PED to be feasible, safe, and effective in achieving arterial recanalization. Further studies will clarify the role of this technique.

Pipeline embolization device for aneurysm recurrence after stent-assisted coiling

OBJECTIVE

Since the emergence of the Pipeline Embolization Device (PED), its off-label use has significantly improved the treatment effectiveness of complex intracranial aneurysms, including the treatment of recurrent aneurysms. Although PED is effective in this situation, there is still a lack of evidence-based medicine for its role in recurrent aneurysms after stent-assisted coiling. The aim of this study is to evaluate the safety and efficacy of PED treatment for recurrent aneurysms after stent-assisted coiling.

METHODS

This study included 10 patients who underwent stent-assisted coiling but subsequently received PED treatment again due to aneurysm recurrence or rebleeding. The mean time between initial treatment and subsequent treatment is 12 months. Clinical outcomes include complications and modified Rankin Scale (mRS) scores, as well as evidence of complete occlusion.

RESULTS

All PEDs were successfully placed, with one case of minor perioperative complications. During the 6-month follow-up after PED implantation, 10 cases of recurrent aneurysms were completely occluded without any adverse clinical sequelae. In one case of vertebral artery aneurysm, balloon dilation was performed before placing PED due to arterial stenosis proximal to the aneurysm.

CONCLUSION

The use of PED to treat recurrent aneurysms after stent-assisted coiling is a safe and effective treatment method.

Off-label in-silico flow diverter performance assessment in posterior communicating artery aneurysms

BACKGROUND

The posterior communicating artery (PComA) is among the most common intracranial aneurysm locations, but flow diverter (FD) treatment with the widely used pipeline embolization device (PED) remains an off-label treatment that is not well understood. PComA aneurysm flow diversion is complicated by the presence of fetal posterior circulation (FPC), which has an estimated prevalence of 4-29% and is more common in people of black (11.5%) than white (4.9%) race. We present the FD-PComA in-silico trial (IST) into FD treatment performance in PComA aneurysms. ISTs use computational modeling and simulation in cohorts of virtual patients to evaluate medical device performance.

METHODS

We modeled FD treatment in 118 virtual patients with 59 distinct PComA aneurysm anatomies, using computational fluid dynamics to assess post-treatment outcome. Boundary conditions were prescribed to model the effects of non-fetal and FPC, allowing for comparison between these subgroups.

RESULTS

FD-PComA predicted reduced treatment success in FPC patients, with an average aneurysm space and time-averaged velocity reduction of 67.8% for non-fetal patients and 46.5% for fetal patients (P<0.001). Space and time-averaged wall shear stress on the device surface was 29.2 Pa averaged across fetal patients and 23.5 Pa across non-fetal (P<0.05) patients, suggesting FD endothelialization may be hindered in FPC patients. Morphological variables, such as the size and shape of the aneurysm and PComA size, did not affect the treatment outcome.

CONCLUSIONS

FD-PComA had significantly lower treatment success rates in PComA aneurysm patients with FPC. We suggest that FPC patients should be treated with an alternative to single PED flow diversion.

Intracranial hemorrhagic events associated with flow diversion treatment: a retrospective analysis from a single academic institution

Intracranial hemorrhages are highly concerning but underreported complications related to flow diversion (FD) treatment of intracranial aneurysms. Herein, we aimed to characterize these complications and the factors influencing their occurrence. We retrospectively reviewed patients treated with FD from 2013 to 2023 at a single U.S. institution, analyzing aneurysm characteristics, comorbidities, antiplatelet and anticoagulation use, and hemorrhage imaging features. Risk factors for intraparenchymal hemorrhages (IPHs) were assessed with univariate analysis. There were 622 patients harboring 788 aneurysms treated in 690 procedures during the study period. Within 7 months of follow-up, 15 intracranial hemorrhages were identified (2.2%): 2 acute subdural hematomas (SDH), 7 IPH, 1 intraventricular hemorrhage (IVH), and 5 subarachnoid hemorrhages (SAH), most of which presented within the first 24 h after initial treatment. Patients experiencing hemorrhages exhibited lower rates of functional independence (mRS ≤ 2) compared to those without hemorrhage (66.7% vs. 93.3%; p < 0.01). IPHs were slightly higher in patients receiving aspirin-ticagrelor (1.2%) compared to those on aspirin-clopidogrel (0.9%) or aspirin-prasugrel (0.0%). A univariate logistic regression model demonstrated an aneurysmal diameter ≥ 12 mm (OR = 8.98; 95% CI = 1.98-16.03) and aneurysms with prior treatment (OR = 7.20; 95% CI = 1.59-32.60) as factors influencing IPHs after treatment. The incidence of hemorrhage decreased over the time interval of study. Intracranial hemorrhages related to FD are rare but highly morbid complications. Treatments involving larger aneurysms and those with prior interventions are associated with a higher risk of IPHs.

Real-world evaluation of CYP2C19 guided antiplatelet therapy in patients undergoing intracranial aneurysm repair

Aim: To evaluate the feasibility and impact of using CYP2C19 genotype to guide selection of antiplatelet therapy in patients undergoing intracranial aneurysm treatment with a flow diversion stent in a real-world clinical setting.Patients & methods: A single-center, retrospective, observational cohort study was conducted in 112 patients undergoing intracranial aneurysm repair with flow-diversion stenting from 2014 to 2021. Data were abstracted from health records. The frequency of clopidogrel or alternative therapy (ticagrelor or prasugrel) use was compared across CYP2C19 status (intermediate or poor metabolizer [IM/PM] vs. normal, rapid, or ultrarapid metabolizer [NM/RM/UM]).Results: In the study population, CYP2C19 genotype testing was performed on 110 (98.2%) patients; of these, 106 (97.2%) had results available prior to the stent procedure and 28 (25.5%) were IM/PMs. Alternative therapy was used more frequently in IM/PMs compared with NM/RM/UMs (57.1 vs. 8.5%, respectively, p < 0.0001). The frequency of thromboembolic events over 12 months did not significantly differ across clopidogrel-treated IM/PMs, clopidogrel-treated NM/RM/UMs and patients on alternative therapy (p = 0.352); although, event numbers were low.Conclusion: A pre-emptive CYP2C19 genotyping strategy to guide antiplatelet therapy selection in intracranial aneurysm repair patients is feasible in a real-world clinical setting. Larger studies are needed to assess the impact on clinical outcomes.

A Novel Scoring System Predicting Aneurysm Incomplete Occlusion After Flow Diversion: A 10-Year Experience

BACKGROUND

Factors impacting the rate of aneurysm occlusion after flow diversion (FD) have been well described in the literature. In this article, we sought to evaluate those variables to develop and validate a scoring system predicting aneurysm incomplete occlusion after FD.

METHODS

Retrospective review of patients with intracranial aneurysms treated with FD at a single institution between March 2013 and March 2023. Multivariable logistic regression model was developed using factors associated with aneurysm incomplete occlusion. The ABC scoring system consisted of: Age (<60 years old: 0, 60-69 years: 1, 70-79: 2, and ≥80: 3), Branch coming out of the aneurysm dome/neck (yes: 2, no: 0), and Cigarette smoking history (never smoker: 1, current or past smoker: 0). The scoring system performance was evaluated with receiver operating characteristic curve and calculating the area under the curve.

RESULTS

A total of 449 patients with 563 aneurysms treated in 482 procedures were evaluated. Most cases were females (81.7%) with a median age of 59 years old. At a median follow-up of 13.2 months, 84.0% of aneurysms were completely or near-complete occluded. The scoring system had an area under the curve of 0.71. A value ≥ 2, reached a sensitivity of 74.4%, a specificity of 60.9%, a likelihood ratio+ of 1.90, and proved to be reliable in predicting the risk of incomplete occlusion (odds ratio = 4.53; 95% confidence interval: 2.73-7.54; P < 0.001).

