Relevance of Antiplatelet Therapy Duration After Stent-Assisted Coil Embolization for Unruptured Intracranial Aneurysms

Impact of duration of dual anti-platelet therapy on risk of complications after stent-assisted coiling of unruptured aneurysms

BACKGROUND

The optimal duration for dual antiplatelet therapy (DAPT) after stent-assisted coiling (SAC) of intracranial aneurysms is unclear. Longer-term therapy may reduce thrombotic complications but increase the risk of bleeding complications.

METHODS

A retrospective review of prospectively maintained data at 12 institutions was conducted on patients with unruptured intracranial aneurysms who underwent SAC between January 1, 2016 and December 31, 2020, and were followed ≥6 months postprocedure. The type and duration of DAPT, stent(s) used, outcome, length of follow-up, complication rates, and incidence of significant in-stent stenosis (ISS) were collected.

RESULTS

Of 556 patients reviewed, 450 met all inclusion criteria. Nine patients treated with DAPT <29 days after SAC and 11 treated for 43-89 days were excluded from the final analysis as none completed their prescribed duration of treatment. Eighty patients received short-term DAPT. There were no significant differences in the rate of thrombotic complications during predefined periods of risk in the short, medium, or long-term treatment groups (1/80, 1.3%; 2/188, 1.1%; and 0/162, 0%, respectively). Similarly, no differences were found in the rate of hemorrhagic complications during period of risk in any group (0/80, 0%; 3/188, 1.6%; and 1/162, 0.6%, respectively). Longer duration DAPT did not reduce ISS risk in any group.

CONCLUSIONS

Continuing DAPT >42 days after SAC did not reduce the risk of thrombotic complications or in-stent stenosis, although the risk of additional hemorrhagic complications remained low. It may be reasonable to discontinue DAPT after 42 days following non-flow diverting SAC of unruptured intracranial aneurysms.

Evaluating the Safety of Stent-Assisted Endovascular Treatment for Unruptured Cerebral Aneurysms in Older Adults: Emphasizing the Role of Antiplatelet Therapy

INTRODUCTION

This study aimed to compare the outcomes and safety in patients aged ≥75 years and those aged <75 years who underwent stent-assisted endovascular treatment for unruptured cerebral aneurysms, specifically focusing on perioperative antiplatelet therapy (APT).

METHODS

This multicenter retrospective study comprised patients who underwent stent-assisted coiling (SAC) or flow diverter stent (FDS) placement for unruptured cerebral aneurysms. The primary outcome was defined as the composite outcomes of perioperative thromboembolic events, bleeding events, or death.

RESULTS

Among 632 patients, 533 (84.3%) were aged <75 years and 99 (15.6%) were aged ≥75 years. No significant differences were observed in the dual APT duration. The primary outcome occurred in 14.3% of patients aged <75 years and in 14.1% of those aged ≥75 years, with no significant difference (p = 1.0). The composites of the primary outcome, including thromboembolic events, bleeding events, and death differed insignificantly. Similar findings were observed when the primary outcomes for SAC (12.7% vs. 11.5%, p = 0.95) and FDS (17.5% vs. 18.4%, p = 1.0) were analyzed. The 30-day, 1-year, and 2-year cumulative event-free survival rates for the primary outcome were 89.5, 87.2%, and 85.2%, respectively, in patients aged <75 years, and 90.9%, 88.7%, and 87.0%, respectively, in those aged ≥75 years. These trends were similar (log-rank test, p = 0.92).

CONCLUSION

No significant differences were observed in the rates of the primary outcomes between patients aged <75 years and those aged ≥75 years. Therefore, refraining from stent-assisted treatment for unruptured aneurysms based solely on age might be inappropriate.

