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Association Between Occluded Vessel Diameter and Clinical Outcomes of Mechanical Thrombectomy for M2 Occlusion
Yasunori Yokochi1, Hiroyuki Ikeda2,3, Masanori Kinosada1
1Department of Neurosurgery, Kurashiki Central Hospital, Kurashiki, Japan.
Background:
The association between occluded vessel diameter measured using pre-recanalization digital subtraction angiograms and clinical outcomes in patients with acute ischemic stroke undergoing mechanical thrombectomy for M2 occlusion remains unclear.
Methods:
Consecutive patients with acute ischemic stroke undergoing mechanical thrombectomy for M2 occlusion at our institution between January 2020 and December 2024 were retrospectively analyzed. Based on pre-recanalization digital subtraction angiograms, patients were classified as having large M2 occlusion (LM2O, ≥ 1.7 mm) or small M2 occlusion (SM2O, < 1.7 mm). Favorable 90-day outcome, defined as modified Rankin Scale 0-2 or recovery to pre-stroke level, were compared between the two groups.
Results:
There were 56 (58.3%) LM2O patients and 40 (41.7%) SM2O patients. Median occluded vessel diameter was 1.85 mm (IQR 1.78-2.11) for LM2O and 1.52 mm (IQR 1.43-1.62) for SM2O. LM2O patients were more likely to have dominant M2 occlusion (67.9% vs. 40.0%, P = 0.012), favorable outcome (62.5% vs. 25.0%; OR 6.67, 95% CI 2.59-17.15; P < 0.001), and first-pass effect (48.2% vs. 17.5%; OR 4.39, 95% CI 1.66-11.57; P = 0.002). In multivariable analysis, occluded vessel diameter ≥ 1.7 mm was independently associated with favorable outcome (OR 10.50, 95% CI 3.17-35.0; P < 0.001). Patients with a catheter-to-vessel ratio < 1.0 experienced higher first-pass effect more frequently than those with a catheter-to-vessel ratio ≥ 1.0 (46.8% vs. 24.5%; P = 0.032).
Conclusions:
Occluded M2 vessel diameter ≥ 1.7 mm may be associated with favorable 90-day outcome in patients with acute ischemic stroke undergoing mechanical thrombectomy for M2 occlusion.
Insights
Large M2 occlusions (≥1.7mm) in acute ischemic stroke patients undergoing mechanical thrombectomy are linked to better 90-day outcomes. This finding aids in predicting stroke recovery after thrombectomy.
Area of Science:
- Neurology
- Interventional Neuroradiology
- Stroke Medicine
Background:
- The relationship between M2 occlusion diameter and patient outcomes after mechanical thrombectomy is not well-established.
- Accurate prediction of outcomes is crucial for guiding treatment decisions in acute ischemic stroke.
Purpose of the Study:
- To investigate the association between pre-recanalization occluded M2 vessel diameter and 90-day clinical outcomes in patients undergoing mechanical thrombectomy.
- To determine if larger M2 occlusions correlate with improved outcomes.
Main Methods:
- Retrospective analysis of consecutive acute ischemic stroke patients with M2 occlusion undergoing mechanical thrombectomy (January 2020 - December 2024).
- Patients were categorized into large M2 occlusion (LM2O, ≥1.7 mm) and small M2 occlusion (SM2O, <1.7 mm) groups based on pre-thrombectomy DSA.
- Favorable 90-day outcomes (modified Rankin Scale 0-2) were compared between groups.
Main Results:
- 56 patients had LM2O (58.3%) and 40 had SM2O (41.7%).
- LM2O was associated with a higher likelihood of dominant M2 occlusion, favorable 90-day outcome (62.5% vs. 25.0%), and first-pass effect.
- In multivariable analysis, occluded vessel diameter ≥1.7 mm independently predicted favorable outcome (OR 10.50).
Conclusions:
- Occluded M2 vessel diameter ≥1.7 mm may be associated with favorable 90-day outcomes in patients with acute ischemic stroke treated with mechanical thrombectomy.
- This finding suggests that larger M2 occlusions might be a positive prognostic indicator in this patient population.