CONCLUSIONS

The proposed ABC scoring system can be used to evaluate the risk of aneurysm incomplete occlusion after treatment with FD, identifying patients who would benefit from adjunctive coiling or alternative treatment modalities.

Surface modification of neurovascular stents: from bench to patient

Flow-diverting stents (FDs) for the treatment of cerebrovascular aneurysms are revolutionary. However, these devices require systemic dual antiplatelet therapy (DAPT) to reduce thromboembolic complications. Given the risk of ischemic complications as well as morbidity and contraindications associated with DAPT, demonstrating safety and efficacy for FDs either without DAPT or reducing the duration of DAPT is a priority. The former may be achieved by surface modifications that decrease device thrombogenicity, and the latter by using coatings that expedite endothelial growth. Biomimetics, commonly achieved by grafting hydrophilic and non-interacting polymers to surfaces, can mask the device surface with nature-derived coatings from circulating factors that normally activate coagulation and inflammation. One strategy is to mimic the surfaces of innocuous circulatory system components. Phosphorylcholine and glycan coatings are naturally inspired and present on the surface of all eukaryotic cell membranes. Another strategy involves linking synthetic biocompatible polymer brushes to the surface of a device that disrupts normal interaction with circulating proteins and cells. Finally, drug immobilization can also impart antithrombotic effects that counteract normal foreign body reactions in the circulatory system without systemic effects. Heparin coatings have been explored since the 1960s and used on a variety of blood contacting surfaces. This concept is now being explored for neurovascular devices. Coatings that improve endothelialization are not as clinically mature as anti-thrombogenic coatings. Coronary stents have used an anti-CD34 antibody coating to capture circulating endothelial progenitor cells on the surface, potentially accelerating endothelial integration. Similarly, coatings with CD31 analogs are being explored for neurovascular implants.

Thromboembolic Events After the Coverage of Anterior Cerebral Artery with Flow Diversion: A Single Institution Series and Systematic Review

BACKGROUND

Advances in the use of flow diversion (FD) now extend to bifurcation aneurysms; herein, we compare thromboembolic events in patients with internal carotid artery (ICA) aneurysms treated with and without exclusion of the anterior cerebral artery (ACA).

METHODS

Retrospective analysis of aneurysms in the terminal ICA treated with FD from 2013 to 2023 at a single-center study. Procedures were classified according to the coverage at the origin of the ACA and compared through bivariate-analysis. A review was also carried on PubMed, Web of Science, and EMBASE until April 2024, adhering to the PRISMA reporting guidelines.

RESULTS

Ninety-five patients harboring 113 aneurysms treated in 102 procedures were evaluated. Fifty-eight were treated covering the ACA origin. Dual antiplatelet regimens included aspirin-clopidogrel (50%), aspirin-ticagrelor (44.1%), and aspirin-prasugrel (4.9%). Thromboembolic events occurred in 6 patients (5.9%), all of which presented with large vessel occlusion of the ICA, but without reaching statistical difference in the 2 treated cohorts (P = 0.46). At a median clinical follow-up of 5.95 months, there were no differences in the functional outcomes in the 2 groups (P = 0.22). Contralateral angiographic runs post-treatment after covering the ACA origin demonstrated increase in the A1 (median: 0.45 mm; IQR = 0.4-1.2) and ICA diameter (median: 0.55 mm; IQR = 0.1-1.2). After pooling data from literature and our cohort, complete side branch occlusion after the coverage of ACA was seen in 25% of branches (95%CI = 0.16-0.36), and thromboembolic events were observed after 3% (95%CI = 0.01-0.04) of procedures.

CONCLUSIONS

Thromboembolic events can occur in distal ICA aneurysms treated with FD, but no significant association was seen with covering the ACA origin.

Thromboembolic Events in the Posterior Circulation After Flow Diversion-A Closer Look at Coverage of the Posterior Cerebral Artery

BACKGROUND

Flow diversion for bifurcation aneurysms requires excluding one of the branches from the parent artery, raising concern for ischemic events. We evaluated thromboembolic events and their relationship with covering the origin of the posterior cerebral artery (PCA).

METHODS

This retrospective analysis included patients with confirmed basilar and proximal PCA aneurysms treated with flow diversion between 2013 and 2023. Procedures were classified according to the coverage of the origin of the PCA. Thromboembolic events associated with the excluded PCA were evaluated.

RESULTS

Of the total 28 aneurysms included, 7 were at the basilar tip, 16 in the basilar trunk, and 5 in the first segment of the PCA; 15 were treated by excluding one of the PCAs. Dual antiplatelet therapy included aspirin and ticagrelor (57.1%), aspirin and clopidogrel (35.7%), or aspirin and prasugrel (3.57%). Complete and near-complete aneurysm occlusion was achieved in 80.8% of the aneurysms treated at a median follow-up of 12.31 months. Thromboembolic complications occurred in 3 patients (2 with basilar perforator stroke and 1 with basilar in-stent thrombosis). However, the difference in these events was not statistically significant between patients with PCA coverage and those without (P = 0.46). Diminished flow and a lack of flow was seen in 8 and 7 of the covered vessels, respectively. A modified Rankin scale score of ≤2 was reported for 89.3% of patients at a median clinical follow-up of 5.5 months.

CONCLUSIONS

The incidence of thromboembolic events is high in distal basilar and proximal PCA aneurysms; however, PCA coverage was not associated with their occurrence. There was no difference in postprocedural disability between patients whose aneurysms were treated by excluding one of the PCAs and those who were not.

Comparative meta-analysis of endovascular strategies for intracranial dissecting aneurysms: Flow diverters versus stents with or without coiling

BACKGROUND

Intracranial dissecting aneurysms present a challenging subset linked to considerable morbidity and mortality, necessitating effective therapeutic strategies to prevent complications. Traditional treatments face technical limitations, while emerging endovascular modalities like stent-assisted coiling, multiple stenting, and flow-diverting devices (FDDs) offer promise in reducing periprocedural risks and enhancing patient outcomes. The aim of this study is to compare the safety and efficacy outcomes of endovascular treatment for intracranial dissecting aneurysms using FDDs versus stents (with or without coiling).

METHODS

A systematic review and meta-analysis were conducted following established guidelines. The search included PubMed, Scopus, Web of Science, and Embase databases up to July 30, 2023. Eligible studies reporting outcomes of interest in both FDD and stent-treated groups were included, and the data was extracted and analyzed using STATA software.

RESULTS

Six studies were analyzed, involving 131 patients in the FDD group and 199 patients in the stent group. The pooled rates for favorable functional outcomes (86.8% vs. 86%), mortality (3.9% vs. 6%), adequate occlusion (79.7% vs. 86.3%), aneurysm recurrence (1.3% vs. 13.3%), in-stent stenosis/thrombosis (7% vs. 6.9%), ischemic events/infarctions (6.7% vs. 7.8%), retreatment (7% vs. 8.6%), and technical success (100% vs. 98.7%) were comparable in individuals treated with FDDs and stents (p > 0.05 in all cases). Additionally, complete occlusion rates were not significantly different between FDD (62.7%) and stent-treated patients (75.2%) (p = 0.06). However, after excluding one study in a leave-one-out analysis of the random effects meta-analysis, a significant difference in the pooled rates of this outcome was observed between the FDD (59.2%) and stent (75.2%) groups (p = 0.034).

CONCLUSION

FDDs present a promising approach for the treatment of intracranial dissecting aneurysms, yielding outcomes that are roughly comparable to stent-based methods. However, the absence of randomized trials and data limitations highlight the need for further research to enhance treatment strategies.

Microsurgical and endovascular treatment of large and giant aneurysms of the anterior circulation: A systematic review

Introduction

Large and Giant intracranial aneurysms (LGIAs) have become the paradigm for which endovascular techniques do not provide satisfactory results. Yet, microsurgery is followed by non-negligible rates of morbimortality. This scenario may have changed since the introduction of flow-diversion devices.

