Mechanical thrombectomy in anterior vs. posterior circulation stroke: A systematic review and meta-analysis

BACKGROUND

High-quality evidence exists for mechanical thrombectomy (MT) treatment of acute ischemic stroke (AIS) due to large vessel occlusion of the anterior circulation (AC-LVO). The evidence for MT treatment of posterior circulation large vessel occlusion (PC-LVO) is weaker, largely drawn from lower quality studies specific to PC-LVO and extrapolated from findings in AC-LVO, and ambiguous with regards to technical success. We performed a systematic review and meta-analysis to compare the technical success and functional outcomes of MT in PC-LVO versus AC-LVO patients.

METHODS

We identified comparative studies reporting on patients treated with MT in AC-LVO versus PC-LVO. The primary outcome of interest was thrombolysis in cerebral infarction (TICI) ≥ 2b. Secondary outcomes included rates of TICI 3, 90-day functional independence, first-pass-effect, average number of passes, and 90-day mortality. A separate random effects model was fit for each outcome measure.

RESULTS

Twenty studies with 12,911 patients, 11,299 (87.5%) in the AC-LVO arm and 1612 (12.5%) in the PC-LVO arm, were included. AC-LVO and PC-LVO patients had comparable rates of successful recanalization [OR = 1.02 [95% CI: 0.79-1.33], p = 0.848). However, the AC-LVO group had greater odds of 90-day functional independence (OR = 1.26 [95% CI: 1.00; 1.59], p = 0.050) and lower odds of 90-day mortality (OR = 0.58 [95% CI: 0.43; 0.79], p = 0.002).

CONCLUSIONS

MT achieves similar rates of recanalization with a similar safety profile in PC-LVO and AC-LVO patients. Patients with PC-LVO are less likely to achieve functional independence after MT. Future studies should identify PC-LVO patients who are likely to achieve favourable functional outcomes.

Predictors for intracerebral hemorrhage after intravenous or intraarterial recanalization in acute major cerebral artery occlusion in Korean patients

OBJECTIVE

To evaluate predictors for intracerebral hemorrhage (ICH) and 1-month mortality after intravenous (IV) or intraarterial (IA) recanalization therapy for major cerebral artery occlusion in Korean patients.

METHODS

From 2011 to 2015, we prospectively gathered data from consecutive patients treated with IV/IA recanalization within 8 h of symptoms in a single center. The effects of demographic, clinical, laboratory, and radiological factors on ICH within 2 weeks were assessed, as well as 1-month mortality.

RESULTS

From a total of 183 patients, symptomatic intracerebral hemorrhage (SICH) occurred in 32 patients (17.5%), and asymptomatic ICH occurred in 37 patients (20.2%). The mortality rate at 1 month in ICH patients was 37.7%. The international normalized ratio (INR) (OR, 4.9; 95% CI, 1.03-23.4; p = 0.046), glucose (OR, 1.119 per mmol/L; 95% CI, 1.015-1.233; p = 0.023), medium-volume infarct (15-69.9 mL) (OR, 2.62; 95% CI, 1.1-6.26; p = 0.03), large-volume infarct (≥70 mL) (OR, 5.54; 95% CI, 2.1-14.6; p = 0.001), and angioplasty or stenting (OR, 6.29; 95% CI, 1.71-23.22; p = 0.006) were predictors of any ICH. Hyperlipidemia or statin medication (OR, 4.17; 95% CI, 1.38-12.59; p = 0.011), INR (OR, 7.13; 95% CI, 0.94-54.22 p = 0.058), and large-volume infarct (≥70 mL) (OR, 7.96; 95% CI, 2.31-27.39; p = 0.001) were predictors of SICH. Hypertension (OR, 5.77; 95% CI, 1.43-23.3; p = 0.014), initial NIHSS score (OR, 1.09; 95% CI, 1.01-1.18; p = 0.27), and SICH (OR, 15.7; 95% CI, 4.04-61.08; p < 0.001) were predictors of 1-month mortality.

CONCLUSION

INR and glucose may be strong modifiable predictors of critical ICH leading to death after IV/IA recanalization therapy in acute cerebral artery occlusion.

