Backgrounds/Aims: Thrombus migration to a distal intracranial artery inaccessible to Endovascular Clot Retrieval (ECR) is an infrequent occurrence – with literature estimating 13.7% presentations.1 Understanding the characteristics and outcomes of this finding may aid in prediction of patients who may or may not benefit.
Methods: All cases (n=451) in a single Comprehensive Stroke Centre over a 3-year period (1st January 2023–2026) with an angiographic finding of thrombus migration at time of ECR were included (n=17). Given rarity, descriptive statistics were used to summarize data to identify clinical patterns.
Results: There was a 3.8% rate of thrombus migration in ECR over 3 years. Median age was 71, median NIHSS and mRS on presentation was 11 and 1 respectively. In this cohort, majority received thrombolysis prior (76.5%), had an M1 occlusion (52.9%), had hypertension (58.8%), and had an underlying cardio-embolic aetiology (70.6%). Median time from symptom-onset to ECR was 4 hours. Median improvement in NIHSS was 4 and the median mRS at 3 months was 2. Home was the discharge destination for 88.2%. In the sub-group who received thrombolysis, median onset-to-thrombolysis time was 3 hours.
Conclusion: Thrombolysis and underlying cardio-embolic aetiology for acute ischaemic stroke were present in the majority of thrombus migration cases. Despite thrombus migration, most patients were able to be discharged home with a mRS of 2 at 3 months. No causation can be inferred and further research will need higher case numbers to compare characteristics and outcomes with patients in whom there is an accessible clot on ECR.