Comparison of 4 mm-sized and 3 mm-sized Stent Retrievers in Mechanical Thrombectomy for M2 Occlusion.

INTRODUCTION: A stent retriever (SR) is widely used in mechanical thrombectomy (MT) for M2 segment occlusion. However, the suitable size of SR in M2 occlusion remains unclear. Therefore, we aimed to compare 4 mm-sized SR with 3 mm-sized SR in M2 occlusion. METHODS: Patients who underwent MT with SR for M2 occlusion were dichotomized into 4×20 mm SR and 3×20 mm SR groups. Then, 1:1 propensity score matching was performed. The M2 segment was divided into proximal and distal segments according to the occlusion site. Subgroup analysis was then performed for each cohort. RESULTS: A total of 111 patients were enrolled, with 4×20 mm SR and 3×20 mm SR applied in 72 (64.9%) and 39 (35.1%) cases, respectively. In propensity score matching, mean number of stent passages for reperfusion was significantly lower in the 4×20 mm SR group than in the 3×20 mm SR group (1.5 ± 0.8 vs. 2.1 ± 1.1; p = 0.004). First-pass reperfusion (FPR) was more highly achieved in the 4×20 mm SR group than in the 3×20 mm SR group (52.6% vs. 42.1%; p = 0.007). In both proximal and distal occlusion cohorts, the 4 mm SR group showed lower mean number of SR passage (p = 0.004 and p =0.003, respectively) and higher FPR rate than the 3 mm SR group (p = 0.003 and p = 0.007, respectively). CONCLUSION: In MT for M2 occlusion, 4×20 mm SR enables an effective procedure with lesser SR passage for reperfusion and a higher rate of FPR than 3×20 mm SR.

Predictors of Emboli in Mechanical Thrombectomy for Anterior Circulation Stroke.

OBJECTIVE: Emboli commonly occurs in mechanical thrombectomy (MT). The objective of this study was to analyze predicting factors of emboli after MT. METHODS: Patients who underwent MT with successful reperfusion for anterior circulation occlusion were enrolled. Emboli included distal emboli at digital subtraction angiography (DSA) and unexpected embolic infarct on diffusion-weighted image (DWI) without distal emboli at DSA. Baseline characteristics, procedural details, angiographic outcomes, and clinical outcomes were reviewed. Multivariable analyses were performed to evaluate predictive factors for the occurrence of emboli. RESULTS: Of 601 patients, 149 (24.8%) patients had distal emboli at DSA, and 169 (28.1%) patients had unexpected embolic infarction on DWI even without distal emboli at DSA. A total of 318 (52.9%) patients were enrolled in the embolic group, and 283 (47.1%) patients were assigned to the non-embolic group. In multivariate analysis, larger microcatheter (OR 1.26, 95% CI 1.12-1.94; p = 0.047), clot passage (OR 1.33, 95% CI 1.07-1.87; p = 0.041), use of balloon guide catheter (BGC) (OR 0.70, 95% CI 0.52-0.92; p = 0.014), early ballooning of BGC (OR 0.68, 95% CI 0.50-0.90; p = 0.009), and longer stent retriever (OR 0.72, 95% CI 0.54-0.90; p = 0.029) were associated with occurrence of emboli. CONCLUSION: MT with only a stent retriever, use of a larger microcatheter, and clot passage might increase the risk of emboli. In contrast, contact aspiration thrombectomy, use of BGC, early ballooning of BGC, and use of longer stent retrievers could reduce the chance of emboli.

Pan-immune-inflammation value predict delayed cerebral ischemia in patients with aneurysmal subarachnoid hemorrhage.

