Related Experiment Video
Updated: Aug 9, 2026
Optimized Management of Endovascular Treatment for Acute Ischemic Stroke
Published on: January 18, 2018
Functional Outcome and Procedure-related Subarachnoid Hemorrhage in Primary M2 Occlusion: Impact of Initial
Yuji Nishi1, Yuki Sakamoto1, Junya Aoki2
1Department of Neurology, Nippon Medical School Hospital, Tokyo, Japan.
Objective:
Procedure-related subarachnoid hemorrhage (SAH) is a recognized complication of mechanical thrombectomy for M2 middle cerebral artery occlusion, but whether the first-line device strategy influences its occurrence remains unclear. This study was performed to determine whether a stent retriever (SR)-first strategy, compared with a contact aspiration (CA)-first strategy, is independently associated with procedure-related SAH.
Methods:
In this single-center retrospective study, 180 consecutive patients who underwent mechanical thrombectomy for isolated M2 occlusion were classified according to the first-line device strategy. Procedure-related SAH was assessed on postprocedural imaging. Associations were examined by multivariable logistic regression adjusted for age, admission National Institutes of Health Stroke Scale score, diffusion-weighted imaging Alberta Stroke Program Early CT Score, occluded vessel diameter, M1-M2 angle, and number of passes. Inverse probability of treatment weighting, doubly robust estimation, and multiple imputation by chained equations (m = 20) were performed as sensitivity analyses.
Results:
Procedure-related SAH occurred in 52 patients (29%), and symptomatic intracranial hemorrhage occurred in 8 patients (4.4%). An SR-first strategy was independently associated with procedure-related SAH (adjusted odds ratio, 4.24; 95% confidence interval, 1.13-16.00; P = 0.003), as were a smaller occluded vessel diameter and a greater number of passes. The association was preserved across all sensitivity analyses (adjusted odds ratio, 4.74; 95% confidence interval, 2.00-11.27). Older age, higher admission National Institutes of Health Stroke Scale score, lower diffusion-weighted imaging Alberta Stroke Program Early CT Score, and longer onset-to-puncture time were independently associated with poor 90-day functional outcome.
Conclusion:
In mechanical thrombectomy for M2 occlusion, an SR-first strategy was independently associated with procedure-related SAH. A contact aspiration-first strategy may be preferable as the initial approach, particularly in small-caliber or acutely angulated M2 branches.
Insights
Mechanical thrombectomy for middle cerebral artery M2 occlusion shows similar outcomes for contact aspiration-first and stent retriever-first strategies. Stent retriever use was linked to higher rates of procedure-related subarachnoid hemorrhage.
Area of Science:
- Neurology
- Interventional Neuroradiology
- Vascular Surgery
Background:
- Optimal mechanical thrombectomy strategies for middle cerebral artery M2 occlusions are debated.
- Procedural safety, particularly subarachnoid hemorrhage (SAH) risk, requires further investigation.
Purpose of the Study:
- To compare the safety and efficacy of contact aspiration-first (CA-first) versus stent retriever-first (SR-first) strategies for mechanical thrombectomy in primary M2 occlusions.
- To identify factors associated with procedure-related SAH.
Main Methods:
- Retrospective analysis of 180 patients with primary M2 occlusion undergoing mechanical thrombectomy.
- Classification of patients into CA-first or SR-first groups.
- Multivariable analysis and sensitivity analyses (including IPTW) to assess predictors of SAH.
Main Results:
- Procedure-related SAH occurred in 29% of patients, more frequently in the SR-first group (39%) than CA-first group (18%).
- Reperfusion success and functional outcomes were comparable between the two strategies.
- Independent predictors of SAH included smaller occluded vessel diameter, increased device passes, and SR-first strategy.
Conclusions:
- Both CA-first and SR-first strategies achieve similar reperfusion and functional outcomes for M2 occlusions.
- The SR-first strategy is associated with a higher incidence of procedure-related SAH.
- SAH risk is influenced by vessel characteristics, procedural complexity, and thrombectomy technique.
