Distal Vessel Occlusion Research Articles

Stroke Network of Wisconsin (SNOW) Scale Predicts Large Vessel Occlusion Stroke in the Prehospital Setting.

In previous trials, the Stroke Network of Wisconsin (SNOW) scale accurately predicted large vessel occlusion (LVO) stroke in the hospital setting. This study evaluated SNOW scale performance in the prehospital setting and its ability to predict LVO or distal medium vessel occlusion (DMVO) in patients suspected of having acute ischemic stroke (AIS), a scenario in which transport time to an endovascular treatment-capable facility (ECSC) is critical. All potential AIS patients with last-known-well time of ≤24 hours were assessed by Milwaukee County Emergency Medical Services for LVO using SNOW. Patients with a positive SNOW score were transferred to the nearest ECSC. One such facility, Aurora St. Luke's Medical Center (ASLMC), was the source of all patient data analyzed in this study. LVO was defined as occlusion of the intracranial carotid artery, middle cerebral artery (M1) segment, or basilar artery. From March 2018 to February 2019, 345 AIS-suspected patients were transported to ASLMC; 19 patients were excluded because no vascular imaging was performed. Of 326 patients, 32 had confirmed LVO and 21 DMVO. For identifying LVO, SNOW scale sensitivity was 0.88, specificity 0.40, positive predictive value (PPV) 0.14, negative predictive value (NPV) 0.97, and area under the curve (AUC) 0.64. Ability to predict DMVO was similar. Overall, the SNOW scale showed sensitivity of 0.83, specificity of 0.39, PPV of 0.10, NPV of 0.97, and AUC of 0.60 in identifying candidates for endovascular thrombectomy. In a prehospital setting, the SNOW scale has high sensitivity in identifying candidates for endovascular thrombectomy and proved highly reliable in ruling out stroke due to LVO.

Advances in Acute Ischemic Stroke Therapy.

The treatment of acute ischemic stroke continues to advance. The mainstay of treatment remains intravenous thrombolysis with alteplase. Recent studies demonstrated that later treatment with alteplase is beneficial in patients selected with advanced imaging techniques. Tenecteplase has been evaluated as an alternative thrombolytic drug and evidence suggests that it is as least as effective as alteplase and may lyse large vessel clots more effectively. Endovascular therapy with mechanical thrombectomy has now been shown to be beneficial up to 24 hours after stroke onset in carefully selected patients with proximal, large vessel occlusions. Ongoing studies are evaluating the effectiveness of thrombectomy in patients with more distal vessel occlusions and patients with proximal large vessel occlusions with larger ischemic core volumes and also in patients with milder neurological deficits. Cytoprotection is another potential acute stroke therapy that has not demonstrated efficacy in prior clinical trials. It should be reconsidered as an adjunct to reperfusion and a variety of new clinical trials can be envisioned to evaluate the potential benefits of cytoprotection in patients before and after reperfusion.

Safety and effectiveness of mechanical thrombectomy for primary isolated distal vessel occlusions: A monocentric retrospective comparative study

BackgroundDistal vessel occlusions represent about 25-40% of acute ischemic stroke (AIS), either as primary occlusion or secondary occlusion complicating mechanical thrombectomy (MT) for large vessel occlusion. ObjectiveOur aim was to evaluate safety and effectiveness of MT associated with the best medical treatment (BMT) in the management of AIS patients with distal vessel occlusion in comparison with the BMT alone. MethodsRetrospective analysis was conducted on AIS patients treated by MT+BMT for primary distal vessel occlusion between 2015 and 2020, and were compared with a historic cohort managed by BMT alone between 2006 and 2015 selected based on the same inclusion criteria. A secondary analysis was conducted using propensity score matching (PSM) including the following: NIHSS, age and treatment with intravenous thrombolysis (IVT) as covariates. ResultsOf 650 patients screened, 44 patients with distal vessel occlusions treated by MT+BMT were selected and compared with 36 patients who received BMT alone. After PSM, 28 patients in each group were matched without significant difference. Good clinical outcome defined as mRS≤2 was achieved by 53.6% of the MT+BMT group and 57% of the BMT group (OR, 0.87; 95%CI, 0.3–2.4; p = 1.00). The mortality rate was comparable in both groups (7% vs. 10.7% in MT+BMT and BMT patients, respectively; OR=0.64; 95%CI, 0.1-4; p = 1.00). Symptomatic intracranial hemorrhage (ICH) was seen in only one patient treated by MT+BMT (3.6%). ConclusionMechanical thrombectomy seems to be comparable with the best medical treatment regarding the effectiveness and safety in the management of patients with distal vessel occlusions.

