Antiplatelets and antithrombotics in neurointerventional procedures: Guideline update

Effects of dual antiplatelet therapy (DAPT) compared to single antiplatelet therapy (SAPT) in patients with traumatic brain injury

Japan is one of the world's most aging societies and the number of elderly patients taking antithrombotic drugs is increasing. In recent years, dual antiplatelet therapy (DAPT), in which two antiplatelet drugs are administered, has become common in anticipation of its high therapeutic efficacy. However, there are concerns about increased bleeding complications in use of DAPT. Therefore, the goal of this study was to investigate the effects of DAPT in patients with traumatic brain injury (TBI). A prospective, multicenter, observational study was conducted from December 2019 to May 2021 to examine the effects of antithrombotic drugs and reversal drugs in 721 elderly patients with TBI. In the current study, the effect of DAPT on TBI was examined in a secondary analysis. Among the registered patients, 132 patients taking antiplatelet drugs only were divided into those treated with single antiplatelet therapy (SAPT) (n=106) and those treated with DAPT (n=26) prior to TBI. Glasgow Coma Scale (GCS) on admission, pupillary findings, course during hospitalization, and outcome were compared in the two groups. A similar analysis was performed in patients with a mild GCS of 13-15 (n=95) and a moderate to severe GCS of 3-12 (n=37) on admission. The DAPT group had significantly more males (67.0 % vs. 96.2 %), a higher severity of illness on admission, and a higher frequency of brain herniation findings on head CT (21.7 % vs. 46.2 %), resulting in significantly higher mortality (12.3 % vs. 30.8 %). The only significant factor for mortality was severity on admission. The rate of DAPT was significantly higher in patients with a moderate to severe GCS on admission, and DAPT was the only significant factor related to severity on admission. These findings suggest that the severity of injury on admission influences the outcome six months after injury, and that patients with more severe TBI on admission are more likely to have been treated with DAPT compared to SAPT.

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.

Flow diversion of ruptured intracranial aneurysms: a single-center study with a standardized antithrombotic treatment protocol

BACKGROUND

The use of antithrombotic medication following acute flow diversion for a ruptured intracranial aneurysm (IA) is challenging with no current guidelines. We investigated the incidence of treatment-related complications and patient outcomes after flow diversion for a ruptured IA before and after the implementation of a standardized antithrombotic medication protocol.

METHODS

We conducted a single-center retrospective study including consecutive patients treated for acutely ruptured IAs with flow diversion during 2015-2023. We divided the patients into two groups: those treated before the implementation of the protocol (pre-protocol) and those treated after the implementation of the protocol (post-protocol). The primary outcomes were hemorrhagic and ischemic complications. A secondary outcome was clinical outcome using the modified Ranking Scale (mRS).

RESULTS

Totally 39 patients with 40 ruptured IAs were treated with flow diversion (69% pre-protocol, 31% post-protocol). The patient mean age was 55 years, 62% were female, 63% of aneurysms were in the posterior circulation, 92% of aneurysms were non-saccular, and 44% were in poor grade on admission. Treatment differences included the use of glycoprotein IIb/IIIa inhibitors (pre-group 48% vs. post-group 100%), and the use of early dual antiplatelets (pre-group 44% vs. 92% post-group). The incidence of ischemic complications was 37% and 42% and the incidence of hemorrhagic complications was 30% and 33% in the pre- and post-groups, respectively, with no between-group differences. There were three (11%) aneurysm re-ruptures in the pre-group and none in the post-group. There were no differences in mortality or mRS 0-2 between the groups at 6 months.

CONCLUSION

We found no major differences in the incidence of ischemic or hemorrhagic complications after the implementation of a standardized antithrombotic protocol for acute flow diversion for ruptured IAs. There is an urgent need for more evidence-based guidelines to optimize antithrombotic treatment after flow diversion in the setting of subarachnoid hemorrhage.

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.

