Use of Platelet Function Testing Before Pipeline Embolization Device Placement

Flow Diversion for Endovascular Treatment of Intracranial Aneurysms: Past, Present, and Future Directions

Flow diversion for intracranial aneurysms emerged as an efficacious and durable treatment option over the last two decades. In a paradigm shift from intrasaccular aneurysm embolization to parent vessel remodeling as the mechanism of action, the proliferation of flow-diverting devices has enabled the treatment of many aneurysms previously considered untreatable. In this review, we review the history and development of flow diverters, highlight the pivotal clinical trials leading to their regulatory approval, review current devices including endoluminal and intrasaccular flow diverters, and discuss current and expanding indications for their use. Areas of clinical equipoise, including ruptured aneurysms and wide-neck bifurcation aneurysms, are summarized with a focus on flow diverters for these pathologies. Finally, we discuss future directions in flow diversion technology including bioresorbable flow diverters, transcriptomics and radiogenomics, and machine learning and artificial intelligence.

The Impact of Preprocedural Platelet Function Testing on Periprocedural Complication Rates Associated With Pipeline Flow Diversion: An International Multicenter Study

BACKGROUND AND OBJECTIVES

Dual antiplatelet therapy (DAPT) is necessary to minimize the risk of periprocedural thromboembolic complications associated with aneurysm embolization using pipeline embolization device (PED). We aimed to assess the impact of platelet function testing (PFT) on reducing periprocedural thromboembolic complications associated with PED flow diversion in patients receiving aspirin and clopidogrel.

METHODS

Patients with unruptured intracranial aneurysms requiring PED flow diversion were identified from 13 centers for retrospective evaluation. Clinical variables including the results of PFT before treatment, periprocedural DAPT regimen, and intracranial complications occurring within 72 h of embolization were identified. Complication rates were compared between PFT and non-PFT groups. Differences between groups were tested for statistical significance using the Wilcoxon rank sum, Fisher exact, or χ 2 tests. A P -value <.05 was statistically significant.

RESULTS

580 patients underwent PED embolization with 262 patients dichotomized to the PFT group and 318 patients to the non-PFT group. 13.7% of PFT group patients were clopidogrel nonresponders requiring changes in their pre-embolization DAPT regimen. Five percentage of PFT group [2.8%, 8.5%] patients experienced thromboembolic complications vs 1.6% of patients in the non-PFT group [0.6%, 3.8%] ( P = .019). Two (15.4%) PFT group patients with thromboembolic complications experienced permanent neurological disability vs 4 (80%) non-PFT group patients. 3.7% of PFT group patients [1.5%, 8.2%] and 3.5% [1.8%, 6.3%] of non-PFT group patients experienced hemorrhagic intracranial complications ( P > .9).

CONCLUSION

Preprocedural PFT before PED treatment of intracranial aneurysms in patients premedicated with an aspirin and clopidogrel DAPT regimen may not be necessary to significantly reduce the risk of procedure-related intracranial complications.

Variability patterns in dual antiplatelet therapy following endovascular repair of intracranial aneurysms: Insight into regimen heterogeneity and the need for a consensus

This comprehensive review delves into the evolving field of neurointervention for intracranial aneurysms, exploring the critical adjunct of Dual Antiplatelet Therapy (DAPT) to endovascular coiling, stent-assisted coiling (SAC), flow-diversion stents, and flow-disruption (intrasaccular) devices. Despite growing evidence supporting the success of DAPT in reducing thromboembolic events, the lack of consensus on optimal regimens, doses, and duration is evident. Factors contributing to this variability include genetic polymorphisms affecting treatment response and ongoing debates regarding the clinical significance of hemorrhagic complications associated with DAPT. This review analyzes pre- and post-procedural antiplatelet usage across various interventions. The imperative lies in ongoing research to define optimal DAPT durations, ensuring a nuanced approach to the delicate balance between thrombosis and hemorrhage in intracranial aneurysm management.

Optimal duration of dual antiplatelet therapy for stent-assisted coiling or flow diverter placement

BACKGROUND

Dual antiplatelet therapy (DAPT) is necessary to prevent thromboembolic complications after stent-assisted coiling (SAC) or flow-diversion (FD) for cerebral aneurysms, but the optimal antiplatelet regimen remains unclear.

OBJECTIVE

To determine the optimal DAPT duration in patients with SAC/FD.

METHODS

This multicenter cohort study enrolled patients who received SAC/FD for cerebral aneurysms at seven Japanese institutions between January 2010 and December 2020. The primary outcome was the time from procedure to the occurrence of a composite of target vessel-related thromboembolic events, procedure-unrelated major bleeding events, or death. The cumulative event-free survival rates were analyzed using a Kaplan-Meier curve, and the differences in each outcome between the groups dichotomized by the duration of DAPT were analyzed using the log-rank test.

RESULTS

Of 632 patients (median observational period, 646 days), primary outcome occurred in 63 patients (10.0%), most frequently within 30 days after the procedure. The cumulative event-free survival rates at 30 days, 1 year, and 2 years after the procedure were 93.3% (91.4 to 95.3%), 91.5% (89.3 to 93.7%), and 89.5% (87.0 to 92.0%), respectively. The cumulative event-free survival rates after switching to monotherapy were similar for the >91 and <90 days DAPT groups in the population limited to patients who were switched from DAPT to monotherapy without major clinical events.

CONCLUSIONS

Thromboembolic events rarely occurred beyond 30 days after SAC/FD. The duration of DAPT may be shortened if patients have a periprocedural period without events. Further prospective studies are warranted to determine the optimal duration of antiplatelet therapy.

TRIAL REGISTRATION NUMBER

UMIN000044122 :https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000050384.

Ticagrelor Versus Clopidogrel in Endovascular Therapy for Cerebral Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND

Antiplatelet therapy is pivotal in endovascular treatment for intracranial aneurysms. However, there is a lack of studies comparing ticagrelor to clopidogrel in patients with aneurysms undergoing endovascular therapy. Additionally, the existing literature lacks adequate sample size, significant subgrouping, and follow-up, making our study important to cover these gaps.

METHODS

We searched 5 databases to collect all relevant studies. Categorical outcomes were pooled as relative risk (R.R.) with a 95% confidence interval (CI). In the single-arm meta-analysis, outcomes were pooled as proportions and their corresponding 95% CI.

RESULTS

This comprehensive analysis of 18 studies involving 2,427 patients. For thromboembolic events, the pooled (R.R.) did not show significant differences, whether considering overall events. A similar pattern was observed for thromboembolic events stratified by aneurysmal rupture status, with no significant differences in overall events. Hemorrhagic events did not also exhibit significant differences in previously mentioned stratifications. Furthermore, there were no substantial differences in death and mRS (0-2) on discharge between Ticagrelor and Clopidogrel. Single-arm meta-analyses for Ticagrelor demonstrated low rates of thromboembolic events, hemorrhage, death, and favorable mRS scores, with associated confidence intervals (CIs). Main line of endovascular treatment did not significantly affect either thromboembolic or hemorrhagic outcomes with Ticagrelor and Clopidogrel.

CONCLUSIONS

We found no significant differences in key outcomes like thromboembolic events, hemorrhagic events, mortality rates, and favorable mRS (0-2) upon discharge in the studied patients between Ticagrelor and Clopidogrel. Moreover, the single-arm meta-analysis for Ticagrelor revealed low rates of thromboembolic events, hemorrhage, mortality, and high rates of favorable mRS scores.

Flow diverter stenting for intracranial aneurysms in the pediatric population: Two case reports and literature review

The Pipeline Embolization Device (PED) is a flow-diverting intraluminal device that is approved for use in adults 18 years or older with internal carotid artery aneurysms. However, it can also be used off-label in pediatric patients with aneurysms that cannot be resolved with traditional endovascular treatments. Herein, we present two cases of flow diversion in the pediatric population with complete obliteration of the aneurysm and excellent outcomes. Flow diversion has been shown to be a safe endovascular option in treating complex aneurysms in children. Larger-sized, multicenter trials are encouraged to compare outcomes between flow diversion and other aneurysm treatment options given the rarity of pediatric aneurysms.

Perioperative Antiplatelet Management in the Flow-Diverter Treatment for Unruptured Cerebral Aneurysms: A Single-Center, Retrospective Analysis

BACKGROUND

Although periprocedural antiplatelet therapy for the treatment of unruptured intracranial aneurysms (UIAs) using flow-diverter stents (FDSs) is necessary to avoid thromboembolic complications, a definite antiplatelet therapy has not been established. We aimed to evaluate the safety and efficacy of periprocedural antiplatelet management in UIA treatment with FDS.

METHODS

A single-center retrospective analysis of consecutive patients with UIAs treated with FDSs between September 2013 and January 2022 was conducted. Patients received dual antiplatelet therapy (DAPT) (aspirin and clopidogrel) for 14-day before and 3-6 months after FDS placement. Platelet aggregation was evaluated prior to treatment using light transmission aggregometry, which was classified into 3 grades; 1-3: promoted, 4-6: appropriate, and 7-9: non-responder, for adenosine diphosphate (ADP) and collagen. By this classification, the antiplatelet regimen was modified. Outcome included hemorrhagic and ischemic events.

RESULTS

193 patients with 200 UIAs underwent 213 FDSs placement. The median platelet aggregability grade before treatment was 5 for ADP and 4 for collagen. Antiplatelet therapy modification was performed in 62 patients (32.1%). The median postoperative DAPT duration was 94 days. Antiplatelet medicine-related hemorrhagic events occurred in 4 patients (2.1%) and ischemic events occurred in 6 patients (3.1%). These patients had no morbido-mortality.

