Evaluation of acute intraprocedural thromboembolism risk factors in endovascular treatment of unruptured intracranial aneurysms

Abstract

Background: Acute intraprocedural thromboembolism (AIT) is not a rare complication that usually occurs immediately after stent deployment during endovascular aneurysm treatment (EVAT). Methods: We retrospectively analyzed the 386 EVAT of 320 patients for the AIT occurrence between 2014 and 2018. The patient's comorbidities, aneurysm location, antiplatelet type, and thrombocyte reactivity to P2Y12 inhibitors were assessed. AIT severity was categorized as severe (hyperacute thrombus filling >50 % stent lumen) or mild (in-stent thrombus <50 %, side/integrated branch occlusion, or distal cortical branch occlusion). The EVAT was categorized on a location basis (proximal or distal), accounting for the terminal edges of the deployed stent. Results: 30 (7.8 %) of 386 EVAT procedures were complicated with AIT. There were 9 (30 %) severe AIT and 21 (70 %) mild AIT, consisting of 12 (40 %) partial in-stent thrombi and 9 (30 %) distal cortical or side branch emboli. Patient comorbidities and type of antiplatelet regimen were not different between the AIT group and uncomplicated cases. Mild AIT was higher in the flow diversion (FD) versus stent-assisted coiling (SAC), (8.1 %, and 2.3 %, respectively, p = 0.012). Deployment of braided SAC (OR: 8.5, p = 0.04) or FD (OR: 18.8, p < 0.01) resulted in significantly higher AIT rates compared to laser-cut SAC. Additionally, stent placement in distal EVAT (beyond the ICA bifurcation or basilar apex) was associated with a significantly higher AIT risk (OR: 8.5, p < 0.01). Conclusion: Patient comorbidities and type of antiplatelet regimen had no association with AIT when sufficient anti-aggregation was achieved. However, AIT risk surged with braid-SAC or FD, especially in the treatment of distal complex aneurysms.