Cerebral venous sinus stenting and jugular bulb embolization for pulsatile tinnitus: A case report

Background

Pulsatile tinnitus (PT) is a rare form of tinnitus that aligns with the heartbeat. It is typically brought on by lesions with significant vascularity, which produce aberrant sound conduction and increase the risk of mental health issues and hearing loss. Venous PT is more prevalent than arterial PT. Open procedures or interventional procedures can be used to treat PT. We present here a case of PT caused by venous luminal stenosis combined with jugular bulb (JB) malformation, which was improved by stenting and JB embolization.

Case presentation

A 59-year-old woman presented with long-term tinnitus consistent with heart rhythm and hearing loss, accompanied by anxiety, insomnia, and depression. The results of brain MRV, CT, and DSA showed stenosis of the right sigmoid sinus and high jugular bulb (JB) with dehiscence of the JB wall. The patient saw a significant improvement in PT symptoms following sigmoid sinus stenting and spring coil embolization of the high JB, following the diagnosis of PT. The patient had no PT recurrence for the course of the 31-month follow-up period.

Conclusion

In the present PT case, there was a simultaneous onset of the right sigmoid sinus stenosis and the high JB with the JB wall abnormalities. Sigmoid sinus stenting and spring coil embolization of high JB may be a treatment for the PT, but the prevention of post-stenting complications is still an issue that requires great attention and needs further study.

Discontinuation of antiplatelet therapy after stent-assisted coil embolisation of cerebral aneurysm: a nationwide cohort study

INTRODUCTION

Stent-assisted coil embolisation (SACE) for the treatment of unruptured cerebral aneurysms has been increasingly used. Long-term advantages of antiplatelet therapy (APT) post-SACE treatment are still not well understood. We investigated the long-term effects of APT on clinical prognosis after SACE.

PATIENTS AND METHODS

We conducted a retrospective study using nationwide health insurance claims data from South Korea, including patients with cerebral aneurysm treated with SACE from January 2009 to December 2020. The study outcomes consisted of the occurrence of cerebral infarction and major haemorrhage. To evaluate the impact of APT, we employed a multivariable time-dependent Cox proportional hazards regression model for each of the three distinct periods: 1-12 months, 12-24 months and >24 months after SACE.

RESULTS

This study included 17 692 unruptured cerebral aneurysm patients treated with SACE. During the mean follow-up of 4.2 years, there were 379 (2.1%) patients with cerebral infarction and 190 (1.1%) patients with major haemorrhage. The percentage of patients receiving APT was 79.5% at 1 year, which gradually decreased to 58.3% at 2 years after SACE. APT was beneficial in preventing cerebral infarction within 12 months after SACE (adjusted HR (aHR) 0.56; 95% CI, 0.35 to 0.89; p=0.014). After 12 months, this association was not evident. APT increased the risk of haemorrhage after 24 months (aHR 1.76; 95% CI 1.11 to 2.87; p=0.016).

DISCUSSION AND CONCLUSION

Our findings suggest that in patients with unruptured cerebral aneurysm treated with SACE, the reasonable duration of APT for preventing cerebral infarction might be 1 year after SACE.

Mechanical thrombectomy in acute in-stent thromboembolism

Following the implantation of a carotid artery stent (CAS), the aetiology of in-stent occlusion typically shifts from embolic events in the acute phase to intimal hyperplasia in the chronic phase. A man in his 70s with a history of CAS implantation (performed 5 years ago) for left internal carotid artery (ICA) stenosis was admitted to our hospital with a chief complaint of left-sided transient scotoma. MRI revealed an acute occlusion of the left ICA, and an urgent digital subtraction angiography (DSA) was performed. The DSA results suggested the presence of an in-stent thrombus instead of in-stent stenosis. An urgent endovascular thrombectomy was performed, and the thrombus was successfully retrieved from the carotid stent. Full reperfusion was achieved, and no damage occurred to the carotid stent. This case highlights the importance of thorough examination of MRI and DSA findings for accurate differentiation between the causes of vessel occlusion.