CONCLUSIONS

Periprocedural antiplatelet management based on the value of platelet aggregability was relatively safe and effective for treating UIA with FDS.

Immune Thrombocytopenic Purpura and Intracranial Stenting

Patients with immune thrombocytopenic purpura (ITP) presenting with indications for dual antiplatelet therapy (DAPT) can be difficult to manage due to the precarious balance of managing the need for increased platelet counts as well as inhibition of platelet activity. This case represents a 65 year old woman with ITP who presented with a bilateral subarachnoid hemorrhage secondary to a left ophthalmic aneurysm that required placement of a pipeline embolization device (PED) necessitating DAPT. After treatment of her ITP with pulse dexamethasone for four days, she was safely discharged on one month of DAPT with aspirin and ticagrelor then switched to aspirin monotherapy without any immediate complications. During her period of DAPT, she did not receive additional medical treatment for her ITP. This case successfully presents a high-risk ITP patient requiring DAPT for a neurosurgical procedure and illustrates that these patients can be safely and successfully treated with DAPT once their ITP is stabilized.

Role of optical coherence tomography in pipeline embolization device for the treatment of vertebral-basilar artery dissecting aneurysms

BACKGROUND

Vertebral-basilar artery dissecting aneurysms (VADAs) are an uncommon phenomenon in all fields of cerebrovascular disease. The flow diverter (FD) can be used as an endoluminal reconstruction device that promotes neointima formation at the aneurysmal neck and preserves the parent artery. To date, imaging examinations such as CT angiography, MR angiography, and DSA are the main methods used to evaluate the vasculature of patients. However, none of these imaging methods can reveal the situation of neointima formation, which is of great importance in evaluating occlusion of VADAs, especially those treated with a FD.

METHODS

Three patients were included in the study from August 2018 to January 2019. All patients underwent preprocedural, postprocedural, and follow-up evaluations with high resolution MRI, DSA, and optical coherence tomography (OCT), as well as the formation of intima on the surface of the scaffold at the 6 month follow-up.

RESULTS

Preprocedural, postoperative, and follow-up high resolution MRI, DSA, and OCT of all three cases successfully evaluated occlusion of the VADAs and occurrence of in stent stenosis from different views of intravascular angiography and neointima formation.

CONCLUSIONS

OCT was feasible and useful to further evaluate VADAs treated with FD from a near pathological perspective, which may contribute toward guiding the duration of antiplatelet medication and early intervention of in stent stenosis.

A Novel Braided Stent With Customized Simulation Software for Treatment of Intracranial Aneurysms: Multicenter Prospective Trial Before Unrestricted Clinical Application

BACKGROUND AND OBJECTIVES

Planning/guidance software became important tools for physicians' presurgical optimal decision-making. However, there are no intracranial stent products with specifically associated simulation software. We report the "premarket" clinical trial of a new braided stent with a customized simulation software.

METHODS

A stent system with 3 mesh density types (16, 24, and 32 wire mesh) was designed based on computational flow dynamics technology, and a simulation software (virtual stent planner [VSP]) was developed for the optimal stent deployment planning. Stents were selected after simulation on preoperative 3D-processed angioimages, and accuracy of the VSP was evaluated.

RESULTS

Thirty-three unruptured intracranial aneurysms were successfully treated with VSP guidance. Twenty aneurysms (61%) were anterior circulation aneurysms, and 13 (39%) were posterior circulation aneurysms. The average aneurysm size was 7.1 mm, and the mean follow-up period was 19.2 months (11-39.0). There was no major recurrence or retreatment during follow-up, 2 morbidity cases, and no mortality. VSP planning presented slightly smaller stent dimensions compared with postdeployment: 24.2 vs 25.5 mm average, error -1.3 mm, and difference rate-5.46%.

CONCLUSION

Based on this result, the new stents and software guidance system were approved by the Ministry of Health and Welfare as a combined medical device. VSP provided precise deployment with minimal error compared with actual stent and can contribute to better stent deployment even for less experienced physicians.

A Review of Current Flow Diverters

Flow diverter (FD) devices are new-generation stents placed in the parent artery at the aneurysmal neck to obstruct intra-aneurysmal blood flow, thus favoring intra-aneurysmal thrombosis. In Japan, about eight years have passed since health insurance approval was granted for FD devices, and FD placement to treat aneurysms has become widespread. Treatment indications have also been expanded with the introduction of novel devices. At present, three types of FD (Pipeline, FRED, and Surpass Streamline) are available in Japan. This report represents a compilation of available FD technologies and describes the current consensus on this treatment.

One year clinical outcome of dual anti-platelet therapy with the Novel Ticagrelor plus Aspirin versus Clopidogrel plus Aspirin for Endovascular Intervention of patients with Intracranial Aneurysm: A meta-analysis

BACKGROUND

The use of stents to treat un-ruptured intracranial aneurysms was first approved in the year 2002 in the United States as a Humanitarian Device Exemption. Antiplatelet therapy is mandatory following stent placement. Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel has been the first line agents for the prevention of thromboembolic events following neuro-endovascular procedures. However, clopidogrel hypo-responsiveness has often been observed. In this analysis, we aimed to systematically compare one year clinical outcome of DAPT with the Novel Ticagrelor plus Aspirin versus Clopidogrel plus Aspirin for Endovascular Intervention of patients with Intracranial Aneurysm.

METHODS

Online electronic databases were searched from June 2023 till July 2023 for relevant studies which compared DAPT with ticagrelor or clopidogrel for endovascular intervention in patients with intracranial aneurysm. The endpoints which were analyzed were classified into thromboembolic and hemorrhagic events. A fixed and a random effect statistical model were used during data analysis respectively. Risk ratio (RR) with 95 % confidence interval (CI) was used to represent the data following analysis.

RESULTS

Five studies with a total number of 893 participants were included in this analysis. Three hundred and fifty eight (358) participants were assigned to the ticagrelor group whereas 535 participants were assigned to clopidogrel group. Participants' enrollment period ranged from the year 2009 to 2019. Our results showed that during a mean follow-up time period of one year, DAPT with ticagrelor was associated with significantly lower thromboembolic events with RR: 0.33, 95 % CI: 0.16 - 0.68; P = 0.003. In addition, at one year, DAPT with ticagrelor was not associated with any increase in hemorrhagic events (RR: 0.66, 95 % CI: 0.29 - 1.50; P = 0.32) when compared to DAPT with clopidogrel.

CONCLUSION

At one year, DAPT with ticagrelor was associated with significantly lower thromboembolic events without any increase in hemorrhagic events when compared to clopidogrel associated DAPT for endovascular intervention of patients with intracranial aneurysm. However, even though ticagrelor-associated DAPT use appeared to be more effective and safe, this hypothesis should only be confirmed in larger upcoming trials.

Safety of dual antiplatelet therapy using aspirin and low-dose Prasugrel with platelet reactivity testing in flow diverter treatment of intracranial aneurysms

BACKGROUND

Dual antiplatelet therapy (DAPT) is standard care for intracranial stenting to prevent thrombotic complications. Clopidogrel resistance has resulted in patients receiving newer P2Y12 inhibitors like Prasugrel, which may reduce thrombotic complications but could increase haemorrhagic complications. This study, utilising platelet reactivity testing, compared thrombotic and haemorrhagic complications associated with Clopidogrel or 20 mg Prasugrel loading in patients treated with flow diverters (FD) for intracranial aneurysms.

METHODS

We retrospectively analysed prospectively collected data from 225 consecutive FD procedures. All patients received aspirin. 147 cases received Clopidogrel and 82 received Prasugrel. All patients had VerifyNow testing before the procedure.

RESULTS

P2Y12 non-responders were significantly more likely to have thrombotic complications than responders and hyper-responders (7% vs. 2%, p = 0.01). Low-dose Prasugrel resulted in a significantly lower rate of non-responders when compared with Clopidogrel (7% vs. 25%, p < 0.01). We found no statistically significant difference in rates of haemorrhage between the Clopidogrel and Prasugrel groups (2.4% vs. 3.9%, p = 0.47). There were 12 complications (≤7 days) in the Clopidogrel group versus 6 in the Prasugrel group (9% vs. 7.8%, respectively, p = 0.91) and a non-significant reduction in thrombotic complications in the Prasugrel group (5.2% vs. 3.9%, p = 0.88). No significant difference was shown in long-term complications between the groups (p = 0.33).

CONCLUSION

These results support the use of platelet reactivity testing and the safety of low-dose Prasugrel for FD treatment of intracranial aneurysms.

An alternative reduced dose regimen of ticagrelor for neuroendovascular patients

OBJECTIVE

There is a growing use of ticagrelor in patients undergoing neuroendovascular procedures, especially those who demonstrate clopidogrel resistance. While multiple dosages are studied in the cardiology literature, the optimal dose for patients with neurological pathology has yet to be established. Here, we describe a single center experience involving 39 patients who underwent neuroendovascular procedures that then received an adjusted lower dose of ticagrelor.

METHODS

A retrospective chart review was performed between 2013 and 2017 for patients on dual anti-platelet therapy (DAPT) for either cervical or intracranial vascular pathologies, as well as stenting of the neurovasculature, including carotid arteries. Patients were placed on ticagrelor if their measured P2Y12 reaction units (PRU) responses to clopidogrel were outside the expected range in our center using the VerifyNow™ P2Y12 test. All patients were maintained on a dose of 45 mg twice daily except for one patient who received 22.5 mg twice daily. Responsiveness to ticagrelor were measured utilizing the VerifyNow™ P2Y12 test.