Research question

Contemporary and standardised revision on microsurgical and endovascular results, with emphasis on anterior circulation LGIAs.

Materials and methods

A systematic literature search was conducted in two databases (PubMed and Embase) on treatment outcomes of LGIAs of the anterior circulation, after the introduction of flow-diverters 2008/01/01, till 2023/05/20. Small case series (<5 cases), series including >15% of posterior circulation aneurysms, and studies not reporting clinical and/or angiographic outcomes were excluded.

Results

44 relevant studies (observational cohorts) were identified, including 2923 LGIAs predominantly from anterior circulation. Mean follow-up 22 (±20) months. 1494 (51%) LGIAs were treated endovascularly and 1427 (49%) microsurgically. According to the random effects model, pooled rates of favourable clinical outcomes were 85.8% (CI 95% 82.6-88.4), complete occlusion 69.4% (CI 95% 63.7-7.46), complications 19.6% (CI 95%16-23.9) and mortality 5.6% (CI 95% 4.4-7.1). Focusing on type of treatment, occlusion rates are higher with microsurgical (842/993, 85% vs 874/1,299, 67%), although good outcomes are slightly more frequent with endovascular (1045/1,135, 92% vs 1120/1,294, 87%).

Discussion and conclusions

According to contemporary data about occlusion rates, functional outcomes, and complications, primary or secondary treatment of LGIAs of the anterior circulation seems justified. Microsurgical occlusion rates are higher in LGIAs. An expert consensus on reporting complications and management strategies is warranted.

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

OBJECTIVE

The 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.

METHODS

PubMed, 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.

RESULTS

We 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.

CONCLUSIONS

Off-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.

Technical success, procedural safety, and efficacy of the Silk Vista Baby in the treatment of cerebral aneurysms over a mid-to-long-term follow-up

Background

Long-term follow-up of cerebral aneurysms treated with the Silk Vista Baby (SVB) flow diverter is lacking. This study aimed to assess the technical success, procedural safety, and efficacy of the SVB (Balt, Montmorency, France) for the treatment of intracranial aneurysms in small cerebral vessels over a mid-to long-term follow-up.

Methods

We retrospectively analyzed a prospectively maintained database of patients treated with the SVB between September 2018 and June 2021. Data regarding patient demographics, aneurysm characteristics, and technical procedures were also collected. Angiographic and clinical findings were recorded during the procedure and over a period of at least 12 months.

Results

Angiographic and clinical follow-up data were available for 50 patients/50 aneurysms. The procedural complication rate was 8%. At 12 months, the final results showed a technical success rate of 100%, the re rupture rate was 0%, neuromorbidity and mortality rates of 4 and 0%, respectively, and an almost complete occlusion rate of 94%.

Conclusion

Treatment of complex intracranial aneurysms with the SVB was safe and effective. Long-term results showed high rates of adequate and stable occlusions.

Endoluminal flow diversion as a primary treatment strategy for pediatric traumatic intracranial aneurysms: a case-based review of literature

BACKGROUND

Traumatic intracranial aneurysms (TICAs) constitute a notable portion of pediatric intracranial aneurysms. Their unstable structure dictates a high incidence of rupture or mass effect from enlarging unruptured aneurysms, necessitating prompt diagnosis and treatment. TICAs often lack a true neck or are wide-necked, making them unsuitable for coil embolization and surgical clipping, and their fragile nature poses a risk of rupture during surgical and intrasaccular interventions. Endoluminal flow diverters (FD), deployed without requiring direct access to the aneurysmal sac, have emerged as an appealing sole treatment modality for TICAs. However, the clinical experience with this technique remains limited in the pediatric population.

METHOD

We describe the successful treatment of a paraclinoid TICA in a 4-year-old female using an endoluminal FD alone. Additionally, we conducted a literature review to assess the safety and effectiveness of this treatment modality in pediatric TICAs.

RESULTS

Endoluminal flow diversion led to complete aneurysm obliteration in our case, with no observed complication, at the 9-month follow-up. Our review of the previously reported pediatric TICAs managed by standalone flow diversion highlights this technique as safe, efficient, and promising as a sole treatment modality, particularly in the anterior circulation, with a high rate of persistent total obliteration and a low rate of complications. However, the requirement for long-term antiplatelet therapy with the possibility of frequent dose monitoring and adjustments warrants special attention when using endoluminal FDs. Until guidelines specifically addressing optimal antiplatelet therapy in children with intracranial FDs are formulated, adherence to existing protocols is imperative to avoid in-stent thrombosis.

CONCLUSION

Our literature review and personal experience indicate that endoluminal flow diversion can be a viable treatment approach for pediatric TICAs. However, prospective studies with extensive follow-ups are required to assess the durability of endoluminal FDs in treating pediatric TICAs, considering the long life expectancy of this demographic.

Emerging Treatments for Subarachnoid Hemorrhage

The current landscape of therapeutic strategies for subarachnoid hemorrhage (SAH), a significant adverse neurological event commonly resulting from the rupture of intracranial aneurysms, is rapidly evolving. Through an in-depth exploration of the natural history of SAH, historical treatment approaches, and emerging management modalities, the present work aims to provide a broad overview of the shifting paradigms in SAH care. By synthesizing the historical management protocols with contemporary therapeutic advancements, patient-specific treatment plans can be individualized and optimized to deliver outstanding care for the best possible SAH-related outcomes.

Patch Technique for Primary Treatment of Type A Carotid Cavernous Fistula: A Case Series and Technical Notes

BACKGROUND

The utilization of flow diverters (FDs) in the treatment of high-flow Type A carotid cavernous fistulas (CCFs) has been described before mainly as an adjunct to the traditional endovascular techniques and rarely as a stand-alone treatment. In this study, we retrospectively evaluated our experience with FDs as the solo nonadjunctive treatment of Type A CCF with severe cortical venous reflux (CVR).

METHODS

A retrospective review was performed of patients with Type A CCFs who were treated using FDs' patch technique (PT). Patients' demographics, clinical data, and preoperative and postoperative ocular examination were recorded. The procedure technique, pipeline embolization device (PED) diameters, and immediate and late procedure outcomes were described.

RESULTS

Three patients were included in this case series. All patients had history of trauma and presented with decreased visual acuity, cranial nerve II deficit, limited extraocular muscles' movement, and increased intraocular pressure (IOP). Diagnostic angiography was performed, which confirmed high-flow Type A CCF. Endovascular treatment was performed through distal radial access in 2 patients and femoral access in 1 patient by deploying 4 sequentially enlarging PEDs with immediate resolution of the ocular symptoms. Follow-up angiography confirmed complete resolution of CCF in 2 patients. One patient was lost to follow-up; however, angiogram at 4 months demonstrated residual small CCF with significant improvement from postprocedure angiogram.

CONCLUSIONS

The patch technique using sequentially enlarging FDs is a reasonable alternative solo technique for the treatment of direct CCF symptoms and results in immediate resolution of CVR while preserving the cavernous sinus anatomy.

Retreatment with a pipeline embolization device for recanalized aneurysms following stent-assisted coiling embolization

Background and purpose

Flow diverters have emerged as viable alternatives for the retreatment of recanalized aneurysms following stent-assisted coiling embolization. In this study, we aim to present our experience of retreatment for such aneurysms using the pipeline embolization device (PED).

Materials and methods

This case series presents a retrospective single-center analysis of patients with recanalized aneurysms who underwent retreatment using the PED between July 2019 and April 2023, subsequent to stent-assisted coiling embolization.