Inflammatory reaction and immune dysregulation are known as components contributing to delayed cerebral ischemia (DCI) in patients with following aneurysmal subarachnoid hemorrhage (aSAH). The objective of this study was to investigate the role of pan-immune-inflammation value (PIV) as a novel comprehensive inflammatory marker in predicting the DCI development following aSAH. A total of 1028 participants with aSAH were enrolled. There were 296 patients with DCI and 732 patients without DCI. Various inflammatory markers were analyzed using peripheral blood sample obtained at admission. Receiver operating characteristic (ROC) analysis was performed to identify the optimal cutoff value of PIV for distinguishing DCI. Multivariate analysis was used to determine independent predictors for DCI. Mean PIV was significantly higher in the DCI (+) group than in the DCI (-) group (437.6 ± 214.7 vs 242.1 ± 154.7, P = 0.007). In ROC analysis, the optimal cutoff value of PIV was 356.7 for predicting DCI (area under the curve [AUC] 0.772, 95 % confidence interval [CI] 0.718-0.816; P < 0.001). Multivariate analysis showed that high Hunt-Hess grade (odds ratio [OR] 1.70, 95 % CI 1.38-2.22; P = 0.007), thick SAH (OR 1.82, 95 % CI 1.44-2.32; P = 0.005), and elevated PIV (≥356.7) (OR 1.42, 95 % CI 1.10-1.74; P = 0.013) were independent predictors of DCI after aSAH. PIV is a potent predictor of DCI in patients with aSAH. Elevated PIV is associated with more DCI development. Thus, PIV has predictive value for DCI development.

Dynamic changes of systemic inflammation response index and systemic immune-inflammation index are associated with delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

OBJECTIVES: Delayed cerebral ischemia (DCI) is a factor contributing to poor outcome of aneurysmal subarachnoid hemorrhage (aSAH). Serial inflammatory response is known to affect the occurrence of DCI. The aim of this study was to evaluate associations of dynamic changes of various inflammatory markers with occurrence of DCI after aSAH. METHODS: A total of 279 patients with interventional treatment for aSAH were enrolled, and dichotomized according to the occurrence of DCI. Various inflammatory markers, including systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), and their dynamic changes were analyzed at four different time points. Receiver operating characteristic (ROC) curve analysis with area under the curve (AUC) and univariate, multivariate Cox regression analyses with hazard ratio (HR) and 95 % confidence interval (CI) were performed to identify predictors for DCI. RESULTS: Differences of SII and SIRI values between DCI (+) and DCI (-) group were significantly higher at 5-7 days than at other time points (P < 0.001 and P < 0.001, respectively). SII and SIRI had higher predicting values for DCI occurrence than other inflammatory markers (AUC: 0.862, 95 % CI: 0.786-0.928; P < 0.001 and AUC: 0.851, 95 % CI: 0.769-0.913; P < 0.001, respectively). SII at 5-7 days (HR: 1.74, 95 % CI: 1.38-3.22, P = 0.020) and SIRI at 5-7 days (HR: 1.62, 95 % CI: 1.28-2.84, P = 0.035) were associated with occurrence of DCI. CONCLUSIONS: Dynamic changes of SII and SII might be predictors of DCI occurrence in patients with aSAH.

The impact of collateral status on cerebral vasospasm and delayed cerebral ischemia in subarachnoid hemorrhage.

OBJECTIVE: Cerebral collateral circulation may affect subarachnoid hemorrhage (SAH) induced cerebral vasospasm and delayed cerebral ischemia. In this study our aim was to investigate the relationship between collateral status, vasospasm and delayed cerebral ischemia (DCI) in both aneurysmal and nonaneurysmal SAH. METHODS: Patients diagnosed as SAH with and without aneurysm were included and their data investigated retrospectively. After the patients diagnosed as SAH according to cerebral computed tomography (CT)/magnetic resonance imaging (MRI), they underwent cerebral angiography to check for cerebral aneurysm. The diagnosis of DCI was made according to the neurological examination and control CT/MRI. All the patients had their control cerebral angiography on days 7 to 10 in order to assess vasospasm and also collateral circulation. The American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) Collateral Flow Grading System was modified to measure collateral circulation. RESULTS: A total of 59 patients data were analyzed. Patients with aneurysmal SAH had higher Fisher scores and DCI was more common. Although there was no statistically significant difference between the patients with and without DCI in terms of demographics and mortality, patients with DCI had worse collateral circulation and more severe vasospasm. These patients had higher Fisher scores and more cerebral aneurysm overall. CONCLUSIONS: According to our data, patients with higher Fisher scores, more severe vasospasm, and poor cerebral collateral circulation may experience DCI more frequently. Additionally aneurysmal SAH had higher Fisher scores and DCI was seen more common. To improve the clinical results for SAH patients, we believe that physicians should be aware of the DCI risk factors.