RESULTS

The mean number of days for follow-up post treatment initiation was 532 days. A total of 39 patients were included in the analysis. Of these, 8 patients (21%) received implantation of intracranial stents (5 patients received pipeline embolization devices, 1 patient received stent-assisted coiling, and 2 patients received intracranial stents for atherosclerotic disease). Fourteen patients (35%) received carotid angioplasty and stenting. Seventeen patients (44%) did not receive permanent implantation of a stent. All patients on the lower dose ticagrelor of 45 mg twice daily achieved responsiveness (i.e., PRU < 194). Hemorrhagic transformation of ischemic stroke occurred in one patient (2.5%). No other hemorrhagic complications were encountered. No thromboembolic events were recorded aside from one patient (2.5%) with intracranial atherosclerotic disease who had an ischemic event.

CONCLUSIONS

A lower dose of ticagrelor (45 mg twice daily) appears to be safe and effective in this small cohort of patients who are resistant to clopidogrel per P2Y12 testing and who have increased risk of ischemic or hemorrhagic strokes due to neurovascular pathologies and implants. Further randomized studies are required to confirm these findings.

Safety and efficacy of tailored antiplatelet therapy using prasugrel or ticagrelor based on clopidogrel responsiveness in endovascular treatment for intracranial aneurysms: a meta-analysis

BACKGROUND

Clopidogrel (CPG)-based dual antiplatelet therapy (DAPT) in combination with aspirin has been widely used before endovascular procedures for intracranial aneurysms to prevent procedural thromboembolic complication (TEC). However, the main drawback of CPG is the high proportion of hyporesponders. This study sought to investigate the usefulness of tailored DAPT using novel P2Y12 inhibitors (prasugrel or ticagrelor, (PSG/TCG)) guided by a platelet reactivity test (PRT), compared with CPG-based conventional DAPT.

METHOD

Data were extracted from PubMed, Embase, and Cochrane Central Register of Controlled Trials by two independent reviewers. A random effects model was used to investigate the procedural TEC and hemorrhagic complications (HEC) of the tailored DAPT and conventional therapy by risk ratios (RR) and 95% confidence intervals (95% CI). Additionally, we performed subgroup analyses to directly compare prasugrel/ticagrelor with CPG.

RESULTS

Six studies comprising 2557 patients were included in the analysis. Compared with conventional non-tailored therapy, PRT-guided tailored DAPT with PSG/TCG was associated with a lower risk of TEC (RR 0.40, 95% CI 0.22 to 0.74, P=0.004) without increasing HEC rates. The subgroup analysis showed that the switch to PSG/TCG in CPG hyporesponders was related to a lower incidence of TEC (RR 0.46, 95% CI 0.23 to 0.95, P=0.03) without a difference in HEC, compared with maintenance of CPG in CPG responders.

CONCLUSION

Evidence from this analysis supports PRT-guided tailored DAPT (using PSG/TCG) as a better choice for preparation towards endovascular procedures to treat aneurysms. Furthermore, it suggests that PSG/TCG is not limited to the role of a substitute for CPG but may be a first-line agent for DAPT.

Use of the Neuroform Atlas stent for wide-necked cerebral aneurysms

To investigate the effect and safety of the Neuroform Atlas (NFA) stent in stent-assisted coiling of wide-necked intracranial aneurysms, patients with wide-necked intracranial aneurysms were retrospectively enrolled and treated with the NFA stent-assisted coiling. The modified Rankin scale (mRS) grades and Raymond grades were used to assess the clinical outcomes and aneurysm occlusion degrees, respectively, after embolization and at follow-up. Totally, 122 patients were enrolled with 129 wide-necked aneurysms, and forty-nine (40.2%) patients experienced subarachnoid hemorrhage. A total of 134 NFA stents were deployed in all patients. Immediately after endovascular embolization, the Raymond grade was I in 112 (86.8%), II in 8 (6.2%), and III in 9 (7.0%). Complications occurred in 7 (5.7%) patients, including stent displacement in 2 (1.6%) patients, thrombosis and cerebral infarction in 4 (3.3%), and death in 1 (0.8%). Clinical follow-up was performed in 113 (92.6%) patients 6-30 (mean 21) months after embolization, with the mRS grade 0 in 99 (87.6%) patients, 1 in 7 (6.2%), 2 in 5 (4.4%), and 3 in 2 (1.8%). Good prognosis (mRS ≤ 2) was achieved in 111 (98.2%) patients while poor prognosis (mRS > 2) in two (1.8%). Digital subtraction angiography was conducted in 98 (80.3%) patients with 104 (80.6%) aneurysms 6-30 (mean 21) months after embolization. The Raymond grade was grade I in 94 (90.4%) aneurysms, II in 4 (3.8%), and III in 6 (5.8%). Compared with the Raymond grades immediately after embolization, 93 (89.4%) aneurysms disappeared, 9 (8.7%) remained unchanged in the occlusion status, and 2 (1.9%) were recurrent. In conclusion, the NFA stent may have a high aneurysm occlusion rate and a low complication rate in assisting coiling of wide-necked intracranial aneurysms even though further studies are necessary to prove this.

Use of Tirofiban to Prevent Ischemic Events in Patients with CYP2C19 Loss-of-Function Alleles during Flow Diversion of Intracranial Aneurysm: A Multicenter Cohort Study

To analyze the effect of tirofiban on ischemic events in CYP2C19 loss-of-function (LOF) allele carriers during pipeline embolization device (PED) implantation. Demographic information, imaging data, ischemic complications, CYP2C19 genotyping, and platelet function test results were collected from patients with PED-treated intracranial aneurysms at three centers. Multivariate logistic regression was used to analyze risk factors for ischemic events. Patients were grouped according to LOF alleles and antiplatelet drugs, the baseline information of LOF allele carriers and non-carriers were compared, and the efficacy of tirofiban was analyzed by comparing the incidence of ischemic events in each group. In total, 278 patients were included in the study, 24 of whom had an ischemic event. 157 (56.5%) patients carried the LOF allele and were more likely to develop resistance to clopidogrel (P < 0.001) and hypertension (P = 0.010). Multivariate logistic regression analysis revealed that the independent risk factors for ischemic events were age of > 55 years (OR = 3.308, P = 0.028), LOF alleles (OR = 3.960, P = 0.036), and clopidogrel nonresponsiveness (OR = 3.301, P = 0.014). For LOF allele carriers, prophylactic use of tirofiban after PED implantation helped to reduce ischemic events (4.3% vs. 16.4%, P = 0.039). This study supports CYP2C19 genotyping before flow diversion because LOF alleles increase the risk of ischemic events. Prophylactic use of tirofiban may help reduce ischemic events in LOF allele carriers.

Safety and effect of pipeline flex embolization device for complex unruptured intracranial aneurysms

To investigate the safety and short-term effect of Pipeline Flex devices in the treatment of complex unruptured intracranial aneurysms, a retrospective study was performed for patients with complex unruptured intracranial aneurysms who were treated with the Pipeline Flex embolization device (PED Flex device) combined with or without coiling. The clinical, endovascular, and follow-up data were analyzed. One hundred and thirty-one patients with 159 complex unruptured cerebral aneurysms were treated with the PED Flex device, with 144 Flex devices deployed. Periprocedural complications occurred in four patients, resulting in the complication rate of 3.1%, including ischemic complications in three patients (2.3%) and hemorrhagic complication in one (0.8%). At discharge, the mRS was 0 in 101 (77.1%) patients, 1 in 25 (19.1%), 2 in four (3.1%), and 4 in one (0.8%), with the good prognosis rate (mRS 0-2) of 99.2%. Clinical follow-up was carried out in 87 (66.4%) patients 3-42 months after the procedure, with the mRS of 0 in 78 (89.7%), 1 in five (5.7%), 2 in three (3.4%), and 4 in one (1.1%). No significant (P = 0.16) difference existed in the mRS at discharge compared with that at clinical follow-up. Angiographic follow-up was performed in 61 (46.7%) patients with 80 (50.3%) aneurysms at 3-40 months, with the OKM grade of D in 57 (71.3%) aneurysms, C in eight (10%), and B in 15 (18.8%). Asymptomatic instent stenosis occurred in four patients (6.6%). In conclusion: The treatment of complex intracranial aneurysms with the Pipeline Flex embolization device may be safe and effective, with a high complete occlusion rate, a decreased complication rate, and a good prognosis rate at medium follow-up.

Effect of Stent Porosity, Platelet Function Test Usage, and Dual Antiplatelet Therapy Duration on Clinical and Radiographic Outcomes After Stenting for Cerebral Aneurysms: A Meta-Analysis

BACKGROUND

The use of stents with various porosities for treating cerebral aneurysms requires dual antiplatelet therapy (DAPT) without clear guidelines on the utility of platelet function tests (PFTs) and the duration of DAPT. We sought to determine the effects of stent porosity, PFT usage, and DAPT duration on the radiographic and clinical outcomes after stenting of cerebral aneurysms.

METHODS

PubMed was searched on March 29, 2021 for studies of cerebral aneurysm stenting that had specified the stent type and DAPT duration. A random effects meta-analysis was used to measure the prevalence of nonprocedural thrombotic and hemorrhagic events, clinical outcomes, aneurysm occlusion, and in-stent stenosis stratified by stent porosity, PFT usage, and DAPT duration.

