Background: Middle cerebral artery division (M2) occlusion was significantly underrepresented in recent mechanical thrombectomy (MT) randomized controlled trials, and the approach to this disease remains heterogeneous. Objective: To conduct a systematic review and meta-analysis of outcomes at 90 days among patients undergoing MT for M2 middle cerebral artery (MCA) occlusions. Methods: Five clinical databases were searched from inception through September 2016. Observational studies reporting 90-day modified Rankin Scale scores for patients undergoing MT for M2 MCA occlusions with an M1 MCA control group were selected. The primary outcome of interest was good clinical outcome 90 days after MT of an M1 or M2 MCA occlusion. Secondary outcomes of interest included mortality and excellent clinical outcome, recanalization rates, significant intracerebral hemorrhage, and procedural complications. Results: A total of 323 publications were identified, and 237 potentially relevant articles were screened. Six studies were included in the analysis (M1 = 1,203, M2 = 258; total n = 1,461). We found no significant differences in good clinical outcomes (1.10 [95% CI, 0.83-1.44]), excellent clinical outcomes (1.07 [0.65-1.79]), mortality at 3 months (0.85 [0.58-1.24]), recanalization rates (1.06 [0.32-3.48]), and significant intracranial hemorrhage (1.19 [0.61-2.30]). Conclusions: MT of M2 MCA occlusions is as safe as that of main trunk MCA occlusions, and comparable in terms of clinical outcomes and hemorrhagic complications. Randomized clinical trials are needed to assess the impact of MT in patients with M2 occlusions, given that M1 MCA occlusions have different natural histories than M2 occlusions.

Objective: Left atrial dilation is considered to be an indirect marker of atrial fibrillation. The purpose of the study is to determine if an enlarged left atrium is a predictor of paroxysmal atrial fibrillation in patients with cryptogenic stroke. Methods: We performed a retrospective chart review of patients who were deemed to have cryptogenic strokes by vascular neurologists at a tertiary care center in Ohio. Patients had an implantable cardiac monitor (ICM) placed at hospital discharge and were monitored for atrial fibrillation. Age (mean: 65.8 years), Sex (male: 49.3%), initial NIHSS score (mean: 4.45), risk factors, CHADS2 score (mean: 3.54) and location were recorded. Results: 829 stroke and 295 TIA patients were screened between September 2012 and July 2016. 79 patients were deemed to have cryptogenic stroke and had an ICM placed. Left atrial size was classified based on the left atrial volume index. Of the 79 patients, 61 (77.2%) patients were found to have a normal left atrium (22 +/- 6 ml/m 2 ), 14 (17.7%) patients had mildly enlarged left atrium (29-33 ml/m 2 ), and 4 (5.06%) patients had moderately enlarged left atrium (34-39 ml/m 2 ). No patients from the cohort had severe enlargement of the left atrium (≥ 40 ml/m 2 ). 21 patients (26.6%) have been detected to have atrial fibrillation on ICM. Of the 21 patients with atrial fibrillation, 6 (28.6%) had mildly enlarged left atrium and 15 (71.4%) were found to have a normal left atrium. A higher NIHSS was found to be a predictor of atrial fibrillation (p=0.037, CI 0.83-0.99), consistent with previous studies showing that patients with atrial fibrillation have more severe strokes. Multivariate analysis failed to reveal any other significant predictors. Conclusion: Left atrial size was not a significant predictor of paroxysmal atrial fibrillation in patients with cryptogenic stroke. A normal atrial size should not preclude placement of an ICM for detection of paroxysmal atrial fibrillation.

OBJECTIVE: Patients referred to stroke centers from community hospitals for intra-arterial stroke treatment (IAT) may experience significant delay during the transfer process. We sought to determine the difference in clinical outcomes amongst patients presenting directly to stroke centers (PD) versus those transferred from outside community hospitals (TR). METHODS: We reviewed records of patients who underwent IAT at our center from July 2012 – July 2014. All patients had intracranial large vessel occlusion and a baseline ASPECT score of ≥ 6. Patients demographics, risk factors, admission clinical and neuroimaging findings, treatment times and methods, procedure related complications and modified Rankin score (mRS) at 90 days were analyzed. For patients who are not yet at 90 days post-treatment, mRS at hospital discharge was used in the final analysis. A favorable outcome was defined as mRS 2 or less at 90 days. RESULTS: Overall 141 consecutively treated patients were identified. Of these, 89 (63.1%) were transferred from community hospitals for IAT. Median time from last known well to stroke center arrival was 50 mins for PD and 245 mins for TR group (T-test p<0.01). Despite this difference final infarct volume, favorable outcome and mortality rates were comparable between the groups (see table). Multivariate logistic regression model identified lower final DWI infarct volume (OR 0.97, 95%CI 0.95-0.99, p<0.01) and low presentation NIHSS (OR 0.85, 95% CI 0.73-0.99, p=0.04) as predictors of favorable outcome. CONCLUSION: Our results indicate that patients with favorable baseline head CT, referred from outlying facilities, may achieve similar clinical outcomes following IAT when compared to those presenting directly to a designated stroke center. Further randomized studies on an intent to treat design are needed to corroborate these findings.

OBJECTIVE: Previous studies have shown age and recanalization as principal variables influencing clinical outcome following intra-arterial stroke treatment (IAT). We sought to study the impact of final DWI infarct volume on patient outcomes following IAT. METHODS: We reviewed records of stroke patients who underwent IAT at our center from Jul 2012 – Jul 2014. Patients demographics, risk factors, admission clinical and neuroimaging findings, treatment times and methods, procedure related complications and modified Rankin score (mRS) at 90 days were analyzed. For patients who are not yet at 90 days post-treatment, mRS at hospital discharge was used in the final analysis. A favorable outcome was defined as mRS 2 or less at 90 days. Infarct volume was calculated using the MIM Maestro automated software on post IAT MR DWI sequences. RESULTS: Overall, 144 consecutively treated patients were identified. Eighty-eight subjects underwent post treatment MRI and are included in this analysis. Patients who achieved successful recanalization (TICI 2b &3) had lower mean infarct burden (53.2 mL) than the cohort with persistent occlusion (95.1 mL), p=0.01. Also, patients with favorable outcomes had significantly lower mean infarct volumes (see table). Multivariate logistic regression model identified lower final DWI infarct volume (OR 0.97, 95% CI 0.95-0.99, p<0.01) and low presentation NIHSS (OR 0.85, 95% CI 0.73-0.99, p=0.04) as predictors of favorable outcome. CONCLUSION: Our study results indicate that final DWI infarct volume is an independent predictor of outcome in patients undergoing IAT. Infarct volume may be utilized as a surrogate for clinical outcome. Larger prospective studies are warranted to corroborate these findings.