Effect of Early Balloon Inflation of Balloon Guide Catheter in Mechanical Thrombectomy for Large Vessel Occlusion.

OBJECTIVE: A balloon guide catheter (BGC) is widely used in mechanical thrombectomy (MT). However, the balloon inflation timing of BGC has not been clearly established. We evaluated whether balloon inflation timing of BGC affects the results of MT. METHODS: Patients who underwent MT with BGC for anterior circulation occlusion were enrolled. Patients were dichotomized into early and late balloon inflation groups, according to the timing of BGC inflation. Angiographic and clinical outcomes were compared between the two groups. Multivariable analyses were performed to evaluate the predictive factors for first-pass reperfusion (FPR) and successful reperfusion (SR). RESULTS: Of 436 patients, the early balloon inflation group showed a shorter procedure time (21 min (11-37) vs. 29 min (14-46), p = 0.014), a higher rate of SR with aspiration only (64.0% vs. 55.4%, p = 0.016), a lower aspiration catheter delivery failure rate (11.1% vs. 19.4%, p = 0.005), less frequent technique conversion (36.0% vs. 44.5%, p = 0.009), higher rate of FPR (58.2% vs. 50.2%, p = 0.011), and a lower rate of distal embolization (7.9% vs. 11.7%, P = 0.006), compared to the late balloon inflation group. In multivariate analysis, early balloon inflation was an independent predictor for FPR (odds ratio, OR 1.53, 95% confidence interval, CI 1.37-2.57; p = 0.011) and SR (OR 1.26, 95% CI 1.18-1.64; p = 0.018). CONCLUSION: Early balloon inflation of BGC enables an effective procedure than late balloon inflation. Early balloon inflation was associated with higher rates of FPR and SR.

Comparison of Neuroform Atlas Stent-Assisted Coiling and Coiling Alone in Ruptured Intracranial Aneurysms: A Propensity Score Matching Analysis.

BACKGROUND: Although Neuroform Atlas stent is commonly used in stent-assisted coiling (SAC) to treat ruptured intracranial aneurysms (RIA), its safety and efficacy remain controversial. OBJECTIVE: To assess the safety and efficacy of SAC using Neuroform Atlas for treating RIA compared with coiling alone by performing a propensity score matching analysis. METHODS: RIA treated with coiling alone and SAC between January 2017 and May 2021 were retrospectively reviewed. Demographics, periprocedural complication rates, angiographic outcomes, and clinical outcomes of the SAC using Neuroform Atlas group and the coiling-alone group were analyzed with 1:1 propensity score matching. RESULTS: A total of 375 aneurysms were enrolled, and 274 (63.1%) aneurysms were treated with coiling alone. In total, 101 (26.9%) aneurysms were treated with SAC, and Neuroform Atlas stent was used in 71 aneurysms. In propensity score matching, the SAC using Neuroform Atlas group showed higher incidence of complete occlusion (69.0% vs 56.3%, P = .029), lower rate of recanalization (11.3% vs 25.4%, P = .011), and lesser need for retreatment (7.0% vs 16.9%, P = .016) compared with the coiling-alone group. However, there were no significant differences in periprocedural complications such as intraprocedural thrombosis or postprocedural cerebral infarct between the 2 groups. CONCLUSION: The use of Neuroform Atlas is safe and effective for SAC in RIA with comparable procedure-related complication rates but better angiographic outcome in comparison with coiling alone.

