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Tortuosity of middle cerebral artery M1 segment and outcomes after mechanical thrombectomy
Takao Hoshino1,2, Shinsuke Sato1,3,4, Kazuki Kushi1,3,4
1Department of Neuroendovascular Therapy, St Luke's International Hospital, Chuo-ku, Tokyo, Japan.
Background:
We aimed to quantify the tortuosity of the middle cerebral artery (MCA) and assess its effects on radiological and clinical outcomes in patients with acute MCA occlusions who received mechanical thrombectomy (MT).
Methods:
This retrospective study enrolled 53 patients with acute ischemic stroke due to MCA M1 or M2 segment occlusion who underwent MT using stent retrievers (SRs). Tortuosity index (TI) was defined to quantify the tortuosity of the MCA M1 segment using the following formula: (actual distance / straight distance) × 100. For each patient, four TIs were measured in the anteroposterior and caudal views for both ipsilateral and contralateral sides to the occluded site (TI-APi, TI-APc, TI-CAUi, and TI-CAUc, respectively) using magnetic resonance angiography (MRA) or computed tomography angiography (CTA). We defined the first-pass effect (FPE) as first-pass mTICI classification ≥2b reperfusion.
Results:
Patients who did not achieve FPE had significantly higher TI-APi (112 vs. 106; P = 0.004), TI-APc (111 vs. 105; P = 0.005), TI-CAUi (110 vs. 105; P = 0.002), and TI-CAUc (110 vs. 105; P = 0.001) than those who achieved FPE. In multivariable analysis, higher TI-APi, TI-CAUi, and TI-APc were independently associated with an increased rate of unsuccessful FPE (odds ratio (OR) [95% confidence interval (CI)]: 1.25 [1.02-1.61], 1.21 [1.01-1.45], and 1.27 [1.03-1.73], respectively). TI-CAUi, TI-APc, and TI-CAUc were also independent predictors of the occurrence of intracranial hemorrhage after MT (OR [95% CI]: 1.15 [1.01-1.38], 1.14 [1.01-1.38], 1.25 [1.02-1.52], respectively).
Conclusions:
The TIs of the MCA M1 segment on both ipsilateral and contralateral sides were associated with unfavourable outcomes after MT.
Insights
Increased middle cerebral artery (MCA) tortuosity is linked to poorer outcomes in acute ischemic stroke patients undergoing mechanical thrombectomy (MT). Higher tortuosity indices correlate with failed first-pass reperfusion and increased risk of intracranial hemorrhage after MT.
Area of Science:
- Neurology
- Vascular Imaging
- Interventional Neurology
Background:
- Acute ischemic stroke due to middle cerebral artery (MCA) occlusion is a leading cause of disability.
- Mechanical thrombectomy (MT) has improved outcomes, but success rates vary.
- Vessel tortuosity may influence procedural success and clinical outcomes.
Purpose of the Study:
- To quantify MCA tortuosity in patients with acute MCA occlusions.
- To assess the impact of MCA tortuosity on radiological and clinical outcomes following MT.
- To investigate the relationship between MCA tortuosity and first-pass effect (FPE) and intracranial hemorrhage (ICH).
Main Methods:
- Retrospective study of 53 patients with acute MCA M1/M2 occlusion undergoing MT with stent retrievers.
- Definition of Tortuosity Index (TI) for the MCA M1 segment: (actual distance / straight distance) × 100.
- Measurement of four TIs (anteroposterior and caudal views, ipsilateral and contralateral) using MRA/CTA.
- Definition of FPE as first-pass mTICI classification ≥2b reperfusion.
Main Results:
- Patients without FPE exhibited significantly higher TI values (ipsilateral and contralateral) compared to those achieving FPE (P < 0.005 for all measures).
- Higher ipsilateral and contralateral TI-AP and TI-CAU were independently associated with unsuccessful FPE (ORs ranging from 1.21 to 1.27).
- Higher TI values (ipsilateral and contralateral) were independent predictors of post-MT intracranial hemorrhage (ORs ranging from 1.14 to 1.25).
Conclusions:
- MCA M1 segment tortuosity, measured by TI, is associated with unfavorable outcomes after MT.
- Increased tortuosity predicts both failed reperfusion and increased risk of intracranial hemorrhage.
- Quantifying MCA tortuosity may aid in predicting MT outcomes.