Results

The study includes five female patients, whose relevant clinical data were recorded. All patients had aneurysms located in the internal carotid artery, comprising two blood blister-like aneurysms and two giant aneurysms. Prior to the retreatment, two LVIS stents, two enterprise stents, and one solitaire stent were implanted. Among the five patients, one experienced a fatal post-operative subarachnoid hemorrhage, while two patients achieved complete embolization, and another patient achieved near-complete embolization during the last follow-up. Furthermore, one patient faced challenges during the placement of the PED and was unable to achieve successful deployment. We propose four overlapping relationships between a newly implanted PED and a previously deployed stent: (1) PED covering only the proximal end of the previous stent, (2) PED covering only the distal end of the previous stent, (3) PED covering both the proximal and distal ends of the previous stent, and (4) PED deployed within the previous stent. Antiplatelet therapy at our center involved daily dual therapy with aspirin (100 mg/day) and clopidogrel (75 mg/day) for at least 5 days before PED placement. Intra-arterial bolus administration of tirofiban (5 mcg/kg) was administered during or immediately after PED deployment, followed by a maintenance dose of 0.08 mcg/kg/min IV infusion for at least 24-48 h if necessary. Postprocedural dual antiplatelet therapy included clopidogrel (75 mg/day) for 6 months and aspirin (100 mg/day) for 12 months.

Conclusion

The findings of this study support the efficacy of the PED for the retreatment of recanalized aneurysms following stent-assisted coiling embolization.

Parent artery occlusion after pipeline embolization device implantation of intracranial saccular and fusiform aneurysms

BACKGROUND

Studies reporting parent artery occlusion (PAO) after pipeline embolization device (PED) implantation are limited. The aim of this study was to investigate the incidence rate and risk factors of PAO after PED implantation.

METHODS

In this retrospective study, we enrolled consecutive patients with intracranial saccular and fusiform aneurysms treated with PED implantation at our institution. Multivariate logistic regression analysis was subsequently performed to determine the risk factors for PAO.

RESULTS

A total of 588 saccular and fusiform aneurysms were finally enrolled in the study. PAO was found in 14 (2.38%) aneurysms. The aneurysm complete occlusion rate was 79.6%. Compared with the non-PAO group, aneurysms in the PAO group were larger in size (20.08 vs 9.61 mm; p<0.001), had a greater neck diameter (9.92 vs 6.15 mm; p=0.001), and had higher frequencies of adjunctive coils (64.3% vs 35.7%; p=0.028). In the multivariate logistic analysis, aneurysm size (OR 1.12, 95% CI 1.02 to 1.24; p=0.016) and the presence of poor wall apposition after balloon angioplasty (OR 7.74, 95% CI 1.28 to 46.82; p=0.026) were associated with PAO occurrence after adjusting for confounding factors.

CONCLUSIONS

In this study, the incidence rate of PAO following PED implantation was 2.38% in intracranial saccular and fusiform aneurysms. Aneurysm size and residual presence of poor wall apposition after balloon angioplasty were risk factors for PAO. Further research is required to better understand the mechanisms of PAO.

Verification of software-based preoperative simulation of flow diverters in clinical cases

OBJECTIVE

The authors sought to verify the use of a preoperative simulation software for the treatment of intracranial aneurysms using flow diverters (FDs) based on three-dimensional rotational angiography (3DRA) data.

METHODS

Based on 3DRA data, the preoperative simulation software (UKNOW) was used to simulate the deployment of virtual FDs. The length and dimensions of virtual and real devices were compared. The deployment plan recommended by the UKNOW software was preliminarily used to complete implantations in the real world. During the experiment, experienced neurointerventional experts were responsible for supervising and judging information such as the length, dimension, and deployment location of the FDs.

RESULTS

This study retrospectively analyzed the data of 29 patients who received FD treatment. There was no statistical difference between the length of the real device and the virtual device (p = 0.6). The dimensions of FDs recommended by the software were consistent with the dimensions used in 24 out of the 29 real cases. In four of the remaining five cases, neurointerventional experts found that the FD dimensions recommended by the software were superior to those were actually used. Thus, the accuracy rate for FD dimension recommendations by the UKNOW software was 96.6% (28/29). Procedures performed in five cases using deployment plans recommended by the UKNOW software all achieved good postoperative results; the deployment positions of the device were reasonable, and all devices showed good wall adherence.

CONCLUSIONS

UKNOW software could accurately simulate the length and deployment position of the real FDs and provide suitable device dimensions.

Pipeline versus Tubridge in the treatment of unruptured posterior circulation aneurysms

BACKGROUND

To compare the safety and efficacy of pipeline embolization device (PED) and Tubridge flow diverter (TFD) for unruptured posterior circulation aneurysms.

METHODS

Posterior aneurysm patients treated with PED or TFD between January, 2019, and December, 2021, were retrospectively reviewed. Patients' demographics, aneurysm characteristics, treatment details, complications, and follow-up information were collected. The procedural-related complications and angiographic and clinical outcome were compared.

RESULTS

A total of 107 patients were involved; PED was applied for 55 patients and TFD for 52 patients. A total of 9 (8.4%) procedural-related complications occurred, including 4 (7.3%) in PED group and 5 (9.6%) in TFD group. During a mean of 10.3-month angiographic follow-up for 81 patients, complete occlusion was achieved in 35 (85.4%) patients in PED group and 30 (75.0%) in TFD group. The occlusion rate of PED group is slightly higher than that of TFD group. A mean of 25.0-month clinical follow-up for 107 patients showed that favorable clinical outcome was achieved in 53 (96.4%) patients in PED group and 50 (96.2%) patients in TFD group, respectively. No statistical difference was found in terms of procedural-related complications (p = 0.737), occlusion rate (p = 0.241), and favorable clinical outcome (0.954) between groups.

CONCLUSIONS

The current study found no difference in complication, occlusion, and clinical outcome between PED and TFD for unruptured PCAs.

Stent-Assisted Coil Embolization Versus Flow-Diverting Stent in Unruptured Vertebral Artery Dissecting Aneurysms: Efficacy and Safety Comparison

BACKGROUND

Reconstructive strategies for unruptured vertebral artery dissecting aneurysms (VADAs) have increasingly relied on newly developed endovascular devices. However, their clinical performance metrics are seldom reported.

OBJECTIVE

To compare stent-assisted coil embolization (SACE) and flow-diverting stent (FDS) deployment as treatments for unruptured VADAs, focusing on efficacy and safety.

METHODS

A total of 72 VADAs were submitted to SACE (n = 48) or FDS (n = 24) between April 2009 and September 2021. We reviewed medical records and radiological data to assess efficacy and safety outcomes by method, building an inverse probability of treatment-weighted (IPTW) logistic regression model and conducting survival analyses.

RESULTS

Ultimately, 24 aneurysms (33.3%) showed signs of recanalization (major, 14; minor, 10) at 6-month follow-up. Initially determined 6-month rates of overall (SACE, 31.2%; FDS, 41.7%) and major (SACE, 20.8%; FDS, 16.7%) recanalization did not differ significantly by modality; but in the IPTW logistic regression model, adjusted for aneurysm morphology, major recanalization at 6 months was lower for the FDS (vs SACE) subset (odds ratio = 0.196; P = .027). Likewise, the cumulative rate of major recanalization was more favorable for the FDS (vs SACE) subset (hazard ratio = 0.291; P = .048) in IPTW Cox proportional hazards model adjusted for aneurysm morphology. Modality-based assessments of procedural and delayed complications were similar.

CONCLUSION

Both reconstructive VADA interventions are safe and effective by adjusting treatment modality depending on the angioanatomic configuration. However, follow-up data after treatment proved more favorable for FDS deployment than for SACE in limiting major recanalization. Case-controlled studies of more sizeable cohorts are needed for corroboration.