Impact of width of susceptibility vessel sign on recanalization following endovascular therapy

BACKGROUND AND PURPOSE

We aimed to investigate the relationship between arterial recanalization following endovascular therapy and the susceptibility vessel sign (SVS) length and width on susceptibility-weighted imaging.

METHODS

We retrospectively evaluated consecutive patients with anterior circulation ischemic stroke who underwent magnetic resonance imaging preceded endovascular therapy, and measured the SVS length and width. Successful recanalization was defined as expanded thrombolysis in cerebral infarction grade of 2b to 3. Logistic regression analysis was executed to determine the independent predictors of successful recanalization and first-pass reperfusion (FPR) after endovascular therapy.

RESULTS

Among 100 patients, successful recanalization and FPR were observed in 77 and 34 patients, respectively. The median SVS length and width were 10.3 mm (interquartile range, 6.8-14.1 mm) and 4.2 mm (interquartile range, 3.1-5.2 mm), respectively. In multivariate logistic regression analysis, SVS width was associated with successful recanalization (odds ratio, 1.88; 95% confidence interval, 1.14-3.07; p = 0.005) and FPR (odds ratio, 1.38; 95% confidence interval, 1.01-1.89; p = 0.039). The optimal cutoff value for the SVS width to predict successful recanalization and FPR were 4.2 mm and 4.0 mm, respectively.

CONCLUSIONS

Larger SVS width may predict successful recanalization and FPR following endovascular therapy.

The initial experience with the Embotrap III stent-retriever in a real world setting

MATERIALS AND METHODS

We performed a retrospective review of our prospectively maintained database to identify all patients treated with the Embotrap 3 stent-retriever between January 2021 and January 2022. We recorded the baseline demographics, NIHSS, ASPECT score and clot characteristics, first pass and final eTICI scores, complications and 90 day mRS.

RESULTS

One hundred and ten patients met the inclusion criteria, average age 69 ± 14 years, 50% were male (n = 55). The median NIHSS at presentation was 18 (range 3-30) and 58.2% received IV tPA prior to MT. The median ASPECT score on plain CT was 8 with average clot length 20.2 ± 14.8 mm (n = 93). The first pass effect (FPE) was seen in 41.8% of cases with modified FPE seen in 59.1%. A 24-hour CT scan (n = 97) showed median ASPECTs of 7. 43.8% of patients achieve mRS ≤ 2 at 90-day mRS (n = 64).

CONCLUSION

The Embotrap 3 stent-retriever has a high rate of FPE and final recanalization in this real world cohort of patients.

Revascularization and functional outcomes after mechanical thrombectomy: an update to key metrics

OBJECTIVE

The advent of mechanical thrombectomy (MT) has become an effective option for the treatment of acute ischemic stroke in addition to tissue plasminogen activator (tPA). With recent advances in device technology, MT has significantly altered the hospital course and functional outcomes of stroke patients. The authors' goal was to establish the most up-to-date reperfusion and functional outcomes with the evolution of MT technology.

METHODS

The authors conducted a retrospective study of 403 patients who underwent MT for ischemic stroke at their institution from 2010 to 2017. They collected data on patient comorbidities, National Institutes of Health Stroke Scale (NIHSS) score on arrival, tPA administration, revascularization outcomes, and functional outcomes on discharge.

RESULTS

In 403 patients, the mean NIHSS score on presentation was 15.8 ± 6.6, with 195 (48.0%) of patients receiving tPA prior to MT. Successful reperfusion (thrombolysis in cerebral infarction score 2B or 3) was achieved in 84.4%. Hemorrhagic conversion with significant mass effect was noted in 9.9% of patients. The median lengths of ICU and hospital stay were 3.0 and 7.0 days, respectively. Functional independence (modified Rankin Scale score 0-2) was noted in 125 (31.0%) patients, while inpatient mortality occurred in 43 (10.7%) patients.

CONCLUSIONS

As MT has established acute ischemic stroke as a neurosurgical disease, there is a pressing need to understand the hospital course, hospital- and procedure-related complications, and outcomes for this new patient population. The authors provide a detailed account of key metrics for MT with the latest device technology and identify the predictors of unfavorable outcomes and inpatient mortality.