Assessing the efficacy of VerifyNow platelet-function testing in predicting postoperative hemorrhagic complications of neuroendovascular surgery: A systematic review and meta-analysis (part 2)

BACKGROUND

Dual antiplatelet therapy is used to reduce the risk of thromboembolic complications in neuroendovascular surgery. However, the predictive utility of preoperative platelet-sensitivity testing for decreasing bleed risk in patients undergoing endovascular neurointervention remains unclear.

OBJECTIVE

We conducted a systematic review and meta-analysis to illustrate the association between platelet response and risk of hemorrhagic complications from neuroendovascular surgery, examine the efficacy of the VerifyNow platelet reactivity unit (PRU) assay in predicting hemorrhagic outcomes, and assess whether a clinically useful threshold for platelet response can be defined to standardize guidelines.

METHODS

PubMed, Embase, and Scopus were searched. Articles were screened for relevance by title and abstract, followed by full text.

RESULTS

Of 735 resultant articles, 17 studies of 2084 patients undergoing neuroendovascular intervention were included. Diagnoses included both intracranial and extracranial pathologies, of which 37.8% were treated with flow diversion, 22.4% with stent-assisted coil embolization, 14.3% with intracranial stenting, 12.8% with simple coil embolization, 5.8% with balloon-assisted coil embolization, 2.0% with extracranial stenting, and 4.8% with an alternate method. Precisely, 52.9% (9 out of 17) of studies determined platelet hyperresponse to be an independent predictor of postoperative hemorrhagic complications, with 11.8% (2 out of 17) of studies reporting a similar but non-statistically significant trend. 35.3% (6 out of 17) of studies found no relationship between platelet response and postoperative hemorrhagic complications. The estimated clinical threshold for PRU to prevent hemorrhagic complications varied considerably across studies (range: <46-118 PRU). Meta-analysis found platelet hyperresponse to have more than a 3-fold increased risk of hemorrhagic complications compared to normoresponders (relative risk = 3.2, p = 0.001).

CONCLUSION

Although this meta-analysis shows the predictive utility of the P2Y12 assay for postoperative hemorrhagic complications in neuroendovascular surgery, the optimal therapeutic threshold for minimizing bleeding risk is still uncertain. To better understand the utility of the P2Y12 assay in the perioperative period, further prospective research is needed.

Prediction of Venous Trans-Stenotic Pressure Gradient Using Shape Features Derived From Magnetic Resonance Venography in Idiopathic Intracranial Hypertension Patients

OBJECTIVE

Idiopathic intracranial hypertension (IIH) is a condition of unknown etiology associated with venous sinus stenosis. This study aimed to develop a magnetic resonance venography (MRV)-based radiomics model for predicting a high trans-stenotic pressure gradient (TPG) in IIH patients diagnosed with venous sinus stenosis.

MATERIALS AND METHODS

This retrospective study included 105 IIH patients (median age [interquartile range], 35 years [27-42 years]; female:male, 82:23) who underwent MRV and catheter venography complemented by venous manometry. Contrast enhanced-MRV was conducted under 1.5 Tesla system, and the images were reconstructed using a standard algorithm. Shape features were derived from MRV images via the PyRadiomics package and selected by utilizing the least absolute shrinkage and selection operator (LASSO) method. A radiomics score for predicting high TPG (≥ 8 mmHg) in IIH patients was formulated using multivariable logistic regression; its discrimination performance was assessed using the area under the receiver operating characteristic curve (AUROC). A nomogram was constructed by incorporating the radiomics scores and clinical features.

RESULTS

Data from 105 patients were randomly divided into two distinct datasets for model training (n = 73; 50 and 23 with and without high TPG, respectively) and testing (n = 32; 22 and 10 with and without high TPG, respectively). Three informative shape features were identified in the training datasets: least axis length, sphericity, and maximum three-dimensional diameter. The radiomics score for predicting high TPG in IIH patients demonstrated an AUROC of 0.906 (95% confidence interval, 0.836-0.976) in the training dataset and 0.877 (95% confidence interval, 0.755-0.999) in the test dataset. The nomogram showed good calibration.