Antiplatelet Therapy in Endovascular Treatment of Cerebral Aneurysms

Thromboembolism is one of the main causes of severe complications in the endovascular treatment of cerebral aneurysms, and antiplatelet therapy (APT) is necessary to prevent such complications. Conversely, prolonged APT has the potential risk of hemorrhagic complications; therefore, the timing of dose reduction or discontinuation is an important aspect of periprocedural APT. However, no clinical evidence of an optimal regimen of APT for cerebral aneurysms exists, and the selection, dosage, duration, or combination of antiplatelets has been dependent on physicians for unruptured or ruptured cerebral aneurysms. Many reports have shown that preoperative APT can reduce ischemic complications without increasing hemorrhagic complications, and some reports have shown that the P2Y12 reaction unit (PRU) value measured using the VerifyNow (Werfen, Barcelona, Spain) system is associated with periprocedural ischemic and hemorrhagic complications. Appropriate dose and duration management adjustments based on the platelet reactivity test, aneurysm morphology, treatment, and patient background may contribute to good outcomes. Although accumulating evidence exists regarding the efficacy of preoperative APT, there is no evidence regarding the optimal duration or discontinuation of APT.

Relation between duration of dual antiplatelet therapy and risk of ischemic stroke after stent-assisted treatment of cerebral aneurysm (DAPTS ACE-registry)

BACKGROUND

The optimal duration of dual antiplatelet therapy (DAPT) in patients with cerebral aneurysm who undergo stent-assisted coil embolization (SACE) has not been established. We aimed to clarify the association between duration of DAPT and incidence of ischemic stroke in patients with cerebral aneurysm.

METHODS

We registered patients with cerebral aneurysm who underwent SACE in 27 hospitals in Japan. Those treated with DAPT (aspirin and clopidogrel) were eligible for inclusion in a previously reported randomized control trial (RCT). Patients who were ineligible or refused to participate to the RCT were followed-up for 15 months after SACE as the non-RCT cohort. Our study examined both the RCT and non-RCT cohorts. The primary and secondary outcomes were ischemic stroke and hemorrhagic events.

RESULTS

Among the 313 patients registered, 296 were included for analysis (of these, 136 were RCT patients and 160 were non-RCT patients). Patients who were treated with DAPT for more than 6 months (n=191) were classified as the long-term DAPT group. Those treated less than 6 months (n=105) were classified as the short-term group. The incidence of ischemic stroke did not significantly differ between the long-term group (2.5 per 100 person-years) and the short-term group (3.2 per 100 person-years); nor did incidence of hemorrhagic events (0.8 and 3.2 per 100 person-years, respectively). The period of DAPT was not significantly associated with incidence rates of ischemic stroke or hemorrhagic events.

CONCLUSIONS

Duration of DAPT was not associated with the incidence of ischemic stroke in the first 15 months after SACE.

Duration of dual-antiplatelet therapy after stent-assisted coil for unruptured intracranial aneurysm: A nationwide cohort study

BACKGROUND

Stent-assisted coil (SAC) is increasingly used to treat unruptured intracranial aneurysm (UIA). However, the optimal duration of dual-antiplatelet therapy (DAPT) after SAC insertion remains unknown.

AIM

To assess the time-dependent effect of DAPT on the risk of ischemic and hemorrhagic complications after SAC.

METHODS

This is a retrospective cohort study among patients with UIA treated with SAC using the nationwide health claims database in South Korea between 2009 and 2020. Multivariate Cox regression analysis was used, which included the use of DAPT as a time-dependent variable. The effect of DAPT was investigated for each period of "within 90 days," "91 to 180 days," "181 to 365 days," and "366 to 730 days" after SAC. The primary outcome was a composite of ischemic stroke and major bleeding in each period within two years after SAC.

RESULTS

Of the 15,918 patients, mean age at SAC was 57.6 ± 10.8 years, and 3815 (24.0%) were men. The proportion of patients on DAPT was 79.4% at 90 days, 58.3% at 180 days, and 28.9% at 1 year after SAC. During the 2 years after SAC, the primary composite outcome occurred in 356 patients (2.2%). DAPT significantly reduced the primary composite outcome within 90 days after SAC (adjusted hazard ratio (aHR), 0.44; 95% confidence interval (CI), 0.28-0.69; p < 0.001); however, this was not the case after 90 days (all p > 0.05). DAPT reduced ischemic stroke risk within 90 days (aHR, 0.31; 95% CI 0.18-0.54; p < 0.001), and 91 to 180 days after SAC (aHR 0.40; 95% CI 0.18-0.88; p = 0.022); however, after 180 days, DAPT was no longer beneficial.

CONCLUSIONS

In patients with UIA treated with SAC, 3 months of DAPT was associated with a decreased risk of the composite of ischemic and hemorrhagic complications.

