Comparison of First-Pass Effect in Aspiration vs. Stent-Retriever for Acute Intracranial ICA Occlusion

The purpose of this study is to evaluate the best endovascular approach (aspiration or stent-retriever) and the impact of stent retriever size and length on clinical and angiographic outcomes in patients with acute intracranial ICA occlusion. We conducted a retrospective analysis of a prospective database of consecutive patients with acute intracranial ICA occlusion undergoing endovascular treatment in four Comprehensive Stroke Center between June-2019 and December-2020. We include 121 patients; Stent-retriever (SR) was used as first technical approach in 107 patients (88.4%) and aspiration was used in 14 patients (11.6%). SR group had higher rate of FPE compared to aspiration group (29 vs. 0%, p = 0.02). In SR subgroup, treatment highlighted higher FPE in the 6 x 50 SR (37.7%), than in the rest of the SR which are 21.2% (4-5 mm size and 20-50 mm length SR) and 19% (6 mm size and 25-40 mm length SR), but it was not found to be statistically significant. There were no other significant differences across the groups regarding primary angiographic or clinical outcomes. In our intracranial ICA occlusion series, stent retrievers were superior to direct aspiration in obtaining FPEs and mFPEs, and longer devices achieved better results with no statistically significant difference. Further studies evaluating the effects of different ICA clot removal approaches are warranted to confirm these results

Acute damage to the posterior limb of the internal capsule on diffusion tensor tractography as an early imaging predictor of motor outcome after stroke

BACKGROUND AND PURPOSE: Early prediction of motor outcome is of interest in stroke management. We aimed to determine whether lesion location at DTT is predictive of motor outcome after acute stroke and whether this information improves the predictive accuracy of the clinical scores. MATERIALS AND METHODS: We evaluated 60 consecutive patients within 12 hours of middle cerebral artery stroke onset. We used DTT to evaluate CST involvement in the motor cortex and premotor cortex, centrum semiovale, corona radiata, and PLIC and in combinations of these regions at admission, at day 3, and at day 30. Severity of limb weakness was assessed by using the motor subindex scores of the National Institutes of Health Stroke Scale (5a, 5b, 6a, 6b). We calculated volumes of infarct and fractional anisotropy values in the CST of the pons. RESULTS: Acute damage to the PLIC was the best predictor associated with poor motor outcome, axonal damage, and clinical severity at admission (P < .001). There was no significant correlation between acute infarct volume and motor outcome at day 90 (P = .176, r = 0.485). The sensitivity, specificity, and positive and negative predictive values of acute CST involvement at the level of the PLIC for motor outcome at day 90 were 73.7%, 100%, 100%, and 89.1%, respectively. In the acute stage, DTT predicted motor outcome at day 90 better than the clinical scores (R2 = 75.50, F = 80.09, P < .001). CONCLUSIONS: In the acute setting, DTT is promising for stroke mapping to predict motor outcome. Acute CST damage at the level of the PLIC is a significant predictor of unfavorable motor outcom

Quantification of thrombus Hounsfield units on noncontrast CT predicts stroke subtype and early recanalization after intravenous recombinant tissue plasminogen activator

BACKGROUND AND PURPOSE: Little is known about the factors that determine recanalization after intravenous thrombolysis. We assessed the value of thrombus Hounsfield unit quantification as a predictive marker of stroke subtype and MCA recanalization after intravenous rtPA treatment. MATERIALS AND METHODS: NCCT scans and CTA were performed on patients with MCA acute stroke within 4.5 hours of symptom onset. Demographics, stroke severity, vessel hyperattenuation, occlusion site, thrombus length, and time to thrombolysis were recorded. Stroke origin was categorized as LAA, cardioembolic, or indeterminate according to TOAST criteria. Two blinded neuroradiologists calculated the Hounsfield unit values for the thrombus and contralateral MCA segment. We used ROC curves to determine the rHU cutoff point to discriminate patients with successful recanalization from those without. We assessed the accuracy (sensitivity, specificity, and positive and negative predictive values) of rHU in the prediction of recanalization. RESULTS: Of 87 consecutive patients, 45 received intravenous rtPA and only 15 (33.3%) patients had acute recanalization. rHU values and stroke mechanism were the highest predictive factors of recanalization. The Matthews correlation coefficient was highest for rHU (0.901). The sensitivity, specificity, and positive and negative predictive values for lack of recanalization after intravenous rtPA for rHU ≤ 1.382 were 100%, 86.67%, 93.75%, and 100%, respectively. LAA thrombi had lower rHU than cardioembolic and indeterminate stroke thrombi (P = .004). CONCLUSIONS: The Hounsfield unit thrombus measurement ratio can predict recanalization with intravenous rtPA and may have clinical utility for endovascular treatment decision making

Wallerian degeneration in the corticospinal tract evaluated by diffusion tensor imaging correlates with motor deficit 30 days after middle cerebral artery ischemic stroke

