Thrombus Migration in the Middle Cerebral Artery: Incidence, Imaging Signs, and Impact on Success of Endovascular Thrombectomy

Abstract

Background Thrombus migration ( TM ) in intracranial vessels during ischemic stroke has been reported in the form of case reports, but its incidence, impact on the technical success of subsequent endovascular thrombectomy and patients' outcome have never been studied systematically. Methods and Results Retrospective analysis was done of 409 patients with isolated middle cerebral artery occlusions treated with endovascular thrombectomy. TM was observed (1) by analyzing discrepancies between computed tomographic angiography and digital subtraction angiography and (2) by comparing infarct pattern in the striatocapsular region with exact, angiographically assessed thrombus location within the M1‐segment and the involvement of the middle cerebral artery perforators. Preinterventional infarction of discrepant regions (infarction in regions supplied by more proximal vessels than those occluded by the clot) was ensured by carefully reviewing available preinterventional multimodal imaging. Adequate imaging inclusion criteria were met by 325 patients. Ninety‐seven patients showed signs of TM (26 with direct evidence, 71 with indirect evidence). There was no difference in the frequency of preinterventional intravenous recombinant tissue plasminogen activator administration between patients with TM and those without (63.9% vs 64.9%, P =0.899). TM was associated with lower rates of complete reperfusion (Thrombolysis in Cerebral Infarction score 3) (adjusted odds ratio 0.400, 95% CI 0.226‐0.707). Subsequently, preinterventional TM was associated with lower rates of substantial neurologic improvement (adjusted odds ratio 0.541, 95% CI 0.309‐0.946). Conclusions Preinterventional TM does not seem to be facilitated by intravenous recombinant tissue plasminogen activator and often occurs spontaneously. However, TM is associated with the risk of incomplete reperfusion in subsequent thrombectomy, suggesting increased clot fragility. Occurrence of TM may thereby have a substantial impact on the outcome of endovascularly treated stroke patients.

Endovascular Treatment With or Without Prior Intravenous Alteplase for Acute Ischemic Stroke

“…24 Conversely, the use of IVT before EVT may also pose a higher risk of emboli migrating to a previously uninvolved territory or thrombus migration to more distal arterial branches that cannot be reached with EVT, which is associated with a worse prognosis. 25 In our study, embolization to a new territory and thrombus migration were not documented. However, the postprocedural eTICI score of ≥2C was similar in both groups.…”

Endovascular Treatment

“…Our objective was to assess technical and safety aspects of EVT in patients with an M2 occlusion. 25 Second, ischemic stroke patients with a large-vessel occlusion who did not undergo EVT are not registered in the MR CLEAN Registry. Therefore, patients with distal M2 occlusions may have been excluded, which could have resulted in selection bias.…”

In vivo brain imaging with multimodal optical coherence microscopy in a mouse model of thromboembolic photochemical stroke

“…Spontaneous clot migrations have also been observed in humans. 35 Using preinterventional computed tomographic angiography and MRA, Kaesmacher et al 35 showed that spontaneous clot migration occurs in 30% of patients who underwent endovascular thrombectomy, regardless of rt-PA administration. In our study, angiomaps of 3-D vascular networks were collected in real time (temporal resolution, 18 s) during stroke and reperfusion, which permitted the imaging of vascular network blood flow changes, thrombi formation, and bidirectional migration.…”