Short- versus long-term Dual AntiPlatelet Therapy for Stent-Assisted treatment of CErebral aneurysm (DAPTS ACE): a multicenter, open-label, randomized clinical trial

BACKGROUND

The optimal duration of dual antiplatelet therapy (DAPT) after stent-assisted coil embolization (SACE) for cerebral aneurysm remains uncertain. This randomized trial of short- versus long-term Dual AntiPlatelet Therapy for Stent-Assisted treatment of CErebral aneurysm (DAPTS ACE) aimed to clarify whether long-term DAPT can reduce the occurrence of ischemic stroke in patients with cerebral aneurysms treated by SACE compared with short-term DAPT.

METHODS

Patients treated for cerebral aneurysm with SACE were enrolled from 17 hospitals in Japan. Patients were enrolled within 30 days after SACE and assigned in a 1:1 ratio to receive long-term (12 months) or short-term (3 months) DAPT with aspirin and clopidogrel. Randomization was performed centrally through a web-based system. The primary outcome was the time to ischemic stroke event during 3 to 12 months after SACE. This trial was registered with the Japan Registry of Clinical Trials (jRCTs051180141).

RESULTS

A total of 142 patients were recruited from November 4, 2016 to January 7, 2019. Among them, 65 and 68 patients assigned to the long- and short-term DAPT groups, respectively, were included in the full analysis set. Ischemic stroke occurred in no patients in the long-term DAPT group and in one patient in the short-term DAPT group. The incidence rate did not differ between the groups (0.0 vs 2.1/100 person-years; log rank test, P=0.33).

CONCLUSIONS

In this multicenter randomized controlled trial, there was not a statistically significant difference in the rate of ischemic strokes between long- and short-term DAPT.

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.

Trends in the Age of Patients Treated for Unruptured Intracranial Aneurysms from 1990 to 2020

BACKGROUND

The decision for treatment for unruptured intracranial aneurysms (UIAs) is often difficult. Innovation in endovascular devices have improved the benefit-to-risk profile especially for elderly patients; however, the treatment guidelines from the past decade often recommend conservative management. It is unknown how these changes have affected the overall age of the patients selected for treatment. Herein, we aimed to study potential changes in the average age of the patients that are being treated over time.

METHODS

A systematic search of the literature was performed to identify all studies describing the age of the UIAs that were treated by any modality. Scatter diagrams with trend lines were used to plot the age of the patients treated over time and assess the presence of a potential significant trend via statistical correlation tests.

RESULTS

A total of 280 studies including 83,437 UIAs treated between 1987 and 2021 met all eligibility criteria and were entered in the analysis. Mean age of the patients was 55.5 years, and 70.7% were female. There was a significant increasing trend in the age of the treated patients over time (Spearman r: 0.250; P < 0.001), with a 1-year increase in the average age of the treated patients every 5 years since 1987.

CONCLUSIONS

The present study indicates that based on the treated UIA patient data published in the literature, older UIAs are being treated over time. This trend is likely driven by safer treatments while suggesting that re-evaluation of certain UIA treatment decision scores may be of great interest.

The Impact of Dual Antiplatelet Therapy Duration on Unruptured Aneurysm Occlusion After Flow Diversion: A Multicenter Study

OBJECTIVE

Endoluminal flow diversion reduces blood flow into intracranial aneurysms, promoting thrombosis. Postprocedural dual antiplatelet therapy (DAPT) is necessary for the prevention of thromboembolic complications. The purpose of this study is to therefore assess the impact that the type and duration of DAPT has on aneurysm occlusion rates and iatrogenic complications after flow diversion.

METHODS

A retrospective review of a multicenter aneurysm database was performed from 2012 to 2020 to identify unruptured intracranial aneurysms treated with single device flow diversion and ≥12-month follow-up. Clinical and radiologic data were analyzed with aneurysm occlusion as a function of DAPT duration serving as a primary outcome measure.

RESULTS

Two hundred five patients underwent flow diversion with a single pipeline embolization device with 12.7% of treated aneurysms remaining nonoccluded during the study period. There were no significant differences in aneurysm morphology or type of DAPT used between occluded and nonoccluded groups. Nonoccluded aneurysms received a longer mean duration of DAPT (9.4 vs 7.1 months, P = 0.016) with a significant effect of DAPT duration on the observed aneurysm occlusion rate (F(2, 202) = 4.2, P = 0.016). There was no significant difference in the rate of complications, including delayed ischemic strokes, observed between patients receiving short (≤6 months) and prolonged duration (>6 months) DAPT (7.9% vs 9.3%, P = 0.76).