RESULTS

The review yielded 105 studies (89 retrospective and 16 prospective) with 117 stenting cohorts (50 high porosity, 17 intermediate porosity, and 50 low porosity). In the high-, intermediate-, and low-porosity stenting cohorts, PFT usage was 26.0%, 47.1%, and 62.0% and the mean DAPT duration was 3.51 ± 2.33, 3.97 ± 1.92, and 5.18 ± 2.27 months, respectively. The intermediate-porosity stents showed a reduced incidence of hemorrhagic events (π = 0.32%) compared with low-porosity stents (π = 1.36%; P = 0.01) and improved aneurysm occlusion (π = 6.18%) compared with high-porosity stents (π = 14.42%; P = 0.001) and low-porosity stents (π = 11.71%; P = 0.04). The prevalence of in-stent stenosis was lower for the intermediate-porosity (π = 0.57%) and high-porosity (π = 1.51%) stents than for the low-porosity stents (π = 3.30%; P < 0.05). PFT use had resulted in fewer poor clinical outcomes (π = 3.54%) compared with those without PFT use (π = 5.94%; P = 0.04). The DAPT duration had no effect on the outcomes.

CONCLUSIONS

In the present meta-analysis, which had selected for studies of cerebral aneurysm stenting that had reported the DAPT duration, intermediate-porosity stents and PFT use had resulted significantly improved outcomes. No effect of DAPT duration could be detected.

Flow Diverting Stents in Cerebral Small Caliber Vessels (< 2 mm) for Aneurysm Treatment : A Three Center Retrospective Study

PURPOSE

The off-label use of flow diverting stents (FDS) for treating cerebral aneurysms in small distal vessels is increasing in clinical practice with encouraging results; however, data directly addressing the parent vessel size are still scarce. Our aim was to evaluate the safety and efficacy of FDS placement in anterior and posterior circulation aneurysms with parent arteries ≤ 2 mm in a real-world representative setting.

METHODS

We retrospectively reviewed patients treated with FDS at the three participating university hospitals between 2009 and 2021. The inclusion criteria were the placement of at least one FDS in a parent vessel with a maximum diameter of 2 mm or less. The primary clinical safety endpoint was the absence of death, major or minor symptomatic stroke, transient ischemic attack and procedure-related intracranial hemorrhage. Clinical outcome was assessed using the modified Rankin Scale (mRS) score at the follow-up visit at 1 year. The primary efficacy endpoint was defined as complete and near-complete occlusion at the 1‑year follow-up.

RESULTS

We identified 55 patients harboring 56 aneurysms. The primary clinical safety endpoint was obtained in 93% of cases. The hemorrhagic and thromboembolic complication rates were 4% and 9%, respectively. No patient died or had a relevant discrepancy (> 1 point) at the pre-mRS and post-mRS. The primary efficacy endpoint was reached in 80% of cases.

CONCLUSION

The use of FDS in vessels < 2 mm is technically feasible with good aneurysm occlusion rates and an acceptable safety profile. Nevertheless, it is essential to be aware of the of the main complications associated when operating in small diameter vessels.

Head and neck angiography in the pediatric population: single-center experience with indications, safety, feasibility, and technical differences among infants, childhood, and adolescents

OBJECTIVE

Pediatric patients are candidates for head and neck endovascular procedures less frequently than adults. Data on utilization, feasibility, safety, and technical details of head and neck angiography in the pediatric population are scarce.

METHODS

The authors performed a retrospective review of their center's endovascular database to identify all patients ≤ 18 years of age who underwent diagnostic or interventional catheter-based angiography of the head and neck. Procedure-related variables for identified patients were compared across infancy (birth to 2 years), childhood (> 2-11 years), and adolescence (> 11-18 years).

RESULTS

One hundred twenty-one pediatric patients who underwent 274 angiogram procedures were included in this study. Of these angiograms, 197 were diagnostic and 118 were interventional (including 41 of the diagnostic angiogram procedures that were performed concurrently with the intervention). The most common indications for diagnostic angiograms were suspected vascular malformations in 52 cases (26.4%) and aneurysms in 23 (11.7%). The rate of positive findings on diagnostic angiograms ranged from 27.3% to 80% according to the indication. Access site-related complications were observed after 2 punctures (0.7%). Procedure-related complications occurred in 3 patients (1.1%). In adolescents, the rates of general anesthesia use and sheathless access were significantly lower (each p < 0.001), and the rates of radial artery access (p < 0.001); 5-French (5F) (p = 0.01), 6F (p < 0.001), and 8F (p = 0.03) access; and closure device usage (p < 0.001) were significantly higher. In infants, the rates of ultrasound guidance, 4F access, and failure of the primary puncture site were significantly higher (each p < 0.001).

CONCLUSIONS

Head and neck angiograms in the pediatric population were feasible and safe in the authors' overall experience. Technical differences were observed across the infant, childhood, and adolescent groups, but safe outcomes were similar throughout these age ranges.

Antiplatelet therapy adjustment improved the radiomic characteristics of acute silent cerebral infarction after stent-assisted coiling in patients with high on-treatment platelet reactivity: A prospective study

Background

We aimed to investigate the effects of high on-treatment platelet reactivity (HPR) and antiplatelet therapy adjustment on high-risk radiomic features in patients with antiplatelet therapy adjustment on acute silent cerebral infarction (ASCI) who had unruptured intracranial aneurysms (UIA) after stent placement.

Methods

This single-institution study prospectively included 230 UIA patients who had ACSI after stent placement in our hospital between January 2015 and July 2020. All patients underwent magnetic resonance imaging with diffusion-weighted imaging (MRI-DWI) after stent placement and 1,485 radiomic features were extracted from each patient. The least absolute shrinkage and selection operator regression methods were used for selection of high-risk radiomic features associated with clinical symptoms. In addition, 199 patients with ASCI were classified into three groups: controls without HPR (n = 113), HPR patients with standard antiplatelet therapy (n = 63) and HPR patients with antiplatelet therapy adjustment (n = 23). We compared high-risk radiomic features between three groups.

Results

Of the patients who had acute infarction after MRI-DWI, 31 (13.5%) exhibited clinical symptoms. Eight risk radiomic features associated with clinical symptoms were selected, and the radiomics signature exhibited good performance. In ASCI patients, compared with controls, the radiomic characteristics of ischemic lesion in HPR patients were consistent with the following high-risk radiomic features associated with clinical symptoms: higher gray-level values, greater variance in intensity values, and greater homogeneity. However, the adjustment of antiplatelet therapy in HPR patients modified the high-risk radiomic features, which showed lower gray-level values, less variance in intensity values, and more heterogeneous texture. The radiomic shape feature of elongation showed no notable difference between three groups.

Conclusion

Adjustment of antiplatelet therapy might reduce the high-risk radiomic features of UIA patients with HPR after stent placement.

Low incidence of hemorrhagic complications both during and after surgical procedures in patients maintained on prasugrel single antiplatelet therapy

BACKGROUND AND PURPOSE

Prasugrel (Pra) is a third-generation thienopyridine that inhibits platelet aggregation via irreversible blockade of P2Y12 receptors. While several published studies have examined the use of Pra and acetylsalicylic acid (ASA) in coronary and neurovascular stenting procedures, there is only anecdotal evidence regarding the use of Pra as single antiplatelet therapy (SAPT) in open surgical procedures. This topic has become important because previous studies have revealed that neurovascular devices with antithrombotic coatings can be implanted using non-invasive procedures in patients maintained on Pra SAPT.

MATERIAL AND METHODS

Patients who underwent open surgery under Pra SAPT between March 2020 and February 2022 were evaluated retrospectively. Adequate platelet inhibition both before and after the procedures was verified in all patients using Multiplate (Roche Diagnostics) and VerifyNow (Accriva) tests. Intraoperative and postoperative hemorrhagic events were recorded based on reviews of the procedure reports and interviews with the surgeons.

RESULTS

The study enrolled 21 patients who underwent 23 open surgical procedures while maintained on Pra SAPT. The procedures included one extirpation of a brain arteriovenous malformation, seven extra-intracranial bypass surgeries, four ventriculoperitoneal shunts, one eye enucleation for an intractable orbital infection, two gastrostomies, one bone flap reinsertion after craniectomy, one decompressive craniectomy, one case requiring cranial surgical wound care, one colporrhaphy, one transurethral resection of urinary bladder cancer, two tumor oophorectomy/hysterectomy procedures, and one aneurysm clipping. None of the 23 procedures resulted in excessive intraoperative or postoperative hemorrhage.

CONCLUSION

In a small retrospective series of patients who required antiplatelet therapy for neurovascular indications, Pra SAPT resulted in no significant increase in the incidence of perioperative and postoperative hemorrhagic complications.

Pipeline embolization devices for the treatment of nonsaccular aneurysms in pediatric patients

Objective

Pediatric nonsaccular aneurysms are rare but challenging lesions; pipeline embolization devices (PEDs) are their potential treatment option. In this study, we aimed to evaluate the safety and efficacy of PEDs for treatment of these aneurysms.

Methods

We retrospectively selected pediatric patients with nonsaccular aneurysms treated using PEDs between June 2015 and July 2021 from our prospectively maintained database. For each patient, demographics, aneurysm characteristics, procedure details, and clinical and angiographic follow-up data were collected and summarized.

Results

This study included 16 pediatric patients with 16 nonsaccular aneurysms treated with PEDs. A median clinical follow-up time of 1,376 days was achieved in 93.75% of the patients. The complication rate of the included patients was 25%, with two patients developing mass effect, one patient undergoing major ischemic stroke, and one patient experiencing stent foreshortening after the procedure. The complete occlusion rate of aneurysms without any neurologic sequelae was 93.33%, with a median angiographic follow-up period of 246 days. The mortality rate was 6.25%.