Early Neurological Improvement Predicts Clinical Outcome After Thrombectomy for Distal Medium Vessel Occlusions.

Background and PurposeGood clinical outcome predictors have been established in mechanical thrombectomy (MT) for acute ischemic stroke (AIS) caused by large vessel occlusion (LVO). An early neurological improvement (ENI), defined as a reduction of ≥8 on the National Institutes of Health Stroke Scale (NIHSS), compared with the baseline score or an NIHSS of 0 or 1 at 24 h after MT, is a strong predictor of favorable outcome. We aimed to study the impact of ENI after MT for distal medium vessel occlusions (DMVO).MethodsWe retrospectively analyzed the data of consecutive patients who underwent MT for a primary DMVO in one large academic center. We compared clinical outcomes between patients with DMVO stratified by ENI. Multivariate analyses were performed to determine the impact of ENI on good 90-day outcome (modified Rankin scale of 0–2) and identify factors contributing to ENI.ResultsBetween January 2018 and January 2021, 61 patients underwent an MT for an AIS with a primary DMVO. An ENI was seen in 24 (39%) patients (ENI+). Outcomes were significantly better in ENI+ patients, with 83% achieving a good outcome at 3 months vs. 43% for patients without ENI (ENI–; p = 0.019). ENI was an independent predictive factor of good clinical outcome even after adjusting for potential confounding factors [odds ratio 12.49 (1.49–105.01), p = 0.020]. The use of intravenous tissue plasminogen activator [IVtPA; Odds-ratio 6.59 (1.82–23.89), p = 0.004] was a positive predictor of ENI.ConclusionENI at day 1 following MT for DMVO stroke is a strong independent predictor of good to excellent 3-month clinical outcome.

Hypoperfusion Intensity Ratio Predicts Infarct Growth After Successful Thrombectomy for Distal Medium Vessel Occlusion.

This study evaluated whether quantitative measurement of collaterals by the hypoperfusion intensity ratio (HIR) on baseline computed tomography perfusion (CTP) correlated with infarct growth and clinical outcome after successful endovascular recanalization of acute ischemic stroke (AIS) caused by primary distal medium vessel occlusions (DMVO). We performed aretrospective analysis of consecutive AIS patients who underwent an initial CTP and were successfully recanalized by thrombectomy (modified thrombolysis In cerebral infarction2b or3) for DMVO. We evaluated the association of baseline HIR with infarct growth and clinical outcome. Between January 2018 and January 2021, 40patients with an AIS caused by aDMVO were successfully recanalized by MT (65%, 26/40 female, median age 72 years, range 65-83 years). Baseline HIR was strongly correlated with infarct growth after successful recanalization (r = 0.501, p = 0.001). An HIR<0.3 was the optimal threshold for good collaterals using ROC analysis. Patients with HIR ≥ 0.3 had higher infarct growth compared to HIR < 0.3 (23.8 mL, IQR: 9.1-45.1 vs. 7.2 mL, interquartile range (IQR): 4.2-11.7, relative risk 7.9, p = 0.024 in multivariate analysis); their clinical outcome was poorer in univariate analysis (75%, 21/28patients with a3months modified Rankin scale of 0-2 vs. 33%,4/12, p < 0.017, odds ratio (OR) 6.0, 1.37-26.20) but it did not remain significant in multivariate analysis (p = 0.107). Good collaterals on initial CTP assessed by an HIR < 0.3 are associated with less infarct growth after successful recanalization of AIS caused by aDMVO.

Contrast-induced neurotoxicity presented as transient cortical blindness after stent-assisted coiling of a medium-sized unruptured basilar artery aneurysm: A case report and review of the literature

Background: Contrast-induced neurotoxicity is a rare event after endovascular diagnostic procedures or interventions and presents as transient neurological deficit. Herewith, we present a case of reversible complete cortical blindness after uneventful stent-assisted coiling of a medium-sized unruptured basilar artery aneurysm.Case Description: A 70-year-old woman with a medium-sized 10 mm/6 mm wide neck basilar tip aneurysm was planned for endovascular obliteration of the lesion. The procedure was done under general anesthesia. The contrast agent was iso-osmolar, nonionic. The aneurysm was coiled, and a stent was placed in the left posterior cerebral artery achieving sufficient aneurysm packing. No signs of vessel obliteration were observed during the procedure. On awakening of anesthesia, the patient reported complete visual loss. Ophthalmological examination was normal. The patient was brought back to the angio-suite but there were no signs of parent vessel compromise from the endovascular implants or distal vessel occlusion. An MRI of the brain was done showing no signs of brain ischemia, just mild brain edema in both occipital lobes. Given the results of the radiological studies and clinical presentation, the diagnosis of contrast-induced neurotoxicity was accepted. In 72 h, the patient had complete resolution of the visual loss and was discharged home with no additional neurological worsening.Conclusion: Contrast-induced neurotoxicity is a rare event that can occur after uneventful endovascular interventions of the brain vessels. Knowledge of this rare complication, after exclusion of all other possible reversible causes, is important for the treatment and prognosis of the patient.

