The correlations of outcomes and vascular morphology with infarct patterns in middle cerebral arterial trunk occlusion

Background and purposeThe large vessel occlusion (LVO) in middle cerebral artery (MCA) trunk (i.e., M1 segment) caused by intracranial atherosclerotic disease (ICAD) could introduce with different infarct patterns. We aimed to compare the clinical outcomes among these patterns and investigate the associations between the morphological parameters of contralateral MCA (cMCA) M1 segment and infarct patterns. MethodsPatients with stroke attributed to M1-ICAD-LVO were enrolled. The infarct patterns were categorized into artery-artery embolism (AAE), large infarct, borderzone infarct (BZI) and perforating artery infarction (PAI). The morphological parameters of cMCA-M1 segment consisted of proximal diameter, distal diameter, arc length and chord length were measured. The tortuosity index of cMCA-M1 segment was calculated by (arc length/chord length-1) x 100%. ResultsA total of 171 subjects were enrolled. Compared to AAE, the risk of poor outcome significantly increased in BZI (odds ratio [OR]= 5.51, 95% confidence interval [CI] = 1.71-17.78, p = 0.004) and large infarct (OR= 10.92, 95% CI = 2.01-59.27, p = 0.006), and was comparable in PAI. The tortuosity index (OR= 2.85, 95% CI = 1.13-7.18, p = 0.026) and arc length (OR= 2.47, 95% CI = 1.02-5.97, p = 0.045) significantly elevated in BZI and were identical in other three patterns. Subjects other than BZI were categorized into large infarct (n = 32) and non-large-infarct (n = 46) groups, and the proximal diameter (OR= 0.22, 95% CI = 0.07-0.72, p = 0.012), arc length (OR= 0.88, 95% CI = 0.78-0.98, p = 0.018) and chord length (OR= 0.87, 95% CI = 0.77-0.995, p = 0.042) were all negatively associated with the onset of large infarct. ConclusionFor patients with M1-ICAD-LVO, the outcomes of large infarct and BZI were poorer than AAE and PAI. The cMCA-M1 segment with elevated tortuosity and arc length was associated with BZI, whereas a thin and short M1 segment was correlated with large infarct in patients with a cMCA trunk of low tortuosity.