Conclusions

The use of PEDs to treat pediatric nonsaccular aneurysms is feasible, with a high rate of complete occlusion of the aneurysm and favorable follow-up outcomes.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Learning Curve for Flow Diversion of Posterior Circulation Aneurysms: A Long-Term International Multicenter Cohort Study

BACKGROUND AND PURPOSE

Flow diversion has gradually become a standard treatment for intracranial aneurysms of the anterior circulation. Recently, the off-label use of the flow diverters to treat posterior circulation aneurysms has also increased despite initial concerns of rupture and the suboptimal results. This study aimed to explore the change in complication rates and treatment outcomes across time for posterior circulation aneurysms treated using flow diversion and to further evaluate the mechanisms and variables that could potentially explain the change and outcomes.

MATERIALS AND METHODS

A retrospective review using a standardized data set at multiple international academic institutions was performed to identify patients with ruptured and unruptured posterior circulation aneurysms treated with flow diversion during a decade spanning January 2011 to January 2020. This period was then categorized into 4 intervals.

RESULTS

A total of 378 procedures were performed during the study period. Across time, there was an increasing tendency to treat more vertebral artery and fewer large vertebrobasilar aneurysms (P = .05). Moreover, interventionalists have been increasingly using fewer overlapping flow diverters per aneurysm (P = .07). There was a trend toward a decrease in the rate of thromboembolic complications from 15.8% in 2011-13 to 8.9% in 2018-19 (P = .34).

CONCLUSIONS

This multicenter experience revealed a trend toward treating fewer basilar aneurysms, smaller aneurysms, and increased usage of a single flow diverter, leading to a decrease in the rate of thromboembolic and hemorrhagic complications.

Clopidogrel hyper-response increases peripheral hemorrhagic complications without increasing intracranial complications in endovascular aneurysm treatments requiring dual antiplatelet therapy

Clinical significance of increased clopidogrel response measured by VerifyNow P2Y12 assay is unclear; management guidelines are lacking in the context of neuroendovascular intervention. Our objective was to assess whether increased clopidogrel response predicts complications from endovascular aneurysm treatment requiring dual antiplatelet therapy. A single-institution, 9-year retrospective study of patients undergoing endovascular treatments for ruptured and unruptured aneurysms requiring aspirin and clopidogrel was conducted. Patients were grouped according to preoperative platelet inhibition in response to clopidogrel measured by the VerifyNow P2Y12 assay (VNP; P2Y12 reactivity units, PRU). Demographic and clinical features were compared across groups. Hemorrhagic complication rates (intracranial, major extracranial, minor extracranial) and thromboembolic complications (in-stent stenosis, stroke/transient ischemic attack) were compared, controlling for potential confounders and multiple comparisons. Data were collected from 284 patients across 317 procedures. Pre-operative VNP assays identified 9 % Extreme Responders (PRU ≤ 15), 13 % Hyper-Responders (PRU 16-60), 62 % Therapeutic Responders (PRU 61-214), 16 % Hypo-Responders (PRU ≥ 215). Increased response to clopidogrel was associated with increased risk of any hemorrhagic complication (≤60 PRU vs > 60 PRU; 39 % vs 24 %, P = 0.050); all intracranial hemorrhages occurred in patients with PRU > 60. Thromboembolic complications were similar between therapeutic and subtherapeutic patients (<215 PRU vs ≥ 215 PRU; 15 % vs 16 %, P = 0.835). Increased preoperative clopidogrel response is associated with increased rate of extracranial hemorrhagic complications in endovascular aneurysm treatments. Hyper-responders (16-60 PRU) and Extreme Responders (≤15 PRU) were not associated with intracranial hemorrhagic or thrombotic complications. Hypo-responders who underwent adjustment of antiplatelet therapy and neurointerventions did not experience higher rates of complications.

Platelet reactivity after clopidogrel loading in patients with acute ischemic stroke

Objective

It remains unclear when sufficient antiplatelet effect is achieved after administration of a loading dose of clopidogrel in patients with acute ischemic stroke (AIS). This study aimed to evaluate the clopidogrel response in patients with AIS identified by the platelet function test (PFT).

Methods

P2Y12 reaction unit (PRU) values measured using VerifyNow at baseline and at 6, 24, and 72 h after administration of a loading dose (300 mg) of clopidogrel were compared between patients with AIS and those of other cerebrovascular diseases (CVD). The prevalence of clopidogrel abnormal response and its associated factors were examined.

Results

The PRU value was significantly reduced with time in the other CVD group (p &lt; 0.0001), and also in the AIS group (p = 0.0073). The PRU values were significantly higher in the AIS group than in the other CVD group (p &lt; 0.0001 between the groups, baseline: 314 ± 53 vs. 284 ± 62, p = 0.35; 6 h: 290 ± 66 vs. 214 ± 71, p = 0.016; 24 h: 270 ± 75 vs. 190 ± 70, p &lt; 0.0001; and 72 h: 231 ± 76 vs. 163 ± 93, p = 0.105). The prevalence of clopidogrel hypo-responder (PRU &gt; 240 at 24 h after administration) was higher in the AIS group (79 vs. 33%, p &lt; 0.0001) and associated with the baseline PRU value but not with the cytochrome P450 2C19 genotype or clinical ischemic events.

Conclusions

Residual platelet reactivity at 24 h after clopidogrel loading was substantially higher in patients with AIS than in patients with other CVD. In addition, most patients with AIS were judged to be hypo-responders on PFT. This should be carefully interpreted in patients with AIS because of poor specificity for predicting clinical ischemic events.

The Effect of Ticagrelor for Endovascular Intervention of Intracranial Aneurysm Patients with or without Clopidogrel Resistant: A Meta-Analysis

Endovascular interventional is an important treatment method for intracranial aneurysms. However, due to the risk of intracranial thrombosis, prophylactic use of antiplatelet drugs is generally required. Clinically, the most commonly used drugs are aspirin and clopidogrel; although the latter can significantly reduce the incidence of thromboembolic complications, there are still some patients with clopidogrel resistance who have ischemic adverse events during antiplatelet therapy. In this study, cohort studies of PubMed, Embase and Cochrane Library Databases were retrieved to compare the efficacy and safety of ticagrelor and clopidogrel in endovascular interventional treatment of intracranial aneurysms. A total of 10 cohort studies involving 1377 patients were included in this study. All patients had intracranial aneurysms and underwent endovascular intervention. Platelet function was measured in four of the studies and switched the patients with clopidogrel resistance to ticagrelor, while the remaining six studies did not test platelet function, but were also treated with ticagrelor or clopidogrel. The results of the study showed that ticagrelor, like clopidogrel, can effectively control thrombotic complications in endovascular interventional patients, and also control the occurrence of ischemic complications in clopidogrel-resistant patients. Ticagrelor, as a novel platelet aggregation inhibitor that can reversibly bind to P2Y12 receptor, can effectively control thromboembolic complications without increasing hemorrhagic complications, and is also effective in patients with clopidogrel resistance.

Progressive volume reduction and long-term aneurysmal collapse following flow diversion treatment of giant and symptomatic cerebral aneurysms

Background

The primary goal of conventional endovascular and microvascular approaches is the clinical and radiological resolution of the symptomatic aneurysm-induced mass effect. This study assessed the volume changes and mass effect reduction due to sac shrinkage after treatment with flow diverter stents (FD) for unruptured cerebral aneurysms.

Methods

We analyzed retrospectively 36 symptomatic aneurysms that were larger or equal to 25 mm in diameter in patients treated at our center from January 2016 to April 2022. Radiological and clinical outcomes were analyzed, including aneurysmal volume changes and resolution of aneurysm-related symptoms.

Results

At 6 months, 25 aneurysms decreased in size, 2 remained unchanged, and 9 aneurysms demonstrated a post-treatment dimensional increase. At 12 months, 30 aneurysms showed a progressive radiological volume reduction. Either no change or negligible shrinkage was observed in the remaining six aneurysms. At 24 months, 32 aneurysms showed aneurysmal shrinkage by a mean 47% volume loss with respect to baseline. At the last follow-up, all 13 patients who had presented with third cranial nerve palsy showed improvements. Complete reversal of the pretreatment edematous changes was confirmed in all cases. The overall post-treatment complication rate was 8.3%, as 3 patients experienced non-fatal delayed rupture of their aneurysm. There was no mortality in this study.

Conclusion

Flow diversion could effectively induce progressive aneurysmal shrinkage and resolution of the mass effect associated with giant symptomatic cerebral aneurysms.

Silk Vista Baby flow diverter stent for ruptured intracranial aneurysms: a retrospective observational study

PURPOSE

Flow diversion changed the approach to complex intracranial aneurysms, leading to a widespread use and a rapid technological evolution. Indeed, indications continued to expand, including ruptured intracranial aneurysms in selected cases. Recently, new devices have been designed specifically to target smaller vessels. Therefore, we conducted a multicenter study to evaluate clinical outcome, complications, and occlusion rate of patients with ruptured aneurysms treated with new generation low profile Silk Vista Baby (SVB) flow diverter stent (FD).

METHODS

We performed a retrospective observational study on consecutive patients who underwent treatment with SVB for ruptured aneurysms at 12 Italian centers. Primary end point was favorable clinical outcome rate, defined as modified ranking score (mRS) of 0-2 at the 3 months. Secondary outcomes were complication rate, aneurysm re-rupture, and complete aneurysm occlusion at last radiological follow-up.