Factors Related to Mechanical Thrombectomy Failure in Large Vessel Occlusion: A Propensity Score Matching Analysis.

OBJECTIVE: Mechanical thrombectomy (MT) is an effective treatment for large vessel occlusion (LVO) with a high successful recanalization (SR) rate. However, MT fails in a proportion of patients, leading to poor clinical outcomes. We analyzed the factors associated with the failure of MT. METHODS: A total of 648 consecutive patients with MT were enrolled. MT failure was defined as 0,1, or 2a of modified Thrombolysis in Cerebral Infarction (mTICI) grade. Failed MTs were divided into 3 categories, reaching failure, passage failure, and recanalization failure (RF). Various factors in RF and SR groups were analyzed with 1: 1 propensity score matching. RESULTS: Failed MT was observed in 97 patients (14.3%). Among them, 69 patients (10.2% of the entire cohort, 71.1% of the failed MT group) were included in the RF group. Propensity matching analysis with 69 patients in each group showed that the RF group had a higher rate of residual intracranial atherosclerotic stenosis (ICAS) than the SR group (30.4% vs. 14.5% P = 0.003). The rates of 4 or more passages and no change of method were significantly higher in the RF group than in the SR group (34.8% vs. 13.0%; P = 0.001 and 28.9% vs. 8.7%; P = 0.001). CONCLUSION: The failure rate for all of the MT was approximately 15%, and RF accounted for more than 70% of the failed MT. RF was associated with residual ICAS. In cases with RF, even in repeated attempts for recanalization, an alteration of the thrombectomy method should be considered.

Elevated blood viscosity is associated with delayed cerebral ischemia in patients with aneurysmal subarachnoid hemorrhage.

OBJECTIVES: Delayed cerebral ischemia (DCI) is a contributing factor for poor clinical outcome in aneurysmal subarachnoid hemorrhage (aSAH). Blood viscosity can reflect flow resistance and dehydration status. Our study aimed to analyze the association between blood viscosity and DCI in patients with aSAH. METHODS: In this retrospective cohort, systolic blood viscosity (SBV) and diastolic blood viscosity (DBV) were measured at admission in patients with aSAH. Receiver operating characteristic curve analysis was used to assess the predictive values of SBV and DBV for DCI after aSAH. Univariate and multivariate logistic regression was performed to analyze the association between blood viscosity and the development of DCI. RESULTS: A total of 470 patients with aSAH were included in this study, and 184 (39.1%) patients had DCI. Optimal cut-off values of DBV and SBV were presented as 12.05 (cP) and 3.75 (cP), respectively. In addition, DBV has higher predictable value of DCI than SBV (DBV: area under the curve [AUC] 0.793; standard error [SE] 0.026; 95% CI 0.722-0.864; P < 0.001, and SBV: AUC 0.702; SE 0.040; 95% CI 0.624-0.781; P < 0.001). In multivariate logistic regression analysis, elevated DBV was a predicting factor for development of DCI (odds ratio: 1.60; 95% confidence interval: 1.32-2.58; P = 0.037). CONCLUSIONS: Blood viscosity is associated with development of DCI in patients with aSAH. Especially, DBV has a higher predictive value for the occurrence of DCI than SBV. Elevated DBV is a potential predicting factor for the occurrence of DCI.

Effectiveness of Anchoring with Balloon Guide Catheter and Stent Retriever in Difficult Mechanical Thrombectomy for Large Vessel Occlusion.

