Antiplatelet therapy for prevention of thromboembolic complications in coiling-only procedures for unruptured brain aneurysms

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.

Feasibility and safety values of activated clotting time-guided systemic heparinization in coil embolization for unruptured intracranial aneurysms

OBJECTIVE

This study aimed to evaluate the feasibility and safety values of activated clotting time (ACT)-guided systemic heparinization in reducing periprocedural thrombosis and bleeding complications during coil embolization of unruptured intracranial aneurysms.

METHODS

A total of 228 procedures performed on 213 patients between 2016 and 2021 were included in the retrospective analysis. The target ACT was set at 250 s. Logistic regression was performed to assess predictors for the occurrence of thrombosis and bleeding. Receiver operating characteristic (ROC) analyses were employed to determine the optimal cut-off values for ACT, heparinization, and procedure time.

RESULTS

Most (85.1%) of procedures were stent-assisted embolization. The mean baseline ACT was 128.8 ± 45.7 s. The mean ACT at 20 min after the initial intravenous heparin loading of 78.2 ± 18.8 IU/kg was 185 ± 46.4 s. The mean peak ACT was 255.6 ± 63.8 s with 51.3% (117 cases) achieving the target ACT level. Peak ACT was associated with symptomatic thrombosis (OR per second, 1.008; 95% CI, 1.000-1.016; P = 0.035) (cut-off value, 275 s; area under ROC (AUROC), 0.7624). Total administered heparin dose per body weight was negatively associated with symptomatic thrombosis (OR per IU/kg, 0.972; 95% CI, 0.949-0995; P = 0.018) (cut-off value, 294 IU/kg; AUROC, 0.7426) but positively associated with significant bleeding (OR, 1.008 per IU/kg; 95% CI, 1.005-1.012; P <0 .001) (cut-off value, 242 IU/kg; AUROC, 0.7391). Procedure time was significantly associated with symptomatic thrombosis (OR per minute, 1.05; 95% CI, 1.017-1.084; P value = 0.002) (cut-off value, 158 min; area under ROC, 0.8338).

CONCLUSION

This study demonstrated that ACT-guided systemic heparinization was feasible to achieve the target ACT value and proposes probable safety thresholds to prevent periprocedural complications through reducing procedure time during coil embolization of unruptured intracranial aneurysms in the stent era.

Thromboembolic complications during and after embolization of unruptured aneurysms: A chronological outcome in periprocedural thromboembolic events

Background

Ischemic complications develop after elective coil embolization procedures at a certain rate. The prevention of these events has been a longstanding issue for many interventional neuroradiologists. This study aimed to clarify whether procedural ischemic events after unruptured aneurysm embolization decrease over time with perioperative anti-thromboembolic treatment or surgical experience.

Methods

This study included patients with cerebral aneurysms in our institution between July 2012 and June 2020. Dual-antiplatelet therapy (DAPT) was performed (Phase 1). Thromboembolic events developed at a certain rate; thus, rivaroxaban was administered with single-antiplatelet therapy (SAPT) to improve thromboembolic results (Phase 2), showing better outcomes than in Phase 1. Subsequently, DAPT was administered again (Phase 3). Ischemic complications were evaluated in each phase or compared between the DAPT group and the direct oral anticoagulant (DOAC) with the clopidogrel (DOAC+SAPT) group.

Results

Relatively, fewer symptomatic ischemic events were noted in Phase 2 or the DOAC+SAPT group, but the outcome was not better in Phase 3 than in Phase 2. Symptomatic complications were more common in Phase 3 than in Phases 1 and 2.

Conclusion

Ischemic complications occurred at a certain rate after endovascular procedures for unruptured aneurysms. The incidence did not decrease over time; particularly, standard DAPT plus postoperative anti-thromboembolic medication did not adequately decrease complications in Phase 3 compared to Phases 1 and 2. Therefore, accumulated experience or a learning curve could not explain the results. DOAC administration might decrease the risk of these events, but further accumulation of evidence or prospective investigation is warranted.

Antithrombotic therapies for neurointerventional surgery: a 2021 French comprehensive national survey

BACKGROUND

Neurointerventionists lack guidelines for the use of antithrombotic therapies in their clinical practice; consequently, there is likely to be significant heterogeneity in antithrombotic use between centers. Through a nationwide survey, we aimed to obtain an exhaustive cross-sectional overview of antithrombotic use in neurointerventional procedures in France.

METHODS

In April 2021, French neurointerventional surgery centers were invited to participate in a nationwide 51-question survey disseminated through an active trainee-led research collaborative network (the JENI-RC).

RESULTS

All 40 centers answered the survey. Fifty-one percent of centers reported using ticagrelor and 43% used clopidogrel as premedication before intracranial stenting. For flow diversion treatment, dual antiplatelet therapy was maintained for 3 or 6 months in 39% and 53% of centers, respectively, and aspirin was prescribed for 12 months or more than 12 months in 63% and 26% of centers, respectively. For unruptured aneurysms, the most common heparin bolus dose was 50 IU/kg (59%), and only 35% of centers monitored heparin activity for dose adjustment. Tirofiban was used in 64% of centers to treat thromboembolic complications. Fifteen percent of these comprehensive stroke centers reported using tenecteplase to treat acute ischemic strokes. Cangrelor appeared as an emergent drug in specific indications.

CONCLUSION

This nationwide survey highlights the important heterogeneity in clinical practices across centers. There is a pressing need for trials and guidelines to further evaluate and harmonize antithrombotic regimens in the neurointerventional field.

