Impact of early division of the middle cerebral artery on outcome following mechanical thrombectomy.

BACKGROUND: Mechanical thrombectomy has become the standard care for acute ischemic stroke caused by large vessel occlusion. However, complete reperfusion cannot be achieved in all cases, and several factors influencing the results of mechanical thrombectomy have been investigated. Among others, a tortuous anatomy is associated with lower rates of complete reperfusion. We aimed to investigate whether an early division of the middle cerebral artery has an impact on reperfusion results in mechanical thrombectomy. METHODS: Retrospective review of consecutive patients with M1 occlusion treated endovascularly between January 2016 and December 2019 at three tertiary care centers. The study group was dichotomized based on the length of the M1 segment. Early division of the middle cerebral artery was defined as a maximum length of 10 mm of the M1 segment. Primary endpoints were first-pass mTICI scores of 3, ≥2c, and ≥2b. Secondary endpoints contained final reperfusion, number of device-passes, time interval from groin puncture to reperfusion, rate of postinterventional symptomatic intracranial hemorrhage, and frequency of emboli of new territory. RESULTS: Among 284 included patients, 70 presented with an early division of the M1 segment (25%). Reperfusion results did not differ significantly between early and late division of M1. A higher rate of symptomatic intracranial hemorrhage was found in the group with an early M1 division treated with aspiration only (14.3% vs. 0%; p = 0.013). Patients with late M1 division had a significantly higher rate of large artery sclerosis (19.2% vs. 8.6%, p = 0.039). CONCLUSION: The anatomic variant of an early division of the middle cerebral artery was not a predictor for incomplete reperfusion.

Validation of the extended thrombolysis in cerebral infarction score in a real world cohort.

BACKGROUND: A thrombolysis in cerebral infarction (TICI) score of 2b is defined as a good recanalization result although the reperfusion may only cover 50% of the affected territory. An additional mTICI2c category was introduced to further differentiate between mTICI scores. Despite the new mTICI2c category, mTICI2b still covers a range of 50-90% reperfusion which might be too imprecise to predict neurological improvement after therapy. AIM: To compare the 7-point "expanded TICI" (eTICI) scale with the traditional mTICI in regard to predict functional independence at 90 days. METHODS: Retrospective review of 225 patients with large artery occlusion. Angiograms were graded by 2 readers according the 7-point eTICI score (0% = eTICI0; reduced clot = eTICI1; 1-49% = eTICI2a, 50-66% = eTICI2b50; 67-89% = eTICI2b67, 90-99% = eTICI2c and complete reperfusion = eTICI3) and the conventional mTICI score. The ability of e- and mTICI to predict favorable outcome at 90days was compared. RESULTS: Given the ROC analysis eTICI was the better predictor of favorable outcome (p-value 0.047). Additionally, eTICI scores 2b50, 2b67 and 2c (former mTICI2b) were significantly superior at predicting the probability of a favorable outcome at 90 days after endovascular therapy with a p-value of 0.033 (probabilities of 17% for mTICI2b50, 24% for mTICI2b67 and 54% for mTICI2c vs. 36% for mTICI2b). CONCLUSIONS: The 7-point eTICI allows for a more accurate outcome prediction compared to the mTICI score because it refines the broad range of former mTICI2b results.