Predictors of Good Outcomes in Patients with Failed Endovascular Thrombectomy

OBJECTIVE

Endovascular thrombectomy (EVT) fails in approximately 20% of anterior circulation large vessel occlusion (AC-LVO). Nonetheless, the factors that affect clinical outcomes of non-recanalized AC-LVO despite EVT are less studied. The purpose of this study was to identify the factors affecting clinical outcomes in non-recanalized AC-LVO patients despite EVT.

MATERIALS AND METHODS

This was a retrospective analysis of clinical and imaging data from 136 consecutive patients who demonstrated recanalization failure (modified thrombolysis in cerebral ischemia [mTICI], 0-2a) despite EVT for AC-LVO. Data were collected in prospectively maintained registries at 16 stroke centers. Collateral status was categorized into good or poor based on the CT angiogram, and the mTICI was categorized as 0-1 or 2a on the final angiogram. Patients with good (modified Rankin Scale [mRS], 0-2) and poor outcomes (mRS, 3-6) were compared in multivariate analysis to evaluate the factors associated with a good outcome.

RESULTS

Thirty-five patients (25.7%) had good outcomes. The good outcome group was younger (odds ratio [OR], 0.962; 95% confidence interval [CI], 0.932-0.992; p = 0.015), had a lower incidence of hypertension (OR, 0.380; 95% CI, 0.173-0.839; p = 0.017) and distal internal carotid artery involvement (OR, 0.149; 95% CI, 0.043-0.520; p = 0.003), lower initial National Institute of Health Stroke Scale (NIHSS) (OR, 0.789; 95% CI, 0.713-0.873; p < 0.001) and good collateral status (OR, 13.818; 95% CI, 3.971-48.090; p < 0.001). In multivariate analysis, the initial NIHSS (OR, 0.760; 95% CI, 0.638-0.905; p = 0.002), good collateral status (OR, 14.130; 95% CI, 2.264-88.212; p = 0.005) and mTICI 2a recanalization (OR, 5.636; 95% CI, 1.216-26.119; p = 0.027) remained as independent factors with good outcome in non-recanalized patients.

CONCLUSION

Baseline NIHSS score, good collateral status, and mTICI 2a recanalization remained independently associated with clinical outcome in non-recanalized patients. mTICI 2a recanalization would benefit patients with good collaterals in non-recanalized AC-LVO patients despite EVT.

Factors Associated with Unsuccessful Recanalization in Mechanical Thrombectomy for Acute Ischemic Stroke

Introduction

Mechanical thrombectomy (MT) for acute ischemic stroke has become a standard therapy, and the recanalization rate has significantly improved. However, some cases of unsuccessful recanalization still occur. We aimed to clarify patient factors associated with unsuccessful recanalization after MT for acute ischemic stroke.

Methods

This was a single-center, retrospective study of 119 consecutive patients with anterior circulation acute ischemic stroke who underwent MT at our hospital between April 2015 and March 2019. Successful recanalization after MT was defined as modified Treatment in Cerebral Ischemia (mTICI) grade 2b or 3, and unsuccessful recanalization was defined as mTICI grades 0–2a. Several factors were analyzed to assess their effect on recanalization rates.

Results

Successful recanalization was achieved in 88 patients (73.9%). The univariate analysis showed that female sex (38.6 vs. 67.7%, p = 0.007), a history of hypertension (53.4 vs. 83.9%, p = 0.003), and a longer time from groin puncture to recanalization (median 75 vs. 124 min, p < 0.001) were significantly associated with unsuccessful recanalization. The multivariate analysis confirmed that female sex (OR 3.18; 95% CI 1.12–9.02, p = 0.030), a history of hypertension (OR 4.84; 95% CI 1.32–17.8, p = 0.018), M2–3 occlusion (OR 4.26; 95% CI 1.36–13.3, p = 0.013), and the time from groin puncture to recanalization (per 10-min increase, OR 1.22; 95% CI 1.09–1.37, p < 0.001) were independently associated with unsuccessful recanalization.

Conclusion

Female sex and a history of hypertension might be predictors of unsuccessful recanalization after MT for anterior circulation acute ischemic stroke. Further studies are needed to fully evaluate predictors of recanalization.