OBJECTIVE: A distal navigation of a large bore aspiration catheter during mechanical thrombectomy (MT) is important. However, delivering a large bore aspiration catheter is difficult to a tortuous or atherosclerotic artery. We report the experience of anchoring with balloon guide catheter (BGC) and stent retriever to facilitate the passage of an aspiration catheter in MT. METHODS: When navigating an aspiration catheter failed with a conventional co-axial microcatheter delivery, an anchoring technique was used. Two types of anchoring technique were applied to facilitate distal navigation of a large bore aspiration catheter during MT. First, a passage of aspiration catheter was attempted with a proximal BGC anchoring technique. If this technique also failed, another anchoring technique with distal stent retriever was tried. Consecutive patients who underwent MT with an anchoring technique were identified. Details of procedure, radiologic outcomes, and safety variables were evaluated. RESULTS: A total of 67 patients underwent MT with an anchoring technique. Initial trial of aspiration catheter passage with proximal BGC anchoring technique was successful for 35 patients (52.2%) and the second trial with distal stent retriever anchoring was successful for 32 patients (47.8%). Overall, navigation of a large bore aspiration catheter was successful for all patients (100%) without any procedure related complications. CONCLUSION: Our study showed the usefulness of anchoring technique with proximal BGC and distal stent retriever during MT, especially in those with an unfavorable anatomical structure. This technique could be an alternative option for delivering an of aspiration catheter to a distal location.

Epidemiology and Management of Iatrogenic Vertebral Artery Injury Associated With Cervical Spine Surgery.

Iatrogenic vertebral artery injury (VAI) caused by surgical interventions involving the cervical spine is an uncommon but catastrophic complication associated with high morbidity or mortality due to ischemic stroke, intra- or extra-dural hemorrhage, and the formation of pseudoaneurysm or arteriovenous fistulae. In cervical spine surgeries, VAI may occur during the peri- or postoperative period. This may be induced by an anterior or posterior surgical approach. Despite advanced imaging techniques and increased anatomical knowledge, VAI during cervical spinal surgery remains a challenge. Techniques for managing VAI include hemostatic tamponade, ligation, microvascular repair or anastomosis, and endovascular management. We need to consider the risk of iatrogenic VAI as a complication in patients undergoing cervical spine surgeries and a better understanding of its mechanism and proper management.

Prognostic significance of platelet-to-lymphocyte and platelet-to-neutrophil ratios in patients with mechanical thrombectomy for acute ischemic stroke.

OBJECTIVE: The present study aimed to analyze the correlation between platelet-to-lymphocyte ratio (PLR) and platelet-to-neutrophil ratio (PNR) with prognosis of patients who underwent mechanical thrombectomy (MT). METHODS: A total of 432 patients was included, PLR and PNR were calculated from laboratory data on admission. Prognosis was evaluated with a modified Rankin Scale at 3 months after MT. Using receiver operating characteristic (ROC) analysis, optimal cutoff values of PLR and PNR were identified to predict the prognosis after MT. Multivariate analyses were performed to identify the relationship of PLR and PLR with prognosis of MT. RESULTS: Patients with favorable outcomes had a lower mean PLR (135.0, standard deviation [SD] 120.3) with a higher mean PNR (47.1 [SD] 24.6) compared with patients with unfavorable outcomes (167.6 [SD] 139.3 and 35.4 [SD] 22.4) (p<0.001 and <0.001, respectively). In ROC analyses, the optimal cutoff value of PLR and PNR to predict the 3 months prognosis were 145 and 41, respectively (p=<0.001 and p=0.006). In multivariate analysis, PLR less than 145 (odds ratio [OR] 1.29, 95% confidence interval [CI] 1.06-2.06; p=0.016) and PNR greater than 41 (OR 1.22, 95% CI 1.10-1.62; p=0.022) were predictors of favorable outcome at 3 months. CONCLUSIONS: In patients with MT, PLR and PNR on admission could be predictive factors of prognosis and mortality at 3 months. Decreased PLR and increased PNR were associated with favorable clinical outcome 3 months after MT.