CONCLUSION

Our study presents the feasibility of a novel model for predicting high TPG in IIH patients using radiomics analysis of noninvasive MRV-based shape features. This information may aid clinicians in identifying patients who may benefit from stenting.

Low dose intravenous cangrelor versus glycoprotein IIb/IIIa inhibitors in endovascular treatment of tandem lesions

OBJECTIVES

Intravenous (IV) periprocedural antiplatelet therapy (APT) for patients undergoing acute carotid stenting during mechanical thrombectomy (MT) is not fully investigated. We aimed to compare the safety profile of IV low dose cangrelor versus IV glycoprotein IIb/IIIa (GP-IIb/IIIa) inhibitors in patients with acute tandem lesions (TLs).

MATERIALS AND METHODS

We retrospectively identified all cases of periprocedural administration of IV cangrelor or GP-IIb/IIIa inhibitors during acute TLs intervention from a multicenter collaboration. Patients were divided in two groups according to the IV APT regimen at the time of MT procedure: 1) cangrelor and 2) GP-IIb/IIIa inhibitors (tirofiban and eptifibatide). Safety outcomes included rates of symptomatic intracranial hemorrhage (sICH), parenchymal hematoma type 1 and 2 (PH1-PH2), and hemorrhagic infarction type 1 and 2 (HI1-HI2).

RESULTS

Sixty-three patients received IV APT during MT, 30 were in the cangrelor group, and 33 were in the GP-IIb/IIIa inhibitors group. There were no significant differences in the rates of sICH (3.3% vs. 12.1%, aOR=0.21, 95%CI 0.02-2.18, p=0.229), HI1-HI2 (21.4% vs 42.4%, aOR=0.21, 95%CI 0.02-2.18, p=0.229), and PH1-PH2 (17.9% vs. 12.1%, aOR=1.63, 95%CI 0.29-9.83, p=0.577) between both treatment groups. However, there was a trend toward reduced hemorrhage rates with cangrelor. Cangrelor was associated with increased odds of complete reperfusion (aOR=5.86; 95%CI 1.57-26.62;p=0.013).

CONCLUSIONS

In this retrospective non-randomized cohort study, our findings suggest that low dose cangrelor has similar safety and increased rate of complete reperfusion compared to IV GP-IIb/IIIa inhibitors. Further prospective studies are warranted to confirm this association.

Mechanical thrombectomy for symptomatic stent thrombosis after carotid artery stenting

Background

As there is still no consensus on the treatment of carotid stent thrombosis (CST), we would like to describe our experience with the revascularization of CST by mechanical thrombectomy.

Methods

We retrospectively studied patients who underwent mechanical thrombectomy after CST at Xuzhou Municipal First People's Hospital and Xuzhou Central Hospital between January 2020 and November 2022. The results of the procedures, complications, and clinical and imaging follow-up were recorded.

Results

A total of six patients were included in this study. The stenosis grade before stent implantation was ≥85% in all patients, and the stenosis length ranged from 7 to 20 mm. Patients experienced CST within 6 days to 45 months after carotid artery stenting (CAS); the median admission on the National Institutes of Health Stroke Scale (NIHSS) at CST was 12 (range 8-25). Mechanical thrombectomy was successfully performed in all patients. There was no periprocedural death, and the modified Rankin Scale (mRS) at the 3-month follow-up was 0-2. All patients showed recovery from their neurological deficits.

Conclusion

The treatment of symptomatic CST with mechanical thrombectomy resulted in satisfactory clinical outcomes. This regimen could be effective and safe, and future prospective and randomized studies are warranted.