An off-label use of flow-diverter stent as a successful treatment of a postoperative middle cerebral artery pseudoaneurysm

A pseudoaneurysm or false aneurysm is the result of the disruption of the vessel wall and the formation of a hematoma in communication with the vascular lumen, restrained by perivascular connective tissue. Intracranial pseudoaneurysms represent a rare entity mainly because of trauma, iatrogenic causes, infectious disease, radiation exposure, connective tissue disease and sometimes spontaneous occurrence. We present a 35-year-old female patient with a history of multiple low-grade glioma debulking surgeries. During the last procedure, laceration of the left middle cerebral artery (MCA) occurred with diffuse subarachnoid hemorrhage. Imaging studies showed the formation of a pseudoaneurysm of the left MCA which was successfully treated with the implantation of a flow diverter across the lesion neck and excellent mid- to long- term results. Flow diverter implantation may be a promising technique for the therapeutic management of cerebral pseudoaneurysms.

Flow Diversion as Destination Treatment of Intracranial Mycotic Aneurysms: A Retrospective Case Series

BACKGROUND

Mycotic aneurysms represent a rare type of intracranial aneurysm. Treatment options usually consist of coiling, clipping, or liquid embolization. Data regarding outcomes after flow diversion of mycotic aneurysms are sparse.

OBJECTIVE

To present a single-center case series regarding our experience with FD as definitive treatment for ruptured mycotic aneurysms initially treated with coil embolization.

METHODS

We retrospectively reviewed a prospectively maintained database of all cerebrovascular procedures performed at a single institution between 2017 and 2021 for cases that used FD for the management of intracranial mycotic aneurysms. Prospectively collected data included patient demographics, medical history, rupture status, aneurysm morphology, aneurysm location, and periprocedural complications. The main outcomes included neurological examination and radiographic occlusion rate on cerebral digital subtraction angiography.

RESULTS

Three patients with 4 ruptured mycotic aneurysms that were initially treated with coil embolization were identified that required retreatment. The aneurysms were located along the middle cerebral artery bifurcation (n = 2), posterior cerebral artery P1/2 junction (n = 1), and basilar artery apex (n = 1), which all demonstrated recurrence after initial coil embolization. Successful retreatment using flow diverting stents was performed in all 3 patients. At the last angiographic follow-up, all aneurysms demonstrated complete occlusion. No patients suffered new periprocedural complications or neurological deficits after FD.

CONCLUSION

Flow-diverting stents may be an effective treatment option for intracranial mycotic aneurysms that are refractory to previous endovascular coiling. Future studies are warranted to establish the associated long-term safety and clinical efficacy.

Plasticity of the adult circle of Willis in response to flow diversion stents

Background

We present five patients with remodeling of the adult circle of Willis in response to flow diverter stents (FDSs) at the anterior communicating artery (AComA) and the posterior communicating artery (PComA). The observed changes provide a paradigm of how flow change can institute anatomic changes in the adult circle of Willis vasculature.

Case Description

In the first two cases, after placement of the FDS covering the AComA, there was an increase in size and flow of the contralateral A1-anterior cerebral artery which had previously been hypoplastic. In one of the cases, this led to the filling of the aneurysm and required placement of coils within the lesion which was curative. In case three, the FDS effect led to asymptomatic occlusion of the PComA and associated aneurysm without change of the ipsilateral P1-segement of posterior-cerebral-artery (P1-PCA) caliber. In the fourth case, the FDS covering an aneurysm with a fetal PCA arising from its neck resulted in significant reduction of the aneurysm size, persistent flow and caliber of the fetal PCA, and the hypoplastic ipsilateral P1-PCA. Finally, in the fifth case, after FDS occlusion of the PComA and aneurysm there was increasement in diameter of the ipsilateral P1-PCA that was previously hypoplastic.

Conclusion

The use of FDS can affect vessels covered by the device and other arteries of the circle of Willis adjacent to the FDS. The phenomena illustrated in the hypoplastic branches appear to be a compensatory response to the hemodynamic changes induced by the divertor and to the altered flow in the circle of Willis.

A review of technological innovations leading to modern endovascular brain aneurysm treatment

Tools and techniques utilized in endovascular brain aneurysm treatment have undergone rapid evolution in recent decades. These technique and device-level innovations have allowed for treatment of highly complex intracranial aneurysms and improved patient outcomes. We review the major innovations within neurointervention that have led to the current state of brain aneurysm treatment.

Complications of Endovascular and Open Aneurysm Surgery in the Era of Flow Diversion

The techniques used for treatment of intracranial aneurysms have progressed dramatically over the decades. The introduction of modern endovascular techniques and the continued refinement of progressively less invasive neurosurgical approaches have contributed to steadily improving clinical outcomes. Moreover, innovations such as flow-diverting stents have achieved dramatic success and have gained rapid widespread adoption. Particularly in lesions for which the application of conventional treatment techniques is difficult, flow diversion technology has revolutionized aneurysm management. This review provides a discussion on the morbidity and mortality encountered in the treatment of intracranial aneurysms in the modern era. Common adverse events faced in the management of these lesions with open surgery and various endovascular techniques are highlighted.

Flow diversion for indirect carotid-cavernous fistula: Still an off-label indication?

Background

Flow diversion (FD) is an established treatment for large or giant wide-necked unruptured intracranial aneurysms. In the past few years, the use of flow diverter devices was extended to several other "off-label" indications, including solitary or adjunctive treatment to coil embolization for direct (Barrow A type) carotid cavernous fistulas (CCFs). The use of liquid embolic agents still represents the first-line treatment for indirect CCFs. Typically, the ipsilateral inferior petrosal sinus or superior ophthalmic vein (SOV) is the preferred transvenous routes to access CCFs. In some cases, vessel tortuosity or different features make the endovascular access challenging, thus requiring different approaches and strategies. The aim of the study is to discuss rational and technical aspect in treating indirect CCFs referring to the most up-to-date literature. An alternative experience-based endovascular strategy with FD is described.

Methods

We report the case of a 54-year-old woman diagnosed with indirect CCF and treated with flow diverter stent.

Results

After multiple unsuccessful attempts at transarterial right SOV catheterization, a right indirect CCF fed by a single trunk at the ophthalmic origin from the internal carotid artery (ICA) was treated by ICA stand-alone FD. Blood flow was redirect and successfully reduced through the fistula, with immediately postprocedure improvement of the patient's clinical status (ipsilateral proptosis and chemosis). Ten-months radiological follow-up showed the complete obliteration of the fistula. No adjunctive endovascular treatment was performed.

Conclusion

FD appears a reasonable alternative stand-alone endovascular strategy also for selected difficult-to-access indirect CCFs, when all conventional routes are judged unfeasible. Further investigations will be necessary to better define and support this potential lesson-learned application.

Pipeline for the treatment of distal cerebral circulation aneurysms: A multicenter study focusing on periprocedural Complications

BACKGROUND AND AIM

Distal cerebral circulation aneurysms (DCCAs) remain treatment challenges for neurointervention. The off-label use of the pipeline embolization device (PED) for these aneurysms remains controversial. This study aimed to evaluate the safety and efficacy of PED for DCCAs in a multicenter cohort of patients.

METHODS

Between March 2016 and June 2021, we retrospectively analyzed the neurointerventional data on the clinical and radiological records of all patients undergoing PED treatment of DCCAs at three medical centers.

RESULTS

A total of 53 consecutive patients with 53 DCCAs were treated with PED. The mean aneurysm size was 12.3 ± 5.7 mm. In total, 75.4% (40/53) were fusiform and 24.5% (13/53) were saccular. Of these, 17.0% (9/53) were recurrent aneurysms that were previously treated with endovascular or microsurgical approaches. The technical success rate was 100%, among which 81.1% (43/53) procedures were completed with a single PED, and the rest (10/53, 18.8%) required telescoping with two devices. Angiographic follow-up data were available for 51 patients, with a median follow-up time of 12 months. At the latest follow-up, 46/51 (90.2%) aneurysms showed complete obliteration, and 4/51 (7.8%) showed reduced filling. Periprocedural complications such as hemorrhage were observed in two patients with MCA aneurysms (3.8%, 2/53), and ischemic events occurred in six patients (11.3%, 6/53). The overall mortality and morbidity rates were 7% (4/53).