RESULTS

Twenty-five patients were included; at 3 months' follow-up, 19 patients (79.1%) had favorable clinical outcome (mRS 0-2). Three patients (12.5%) died during follow-up. In-stent thrombosis occurred in two cases (8.3%), managed with glycoprotein IIb/IIIA and intra-stent angioplasty, without clinical consequences. In 18 (85.7%) patients, complete occlusion at 3 months was demonstrated. No rebleeding occurred during follow-up. Presentation with unfavorable World Federation of Neurosurgical Societies grading system (WFNS) and posterior circulation location were both significantly correlated with unfavorable clinical outcome (p = 0.005 and p = 0.02).

CONCLUSIONS

Our data suggests that low profile FD treatment of ruptured intracranial aneurysms located distally of the circle of Willis is feasible. New generation low profile FD may represent an alternative option in carefully selected cases.

Excessive platelet inhibition following Pipeline embolization of intracranial aneurysms

BACKGROUND

High levels of platelet inhibition have been associated with hemorrhagic complications following Pipeline embolization of intracranial aneurysms. We therefore titrate clopidogrel dosing to maintain a moderate level of platelet inhibition using the VerifyNow P2Y12 assay. However, many patients demonstrate dramatic increases in platelet inhibition following treatment despite being on a consistent antiplatelet regimen. We therefore elected to explore the incidence of this phenomenon and possible predisposing factors.

METHODS

All successful Pipeline aneurysm treatments performed at our institution from 2011 to 2019 with moderate procedure-day platelet inhibition levels as indicated by a VerifyNow PRU of 60-235 were included. Patients who received glycoprotein IIb/IIIa inhibitors and those treated for ruptured/symptomatic lesions were excluded. The incidence of excessive platelet inhibition defined by a PRU<60 within 8 weeks of treatment was noted. Multivariable logistic regression was performed to determined independent predictors of the phenomenon.

RESULTS

Some 190 treatments were performed in 178 qualifying patients. A post-procedure PRU <60 occurred following 79% of treatments, documented on average after 8.5 (range 1-47) days. A higher procedure day hematocrit level (P=0.003, OR 1.09, 95% CI 1.029 to 1.152) was an independent predictor of reaching a PRU <60, while intra-procedural midazolam exposure (P=0.044, OR 0.44, 95% CI 0.201 to 0.980) and a higher procedure-day PRU (P=0.047, OR 0.99, 95% CI 0.982 to 1.000) were associated with a reduced odds. Time-since-procedure and hematocrit levels were associated with excessive platelet inhibition when excluding patients who initially demonstrated hyperresponse.

CONCLUSION

Elevations in platelet inhibition were frequently observed following flow diversion with Pipeline.

A Single Flow Re-direction Endoluminal Device for the Treatment of Large and Giant Anterior Circulation Intracranial Aneurysms

PURPOSE

The purpose of this study was to report the author's experiences in treating large (10-25 mm) and giant (>25 mm) intracranial aneurysms (IAs) using a single Flow Re-direction Endoluminal Device (FRED) without assistant coiling, with a focus on procedure-related complications.

MATERIALS AND METHODS

A total of 33 patients who were treated with FRED between January 2018 and July 2020 were retrospectively reviewed. The timing of procedure-related complications was chronologically categorized as acute (within 7 days), subacute (8 to 21 days), and delayed (after 21 days) periods. Follow-up angiography was performed at 2 to 27 months (mean 9.7 months), and clinical follow-up was performed at 1 to 31 months (mean 14.1 months) in all patients.

RESULTS

Six (18.2%) patients experienced procedure-related complications, including 2 (6.1%) in acute period, 1 (3.0%) in subacute period, and 3 (9.1%) in delayed period. Thromboembolic complications occurred in 5 (15.2%) patients and hemorrhagic complications in 1 (3.0%). Permanent morbidity and mortality rates were 3.0% each. Non-internal carotid artery (ICA) location of IAs (odds ratio 6.532; 95% confidence interval, 1.335-17.816; p=0.034) was the only independent risk factor for procedure-related complications on multivariate logistic regression analysis.

CONCLUSION

The procedure-related complication rate was 18.2% in this study. Procedure-related complications might increase when treating large and giant IAs located on a non-ICA, especially on the middle cerebral artery. Therefore, it may be suggested that neurointerventionists and endovascular neurosurgeons should pay attention to the location of IAs when treating large and giant IAs with a single FRED.

Safety and Efficacy of Cangrelor Among Three Antiplatelet Regimens During Stent-Assisted Endovascular Treatment of Unruptured Intracranial Aneurysm: A Single-Center Retrospective Study

Introduction

Thromboembolic events represent the most frequent complications of endovascular treatment of unruptured intracranial aneurysm using stent-assisted coilling or flow diverter stents. Dual antiplatelet therapy has become the standard to prevent these but remains unstandardized. We present here a single center experience of 3 standardized antiplatelet regimens during brain aneurysm treatment, while emphasizing the use of the Cangrelor.

Method

We retrospectively reviewed data from patients treated using stent-assisted coilling or flow diverter stents from 2016 to 2021. We collected and compared safety and efficacy data within 6 months of three groups of patients corresponding to three antiplatelet standardized regimens: group T with Ticagrelor, with preprocedural preparation; group E with Eptifibatide, injected during procedure; group C with Cangrelor, injected during procedure.

Results

Data of 112 patients were analyzed and 76 belonged to group T, 21 to group E, and 15 to group C. Eleven events over the 14 recorded were adjudicated to be related to antiplatelets, their repartition did not differ between the 3 groups (p = 0.43). All symptomatic events (N = 8) were not distributed significantly differently between the 3 groups (p = 0.11) and asymptomatic events were also balanced (p = 1.00). Of these, 6 subjects had a change in the mRS score at 3–6 months. Thrombo-embolic events represented the most encountered events in the sample: 2 acute ischemic strokes were recorded in group E and 1 in group T; 1 transient ischemic stroke was noted in group E; 4 silent infarcts were found on control MRI (2 belonged to group T, 1 to group E and 1 to group C). Among 3 intracranial bleeding events, 1 was symptomatic in group C, 2 were asymptomatic in group T. On the control evaluation performed at 6 months, there was no significant difference on aneurysmal occlusion (p = 0.67).

Conclusion

This single-center retrospective study compared 3 antiplatelet regimens, finding no significant difference in the safety and efficacy in the context of endovascular treatments of unruptured aneurysm using stent or flow diverters. This study adds data for the Cangrelor use and suggests its usefulness in the field of neuro-endovascular intervention. Randomized controlled studies are warranted to confirm these results.

Endovascular Management of Hemorrhagic Stroke

Significant advances in endovascular neurosurgery tools, devices, and techniques are changing the approach to the management of acute hemorrhagic stroke. The endovascular treatment of intracranial aneurysms emerged in the early 1990s with Guglielmi detachable coils, and since then, it gained rapid popularity that surpassed open surgery. Stent-assisted coiling and balloon remodeling techniques have made the treatment of wide-necked aneurysms more durable. With the introduction of flow diverters and flow disrupters, many aneurysms with complex geometrics can now be reliably managed. Arteriovenous malformations and fistulae can also benefit from endovascular therapy by embolization using n-butyl cyanoacrylate (NBCA), Onyx, polyvinyl alcohol (PVA), and coils. In this article, we describe the role of endovascular treatment for the most common causes of intracerebral and subarachnoid hemorrhages, particularly ruptured aneurysms and vascular malformations.

Vertebral artery dissection and associated ruptured intracranial pseudoaneurysm successfully treated with coil assisted flow diversion: A case report and review of the literature

Dissecting intracranial pseudoaneurysms (IPs) are associated with a high incidence of rupture and poor neurologic outcomes. Lesions in the posterior circulation are particularly malignant and pose even greater management challenges. Traditional management consists of microsurgical vessel sacrifice with or without bypass. Flow diversion (FD) in the setting of subarachnoid hemorrhage (SAH) represents a reconstructive treatment option and can be paired with coil embolization to promote more rapid thrombosis of the lesion. We report a case of a ruptured dissecting vertebral artery (VA) IP successfully acutely treated with coil-assisted FD. A 53-year-old male presented with a right V4 dissection spanning the origin of the posterior inferior cerebellar artery and associated ruptured V4 IP. The patient was treated with coil-assisted FD. Oral dual-antiplatelet therapy (DAPT) was initiated during the procedure, and intravenous tirofiban was used as a bridging agent. Immediate obliteration of the IP was achieved, with near-complete resolution of the dissection within 48 h. The patient made a complete recovery, and angiography at 6 weeks confirmed total IP obliteration, reconstruction of the VA, and a patent stent. The use of FD and DAPT in the setting of acute SAH remains controversial. We believe that coil-assisted FD in carefully selected patients offers significant advantages over traditional microsurgical and endovascular options. The risks posed by DAPT and potential for delayed thrombosis with FD can be effectively mitigated with planning and the development of protocols. We discuss the current literature in the context of our case and review the challenges associated with treating these often devastating lesions.

Severe, Intolerable Fatigue Associated with Hyperresponse to Clopidogrel

OBJECTIVE

Clopidogrel is a commonly used antiplatelet agent for the prevention of thromboembolic complications following neuroendovascular procedures, but anecdotal data have raised concern for the possibility that clopidogrel may induce severe, intolerable fatigue. The purpose of this study is to systematically investigate this phenomenon.

METHODS

We performed a dual-institution, 9-year, retrospective study of patients undergoing clopidogrel therapy for neuroendovascular procedures. Patients were included only if their response to clopidogrel was assessed by platelet function testing using the VerifyNow P2Y₁₂ (VNP) assay. Hyperresponse to clopidogrel was defined as P2Y₁₂ reaction units ≤60. Patients were considered to have had clopidogrel-induced severe fatigue if the onset of symptoms followed the initiation of clopidogrel therapy; symptoms improved following a reduction in the dose of clopidogrel; and symptoms could not be attributed to any other medical explanation.