CONCLUSIONS

After flow diversion, an abbreviated duration of DAPT lasting 6 months may be most appropriate before transitioning to low-dose aspirin monotherapy to promote timely aneurysm occlusion while minimizing thromboembolic complications.

Dolenc approach for clipping of giant C6 and C7 segment aneurysms of the internal carotid artery

Objective

Surgical treatment for giant aneurysms of the ICA-ophthalmic segment (C6) and communicating artery segment (C7) is a challenge for neurosurgeons because of their high risks and poor outcomes. We aim to explore the advantages and disadvantages of the Dolenc approach in the treatment of giant C6-C7 segment aneurysms.

Methods

We retrospectively reviewed the clinical data of 13 cases with giant C6 aneurysms and 4 cases with giant C7 aneurysms treated with the Dolenc approach.

Results

All 17 cases of aneurysms were clipped successfully using the Dolenc approach, of which, 1 case with ipsilateral MCA occlusion underwent extracranial-intracranial artery bypass after the aneurysm clipping. Regarding clinical outcomes, six out of nine cases with preoperative visual impairment improved after surgery, two cases saw no change, and one case deteriorated. Of all the cases, one had new-onset vision loss, four had new-onset oculomotor paralysis, three had surgical side cerebral infarction, and two had diabetes insipidus. DSA or CTA examination within 2 weeks after surgery showed that all aneurysms were completely clipped without residual. After a follow-up of 9-12 months, 17 patients were evaluated based on GOS and CTA examination. A total of 14 cases had GOS 5 scores, 2 cases had GOS 4 scores, 1 case had GOS 2 scores, and no cases had death. None of the patients had recurrence based on CTA examinations.

Conclusion

Through the Dolenc approach, we could achieve more operation space and expose clinoid segments for temporary occlusion. Therefore, the Dolenc approach was shown to be a safe, effective, and feasible treatment for giant C6-C7 aneurysms.

Three-dimensional reconstruction imaging by C-arm computed tomography accurately visualizes in-stent neointimal formation in patients with stent-assisted coil embolization

Background

Stent apposition to the vessel wall and in-stent neointimal formation after stent-assisted coil embolization for intracranial aneurysm are important factors associated with postoperative thromboembolic complications. No assessment methods have been established to depict 3-dimensional (3D) all-round in-stent neointimal formation.

Objective

To demonstrate the superiority of Dyna-3D imaging assessment as a modality for all-round ISNF in comparison with conventional two-dimensional digital subtraction angiography (2D-DSA).

Methods

Consecutive patients who underwent braided stent-assisted coil embolization for unruptured aneurysm between November 2016 and September 2021 were enrolled. Radiological assessments for stent apposition to the parent vessel after stent deployment and in-stent neointimal formation after 3 months were obtained. Dyna-3D was reconstructed by overlapping a plain image showing stent struts with a rotational DSA image showing the vessel lumen. Reconstructed Dyna-3D images can be rotated to any angle on the screen to evaluate to stent apposition around the vessel and in-stent neointimal formation in 3D, for comparison with 2D-DSA evaluations.

Results

Among the 73 patients enrolled, 70 patients (96%) showed complete stent wall apposition on Dyna-3D. Higher intra-rater agreement was confirmed on assessment of in-stent neointimal formation with Dyna-3D (Cohen's κ = 0.811) than with conventional 2D-DSA (Cohen's κ = 0.517). in-stent neointimal formation could not be confirmed on conventional imaging in 9 cases (16%) and on Dyna-3D in 2 cases (3%). The number of in-stent neointimal formations rated as stent wire completely outside the endothelial line was significantly higher with Dyna-3D than with 2D-DSA (p = 0.0001).

Conclusion

All-round 3D evaluation by Dyna-3D imaging appears useful for confirming in-stent neointimal formation after braided stent deployment in patients after stent-assisted coil embolization.

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.

