Purpose Endovascular treatment (ET) for the acute management of ischemic stroke due to large vessel occlusions is the standard of care for anterior circulation. Meta-analysis has suggested equivalent recanalization and better clinical outcomes after ET for ICA and proximal MCA occlusion (1–2). The aim of our study was to compare these two cohorts and identify any variability/bias in presentations, imaging selection, technical and clinical efficacy.

Materials and Methods This is a retrospective study of patients that underwent ET for ICA/MCA occlusions over a four-year period at three comprehensive stroke centers. We studied patient demographics, vascular risk factors, NIHSS, time of presentation, imaging, procedures details, and clinical outcomes. Chi-square, Mann-Whitney U and student t-tests were used for variables univariate analysis as appropriate. Multivariate analysis was performed to assess the comparability of the groups based on demographics and risk factors.

Results 185 patients were studied (mean age, 68 ± 17; 55% women; median NIHSS, 16 ± 6). Both study cohorts were comparable regarding their age (65 ± 20 vs 69 ± 17, p=0.26) and past medical history of Hypertension, Diabetes Mellitus, Hyperlipidemia and Smoking habit (p=0.64, p=0.68, p=0.55, p=0.47 respectively). There was no statistically significant difference between both cohorts regarding their NIHSS (17 ± 6 vs 16 ± 6, p=0.23) or the time from onset to groin puncture (mean 5:43:48 vs 5:24:58, p=0.54). Moreover, there was no significant difference between mean ASPECT (8.3 ± 1.3 vs 8.6 ± 1.3, p=0.19) and mean CTP-rCBF<30% (24.5 ml ± 36 vs 28.3 ml ± 38, p=0.6). During the procedure ICA occlusions were associated with a higher number of stent retriever passes to achieve recanalization (mean 2.5 vs 1.9, p=0.028), and longer time from groin puncture to recanalization (mean 1:02:11 vs 00:51:48, p=0.034). Also, there was a trend toward significance in the rate of successful recanalization after the first pass of stent retriever in the MCA occlusion cohort (46% vs 33%, p=0.09). However, there was no statistically significant difference regarding the rate of successful recanalization TICI ≥ 2b (91% in group A vs 95% in group B, p=0.35) or the rate of complete recanalization TICI 2c/3 (45% vs 52%, p=0.39). Although, the 90-days outcome measured by mRS was not statistically significantly different between both groups (mean 2.5 vs 3.1, p=0.09), however, the outcome was trending to be worse in MCA occlusion patients, this could be the result of the relatively higher rate of procedural complications in MCA occlusions, 18.5% in MCA (24/130 cases, 13 distal embolic, 8 SAH/sICH, 3 arterial dissections) versus 12.5% (7/55 cases, 4 distal embolic, 3 SAH/sICH).

Conclusions Significant procedural difficulty is encountered during ET of ICA relative to MCA occlusions, requiring increased procedural time and passes. Although final successful recanalization rates are equivalent, we noted a paradoxical trend for less functional independence with MCA occlusions this could be due to the higher rate of complications in the MCA cohort, and the better collaterals through the circle of Willis in the ICA cohort.

Disclosures M. Aly: None. R. Abdalla: None. M. Hurley: None. A. Shaibani: None. S. Ansari: None.