Systemic Inflammation Response Index and Systemic Immune-Inflammation Index Are Associated with Clinical Outcomes in Patients Treated with Mechanical Thrombectomy for Large Artery Occlusion.

BACKGROUND: Inflammation plays a pivotal role in acute ischemic stroke, and various inflammatory markers are known to predict prognosis of acute ischemic stroke. This study aimed to evaluate the prognostic value of systemic inflammation response index (SIRI) and systemic immune-inflammation index (SII) after mechanical thrombectomy (MT) for acute ischemic stroke caused by large artery occlusion. METHODS: The study enrolled 440 patients who underwent MT for large artery occlusion. SIRI and SII were calculated using laboratory data on admission. Prognosis was estimated with modified Rankin Scale at 3 months, and favorable clinical outcome was defined by a modified Rankin Scale score of 0-2. Receiver operating characteristic analysis was used to calculate the optimal cutoff values of SIRI and SII for predicting clinical outcome. Multivariate analysis was used to assess the relationship of SIRI and SII with clinical outcome. RESULTS: In receiver operating characteristic analysis, the optimal cutoff values for SIRI and SII were 2.9 and 853, respectively (area under the curve 0.799, 95% confidence interval [CI] 0.756-0.843, P < 0.001 and area under the curve 0.679, 95% CI 0.643-0.745, P < 0.001, respectively). Multivariate analysis revealed that SIRI <2.9 (odds ratio 2.27, 95% CI 1.29-5.17, P = 0.019) and SII <853 (OR 1.82, 95% CI 1.16-3.10, P = 0.031) were independent predictors of favorable clinical outcome after MT. CONCLUSIONS: Decreased SIRI and SII were associated with favorable clinical outcome after MT. SIRI and SII represent potential prognostic factors in patients undergoing MT for large artery occlusion.

The Long-Term Functional Effect of Thrombectomy on Patients with Middle Cerebral Artery Occlusion Who Exhibit Moderate to Severe Disability.

Background and Objectives: Endovascular thrombectomy (EVT is an emerging gold standard treatment for acute cerebral infarction and may allow functional improvement after subacute cerebral infarction. However, the long-term functional benefits of EVT in patients with moderate to severe disability remain unclear. We investigated the effects of EVT on the activities of daily living (ADL), handicap, gait, and eating in patients with middle cerebral artery (MCA) occlusion who exhibited moderate to severe disability (score of 3-5 on the modified Rankin scale (mRS)) due to stroke, up to six months after onset. Materials and Methods: This retrospective longitudinal case-control study assessed 45 patients with MCA occlusion who exhibited moderate to severe disability (mRS score ≥ 3): 15 underwent EVT and 30 served as controls. Clinical assessments were conducted at two weeks (12-16 days), four weeks (26-30 days), and six months (180-210 days) after stroke onset. Functional assessments comprised the Korean version of the modified Barthel index (MBI), mRS, functional ambulation category (FAC), and dysphagia outcome severity scale (DOSS) to assess disability, handicap, gait, and eating. Results: The MBI, mRS, FAC, and DOSS scores all improved significantly (all p < 0.05) in the EVT group, compared to the controls. Conclusions: EVT has favorable effects on performing routine ADL, the handicap itself, walking, and eating. Therefore, EVT is recommended for patients with acute MCA occlusion, including those with severe disability at the initial assessment.

Systemic Inflammation Response Index and Systemic Immune-inflammation Index for Predicting the Prognosis of Patients with Aneurysmal Subarachnoid Hemorrhage.