Antiplatelet therapy discontinuation after stent-assisted coil embolization for intracranial aneurysms: a single-center, long-term, retrospective, observational study

OBJECTIVE

The protocol for antiplatelet therapy after stent-assisted coil embolization (SACE) for intracranial aneurysms is not well established. In particular, the indications for single antiplatelet therapy (SAPT) discontinuation remain controversial. The authors investigated the long-term outcomes of SAPT discontinuation after SACE among patients at a single institution.

METHODS

Patients who underwent SACE during the period from 2010 to 2020 and who were followed up for > 1 year were included in this study. The delayed ischemic and hemorrhagic complication rates were examined during follow-up. Moreover, the risk factors of antiplatelet therapy reduction or discontinuation and the outcomes of SAPT discontinuation were examined.

RESULTS

In total, 240 patients were included in the analysis. The average patient age was 60.3 years, and the average follow-up period was 46.7 months. Nine (3.8%) patients presented with symptomatic delayed ischemic complication, and 3 (1.3%) patients experienced a decline in modified Rankin Scale score. The stent configuration (T- or Y-stent) was the only risk factor associated with delayed ischemic complication (p < 0.001). SAPT was discontinued in 147 (71.7%) of 205 patients who were followed up for > 2 years, and no ischemic complications were observed.

CONCLUSIONS

It is safe to discontinue SAPT in patients without ischemic complications and with stable intraaneurysmal signals on MRA 2 years after SACE. The T- or Y-stent is a high-risk factor for delayed ischemic complications, and antiplatelet therapy reduction or discontinuation should be cautiously considered.

Is it safe to discontinue antiplatelet medication after stent-assisted coil embolization? If so, when is the best time?

PURPOSE

Antiplatelet maintenance after stent-assisted coil embolization (SACE) is generally considered essential to avoid post-procedural thromboembolic complications. However, there is still debate as to whether it is safe to discontinue antiplatelet drugs after SACE or when is the best time to do so. We investigate herein the clinical outcomes experienced by patients who discontinue antiplatelet agents after SACE.

METHODS

From a prospective database, we retrieved the data for 120 consecutive patients (harboring 130 aneurysms) in whom antiplatelet agents were discontinued after SACE between January 2010 and December 2019. We defined thromboembolic complications associated with discontinuation as neurologic or radiographic ischemia that occurred within 6 months of discontinuation of antiplatelet agents; the lesion was required to be correlated with the stented artery.

RESULTS

The mean time of discontinuation of antiplatelet medication was 31.4 ± 18.3 months after SACE (median, 26 months). The majority of patients stopped antiplatelet medication between 18 and 36 months after SACE (74 patients, 61.6%). Laser-cut closed-cell stent was most commonly applied in 91 aneurysms (70.0%), followed by braided closed-cell (n=29; 22.3 %) and laser-cut open-cell stent 10 (7.7 %). No patients experienced cerebral ischemia related to discontinuation of antiplatelet medication.

CONCLUSION

Our preliminary study suggests that it may be safe to discontinue antiplatelet medication after SACE in patients at low risk for ischemia. The optimal time to discontinue might be around 18 to 36 months after SACE. Large cohort-based studies or randomized clinical trials are warranted to confirm these results.

Perioperative Antiplatelet Therapy for the Stent-Assisted Coil Embolization: Results of the Questionnaire Survey

Objective

This study aimed to determine the status of perioperative antiplatelet therapy in stent-assisted coil embolization (SAC) in Japan.

Methods

The questionnaire consisted of 13 questions and used Google forms, and was sent to institutions where endovascular specialists were employed. The results were analyzed.

Results

The responses from 307 centers indicated that the timing of initiation of antiplatelet therapy was 14 days-1 month before treatment in half of centers, and 7-14 days before treatment in the other half. Platelet function tests were performed at 165 centers (56.2%), of which 136 centers (46.3%) performed these tests for all patients, with the VerifyNow system being the most widely used tool. The duration of postoperative dual antiplatelet therapy was 6, 3, and 12 months in 169 (57.7%), 70 (23.5%), and 42 (14.3%) centers, respectively. The antiplatelet agents used for monotherapy were P2Y12 receptor antagonists or aspirin, with a postoperative period of up to 12 months in 139 centers (47.3%), 24 months in 68 centers (23.1%), and longer than 24 months in 50 centers (17%).