Primary coiling of a wide-neck unruptured aneurysm in the trifurcation of the P2 segment of the posterior cerebral artery: A case report

Intracranial aneurysms are now treatable with coils, stents, and flow diverters in recent years. For saccular aneurysms with broad necks and short domes, stent-assisted coiling has become a common technique, but over time, the complications—both intraprocedural and in a delayed fashion—occur more frequently than coiling alone. Nonstent or balloon-assisted coiling results in lower aneurysm recanalization, lower aneurysm rupture or re-rupture, or lower aneurysm retreatment. This paper illustrates a successful coiling of wide-neck unruptured aneurysm in the trifurcation of the left P2 posterior cerebral artery done without the assistance of stents or balloons.

Outflow angle: a risk factor for thromboembolic complications in coil embolisation for treating unruptured middle cerebral artery bifurcation aneurysms

BACKGROUND

Thromboembolic complications are a relevant risk in coil embolisation of cerebral aneurysms. This retrospective study aimed to assess the treatment outcomes of unruptured middle cerebral artery (MCA) bifurcation aneurysms and the predictors for thromboembolic complications based on the aneurysm morphological characteristics. We examined the following three features: inflow angle, outflow angle (OA), and bifurcation angle, formed by the aneurysm and neighbouring blood vessels.

METHODS

A total of 32 MCA bifurcation aneurysms were retrospectively investigated in 32 patients treated consecutively at our institute between April 2008 and March 2019. The predictors for thromboembolic complications were analysed in two groups: patients with and without thromboembolic complications.

RESULTS

Perioperative thromboembolic complications were detected in six patients (18.8%), including two and six intra- and post-procedural thromboembolic complications, respectively; all cases were resolved. Regarding the aneurysms' morphological characteristics, the group with thromboembolic complications showed a significantly smaller OA (55.58° ± 14.05° vs. 86.04° ± 28.58°, P = 0.01) than the group without complications. Multivariate analysis revealed that smoking habits and OA < 70° were significant predictors of thromboembolic complications (smoking habits: P = 0.01, odds ratio [OR]: 6.89, 95% confidence interval [CI]: 3.78-12.62; OA < 70°: P = 0.04, OR: 3.19, 95% CI: 1.52-6.56).

CONCLUSIONS

Our findings indicate significant pre-procedural predictors of thromboembolic complications to consider for safe treatment; clipping should be preferred to coil embolisation in high-risk patients. The method of choice should be considered in each case to allow the safe treatment of unruptured MCA aneurysms.

Antiplatelet therapy for standalone coiling of ruptured intracranial aneurysms: a systematic review and meta-analysis

BACKGROUND

Endovascular embolization using standalone coils is the preferred treatment option for ruptured cerebral aneurysms to avoid the use of dual antiplatelet therapy with stent coiling or endoluminal flow diversion devices. However, it has been reported that patients undergoing the standalone coiling approach are at risk for periprocedural thromboembolism. Therefore, this systematic review and meta-analysis was performed to clarify the risks and benefits of antiplatelet therapy (AT) during coiling procedures performed to treat ruptured aneurysms, including the incidence of early thromboembolic events, hemorrhagic and delayed ischemic events, as well as clinical outcomes.

METHODS

A comprehensive search of three databases was performed for articles from inception to June 2021. After fulfilling the inclusion criteria, five studies were included in this meta-analysis and 462 patients with aneurysmal subarachnoid hemorrhage (aSAH) were identified who underwent endovascular standalone coiling treatment. Aneurysm location, patient characteristics, and aSAH grades were comparable between the AT and non-AT groups.

RESULTS

AT significantly decreased the incidence of thromboembolic events immediately after the coiling procedures compared with non-AT (OR 3.42; 95% CI 1.77 to 6.61, p<0.001). The incidences of hemorrhage, delayed ischemia, and clinical outcomes with or without AT were not significantly different between groups.

CONCLUSIONS

Although this study showed no beneficial effect of AT on clinical outcomes, the results suggest that AT could be combined with standalone coiling to avoid thromboembolism during the perioperative period. A large prospective study and/or an additional meta-analysis would be required to further investigate how AT benefits standalone coil embolization in aSAH.

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.

Predictors of Cerebral Aneurysm Rupture after Coil Embolization: Single-Center Experience with Recanalized Aneurysms

BACKGROUND AND PURPOSE

Recanalization after coil embolization is widely studied. However, there are limited data on how recanalized aneurysms rupture. Herein, we describe our experience with the rupture of recanalized aneurysms and discuss the type of recanalized aneurysms at greatest rupture risk.

MATERIALS AND METHODS

A total of 426 unruptured aneurysms and 169 ruptured aneurysms underwent coil embolization in our institution between January 2009 and December 2017. Recanalization occurred in 38 (8.9%) of 426 unruptured aneurysms (unruptured group) and 37 (21.9%) of 169 ruptured aneurysms (ruptured group). The Modified Raymond-Roy classification on DSA was used to categorize the recanalization type. Follow-up DSA was scheduled until 6 months after treatment, and follow-up MRA was scheduled yearly. If recanalization was suspected on MRA, DSA was performed.

RESULTS

In the unruptured group, the median follow-up term was 74.0 months. Retreatment for recanalization was performed in 18 aneurysms. Four of 20 untreated recanalized aneurysms (0.94% of total coiled aneurysms) ruptured. In untreated recanalized aneurysms, class IIIb aneurysms ruptured significantly more frequently than class II and IIIa (P = .025). In the ruptured group, the median follow-up term was 28.0 months. Retreatment for recanalization was performed in 16 aneurysms. Four of 21 untreated recanalized aneurysms (2.37% of total coiled aneurysms) ruptured. Class IIIb aneurysms ruptured significantly more frequently than class II and IIIa (P = .02).

CONCLUSIONS

The types of recanalization after coil embolization may be predictors of rupture. Coiled aneurysms with class IIIb recanalization should undergo early retreatment because of an increased rupture risk.