Mechanical Thrombectomy Outcome Predictors in Stroke Patients with M2 Occlusion: A Single-Center Retrospective Study

BACKGROUND

Mechanical thrombectomy (MT) has demonstrated benefit in patients with acute ischemic stroke due to proximal large-vessel occlusion. However, it is unclear whether these results can be extrapolated to patients with an occlusion of the second segment (M2) of the middle cerebral artery (MCA). We sought to study outcomes in patients with M2 occlusion treated with MT and to better understand clinical predictors of these outcomes.

METHODS

We performed a single-center retrospective analysis of consecutive patients with acute MCA M2 segment occlusion who underwent stent retriever MT. We correlated clinical and radiographic outcomes with demographic, clinical, and technical characteristics.

RESULTS

Thirty-seven patients were included in the analysis (median admission National Institutes of Health Stroke Scale [NIHSS] score, 15 [12-19], mean age 74 [67-80] years, 48.6% women). Good clinical outcome at 3 months (modified Rankin Scale ≤2) was achieved in 48.6% of patients. Baseline NIHSS was a predictor of clinical outcomes, based on modified Rankin Scale distribution at 3 months after MT (P = 0.015, odds ratio 1.63, 95% confidence interval 1.01-2.43).

CONCLUSIONS

The results of our single-institution experience suggest that MT-based endovascular therapy for M2 occlusions is safe and effective. Baseline NIHSS was a predictor of outcomes in patients treated with MT for M2 segment occlusion of the MCA.

A review of the diagnosis and management of vertebral basilar (posterior) circulation disease

We have reviewed the English literature published in the last 70 years on Diseases of the Vertebral Basilar Circulation, or Posterior Circulation Disease (PCD). We have found that errors have been made in the conduct and interpretation of these studies that have led to incorrect approaches to the management of PCD. Because of the difficulty in evaluating the PC, the management of PCD has been incorrectly applied from anterior circulation disease (ACD) experience to PCD. PCD is a common form of stroke affecting 20-40% patients with stroke. Yet, the evidence is strong that the Anterior Circulation (AC) and Posterior Circulations (PC) differ in their pathology, in their clinical presentations, in the rapidity of development of symptoms, in optimal imaging methods, and in available treatments. There appears to be two categories of patients who present with PCD. The first, acute basilar artery occlusion has a more rapid onset. The diagnosis must be made quickly and if imaging proves a diagnosis of Basilar Artery Occlusion (BAO), the treatment of choice is Interventional removal of the basilar artery thrombosis or embolus. The second category of PCD and the most commonly seen PCD disease process presents with non-specific symptoms and early warnings of PCD that now can be related to ischemic events in the entire PC vessels. These warning symptoms and signs occur much earlier than those in the AC. IA angiography is still the gold standard of diagnosis and is superior in definition to MR and CT angiography which are commonly used as a convenient screening imaging tool to evaluate PCD but are both inferior to IA angiography in definition for lesions below 3-4 mm. In at least two reported studies 7T MR angiography appears superior to other imaging modalities and will become the gold standard of imaging of PCD in the future. Medical treatments applied to the ACD have not been proven of value in specific forms of PCD. Interventional therapy was promising but of unproven value in Randomized Controlled Trials (RCT) except for the treatment of Basilar Artery Occlusion (BAO). Surgical revascularization has been proved to be highly successful in patients, who are refractory to medical therapy. These studies have been ignored by the scientific community basically because of an incorrect interpretation of the flawed EC-IC Bypass Trial in 1985 as applying to all stroke patients. Moreover, the EC-IC Bypass Study did not include PCD patients in their study population, but the study results were extrapolated to patients with PCD without any scientific basis. This experience led clinicians to an incorrect bias that surgical treatments are of no value in PCD. Thus, incorrectly, surgical treatments of PCD have not been considered among the therapeutic possibilities for PCD. QMRA is a new quantitative MR technique that measures specific blood flow in extra and intracranial vessels. QMRA has been used to select those patients who may benefit from medical, or interventional, or surgical treatment for PCD based on flow determinations with a high success rate. QMRA accurately predicts the flows in many large and small vessels in the PC and AC and clearly indicates that both circulations are intimately related. From medical and surgical studies, the longer one waits for surgical treatment the higher the risk of a poor outcome results. This observation becomes obvious when the rapidity of development of PCD is compared with ACD. Recent advances in endovascular therapy in the treatment of acute basilar thrombosis is a clear sign that early diagnosis and treatment of PCD will reduce the morbidity and mortality of these diseases. In this review it is evident that there are multiple medical and surgical treatments for PCD depending upon the location of the lesion(s) and the collateral circulation demonstrated. It is clear that the AC and PC have significant differences. With the exception of the large population studies from Oxford England, the reported studies on the management of PCD in the literature represent small selected subsets of the universe of PC diseases, the information from which is not generalizable to the universe of PCD patients. At this point in the history of PCD, there are not large enough databases of similar patients to provide a basis for valid randomized studies, with the exception of the surgical studies. Thus, a high index of suspicion of the early warning symptoms of PCD should lead to a rapid individual clinical assessment of patients selecting those with PCD. Medical, interventional, and/or surgical treatments should be chosen based on knowledge presented in this review. Recording the results in a national Registry on a continuing basis will provide the data that may help advance the management of PCD based on larger data bases of well documented patient information to guide the selection of future therapies for PCD treatments. It is also clear that the management of patients within the complex of diseases that comprise PCD should be performed in centers with expertise in the imaging, medical, interventional and surgical approaches to diseases of the PCD.