CONCLUSIONS

PED is a viable option for treating DCCAs, especially for recurrent aneurysms. Coverage of bifurcation branches and perforator may increase the risk of complications.

Clinical outcomes of pipeline embolization devices with shield technology for treating intracranial aneurysms

INTRODUCTION

As a common endovascular treatment for intracranial aneurysms, the pipeline embolization device (PED) is considered a standard treatment option, especially for large, giant, wide-necked, or dissecting aneurysms. A layer of phosphorylcholine biocompatible polymer added to the surface of the PED can substantially improve this technology. This PED with shield technology (pipeline shield) is relatively novel; its early technical success and safety have been reported. We conducted a systematic literature review with the aim of evaluating the efficacy and safety of the pipeline shield.

METHODS

We searched the PubMed, Embase, and Cochrane databases, following the preferred reporting items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines.

RESULTS

We selected five prospective and two retrospective studies for review. A total of 572 aneurysms were included; of these, 506 (88.5%) were unruptured. The antiplatelet regimens were heterogeneous. The rate of perioperative and postoperative complications was 11.1% [95% confidence interval (CI): 6.5-18.9%]. The adequate occlusion rate at 6 months was 73.9% (95% CI: 69.1-78.7%). The adequate occlusion rate of more than 12 months was 80.9% (95% CI: 75.1-86.1%). The mortality rate was 0.7% (95% CI: 0.2-1.5%). Subgroup analyses showed that aneurysm rupture status had no effect on aneurysm occlusion rate, patient morbidity, or mortality.

CONCLUSION

This review demonstrates the safety and efficacy of the pipeline shield for treating intracranial aneurysms. However, direct comparisons of the pipeline shield with other flow diverters are needed to better understand the relative safety and effectiveness of different devices.

North American multicenter experience with the Flow Redirection Endoluminal Device in the treatment of intracranial aneurysms

OBJECTIVE

Flow diverters have revolutionized the endovascular treatment of intracranial aneurysms. Here, the authors present the first large-scale North American multicenter experience using the Flow Redirection Endoluminal Device (FRED) in the treatment of cerebral aneurysms.

METHODS

Consecutive cerebral aneurysms treated with FRED at 7 North American centers between June 2020 and November 2021 were included. Data collected included patient demographic characteristics, aneurysm characteristics, periprocedural and long-term complications, modified Rankin Scale (mRS) scores, and radiological follow-up.

RESULTS

In total, 133 aneurysms in 116 patients were treated with 123 FRED deployment procedures and included in this study. One hundred twenty-six aneurysms (94.7%) were unruptured, 117 (88.0%) saccular, and 123 (92.5%) located in anterior circulation. The mean (range) aneurysm maximal width and neck width sizes were 7.2 (1.5-42.5) mm and 4.1 (1.0-15.1) mm, respectively. Successful FRED deployment was achieved in 122 procedures (99.2%). Adjunctive coiling was used in 4 procedures (3.3%). Radiological follow-up was available for 101 aneurysms at a median duration of 7.0 months. At last follow-up, complete occlusion was observed in 55.4% of patients, residual neck in 8.9%, and filling aneurysm in 35.6%; among cases with radiological follow-up duration > 10 months, these values were 21/43 (48.8%), 3/43 (7.0%), and 19/43 (44.2%), respectively. On multivariate regression analysis, age (OR 0.93, p = 0.001) and aneurysm neck size (OR 0.83, p = 0.048) were negatively correlated with odds of complete occlusion at latest follow-up. The retreatment rate was 6/124 (4.8%). The overall complication rate was 31/116 (26.7%). Parent vessel occlusion, covered branch occlusion, and in-stent stenosis were detected in 9/99 (9.1%), 6/63 (9.5%), and 15/99 (15.2%) cases, respectively. The FRED-related, symptomatic, thromboembolic, and hemorrhagic complication rates were 22.4%, 12.9%, 6.9%, and 0.9% respectively. The morbidity rate was 10/116 patients (8.6%). There was 1 death due to massive periprocedural internal carotid artery stroke, and 3.6% of the patients had an mRS score > 2 at the last follow-up (vs 0.9% at baseline).

CONCLUSIONS

As the first large-scale North American multicenter FRED experience, this study confirmed the ease of successful FRED deployment but suggested lower efficacy and a higher rate of complications than reported by previous European and South American studies on FRED and other flow-diverting devices. The authors recommend judicious use of this device until future studies can better elucidate the long-term outcomes of FRED treatment.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Intrasaccular neck-bridging: A technical note on Nautilus-assisted coiling of wide-necked cerebral aneurysms. Feasibility study, immediate and early angiographic results

PURPOSE

Various adjunctive devices have been reported to be helpful during the endovascular coiling of complex, wide-necked cerebral aneurysms. This study aimed to describe the utilization of a recently introduced intrasaccular neck-bridging implant specifically designed to facilitate coil embolization.

METHODS

We retrospectively reviewed eight consecutive patients who underwent treatment for intracranial aneurysms with the Nautilus intrasaccular bridging system between February 2022 to May 2022. We evaluated the angiographic appearances of treated aneurysms at the end of the procedure and early follow-up, the clinical status and complications.

RESULTS

Eight patients with eight cerebral aneurysms (3 men and 5 women, mean age 52.8 years (range 39-66) were analyzed. Five of the treated aneurysms were managed in an acute case scenario. There were no technical difficulties while executing the technique. No other procedural adverse events were documented. Immediate complete occlusion of the aneurysm was seen in 6 patients, neck remnant in 1 and stable aneurysm reperfusion in one case. Early radiological follow-up was available in five patients, and the observed occlusion rates were - RR class I in all radiologically screened aneurysms.

CONCLUSION

Nautilus-assisted coil embolization represents a rapid and safe solution for complex cerebral aneurysms. In our opinion this device symbolizes a significant step forward in treating intracranial aneurysms. We believe that the technique's actual value consists of the fact that the device is fully compatible with the modern low-profile microcatheter technology and does not involve the need for antiplatelet medications.

Comparison of Pipeline Embolization Device and Traditional Endovascular Therapeutic Approaches in Distal Cerebral Circulation Aneurysms Using Propensity Score Matching Analysis

Background

Coiling and stent-assisted coiling remain the first-line treatments for distal cerebral circulation aneurysms (DCCAs). The off-label use of the pipeline embolization device (PED) for these aneurysms has been explored recently but remains controversial.

Objective

To compare traditional endovascular therapeutic approaches (coiling and stent-assisted coiling) and PED for DCCAs in a multicenter cohort of patients.

Methods

A multicenter, retrospective cohort comparison study was conducted that included consecutive patients with unruptured DCCAs treated with either traditional endovascular therapeutic approaches or PED placement at three centers between 2016 and 2020. Propensity score matching analysis was applied to adjust for baseline risk factors between the PED and TET groups. Matching was based on age, sex, aneurysm size, location, morphology, adjunctive coiling, treatment history, and preoperative mRS score.

Results

In total, 209 patients with DCCAs treated with PED or traditional endovascular therapeutic approaches were identified. Thirty-seven patients underwent PED treatment, and 172 patients underwent traditional endovascular therapeutic approaches. After propensity score matching, 37 aneurysm pairs were matched, and the baseline characteristics of the patients were balanced between the groups. The complete occlusion rate between PED and traditional endovascular therapeutic approach in both matched cohorts (91.7 vs. 92.3%, p > 0.78) was similar. The rate of periprocedural treatment-related complications in both the PED and traditional endovascular therapeutic groups was 13.5%. Univariate analysis identified average parent vessel diameter as the only predictor of complete occlusion (p = 0.038).

Conclusions

PED is a viable option for treating DCCAs by providing occlusion and complication rates similar to those of traditional endovascular therapeutic approaches. A rigid patient selection procedure and proper planning should be undertaken to reduce treatment-related complications.