OBJECTIVES: Inflammatory response plays a pivotal role in the progress of aneurysmal subarachnoid hemorrhage (aSAH). As novel inflammatory markers, systemic inflammation response index (SIRI) and systemic immune-inflammation (SII) index could reflect clinical outcomes of patients with various diseases. The aim of this study was to ascertain whether initial SIRI and SII index were associated with prognosis of aSAH patients. METHODS: A total of 680 patients with aSAH were enrolled. Their prognosis was evaluated with modified Rankin Scale (mRS) at 3 months, and unfavorable clinical outcome was defined as mRS score of 3-6. Receiver operating characteristic (ROC) curve analysis was performed to identify cutoff values of SIRI and SII index for predicting clinical outcomes. Univariate and multivariate regression analyses were performed to explore relationships of SIRI and SII index with prognosis of patients. RESULTS: Optimal cutoff values of SIRI and SII index to discriminate between favorable and unfavorable clinical outcomes were 3.2 × 109/L and 960 × 109/L, respectively (P < 0.001 and 0.004, respectively). In multivariate analysis, SIRI value ≥ 3.2 × 109/L (odds ratio [OR]: 1.82, 95% CI: 1.46-3.24; P = 0.021) and SII index value ≥ 960 × 109/L (OR: 1.68, 95% CI: 1.24-2.74; P = 0.040) were independent predicting factors for poor prognosis after aSAH. CONCLUSIONS: SIRI and SII index values are associated with clinical outcomes of patients with aSAH. Elevated SIRI and SII index could be independent predicting factors for a poor prognosis after aSAH.

Preliminary Experience of Neuroform Atlas Stenting as a Rescue Treatment after Failure of Mechanical Thrombectomy Caused by Residual Intracranial Atherosclerotic Stenosis.

OBJECTIVE: The low-profile Neuroform Atlas stent can be deployed directly without an exchange maneuver by navigating into the Gateway balloon. This retrospective study assessed the safety and efficacy of Neuroform Atlas stenting as a rescue treatment after failure of mechanical thrombetomy (MT) for large artery occlusion. METHODS: Between June 2018 and December 2019, a total of 31 patients underwent Neuroform Atlas stenting with prior Gateway balloon angioplasty after failure of conventional MT caused by residual intracranial atherosclerotic stenosis (ICAS). Primary outcomes were successful recanalization and patency of the vessel 24 hours after intervention. Secondary outcomes were vessel patency after 14 days and 3-month modified Rankin Scale. Peri-procedural complications, intracerebral hemorrhage (ICH), and 3-month mortality were reviewed. RESULTS: With a 100% of successful recanalization, median value of stenosis was reduced from 79.0% to 23.5%. Twenty-eight patients (90.3%) showed tolerable vessel patency after 14 days. New infarctions occurred in three patients (9.7%) over a period of 14 days; two patient (6.5%) underwent stent occlusion at 24 hours, and the other patient (3.2%) with delayed stent occlusion had a non-symptomatic dot infarct. There were no peri-procedural complications. Two patients (6.5%) developed an ICH immediately after the procedure with one of them is symptomatic. CONCLUSION: Neuroform Atlas stenting seems to be an effective and safe rescue treatment modality for failed MT with residual ICAS, by its high successful recanalization rate with tolerable patency, and low peri-procedural complication rate. Further multicenter and randomized controlled trials are needed to confirm our findings.

Effect on Successful Recanalization of Thrombus Length in Susceptibility- weighted Imaging in Mechanical Thrombectomy with Stentretrieval.

