Treatment of posterior circulation strokes by mechanical thrombectomy with a stent-retriever: a retrospective observational study at a single center.

Objectives: To determine the rate of recanalization, functional outcome at three months, and independent prognostic factors in patients with posterior circulation strokes treated with stent-retrievers and to compare these results with those of patients in an earlier series treated with "classical methods".

Material And Methods: This was a retrospective study of consecutive patients with posterior circulation strokes treated with stent-retrievers at our center between December 1, 2011 and May 1, 2018. The main outcome variables were the rate of recanalization according to the Thrombosis in Cerebral Infarction (TICI) scale and functional independence score 90 days after treatment according to the modified Rankin Scale (mRS). We analyzed demographics, cerebrovascular risk factors, clinical findings, and probable origin. Descriptive statistics and a binary logistic regression model were used to analyze the data.

Results: We included 75 patients: 27 treated with "classical methods" and 48 treated with stent-retrievers (10 women; mean age, 63.9 years; median National Institute of Health Stroke Score, 15.8 (IQR 9-25); median Glasgow Coma Scale (GCS), 9.1 (IQR 6-14,5). TICI 2b-3 recanalization was achieved in 46 (95.8%) patients treated with stent-retrievers and in 15 (55.6%) patients treated with "classical methods" (p<0.0001). No significant differences were observed in the rate of patients achieving mRS 0-2 at 90 days (19 (39.6%) of those treated with stent-retrievers vs. 6 (22.2%) of those treated with "classical methods"). Mortality was lower among patients treated with stent-retrievers (14 (29.2% vs. 15 (55.6%) in those treated with "classical methods", p=0.024). GCS score was independently associated with mRS at 90 days (OR:0.67; 95%CI:0.5-0.91; p=0.01).

Conclusions: In patients with posterior circulation infarcts, treatment with stent-retrievers achieved high rates of recanalization and functional independence at 90 days. The rate of complications was similar to those reported in other studies. GCS is an independent predictor of functional independence at 90 days.