Pipeline Embolization Stent for the Treatment of Giant Supraclinoid Aneurysms: A Case Series

Cerebrovascular aneurysms of the supraclinoid region are a technical challenge and can be particularly difficult to treat when greater than 25 mm in diameter. Such giant aneurysms can be approached with various skull-based and endovascular surgical techniques, and the advent of the Pipeline embolization stent presents a new treatment modality. Previously used for the treatment of small aneurysms, the Pipeline embolization device (PED) is a flow diverter device that has more recently been investigated in its use for the treatment of giant aneurysms with few studies to date published about its procedural outcomes. Here, we highlight the case of three patients (two elderly and one middle-aged) presenting symptomatically with giant supraclinoid aneurysms of the cavernous internal carotid artery (ICA) and posterior communicating artery treated with the Pipeline stent and monitored on follow-up visits. We further review the most current case reports and the two clinical trials to date investigating the utility of the Pipeline stent in the treatment of large and giant cerebral aneurysms, highlighting the emerging evidence of its efficacy and long-term patient outcomes. We report successful resolution of symptoms and radiographic evidence of aneurysm size reduction on all patient follow-ups and suggest the Pipeline embolization device as a novel technique that can be utilized for the treatment of giant cerebrovascular aneurysms with emerging evidence of immediate and long-term success.

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

BACKGROUND

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.

OBJECTIVE

To compare "off-label" and "on-label" PED treatment.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Giant Aneurysm Management

The treatment of giant aneurysms has always been a challenge in the field of neurovascular disease. Giant aneurysms are larger in size and are associated with thrombosis development and the calcification of the aneurysmal wall and neck, which often interfere with direct clipping. Most giant aneurysms have a wide neck with an incomplete thrombus, making complete embolization almost impossible. Giant aneurysms of different sites have entirely different hemodynamic characteristics. Moreover, aneurysms at the same site may exhibit very different hemodynamics among different individuals. Therefore, careful assessment of each case is required before and during treatment to develop and carry out an individualized treatment plan.

Treatment of carotid cavernous sinus fistulas with flow diverters. A case report and systematic review

INTRODUCTION

Carotid cavernous fistulas (CCFs) are rare, usually follow head trauma or aneurysmal rupture. Recent treatment options include endovascular techniques such as flow diversion devices (FDDs).

OBJECTIVE

To present our case treated with FDD application with transarterial cavernous-sinus coiling and present a systematic review on the use and effectiveness of FDDs in CCF treatment.

MATERIALS AND METHODS

We present our case of CCF treatment with FDD. A search was also conducted in PubMed, EMBASE and Cochrane until November 2020. Reference lists were also cross-checked.

RESULTS

Including our case, thirty-eight patients were identified with a CCF that was treated with FDDs in sixteen studies. Twenty-two patients were females, nine were males and the rest unidentified. The mean age was 52,6 years (range 17-86, SD± 19.28). Thirty-six patients suffered from direct and two from indirect CCFs. Single FDD was used in four cases, single FDD with embolic materials in eleven cases, multiple overlapping FDDs were used in six cases and multiple overlapping FDDs with embolic materials were used in seventeen cases. Thirty-five patients (92,1%) had clinical improvement, immediate angiographic occlusion was seen in 44,7% of the cases, while long-term occlusion rate was 100% but with variable follow-up periods. One patient (2,6%) presented with a neurological deficit related to FDD deployment.

CONCLUSION

Targeted treatment of CCFs with single or overlapping FDDs with or without adjunct embolic agents offers a high success rate, both clinically and long-term angiographically compared to other endovascular methods alone. However, further research with multi-center prospective trials is warranted.

Combined Pipeline Embolization Device with Endoscopic Endonasal Fascia Lata/Muscle Graft Repair as a Salvage Technique for Treatment of Iatrogenic Carotid Artery Pseudoaneurysm

The incidence of internal carotid artery (ICA) injury associated with endoscopic endonasal approaches to the pituitary is less than 1%. While parent vessel sacrifice has historically been the choice of treatment, vessel-preserving endovascular techniques have been reported. Although flow diversion offers endoluminal reconstruction, its major limitation is the delay in obtaining complete occlusion. We describe the use of a combined Pipeline embolization device (PED) with endoscopic endonasal repair using a fascia lata/muscle graft to treat an iatrogenic ICA pseudoaneurysm and report long-term radiographic follow-up. Further investigation into the utility of directed endoscopic endonasal repair of iatrogenic pseudoaneurysms initially treated with PED is necessary, especially given the need of post-PED anticoagulation and the rate of permanent neurological deficit after ICA sacrifice.

Pipeline embolization of MCA aneurysms in the M2-M4 segment: Dual center study and meta-analysis

OBJECTIVE

Flow diversion of distal MCA aneurysms in the M2-M4 segments with Pipeline embolization device is promising, but further study is needed. Here, we seek to quantify the safety and efficacy of Pipeline embolization in the M2-M4 region in a dual-center cohort and comprehensive meta-analysis.

METHODS

Clinical and angiographic data of eligible patients was obtained from participating centers. A systematic review was performed with searches of Pubmed, Scopus, Embase, and the Cochrane Library for articles from inception to May 2021. 86 studies were identified in systematic review. Of these, 7 studies with 46 aneurysms met the inclusion criteria and were aggregated with 8 aneurysms from our dual-center cohort for analysis.

RESULTS

In our dual-center cohort, complete occlusion was observed in 88% (7/8) of aneurysms, and no patients experienced hemorrhagic or thromboembolic complications. Clinical outcomes were reported for 100% (54/54) of aneurysms included in meta-analysis and angiographic follow-up was available for 91% (49/54). The overall rate of complete aneurysm occlusion was 80% (95% CI, 69-91%), and the overall rate of clinical complication was 9% (95% CI, 2-16%).

CONCLUSION

Pipeline embolization of cerebral aneurysms of the M2-M4 segments of the MCA was reasonably effective and safe in a small group of selected patients, but further study is needed to validate these preliminary results.

Pipeline Embolization Device for the Treatment of Ruptured Intracerebral Aneurysms: A Multicenter Retrospective Study

Background and Purpose: The utilization of flow diversion for ruptured intracerebral aneurysms (IAs) is still limited. We aimed to demonstrate our multicenter experience using the pipeline embolization device (PED) for ruptured IAs that were difficult to treat by clipping and coiling.

Methods: Thirty-eight patients with ruptured IAs who underwent PED treatment from 2015 to 2020 were retrospectively reviewed. Factors associated with procedure-related stroke (ischemic and hemorrhagic) and clinical and angiography outcomes were analyzed.

Results: There were 14 (36.8%) saccular IAs, 12 (31.6%) blister-like IAs, and 12 (31.6%) dissecting IAs. Perforator involvement was noted in 10 (26.3%) IAs. Early PED placement ( ≤ 15 days) and adjunctive coiling treatment were performed in 27 (71.1%) and 22 (57.9%) cases, respectively. The overall rate of stroke-related complications was 31.6% (12/38) (including rates of 10.5% for procedure-related hemorrhagic complications and 15.8% for procedure-related infarction). The mortality rate was 13.2% (5/38), and 84.2% of patients (32/38) had favorable outcomes. Thirty-two (84.2%) patients underwent follow-up angiographic evaluations; of these, 84.4% (27 patients) had complete occlusion and 15.6% had incomplete obliteration. Multivariate analysis revealed that early PED placement was not associated with a high risk of procedure-related stroke or an unfavorable outcome. Adjunctive coiling exhibited an association with procedure-related stroke (p = 0.073). Procedure-related hemorrhagic complications were significantly associated with an unfavorable outcome (p = 0.003). Immediate contrast stasis in the venous phase was associated with complete occlusion during follow-up (p = 0.050).