Thrombectomy using the EmboTrap device: core laboratory-assessed results in 201 consecutive patients in a real-world setting

Background

We studied patients treated with the EmboTrap revascularization device in a prospective registry which is core laboratory evaluated by physicians from external centers. The goal was to determine how the EmboTrap would perform under the everyday conditions of a high-volume stroke center.

Methods

We examined all patients with acute stroke treated with the Embotrap device from October 2013 to March 2017 in our center. Imaging parameters and times were adjudicated by core laboratory personnel blinded to clinical information, treating physician, and clinical outcomes. Clinical evaluation was performed by independent neurologists and entered in a national registry. Evaluated endpoints were: successful revascularization (modified Thrombolysis in Cerebral Infarction (mTICI) 2b–3) and good clinical outcomes at 3 months (modified Rankin Scale (mRS) 0–2).

Results

201 consecutive patients with a median NIH Stroke Scale (NIHSS) score of 15 (range 2–30) were included. 170 patients (84.6%) achieved mTICI 2b–3 reperfusion. The median number of attempts was 2 (range 1–10) with 52.8% of the population achieving good functional outcomes (mRS 0–2) at 3 months. On univariate analysis, good functional outcome was associated with the number of attempts, puncture-to-reperfusion time, anterior circulation occlusion, and NIHSS score. On multivariate analysis, pre-treatment NIHSS (OR 0.845 per point, 95% CI 0.793 to 0.908, P<0.001) and puncture-to-reperfusion time (OR 0.9952 per min, 95% CI 0.9914 to 0.9975, P=0.023) were associated with good functional outcomes at 3 months.

Conclusion

The Embotrap device has a high rate of successful reperfusion. Our core laboratory-audited single-center experience suggests the technical feasibility and safety of the Embotrap for first-line use in a real-world setting.

A simple prediction score system for malignant brain edema progression in large hemispheric infarction

Malignant brain edema (MBE) due to hemispheric infarction can result in brain herniation, poor outcomes, and death; outcome may be improved if certain interventions, such as decompressive craniectomy, are performed early. We sought to generate a prediction score to easily identify those patients at high risk for MBE. 121 patients with large hemispheric infarction (LHI) (2011 to 2014) were included. Patients were divided into two groups: those who developed MBE and those who did not. Independent predictors of MBE were identified by logistic regression and a score was developed. Four factors were independently associated with MBE: baseline National Institutes of Health Stroke Scale (NIHSS) score (p = 0.048), Alberta Stroke Program Early Computed Tomography Score (ASPECTS) (p = 0.007), collateral score (CS) (p<0.001) and revascularization failure (p = 0.013). Points were assigned for each factor as follows: NIHSS ≤ 8 (= 0), 9–17 (= 1), ≥ 18 (= 2); ASPECTS≤ 7 (= 1), >8 (= 0); CS<2 (= 1), ≥2 (= 0); revascularization failure (= 1),success (= 0). The MBE Score (MBES) represents the sum of these individual points. Of 26 patients with a MBES of 0 to 1, none developed MBE. All patients with a MBES of 6 developed MBE. Both MBE development and functional outcomes were strongly associated with the MBES (p = 0.007 and 0.002, respectively). The MBE score is a simple reliable tool for the prediction of MBE.