Conclusion

Current antiplatelet therapy for SAC in Japan varies widely among institutions. Moreover, each center has its own empirical rules for SAC. Therefore, the findings of this survey suggest the need to establish guidelines for optimal periprocedural antiplatelet therapy for SAC.

Case report: Late in-stent thrombosis in a patient with vertebrobasilar dolichoectasia after stent-assisted coil embolization due to the discontinuation of antiplatelet therapy

Vertebrobasilar dolichoectasia (VBD) is a rare type of cerebrovascular disorder with high rates of morbidity and mortality. Due to the distinct pathological characteristics that fragmented internal elastic lamina and multiple dissections, VBD is difficult to treat and cured. Stent-assisted coil embolization is one of the main treatment modalities for such lesions. However, the duration of healing remained questionable, and there were no effective measures for evaluating endothelial coverage. Before complete endothelial coverage, the discontinuation of antiplatelet therapy may lead to fatal in-stent thrombosis; however, continued antiplatelet therapy could also result in bleeding complications. Thus, we present an autopsy case of late in-stent thrombosis due to the discontinuation of antiplatelet therapy and systematically review the literature to provide a reference for endovascular treatment and antiplatelet regimen of VBD.

Higher oscillatory shear index is related to aneurysm recanalization after coil embolization in posterior communicating artery aneurysms

BACKGROUND

The recurrence rate of posterior communicating artery (Pcom) aneurysms after endovascular treatment (EVT) is higher than that for aneurysms located in other sites. However, it is still unclear what mechanisms are responsible for the recanalization of cerebral aneurysms. In this investigation, we compared hemodynamic factors related with recanalization of Pcom aneurysms treated by endoluminal coiling using computational fluid dynamics (CFD) with high-resolution three-dimensional digital subtraction angiography images.

METHODS

Twenty patients were enrolled. A double-sinogram acquisition was performed with and without contrast injection after coil embolization to get true blood vessel lumen by relatively complementing the first sinogram with the second. Adaptive Cartesian meshing was performed to produce vascular wall objects for CFD simulation. The boundary condition for inlet (ICA) was set for dynamic velocity according to the cardiac cycle (0.8 s). Hemodynamic parameters were recorded at two specific points (branching point of Pcom and residual sac). The peak pressure, peak WSS, and oscillatory shear index (OSI) were recorded and analyzed.

RESULTS

The median age was 61.0 years, and 18 patients (90%) were female. During a median follow-up of 12 months, seven (35%) treated aneurysms showed recanalization. The median aneurysm volume was significantly higher, and aneurysm height and neck sizes were significantly longer in the recanalization group than those in the stable group. At the branching point of the Pcom, the peak pressure, peak WSS, or OSI did not significantly differ between the two groups. The only statistically significant hemodynamic parameter related with recanalization was the OSI at the aneurysm point. Multivariate logistic regression showed that with an increase of 0.01 OSI at the aneurysm point, the odds ratio for the aneurysm recanalization was 1.19.

CONCLUSIONS

A higher OSI is related with recanalization after coil embolization for a Pcom aneurysm.

Long-term complications after stent assist coiling dependent on clopidogrel response

BACKGROUND

Dual antiplatelet therapy (DAPT) is necessary for stent assisted coiling. However, long term use of DAPT has a potential risk of hemorrhagic events. We aimed to examine the relationship between clopidogrel reactivity and complications.

METHODS

Patients who underwent stent assisted coiling for unruptured aneurysms or previously treated aneurysms and received periprocedural DAPT in our institution between August 2011 to March 2020 were included. Platelet reactivity for clopidogrel was measured by VerifyNow assay system, and we defined the cut off value of P2Y12 Reaction Units (PRU) at 208 and classified patients as hypo-responders (PRU≧208) or responders (PRU<208). The rates of hemorrhagic and thrombotic events within 30 days (acute phase) and 30 days after the procedure (delayed phase) were compared between the two groups. Furthermore, changes in hemoglobin levels were measured before and after the procedure and at chronic stages (1 to 6 months thereafter).