Conclusion: The PED is a feasible and effective treatment to prevent rebleeding and achieve aneurysm occlusion, but it is associated with a substantial risk of periprocedural hemorrhage and ischemic complications in acute ruptured IAs. Therefore, the PED should be used selectively for acutely ruptured IAs. Additionally, adjunctive coiling might increase procedure-related stroke; however, it may reduce aneurysm rebleeding in acutely ruptured IAs. Patients with immediate contrast stasis in the venous phase were more likely to achieve total occlusion. A prospective study with a larger sample size should be performed to verify our results.

Efficacy and safety of flow diverters in posterior circulation aneurysms and comparison with their efficacy in anterior circulation aneurysms: A systematic review and meta-analysis

PURPOSE

We aimed to assess the efficacy and safety of flow-diverter stents (FDs) in the management of posterior circulation cerebral aneurysms and compare FD efficacy between anterior and posterior circulation aneurysms.

METHODS

We searched the PubMed, Scopus, Cochrane, and Web of Science databases for relevant studies through March 2020. Studies assessing FDs for posterior circulation aneurysms that included ≥20 treated aneurysms were included. Moreover, the studies compared FD efficacy between anterior and posterior circulation aneurysms were included. Data regarding angiographic aneurysmal occlusion, procedural complications, mortality, and morbidity were extracted and pooled in a random-effects meta-analysis model.

RESULTS

Fourteen studies with a total of 659 patients and 676 posterior circulation aneurysms were included. The pooled rate of aneurysmal occlusion at long-term angiographic follow-up was 78% [95% confidence interval (CI), 71-85]. The pooled rates of intraparenchymal hemorrhage, ischemia, and procedure-related mortality and neurological morbidity were 2%, 8%, 7%, and 6%, respectively. Complete occlusion occurred in 82.4% of the posterior circulation aneurysm subgroup and 77.5% of the anterior circulation aneurysm subgroup. The difference was not significant (relative risk 1.01; 95% CI, 0.86-1.19; p = 0.91). Regression analysis showed that elderly patients and females had higher morbidity.

CONCLUSION

Posterior circulation aneurysms can be effectively treated with FDs with comparable occlusion rates to those in anterior circulation aneurysms. However, periprocedural complications are not negligible.

A novel score for evaluating cerebral aneurysms treated with flow diversion: 4F-flow diversion predictive score

Background and purpose

Although grading scales for angiography outcomes following cerebral aneurysm treatment with flow diversion have been published, physicians have not widely adopted these scales in practice. The aim of this study is to propose and validate a novel Flow diversion Predictive Score (4F-FPS) grading scale based on previously established scales that is simple and reliable.

Methods

We retrospectively analyzed consecutive patients who underwent endovascular treatment for cerebral aneurysms with flow diversion between January 2014 and September 2019. The included patients were randomly divided into the derivation and validation group in a 70/30 ratio, respectively. Aneurysms were classified as incomplete or complete occlusion based on final angiography outcomes. 4F-FPS was derived to predict aneurysm occlusion from multivariate logistic regression analyses in the derivation group and validated with previously published grading scales in the validation group.

Results

Overall, 662 patients [mean age, 53.8 years; 72.5% (480/662) female] with 662 aneurysms treated with the Pipeline^TM flow diverter were included [69.9% (463/662) derivation group, 30.1% (199/662) validation group]. The incidence of aneurysm occlusion was 82.7%. 4F-FPS demonstrated significant discrimination in 10-fold cross validation [mean receiver operating characteristic (ROC) area, 0.862 ± 0.055] and calibration (Cox & Snell R ², 0.251; Nagelkerke R ², 0.413) in the derivation group. The ROC area of 4F-FPS score in both the derivation and validation groups is the largest compared with previously published grading scales/scores (p < 0.05), which shows better sensitivity and specificity. The 4F-FPS score showed excellent prediction, discrimination, and calibration properties.

Conclusion

The 4F-FPS score is a simple and reliable tool to predict angiography outcome after flow diversion treatment. If widely adopted, it may provide a common language to be used in future reporting of flow diversion results for clinical trials and daily practice.

Clinical trial registration

http://www.clinicaltrials.gov. Unique identifier: NCT03831672.

Current Strategies in the Treatment of Intracranial Large and Giant Aneurysms

INTRODUCTION

Very large and giant aneurysms are among the most challenging cerebrovascular pathologies in neurosurgery.

METHODS

The aim of this paper is to review the current literature on the management of very large and giant aneurysms and to describe representative cases illustrating possible treatment strategies.

RESULTS

In view of the poor natural history, active management using multiprofessional individualized approaches is required to achieve aneurysm occlusion, relief of mass effect, and obliteration of the embolic source. Both reconstructive (clipping, coiling, stent-assisted coiling, flow diversion [FD]) and deconstructive techniques (parent artery occlusion [PAO], PAO in conjunction with bypass surgery, and strategies of flow modification) are available to achieve definitive treatment with acceptable morbidity.

CONCLUSIONS

Patients harboring such lesions should be managed at high-volume cerebrovascular centers by multidisciplinary teams trained in all techniques of open and endovascular neurosurgery.

Endovascular Management of Distal Anterior Cerebral Artery Aneurysms: A Multicenter Retrospective Review

INTRODUCTION

Distal anterior cerebral artery aneurysms (DACAA) are a rare and difficult entity to manage. Endovascular treatment has evolved for safe and durable treatment of these lesions. The objective of this study is to report the safety, efficacy, and outcomes of endovascular treatment of DACAA.

METHODS

A retrospective review of DACAA endovascularly treated at 5 different institutions was performed. Data included demographics, rupture status, radiographic features, endovascular technique, complication rates, and long-term angiographic and clinical outcomes. A primary endpoint was a good clinical outcome (modified Rankin scale 0-2). Secondary endpoints included complications and radiographic occlusion at follow-up.

RESULTS

A total of 84 patients were reviewed. The mean age was 56, and 64 (71.4%) were female. Fifty-two (61.9%) aneurysms were ruptured. A good functional outcome was achieved in 59 patients (85.5%). Sixty (71.4%) aneurysms were treated with primary coiling, and the remaining 24 were treated with flow diversion. Adequate occlusion was achieved in 41 (95.3%) aneurysms treated with coiling, and 17 (89.5%) with flow diversion. There were total 11 (13%) complications. In the flow diversion category, there were 2, both related to femoral access. In the coiling category, there were 9: 5 thromboembolic, 3 ruptures, and 1 related to femoral access.

CONCLUSION

Endovascular treatment, and in particular, flow diversion for DACAA, is safe, feasible, and associated with good long-term angiographic and clinical outcomes.

The value of long-term angiographic follow-up following Pipeline embolization of intracranial aneurysms

BACKGROUND

Flow diversion of intracranial aneurysms with the Pipeline Embolization Device (PED) is commonly performed, but the value of long-term angiographic follow-up has not been rigorously evaluated. Here we examine the prevalence of actionable findings of aneurysm recurrence and development of in-stent stenosis in a cohort of patients that underwent long-term angiographic follow-up at multiple time points.

METHODS

Angiographic data from eligible patients were retrospectively assessed for aneurysm occlusion, in-stent stenosis, and aneurysm regrowth or recurrence. Patients were included in this study if they underwent angiographic imaging at 6 months post-treatment and at least one later time point.

RESULTS

100% (132/132) of aneurysms occluded at 6 months remained occluded at final follow-up. 85.7% (6/7), 56.3% (27/48), and 25% (6/24) of aneurysms with entry remnant, subtotal filling, and total filling, respectively, at 6 months were completely occluded at final follow-up. 98.7% (147/149) of PED constructs that demonstrated no stenosis at 6 months demonstrated no stenosis at final angiography, while 44.4% (8/18) of PED constructs demonstrating in-stent stenosis at 6 months had resolution of stenosis on final angiography.

CONCLUSIONS

Among patients who undergo treatment of intracranial aneurysms with PED, the value of long-term angiography in patients demonstrating complete aneurysm occlusion and no in-stent stenosis on 6 month post-treatment angiography is low.