Sami Al Kasab, MD

Mosimann PJ, Kaesmacher J, Gautschi D, Bellwald S, Panos L, Piechowiak E, et al. Predictors of Unexpected Early Reocclusion After Successful Mechanical Thrombectomy in Acute Ischemic Stroke Patients. Stroke. 2018

Mechanical thrombectomy (MT) is now the standard of care for patients presenting with anterior circulation LVO, who otherwise have small core infarct defined by ASPECTS score or perfusion scans admission. Rapid and complete revascularization have been shown to predict good functional outcome. Data on the rate of early revascularization are scares. In this article, Mosimann et al. evaluate the prevalence and predictors of early reocclusion following successful MT and its impact on long-term functional outcome.

A total of 711 patients were included in this study; all patients underwent MT and had revascularization score of TICI2b or 3 at the end of the procedure; intravenous thrombolysis was administered when indicated. Post-thrombectomy care was performed according to the standard institutional guidelines. Etiology for stroke was documented according to the TOAST classification system. Early reocclusion was defined as reocclusion seen on CTA or MRA during the first 48 hours following MT.

Mean age was 70.2, and 49% were female. 43.6% had cardio-embolic stroke, 10.7% had stroke due to large artery atherosclerosis, and 45.7% had stroke due to other or unknown etiology. 12.5% of patients had intracranial ICA or carotid T occlusion, 43.8% had M1 occlusion, 37.5% had M2/M3/A1 occlusion and 6.3% had post circulation occlusion. Early reocclusion was observed in 16/711 patients (2.3%). Median time to diagnosis of reocclusion was 20 hours after initial imaging on admission. Reocclusion was associated with lack of improvement in 3 patients, worsening of exam after the intervention in 11 patients, and in 2 patients reocclusion was asymptomatic. 3 patients underwent repeated MT; however, this was not associated with significant improvement. Patients with early reocclusion had poor functional outcome when compared to those who didn’t ( mRS 0-2: 20.0% vs 51.3%; p=0.019); however, mortality rate didn’t differ between the two groups.

With regards to predictors to reocclusion, the authors found that higher admission platelet count (≥ 220), stroke of undetermined etiology or caused by other causes in the TOAST criteria, and initial occlusion at M2, M3 and A1, and residual stenosis at the final run following MT were associated with higher likelihood of early reocclusion. Importantly, the number of passes, the use of aspiration vs stent retriever, the use of balloon-guiding catheter and tandem lesions didn’t affect the rate of early reocclusion.

This study provided important information regarding the prevalence and predictors of early reocclusion. Patients with higher platelet count on admission and residual stenosis on admission are at higher risk of early reocclusion. Carefully evaluating and addressing any residual stenosis in situ during the final run following MT might help reduce this risk.