Challenges in Coagulation Management in Neurosurgical Diseases: A Scoping Review, Development, and Implementation of Coagulation Management Strategies

Bleeding and thromboembolic (TE) complications in neurosurgical diseases have a detrimental impact on clinical outcomes. The aim of this study is to provide a scoping review of the available literature and address challenges and knowledge gaps in the management of coagulation disorders in neurosurgical diseases. Additionally, we introduce a novel research project that seeks to reduce coagulation disorder-associated complications in neurosurgical patients. The risk of bleeding after elective craniotomy is about 3%, and higher (14-33%) in other indications, such as trauma and intracranial hemorrhage. In spinal surgery, the incidence of postoperative clinically relevant bleeding is approximately 0.5-1.4%. The risk for TE complications in intracranial pathologies ranges from 3 to 20%, whereas in spinal surgery it is around 7%. These findings highlight a relevant problem in neurosurgical diseases and current guidelines do not adequately address individual circumstances. The multidisciplinary COagulation MAnagement in Neurosurgical Diseases (COMAND) project has been developed to tackle this challenge by devising an individualized coagulation management strategy for patients with neurosurgical diseases. Importantly, this project is designed to ensure that these management strategies can be readily implemented into healthcare practices of different types and with sustainable integration.

Artificial Intelligence and Neurosurgery: Tracking Antiplatelet Response Patterns for Endovascular Intervention

Platelets play a critical role in blood clotting and the development of arterial blockages. Antiplatelet therapy is vital for preventing recurring events in conditions like coronary artery disease and strokes. However, there is a lack of comprehensive guidelines for using antiplatelet agents in elective neurosurgery. Continuing therapy during surgery poses a bleeding risk, while discontinuing it before surgery increases the risk of thrombosis. Discontinuation is recommended in neurosurgical settings but carries an elevated risk of ischemic events. Conversely, maintaining antithrombotic therapy may increase bleeding and the need for transfusions, leading to a poor prognosis. Artificial intelligence (AI) holds promise in making difficult decisions regarding antiplatelet therapy. This paper discusses current clinical guidelines and supported regimens for antiplatelet therapy in neurosurgery. It also explores methodologies like P2Y12 reaction units (PRU) monitoring and thromboelastography (TEG) mapping for monitoring the use of antiplatelet regimens as well as their limitations. The paper explores the potential of AI to overcome such limitations associated with PRU monitoring and TEG mapping. It highlights various studies in the field of cardiovascular and neuroendovascular surgery which use AI prediction models to forecast adverse outcomes such as ischemia and bleeding, offering assistance in decision-making for antiplatelet therapy. In addition, the use of AI to improve patient adherence to antiplatelet regimens is also considered. Overall, this research aims to provide insights into the use of antiplatelet therapy and the role of AI in optimizing treatment plans in neurosurgical settings.

Trends in Dual Antiplatelet Therapy Use for Neurointerventional Procedures for the Management of Intracranial Aneurysms

The use of periprocedural dual antiplatelet therapy (DAPT) has significantly evolved along with innovations in the endovascular management of intracranial aneurysms. Historically, aspirin and clopidogrel have been the most commonly employed regimen due to its safety and efficacy. However, recent studies highlight the importance of tailoring DAPT regimens to individual patient characteristics which may affect clopidogrel metabolism, such as genetic polymorphisms. In the present report, a systematic review of the literature was performed to determine optimal antiplatelet use with flow diverting stents, intracranial stents, intrasaccular devices, and stent-assisted coiling. Studies were analyzed for the number of aneurysms treated, DAPT regimen, and any thromboembolic complications. Based on inclusion criteria, 368 studies were selected, which revealed the increasing popularity of alternative DAPT regimens with the aforementioned devices. Thromboembolic or hemorrhagic complications associated with antiplatelet medications were similar across all medications. DAPT with ticagrelor, tirofiban, or prasugrel are effective and safe alternatives to clopidogrel and do not require enzymatic activation. Further clinical trials are needed to evaluate different antiplatelet regimens with various devices to establish highest-level evidence-based guidelines and recommendations.