Predictive Factors for Good Outcome and Mortality After Stent-Retriever Thrombectomy in Patients With Acute Anterior Circulation Stroke

Background and Purpose

Predictive factors associated with stent-retriever thrombectomy for patients with acute anterior circulation stroke remain to be elucidated. This study aimed to investigate clinical and procedural factors predictive of good outcome and mortality after stent-retriever thrombectomy in a large cohort of patients with acute anterior circulation stroke.

Methods

We analyzed clinical and procedural data in 335 patients with acute anterior circulation stroke treated with stent-retriever thrombectomy. A good outcome was defined as a modified Rankin Scale score of 0 to 2 at 3 months. The associations between clinical, imaging, and procedural factors and good outcome and mortality, respectively, were evaluated using logistic regression analysis.

Results

Using multivariate analysis, age (odds ratio [OR], 0.965; 95% confidence interval [CI], 0.944-0.986; P=0.001), successful revascularization (OR, 4.658; 95% CI, 2.240-9.689; P<0.001), parenchymal hemorrhage (OR, 0.150; 95% CI, 0.049-0.460; P=0.001), and baseline NIHSS score (OR, 0.908; 95% CI, 0.855-0.965; P=0.002) were independent predictors of good outcome. Independent predictors of mortality were age (OR, 1.043; 95% CI, 1.002-1.086; P=0.041), successful revascularization (OR, 0.171; 95% CI, 0.079-0.370; P<0.001), parenchymal hemorrhage (OR, 2.961; 95% CI, 1.059-8.276; P=0.038), and a history of previous stroke/TIA (OR, 3.124; 95% CI, 1.340-7.281; P=0.008).

Conclusions

Age, revascularization status, and parenchymal hemorrhage are independent predictors of both good outcome and mortality after stent retriever thrombectomy for acute anterior circulation stroke. In addition, NIHSS score on admission is independently associated with good outcome, whereas a history of previous stroke is independently associated with mortality.

Mechanical thrombectomy with the ERIC retrieval device: initial experience

Objective

To report our experience with the Embolus Retriever with Interlinked Cage (ERIC) stentriever for use in mechanical endovascular thrombectomy (MET).

Methods

Thirty-four consecutive patients with acute stroke (21 men and 13 women; median age 66 years) determined appropriate for MET were treated with ERIC and prospectively included over a 6-month period at three different centers. The ERIC device differs from typical stentrievers in that it is designed with a series of interlinked adjustable nitinol cages that allow for fast thrombus capture, integration, and withdrawal. The evaluated endpoints were successful revascularization (Thrombolysis in Cerebral Infarction (TICI) 2b–3) and good clinical outcomes at 3 months (modified Rankin Scale (mRS) 0–2).

Results

Locations of the occlusions included the middle cerebral artery (13 patients), terminal carotid artery (11 patients), basilar artery (1 patient), and tandem occlusions (9 patients). IV thrombolysis was performed in 20/34 (58.8%) patients. Median times from symptom onset to recanalization and from puncture to recanalization were 325.5 min (180–557) and 78.5 min (14–183), respectively. Used as the first-line device, ERIC achieved a successful recanalization in 20/24 (83.3%) patients. Successful recanalization was associated with lower National Institutes of Health Stroke Scale scores at 24 h (8±6.5 vs 21.5±2.1; p=0.008) and lower mRS at 3 months (2.7±2.1 vs 5.3±1.1; p=0.04). Three procedural complications and four asymptomatic hemorrhages were recorded. Good clinical outcomes at 3 months were seen in 15/31 (48.4%) patients.

Conclusions

The ERIC device is an innovative stentriever allowing fast, effective, and safe MET.