BACKGROUND AND PURPOSE: The quantification and clinical significance of WD in CSTs following supratentorial stroke are not well understood. We evaluated the anisotropy by using DTI and signalintensity changes on conventional MR imaging in the CST to determine whether these findings are correlated with limb motor deficit in patients with MCA ischemic stroke. MATERIALS AND METHODS: We studied 60 patients within 12 hours of stroke onset. At admission, day 3, and day 30 of evolution, patients underwent multimodal MR imaging, including DTI sequences. We assessed the severity of limb weakness by using the motor subindex scores (5a, 5b, 6a, 6b) of the m-NIHSS and established 3 groups: I (m-NIHSS scores of 0), II (m-NIHSS, 1-4), and III (m-NIHSS, 5-8). FA values and rFAs were measured on the affected and the unaffected CSTs in the pons. RESULTS: FA values for the CST were significantly lower on the affected side compared with the unaffected side only at day 30 (P < .001), and the rFA was significantly correlated with the motor deficit at day 30 (P < .001; r=-0.793). The sensitivity, specificity, and positive and negative predictive values for motor deficit by rFA < 0.925 were 95.2%, 94.9%, 90.9%, and 97.4%, respectively. CONCLUSIONS: WD in the CST revealed by DTI correlates with motor deficit 30 days after MCA ischemic stroke. This study highlights the utility of imaging follow-up at 30 days and the potential of DTI as a surrogate marker in clinical trial

Prognostic Accuracy of N20 Somatosensory Potential in Patients With Acute Ischemic Stroke and Endovascular Thrombectomy

Background Somatosensory evoked potentials may add substantial prognostic value in patients with acute ischemic stroke and contribute to the selection of patients who may benefit from revascularization therapies beyond the accepted therapeutic time windows. We aimed to study the prognostic accuracy of the N20 somatosensory evoked potential component of the ischemic hemisphere in patients with anterior large‐vessel occlusion undergoing endovascular thrombectomy (EVT). Methods Presence and amplitude of the N20 response were recorded before and after EVT. Its adjusted predictive value for functional independence (modified Rankin scale score, ≤2) at day 7 was analyzed by binary logistic regression adjusting by age, mean arterial blood pressure, National Institute of Health Stroke Scale, Alberta Stroke Program Early CT Score, and serum glucose. N20 predictive power was compared with that of clinical and imaging models by using receiver operating characteristics curve analysis. Results A total of 223 consecutive patients were studied (mean age, 70 years; median National Institute of Health Stroke Scale score, 18). Somatosensory evoked potential recordings identified the presence of N20 in 110 (49.3%), absence in 58 (26%), and not assessable in 55 patients due to radiofrequency interferences in the angiography room. Before EVT, N20 predicted functional independence with a sensitivity of 93% (95% CI, 78%–98%) and negative predictive value of 93% (95% CI, 80%–98%). The adjusted odds ratio for functional independence was 9.9 (95% CI, 3.1–44.6). In receiver operating characteristics curve analysis, N20 amplitude showed a higher area under the curve than prehospital or in‐hospital variables, including advanced imaging. Sensitivity increased to 100% (95% CI, 0.85–1) when N20 was present after EVT. Conclusion Somatosensory evoked potential monitoring is a noninvasive and bedside technique that could help eligibility of patients with acute ischemic stroke for EVT and predict functional recovery

Early and delayed infarct growth in patients undergoing mechanical thrombectomy: a prospective, serial MRI study

BACKGROUND: We studied the evolution over time of diffusion weighted imaging (DWI) lesion volume and the factors involved on early and late infarct growth (EIG and LIG) in stroke patients undergoing endovascular treatment (EVT) according to the final revascularization grade. METHODS: This is a prospective cohort of patients with anterior large artery occlusion undergoing EVT arriving at 1 comprehensive stroke center. Magnetic resonance imaging was performed on arrival (pre-EVT), <2 hours after EVT (post-EVT), and on day 5. DWI lesions and perfusion maps were evaluated. Arterial revascularization was assessed according to the modified Thrombolysis in Cerebral Infarction (mTICI) grades. We recorded National Institutes of Health Stroke Scale at arrival and at day 7. EIG was defined as (DWI volume post-EVT–DWI volume pre-EVT), and LIG was defined as (DWI volume at 5d–DWI volume post-EVT). Factors involved in EIG and LIG were tested via multivariable lineal models. RESULTS: We included 98 patients (mean age 70, median National Institutes of Health Stroke Scale score 17, final mTICI=2b 86%). Median EIG and LIG were 48 and 63.3 mL in patients with final mTICI<2b, and 3.6 and 3.9 cc in patients with final mTICI=2b. Both EIG and LIG were associated with higher National Institutes of Health Stroke Scale at day 7 (¿=0.667; P<0.01 and ¿=0.614; P<0.01, respectively). In patients with final mTICI=2b, each 10% increase in the volume of DWI pre-EVT and each extra pass leaded to growths of 9% (95% CI, 7%–10%) and 14% (95% CI, 2%–28%) in the DWI volume post-EVT, respectively. Furthermore, each 10% increase in the volume of DWI post-EVT, each extra pass, and each 10 mL increase in TMax6s post-EVT were associated with growths of 8% (95% CI, 6%–9%), 9% (95% CI, 0%–19%), and 12% (95% CI, 5%–20%) in the volume of DWI post-EVT, respectively. CONCLUSIONS: Infarct grows during and after EVT, especially in nonrecanalizers but also to a lesser extent in recanalizers. In recanalizers, number of passes and DWI volume influence EIG, while number of passes, DWI, and hypoperfused volume after the procedure determine LIG.Postprint (author's final draft