RESULTS

From 61 patients included in this study, 36 patients were hypo-responders and 25 patients were responders. Hemorrhagic events occurred 8.0% only in responders in the acute phase (p = 0.16), and 2.78% in hypo-responders and 20.0% in responders in the delayed phase (p = 0.037). Changes in hemoglobin levels before and after the procedure were 1.22 g/dl in hypo-responders and 1.74 g/dl in responders (p = 0.032) while before the procedure and chronic stages they were 0.39 g/dl in hypo-responders and 1.39 g/dl in responders (p <  0.01). Thrombotic events were not significantly different between the two groups.

CONCLUSION

Long term use of DAPT after stent assisted coiling is related to hemorrhagic events in the delayed phase. Preventing for hemorrhagic events, the duration of DAPT should be carefully considered in clopidogrel responders.

Long-term Durability of Coil Embolization for Unruptured Aneurysm after Introduction of the Neck-bridge Stent: Comparison between the Pre-stent Era and the Stent Era

More complex aneurysms can be treated by coil embolization with neck-bridge stent assistance. However, concerns about postprocedural ischemic or hemorrhagic complications remain. In this study, we assessed the long-term durability after introduction of neck-bridge stent in the context of coil embolization for unruptured aneurysm by comparing re-treatment and neurological events between the pre-stent and stent eras. Unruptured aneurysms treated by coil embolization between April 2005 and May 2018 were analyzed retrospectively. We divided cases into two groups: the pre-stent era and the stent era. The cumulative rate of re-treatment and neurological events were assessed and compared. During the period, 177 aneurysms were treated in the pre-stent era and 354 aneurysms were treated in the stent era. The median follow-up was 55 months. In the stent era, the dome/neck (D/N) ratio was significantly lower (P <0.001) and the number of aneurysms located at the posterior circulation was higher (P <0.001). A stent was used in 31.92% of cases in the stent era. The cumulative rate of re-treatment was significantly higher in the pre-stent era than it was in the stent era in univariate and multivariate analyses (P = 0.008, P = 0.008, respectively). The cumulative rate of neurological events was not significantly different between the two groups. The re-treatment rate has been improved without increasing neurological complications after introduction of the neck-bridge stent.

Association of Anterior Cerebral Artery Variants and Cerebral Infarction in Patients with Balloon-Assisted Coil Embolization for Unruptured Internal Carotid Artery Aneurysms

BACKGROUND

Balloon-assisted coiling (BAC) is an endovascular treatment that may be associated with increased complications and thromboembolic events compared with other coiling techniques. We compared clinical outcomes of endovascular treatment (simple coiling, stent-assisted coiling, and BAC) in patients with unruptured intracranial aneurysms at the internal carotid artery and assessed risk factors that could cause cerebral infarction in patients who underwent BAC.

METHODS

We retrospectively reviewed the records of 528 patients with 544 aneurysms who underwent endovascular treatment for unruptured intracranial aneurysms between January 2013 and November 2019. Demographic features, clinical information, balloon inflation time, fetal posterior cerebral artery, anterior cerebral artery (ACA) variants, and angiographic results were analyzed to determine risk factors for cerebral infarction.

RESULTS

There were no significant differences among the 3 groups in terms of general characteristics. In the BAC group, 14 of 39 patients showed a significantly higher incidence of cerebral infarction on diffusion magnetic resonance imaging compared with the stent-assisted coiling (37/238) and simple coiling (21/267) groups (P < 0.001). There was no significant difference between the ACA variants (normal vs. hypoplasia or aplasia) and cerebral infarction in the simple coiling and stent-assisted coiling groups, but the proportion of aplasia or hypoplasia in the BAC group was significantly higher (P = 0.001).

CONCLUSIONS

There is a significant association between anatomic ACA variants and cerebral infarction occurrence after BAC. Identifying the variant of the anatomic ACA using digital subtraction angiography would help to predict cerebral infarction after BAC.

Neuroform Atlas stent-assisted coiling of ruptured intracranial aneurysms: A multicenter study

PURPOSE

To assess efficacy, safety and to discuss optimal medical therapy of stent-assisted coiling of ruptured intracranial aneurysms.

METHODS

Ruptured intracranial aneurysms treated with stent-assisted coiling in eight different institutions were retrospectively reviewed. Medical treatment regimens varied among the centers, mainly regarding heparin administration and post-procedural single or double antiplatelet therapy. Clinical and angiographic results, including complications and outcomes were analyzed and related to the different therapies.

