Antiplatelet therapy for the prevention of peri-coiling thromboembolism in high-risk patients with ruptured intracranial aneurysms

Abstract

OBJECTIVE The most frequent procedural complication of the endovascular treatment of intracranial aneurysms is a thromboembolic event (TEE); in a subset of patients, such events will cause permanent neurological disability. In patients with unruptured aneurysms, increasing evidence supports the use of periprocedural antiplatelet therapy to prevent TEEs. The object of this study was to evaluate whether patients with ruptured aneurysms and subarachnoid hemorrhage would also benefit from periprocedural antiplatelet therapy. METHODS The authors reviewed a prospective registry of 169 patients with endovascularly treated intracranial aneurysms to delineate angiographic features associated with periprocedural TEEs. They then performed a controlled before-and-after study in 79 patients with ruptured aneurysms who were deemed to be at high risk for TEEs (for example, patients with at least 1 angiographic feature associated with TEEs) to evaluate whether selective aspirin administration would reduce the rate of periprocedural thromboembolism without increasing major hemorrhagic complications. RESULTS Six angiographic features were associated with periprocedural TEEs in the study cohort: wide aneurysm neck, coil or loop protrusion, small parent artery diameter, an incorporated branch, intraprocedural thrombus formation, and intracranial parent vessel atherosclerosis. Aspirin administration to high-risk patients significantly decreased the rate of periprocedural TEEs, from 53.8% in the control group to 10.6% in the aspirin-treated group (p = 0.001). The reduction in TEEs in the aspirin-treated group continued to be statistically significant even when adjusted for age, sex, cardiovascular risk factors (smoking, diabetes, hypertension, dyslipidemia, coronary artery disease), and factors associated with TEEs in other large studies (wide aneurysm neck, aneurysm size ≥ 10 mm), with an adjusted OR of 0.16 (95% CI 0.03-0.8). There were no major systemic hemorrhagic complications, and aspirin did not increase the risk of aneurysm rebleeding, symptomatic intracranial hemorrhage, or major external ventricular drain (EVD)-associated hemorrhage (p = 0.3), though there was an increase in asymptomatic, minor (< 1 cm) EVD-associated hemorrhage in the aspirin-treated group (p = 0.02). CONCLUSIONS The study findings suggest that for ruptured aneurysm patients with high-risk features, antiplatelet therapy can significantly reduce the rate of periprocedural TEE without increasing major systemic or intracranial hemorrhages.

Association of plasma D-dimer level with thromboembolic events after endovascular coil treatment of ruptured cerebral aneurysms

“…25,27 Thus, a wide aneurysm neck was reported to be associated with an increased incidence of thromboembolic events due to a larger coil-lumen interface in the treatment of unruptured aneurysms. 6,21 In addition, our results suggest that hypercoagulability associated with SAH also contributes to thrombus formation and the incidence of thromboembolic events in the treatment of ruptured aneurysms. On the other hand, 8 of 11 cases of thromboembolic events were not associated with thrombus formation around the aneurysm neck, suggesting other sources of thromboembolism.…”

“…10,14 Thromboembolic events without visible thrombus formation at the neck of the aneurysm during endovascular coiling may be caused by catheter insertion into a diseased parent vessel, as represented by elevated D-dimer levels. 6 In addition, chronic derangements in systemic coagulation states from comorbid burden, such as deep venous thrombosis and malignancies, may be associated with D-dimer elevations and thromboembolic events unrelated to endovascular procedures, 10,22 although screening for these pathologies was not performed in the present study.…”

“…Although the rescue therapy protocol described in Methods may have biased the incidence of thromboembolic events in the subgroup of patients with observed intraoperative thrombus formation, one possible explanation of thromboembolic events without thrombus formation around the aneurysm neck is thrombus formed through shear stress between catheters and parent vessels with atherosclerosis. 6 The plasma level of D-dimer may be elevated not only as an acute systemic response for SAH but also depending on patients' premorbid status, including aging. 10,20 Atherosclerotic change is presumed to be one of the causes of D-dimer elevation in elderly patients.…”

“…However, because aneurysmal SAH is associated with hemorrhagic complications, including clot-induced pial injury and external ventricular drainage-related hemorrhage, routine use of antiplatelet agents in the treatment of ruptured aneurysms may not be justified. 2,6,7 Elective use of intraprocedural aspirin at a dose of 650 mg for patients with angiographic high-risk features was reported to reduce thromboembolic events in the treatment of ruptured aneurysms without significantly increasing hemorrhagic complications. 6 A similar approach may be beneficial to reduce thromboembolic complications in patients with elevated D-dimer levels.…”

“…17,23 Anatomical factors, including wide aneurysm neck, small parent artery diameter, and branches arising from aneurysmal walls, were reported as risk factors for thromboembolic events. 6,21 Procedure-related thromboembolic events are observed more frequently in endovascular coiling of ruptured aneu-rysms than in coiling of unruptured ones. 17 In the treatment of ruptured aneurysms, hypercoagulability as a systemic response to acute subarachnoid hemorrhage (SAH) 9,13 may be associated with an increased incidence of thromboembolic events in addition to the aforementioned anatomical factors.…”