RESULTS

Data were collected on 349 patients. Five patients (1.4%) met criteria for clopidogrel-induced severe fatigue. All 5 patients were female, ages 39-68. VNP assessments obtained while patients were symptomatic revealed hyperresponse to clopidogrel (0-22 P2Y₁₂ reaction units). Symptoms improved in all 5 patients when the dose of clopidogrel was reduced by half. Notably, 30% of patients (n = 103) demonstrated a hyperresponse to clopidogrel on at least 1 VNP assessment, but 98 of these patients did not suffer from severe fatigue.

CONCLUSIONS

A syndrome of severe fatigue and other constitutional symptoms is a rare but clinically significant side effect of hyperresponse to clopidogrel in patients undergoing neuroendovasular intervention.

Effect of Adjusted Antiplatelet Therapy on Preventing Ischemic Events After Stenting for Intracranial Aneurysms

BACKGROUND AND PURPOSE

This study tests whether patients with unruptured intracranial aneurysm who underwent stent placement benefitted from platelet function monitoring-guided adjustment of antiplatelet therapy.

METHODS

We conducted a randomized, open-label, parallel group, assessor-blinded trial. Patients with unruptured intracranial aneurysm who underwent stent placement were assigned in a 1:1 ratio to receive either drug adjustment (patients who had high on-treatment platelet reactivity to antiplatelet therapy on the basis of platelet function monitoring [monitoring group]) or conventional therapy (without monitoring and drug adjustment [conventional group]). The second monitoring was performed 14 days after randomization in patients with drug adjustment. The primary outcome was the composite frequency of ischemic stroke, transient ischemic attack, stent thrombosis, urgent revascularization, and cerebrovascular death within 7 days after stent implantation. The safety outcome was the composite frequency of major, minor, or minimal bleeding within 1 month after stent implantation.

RESULTS

In total, 314 patients were included (n=157 per group). The primary combined outcome occurred in 19 patients (12.1%) in the conventional group and 8 patients (5.1%) in the monitoring group (hazard ratio, 0.39 [95% CI, 0.17-0.92]; P=0.03). Ischemic stroke occurred at a lower frequency in the monitoring group compared with that in the conventional group (4.5% versus 12.1%; hazard ratio, 0.34 [95% CI, 0.14-0.83]; P=0.01), which drove the overall primary combined outcome. The safety outcome occurred in the monitoring group (7.0%) and in the conventional group (1.9%; hazard ratio, 3.87 [95% CI, 1.06-14.14]; P=0.03). A significant difference was observed in the frequency of minor or minimal bleeding events between the two groups (monitoring group versus conventional group, 6.4% versus 1.3%; P=0.02) but not in the frequency of major bleeding events between the two groups.

CONCLUSIONS

Platelet function monitoring-guided antiplatelet therapy reduces thromboembolic events in patients with unruptured intracranial aneurysm after stent placement, significantly enhancing minor or minimal bleeding events but not major bleeding events. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03989557.

PON1 Q192R is associated with high platelet reactivity with clopidogrel in patients undergoing elective neurointervention: A prospective single-center cohort study

Background and purpose

The impact of the paraoxonase-1 (PON1) polymorphism, Q192R, on platelet inhibition in response to clopidogrel remains controversial. We aimed to investigate the association between carrier status of PON1 Q192R and high platelet reactivity (HPR) with clopidogrel in patients undergoing elective neurointervention.

Methods

Post-clopidogrel platelet reactivity was measured using a VerifyNow^® P2Y12 assay in P2Y12 reaction units (PRU) for consecutive patients before the treatment. Genotype testing was performed for PON1 Q192R and CYP2C19*2 and *3 (no function alleles), and *17. PRU was corrected on the basis of hematocrit. We investigated associations between factors including carrying ≥1 PON1 192R allele and HPR defined as original and corrected PRU ≥208.

Results

Of 475 patients (232 men, median age, 68 years), HPR by original and corrected PRU was observed in 259 and 199 patients (54.5% and 41.9%), respectively. Carriers of ≥1 PON1 192R allele more frequently had HPR by original and corrected PRU compared with non-carriers (91.5% vs 85.2%, P = 0.031 and 92.5% vs 85.9%, P = 0.026, respectively). In multivariate analyses, carrying ≥1 PON1 192R allele was associated with HPR by original (odds ratio [OR] 1.96, 95% confidence interval [CI] 1.03–3.76) and corrected PRU (OR 2.34, 95% CI 1.21–4.74) after adjustment for age, sex, treatment with antihypertensive medications, hematocrit, platelet count, total cholesterol, and carrying ≥1 CYP2C19 no function allele.

Conclusions

Carrying ≥1 PON1 192R allele is associated with HPR by original and corrected PRU with clopidogrel in patients undergoing elective neurointervention, although alternative results related to other genetic polymorphisms cannot be excluded.

Comparison of Blister Aneurysm Treatment Techniques: A Systematic Review and Meta-Analysis

OBJECTIVE

Blood blister aneurysms are small, thin-walled, rapidly growing side-wall aneurysms that have proved particularly difficult to treat, and evidence-based guidance for treatment strategies is lacking. A systematic review and meta-analysis was performed to aggregate the available data and compare the 3 primary treatment modalities.

METHODS

We performed a comprehensive literature search according to PRISMA guidelines followed by an indirect meta-analysis that compares the safety and efficacy of surgical, flow-diverting stents (FDS), and other endovascular approaches for the treatment of ruptured blood blister aneurysms.

RESULTS

A total of 102 studies were included for quantitative synthesis, with sample sizes of 687 treated surgically, 704 treated endovascularly without FDS, and 125 treated via flow diversion. Comparatively, FDS achieved significantly reduced rates of perioperative retreatment compared with both surgical (P = 0.025) and non-FDS endovascular (P < 0.001). The FDS subgroup also achieved a significantly lower incidence of perioperative rebleed (P < 0.001), perioperative hydrocephalus (P = 0.012), postoperative infarction (P = 0.002), postoperative hydrocephalus (P < 0.001), and postoperative vasospasm (P = 0.002) compared with those patients in the open surgical subgroup. Although no significant differences were found among groups on the basis of functional outcomes, angiographic outcomes detailed by rates of radiographic complete occlusion were highest for surgical (90.7%, 262/289) and FDS (89.1%, 98/110) subgroups versus the non-FDS endovascular subgroup (82.7%, 268/324).

CONCLUSIONS

Flow diversion seems to be an effective treatment strategy for ruptured blood blister aneurysms, with lower rates of perioperative complications compared with surgical and other endovascular techniques, but studies investigating long-term outcomes after flow diversion warrant further study.

Thromboelastography (TEG) results are predictive of ischemic and hemorrhagic complications in patients with unruptured intracranial aneurysms treated with flow diversion

INTRODUCTION

Flow diversion is an effective treatment modality for intracranial aneurysms but is associated with ischemic and hemorrhagic complications. Patients treated with flow diversion require dual antiplatelet therapy and subsequent platelet function tests. At our institution, Thromboelastography with Platelet Mapping (TEG-PM) is the test of choice. The primary objective of this study was to identify TEG parameters that are predictive of postoperative complications in patients treated with elective flow diversion.

METHODS

This was a retrospective study of 118 patients with unruptured intracranial aneurysms treated with flow diversion. Data was collected via chart review. Bivariate analyses were performed to identify significant variables in patients who suffered an ischemic stroke or a groin hematoma. ROC curves were constructed for the TEG parameters with statistical significance. Bivariate analyses were repeated using dichotomized TEG results.

RESULTS

Patients who experienced a symptomatic ischemic stroke had a history of stroke (p value = 0.007), larger aneurysm neck width (p value = 0.017), and a higher alpha angle (p value = 0.013). Cut off point for ischemic complication is 63° on ROC curve with a sensitivity of 100% and specificity of 65%. Patients who experienced a groin hematoma were no different from their healthy peers but had a lower alpha angle (p value = 0.033). Cut off point for hemorrhagic complication is 53.3° with a sensitivity of 82% and specificity of 67%.

CONCLUSION

The Alpha Angle parameter of TEG-PM has a sizeable predictive ability for both ischemic complications of the central nervous system and hemorrhagic complications of the access site after elective flow diversion.

Treatment of intracranial aneurysms using the new Surpass Evolve flow diverter: Safety outcomes and six-month imaging follow-up

BACKGROUND AND PURPOSE

Several studies have reported good long-term results in the occlusion of intracranial aneurysms with flow diverter treatment. The aim of this study was to report the safety and six-month follow-up outcomes using the new Surpass Evolve flow diverter in the treatment of intracranial aneurysms.

MATERIALS AND METHODS

Consecutive patients with intracranial aneurysm treated with Surpass Evolve flow diverter in two high-volume neurovascular centers between May 2019 and January 2020 were retrospectively reviewed. Procedure-related complications, aneurysm occlusion (O'Kelly-Marotta grading scale), and clinical outcomes were assessed.

RESULTS

Twenty-nine patients with 30 aneurysms were included in the study. Favorable aneurysm occlusion (O'Kelly Marotta grading scale C-D) at six-month follow-up was achieved in 21/27 (78%) aneurysms. No clinical procedure related thromboembolic complications were encountered. Twenty-three out of 24 patients with unruptured aneurysms treated with Surpass Evolve remained clinically intact at clinical follow-up. There was one fatal hemorrhagic procedure-related complication (3%). In five patients with ruptured aneurysms, no early or late rebleeds occurred from the aneurysms.