RESULTS

Sixty-one consecutive patients (male/female 23/38), aged 59.1 years (36-86) underwent stent-assisted coiling for ruptured intracranial aneurysm without antiplatelet pre-medication. Intravenous acetylsalicylic acid (ASA) 500mg was administered to all patients immediately after stent deployment. At the same time heparin was given as bolus in 15 patients (24.6%) as part of local protocol. Intravenous glycoprotein 2b/3a inhibitors (antiGP2b3a) were used as bail-out therapy for stent thrombosis. Stent thrombosis occurred in 22 patients (36.1%), of which 4 (6.5%) lead to incomplete and 18 (29.6) to complete occlusion of the stent. Heparin administration had no effect on thrombosis rate. Thrombosis resolution occurred in all cases with intravenous antiGP2b3a (7 tirofiban, 15 abciximab), without increasing overall complication rate. Single antiplatelet therapy with ASA (28 patients, 45.9%) or double antiplatelet therapy including ASA and clopidogrel (33 patients, 54.1%) were administered after procedure, depending on local protocols and on neurointerventionists' experience. Overall complication rate, including ischemia and hemorrhage was higher in patients in which only ASA was administered (21.4% vs. 12.1%). No late stent thrombosis was seen, regardless of whether a single or double antiplatelet regimen was used. Nevertheless, the small sample size suggests caution in interpreting these results. Moreover, a possible bias may arise from the decision whether to modify the maintenance therapy or not depending on the severity of the intracranial hemorrhage in a case-by-case assessment. At three months, 34 out of 38 patients with HH grade 1-2 (89.4%), and 11 out of 23 with Hunt-Hess grade of 3-4 (47.8%) were independent (Modified Ranking Scale 0-2).

CONCLUSION

Stent assisted coiling of ruptured intracranial aneurysms is a feasible option when simple coiling is not possible. Optimal medical treatment is still controversial because balance between hemorrhagic and ischemic risks is difficult to evaluate. In our series, heparin bolus had no effect on subsequent stent thrombosis. In all cases peri-operative stent thrombosis was successfully managed using bail-out intravenous antiGP2b3a, which did not increase post-procedural hemorrhage rates. A non-significant trend towards increased complications rate was noticed in patients treated with single antiplatelet therapy versus double antiplatelet therapy.

Single Center Experience in Stent-Assisted Coiling of Complex Intracranial Aneurysms Using Low-Profile Stents : The ACCLINO® Stent Versus the ACCLINO® Flex Stent

PURPOSE

The introduction of low-profile stent systems has broadened and facilitated the treatment of complex intracranial aneurysms. This retrospective case series study was conducted to assess and compare the clinical and angiographic outcomes of patients with complex intracranial aneurysms who were treated with ACCLINO® (AS) and ACCLINO® flex stents (AFS).

METHODS

In 85 patients (female 61; male 24) a total of 95 complex intracranial aneurysms, 71 (74.7%) in the anterior circulation and 24 (25.3%) in the posterior circulation were treated. Angiographic and clinical data, aneurysm characteristics and follow-up results were analyzed.

RESULTS

The AS was used in 47 cases (49.5%) and the AFS in 48 cases (50.5%). Initial angiography after the intervention showed a complete occlusion in 52.6% (Raymond-Roy occlusion classification [RROC] 1), a neck remnant in 38.9% (RROC 2) and an incomplete occlusion in 8.4% (RROC 3). Follow-up (AS: 25.2 ± 15.4 months; AFS: 9.6 ± 8.0 months) revealed an occlusion rate of 70.5% (RROC 1), 27.4% (RROC 2) and 2.1% (RROC 3). There was no statistically significant difference between the initial (p = 0.484) and the follow-up occlusion rate (p = 0.284) when comparing the two devices. Recoiling was performed in 8 cases (8.4%). The overall complication rate was 9.5% with 5 strokes (5.3%), 2 hemorrhages (2.1%), 1 in-stent stenosis (1.1%), 1 stent occlusion (1.1%) and 2 stent thromboses (2.1%). There was no procedure-related mortality.

CONCLUSION

Using the ACCLINO® and ACCLINO® flex stent system is a feasible and effective procedure with an acceptable safety profile. Initial and follow-up angiographic results were satisfactory.