INTRODUCTION: Susceptibility-Eeighted Imaging (SWI) enables visualization of thrombotic material in acute ischemic stroke. We analyzed the association between thrombus length on SWI and the success rate of recanalization in stent-retriever mechanical thrombectomy. METHODS: A retrospective study was performed on 128 patients with Middle Cerebral Artery (MCA) thrombus on pretreatment SWI. The patients were divided into 2 groups, the successful recanalization and the failed recanalization group. Thrombus visibility and location on SWI were compared to those on Maximum Intensity Projection (MIP) in Computed Tomography (CT) angiography. A comparative analysis was performed in terms of clinical and radiologic outcomes as well as complications with respect to multiple categories. RESULTS: No significant differences were noted in terms of baseline characteristics and clinical outcomes between the 2 groups. However, compared with the successful recanalization group, the failed recanalization group had a larger number of stent-retriever passages and a longer thrombus length (p = 0.027 and 0.014, respectively). Multivariate analyses revealed that a larger mean number of stent-retriever passages was a predictive factor for failure of recanalization (odds ratio [OR] 1.60; 95% confidence Interval [CI] 1.12-2.08; p = 0.04). Thrombus length (OR 9.91; 95% CI 3.89-13.87; p < 0.001) and atrial fibrillation (OR 5.38; 95% CI 1.51-9.58; p = 0.008) were separately associated with more than 3 stent-retriever passages. CONCLUSION: Thrombus length has been identified as a predictor of recanalization failure in mechanical thrombectomy. A significant decline in the success rate of recanalization was associated with longer thrombus length.

Effectiveness and Technical Considerations of Solitaire Platinum 4×40 mm Stent Retriever in Mechanical Thrombectomy with Solumbra Technique.

OBJECTIVE: The Solitaire Platinum 4×40 mm stent retriever contains radiopaque markers with a long length. We evaluated the effect of Solitaire Platinum 4×40 mm stent retriever in Solumbra technique thrombectomy, and compared it with shorter Solitaire stent retrievers. METHODS: A total of 70 patients who underwent Solumbra technique thrombectomy with equal diameter (4 mm) and different length (40 vs. 20 mm) Solitaire stent retrievers were divided into two groups : the Solitaire Platinum 4×40 mm stent (4×40) group and the Solitaire FR 4×20 mm stent or Solitaire Platinum 4×20 mm stent (4×20) group. The clinical outcomes, Thrombolysis in Cerebral Infarction score, the first pass reperfusion status, and complications were evaluated and compared between the two groups. Multivariate analysis was performed to evaluate the predictive factors for reperfusion and complete reperfusion from the first pass. RESULTS: Higher first-pass reperfusion and complete reperfusion were achieved in the 4×40 group (68.0% and 48.0%) than in the 4×20 group (46.7% and 33.3%; p=0.004 and 0.007, respectively). In multivariate analysis, radiopaque device and longer stent retriever were correlated with first-pass reperfusion (p=0.014 and 0.008, respectively) and first-pass complete reperfusion (p=0.022 and 0.012, respectively). CONCLUSION: Our study demonstrated the usefulness of the Solitaire Platinum 4×40 mm stent retriever, which led to higher firstpass reperfusion and complete reperfusion rates than the Solitaire FR 4×20 mm stent or the Solitaire Platinum 4×20 mm stent, especially in Solumbra technique thrombectomy.

Association of blood viscosity with first-pass reperfusion in mechanical thrombectomy for acute ischemic stroke.

BACKGROUND: Elevated blood viscosity has been reported as a risk factor for cerebrovascular disease. OBJECTIVE: The relationship between blood viscosity and outcomes of mechanical thrombectomy (MT) for large artery occlusion (LAO) were investigated in the present study. METHODS: A total of 238 patients were enrolled and systolic blood viscosity (SBV) and diastolic blood viscosity (DBV) were measured using the scanning capillary tube viscometer. Receiver operating characteristic (ROC) analysis was performed to specify the association of viscosity with the first-pass reperfusion (FPR). Multivariable and regression analyses were performed to evaluate the relationship of viscosity with FPR and various variables. RESULTS: Based on ROC analysis, the best DBV cutoff value was 10.55 (cP). In multivariable analysis, high DBV was associated with FPR failure (odds ratio 2.82, 95% confidence interval 1.64-4.22; p = 0.001). Increased DVB could be associated with elevated SBV, hematocrit level, and blood urea nitrogen/creatinine ratio (p = <0.001, 0.004, and 0.002, respectively). CONCLUSIONS: Elevated DBV was associated with FPR failure. Patients with high DBV had longer thrombus length and required more stent passages than patients with low DBV.