CONCLUSIONS

Surpass Evolve FD worked technically well with no intraprocedural thromboembolic complications and occlusion rates comparable to other FDs.

The Prophylactic Use of Tirofiban versus Oral Antiplatelet Medications in Stent-Assisted Coiling of Intracranial Aneurysms: A Meta-analysis

BACKGROUND

The protocol for optimal antiplatelet therapy to prevent thromboembolic and hemorrhagic complications in patients with cerebral aneurysms using an endovascular approach is not clear.

PURPOSE

Our study analyzed the safety and efficacy of prophylactic tirofiban administration compared with oral antiplatelet drug therapy.

DATA SOURCES

We used the PubMed, EMBASE, MEDLINE, and Cochrane library data bases.

STUDY SELECTION

Our study consisted of all case series with >5 patients that reported treatment-related outcomes of patients undergoing endovascular procedures pretreated with tirofiban or oral antiplatelet drug therapy.

DATA ANALYSIS

Random effects or fixed effects meta-analysis was used to pool the cumulative rate of complications, perioperative mortality, and good clinical outcomes.

DATA SYNTHESIS

Fifteen studies with 1981 patients were registered. Thromboembolic complications were significantly lower in the tirofiban group (3.6%; 95% CI, 1.9%-5.8%) compared with the dual-antiplatelet therapy group (8.5%, 95% CI, 4.5%-13%; P = .04). Pretreatment with tirofiban did not remarkably increase the rate of hemorrhagic complications (3.5%; 95% CI, 1.8%-5.6%) compared with dual-antiplatelet therapy (5.1%; 95% CI, 2.6%-8.5%; P = .371). There was a trend toward lower perioperative mortality with tirofiban (0.8%; 95% CI, 0.2%-1.6%) compared with dual-antiplatelet therapy (1.2%; 95% CI, 0.7%-2.0%; P = .412). There was no significant difference in the safety and efficacy between the tirofiban bolus plus drip and drip alone.

LIMITATIONS

The limitations are selection and publication biases.

CONCLUSIONS

Prophylactic therapy with tirofiban resulted in significantly lower rates of thromboembolic complications with no increase in hemorrhagic events or mortality than the prophylactic use of dual-antiplatelet therapy.

Antiplatelet Drugs for Neurointerventions: Part 2 Clinical Applications

Endovascular techniques have expanded to include balloon and stent-assistance, flow diversion and individualized endovascular occlusion devices, to widen the treatment spectrum for more complex aneurysm morphologies. While usually well-tolerated by patients, endovascular treatment of intracranial aneurysms carries the risk of complications, with procedure-related ischemic complications being the most common. Several antiplatelet agents have been studied in a neurointerventional setting for both prophylaxis and in the setting of intraprocedural thrombotic complications. Knowledge of these antiplatelet agents, evidence for their use and common dosages is important for the practicing neurointerventionist to ensure the proper application of these agents.Part one of this two-part review focused on basic platelet physiology, pharmacology of common antiplatelet medications and future directions and therapies. Part two focuses on clinical applications and evidence based therapeutic regimens.

P2Y12 inhibitors in neuroendovascular surgery: An opportunity for precision medicine

INTRODUCTION

Dual antiplatelet therapy (DAPT), primarily the combination of aspirin with a P2Y12 inhibitor, in patients undergoing intravascular stent or flow diverter placement remains the primary strategy to reduce device-related thromboembolic complications. However, selection, timing, and dosing of DAPT is critical and can be challenging given the existing significant inter- and intraindividual response variations to P2Y12 inhibitors.

METHODS

Assessment of indexed, peer-reviewed literature from 2000 to 2020 in interventional cardiology and neuroendovascular therapeutics with critical, peer-reviewed appraisal and extraction of evidence and strategies to utilize DAPT in cardio- and neurovascular patients with endoluminal devices.

RESULTS

Both geno- and phenotyping for DAPT are rapidly and conveniently available as point-of-care testing at a favorable cost-benefit ratio. Furthermore, systematic inclusion of a quantifying clinical risk score combined with an operator-linked, technical risk assessment for potential adverse events allows a more precise and individualized approach to new P2Y12 inhibitor therapy.

CONCLUSIONS

The latest evidence, primarily obtained from cardiovascular intervention trials, supports that combining patient pharmacogenetics with drug response monitoring, as part of an individually tailored, precision medicine approach, is both predictive and cost-effective in achieving and maintaining individual target platelet inhibition levels. Indirect evidence supports that this gain in optimizing drug responses translates to reducing main adverse events and overall treatment costs in patients undergoing DAPT after intracranial stent or flow diverting treatment.

Effect of bodyweight on VerifyNow Aspirin platelet function test: a retrospective review

BACKGROUND

Antiplatelet therapy is used to prevent stent thrombosis in intracranial stents, but the optimal dose of aspirin is unknown. This study sought to determine whether the degree of platelet inhibition with aspirin is affected by bodyweight as observed through a platelet reactivity assay.

METHODS

This is a retrospective review of patients who underwent neurovascular stent placement and had a VerifyNow Aspirin assay result. The primary outcome was the correlation between the VerifyNow Aspirin result, bodyweight, and the initial dose of aspirin. Secondary outcomes included the impact of the VerifyNow P2Y12 result and of weight on the incidence of bleeding or a thrombotic event.

RESULTS

Of the 142 included patients, 62.7% weighed ≥70 kg and 88.7% were initiated on aspirin 300-325 mg daily. 83.8% achieved a therapeutic VerifyNow Aspirin result. There was minimal correlation between the VerifyNow Aspirin result, bodyweight, and aspirin dose (R²=0.02). Between patients who weighed <70 kg versus ≥70 kg, there was no difference in the mean aspirin reaction units (ARU) (449 vs 435, p=0.32) or in the incidence of bleeding (28% vs 17.1%, p=0.14) or a thrombotic event (4% vs 5.3%, p=0.59). No patient experienced stent thrombosis and eight patients experienced in-stent stenosis. In a multivariate analysis, only the VerifyNow P2Y12 result predicted the development of either bleeding or a thrombotic event (p<0.01).

CONCLUSIONS

Bodyweight did not influence the likelihood of obtaining a therapeutic VerifyNow Aspirin result. The clinical utility of obtaining VerifyNow Aspirin assays for this patient population is unknown.

Prophylactic administration of tirofiban for preventing thromboembolic events in flow diversion treatment of intracranial aneurysms

BACKGROUND

Flow diverter (FD) is widely used in the treatment of intracranial aneurysms. However, thromboembolic events (TEs) continue to be the major complications during the periprocedural phase. To evaluate the safety and efficacy of the prophylactic use of tirofiban, combined with the conventional dual antiplatelet therapy (DAT), as a new antiplatelet protocol in patients with intracranial aneurysms treated with FDs.

METHODS

At least 3-5 days before the procedure, daily DAT were administrated to the patients. Tirofiban was administered as an intravenous bolus (5 µg/kg) over a 3 min period during or immediately after FD deployment, followed by a 0.05 µg/kg/min maintenance infusion for 24-48 hours. Periprocedural TEs and hemorrhagic events (HEs) were recorded.

RESULTS

A total of 331 patients were included, including 229 (69.2%) who received tirofiban administration (tirofiban group) and 102 (30.8%) who received only DAT (non-tirofiban group). Periprocedural TEs occurred in 12 (3.6%) patients, including eight (7.8%) in the non-tirofiban group and four (1.7%) in the tirofiban group. In multivariate analysis, patients receiving tirofiban administration had significantly lower TEs as compared with those who received only DAT (P=0.004). Balloon angioplasty and longer procedure time (>137 min) were also risk factors for TEs. Also, no increase was observed in the rate of HEs related to tirofiban administration.

CONCLUSIONS

The current study suggested that prophylactic administration of tirofiban combined with conventional oral DAT seems safe and efficient for preventing TEs during FD treatment of unruptured intracranial aneurysms. Balloon angioplasty and prolonged procedure are associated with a high risk of TEs.

The use of cangrelor in neurovascular interventions: a multicenter experience

PURPOSE

Thromboembolic events represent the most common procedure-related complication associated with neurointerventions. Cangrelor is a potent, intravenous (IV), P2Y12-receptor antagonist with a rapid onset and offset presented as an alternative antiplatelet agent. We aim to evaluate the safety and effectiveness of IV cangrelor in neurovascular intervention.

METHODS

This is a retrospective analysis of data from four cerebrovascular interventional centers. We identified patients who underwent acute neurovascular intervention and received cangrelor as part of their optimum care. Patients were divided into 2 groups: ischemic and aneurysm. Periprocedural thromboembolic events, hemorrhagic complications, and outcomes were analyzed.

RESULTS

Sixty-six patients were included, 42 allocated into the ischemic group (IG), and 24 into aneurysm group (AG). The IG periprocedural symptomatic complication rate was 9.5%, represented by 3 postoperative intracranial hemorrhages and 1 retroperitoneal hematoma. At discharge, 47.6% had a favorable outcome and the mortality rate was 2.4%, related to clinical deterioration of a large infarct. In the AG, 4.2% had a periprocedural complication during or after cangrelor infusion, represented by an intracranial hemorrhage in an initially ruptured aneurysm. Favorable clinical outcome was seen in 56.2% and 87.7% of ruptured and unruptured aneurysms, respectively, upon discharge.

CONCLUSIONS

Cangrelor may be a feasible alternative for patients requiring immediate intervention with the use of endoluminal devices. It allows the possibility for a secure transition to long-term ticagrelor and progression to surgery in the setting of unexpected complications.