Abstract TP102: Hypoperfusion Intensity Ratio Predicts Infarct Growth After Successful Thrombectomy For Distal Medium Vessel Occlusions

Background and Purpose: We evaluated whether quantitative measurement of collaterals by the hypoperfusion-intensity-ratio (HIR) on baseline computed-tomography-perfusion (CTP) was correlated with infarct growth after successful endovascular recanalization of acute ischemic stroke (AIS) with primary distal, medium vessel occlusions (DMVO), as well as clinical outcome. Methods: We performed a retrospective analysis of consecutive AIS patients who underwent an initial CTP and were successfully recanalized by thrombectomy for DMVO. We evaluated the association of baseline HIR with infarct growth and clinical outcome. Results: Between January 2018 and January 2021, 40 patients suffering from an AIS with DMVO were successfully recanalized by MT (65% [26/40] female, median age 72 [65-83] years). Baseline HIR was strongly correlated with Infarct growth after successful recanalization (r=0.501, p=0.001). ROC analysis determined that a HIR&lt;0.306 was an optimal threshold, it was associated with lower infarct growth compared to HIR≥0.306 (respectively 7.2 mL [IQR: 4.2-11.7] vs. 23.8 mL [IQR: 9.1-45.1], relative-risk of 0.38 [0.08-0.68], p = 0.015); as-well-as higher rates of good clinical outcome (75% [21/28] vs. 33% [4/12], p &lt; 0.017, Odds ratio 6.0 [1.37-26.20]). Conclusion: Good collaterals on initial CTP assessed by an HIR&lt;0.306 may be associated with less infarct growth and better clinical outcomes after MT recanalization for AIS with DMVO.

Abstract WMP63: Artificial Intelligence Assessment Of Non-contrast Ct Increases Intracranial Occlusion Detection As Compared With Ct-angiograhy Readings

Artificial Intelligence (AI) can assist in vessel occlusion (VO) identification in acute stroke patients. We aim to investigate the impact of using an AI-based software for automated VO detection on non-contrast CT (AI-VO) as compared to CT-Aangiograpphy (CTA). Methods: From April to October 2020 all patients admitted with a suspected acute ischemic stroke underwent urgent non-contrast CT / CTA / CTP and were treated accordingly. Hypoperfusion areas defined as Tmax&gt;6s on CTP (RAPID software), congruent with the clinical symptoms and a vascular territory, were considered VO (CTP-VO: ground truth). In addition, two experienced neuroradiologists blinded to CTP but not to clinical symptoms retrospectively evaluated CT and CTA to identify intracranial VO (CTA-VO). AI-VO was automatically determined by an AI-based software (Methinks). Results: Of the 338 patients included, 157 (46.5%) showed a CTP-VO (median Tmax&gt;6s: 73[29-127]ml). Overall sensitivity to detect CTP-VO was 50.3% for CTA-VO and 66.9% for AI-VO; specificity was 97.8% for CTA-VO and 86.2% for AI-VO. EVT was performed in 103 patients (EVT-VO: 65.6% of CTP-VO; Tmax&gt;6s: 102[63-160]ml); sensitivity to detect EVT-VO was 69% for CTA-VO and 79.6% for AI-VO; specificity was 95.3% for CTA-VO and 79.6% for AI-VO. The probability to detect a CTP-VO was higher with AI than with CTA for distal occlusions (figure). Accordingly, AI-VO sensitivity was higher than CTA-VO for angiographically confirmed M2/M3-MCA occlusions (80.7% vs 34.6%; p=0.002) but not for M1-MCA/ICA occlusions (82.1% Vs 88.1%;p=0.467). Conclusion: AI-assisted vessel occlusion identification on non-contrast CT may be a useful tool in acute stroke evaluation, especially for distal VO identification, potentially increasing endovascular treatment in these cases.

Predictors of Good Clinical Outcome after Thrombectomy for Distal Medium Vessel Occlusions

Good clinical outcome predictors have been emphasized in mechanical thrombectomy (MT) for acute ischemic stroke (AIS) with large vessel occlusion. MT for distal, medium vessel occlusions (DMVO) is still debated. We sought to assess the factors associated with clinical outcome after MT for DMVO. We retrospectively analyzed the data of consecutive patients who underwent MT for a primary DMVO in 1 large academic center and aimed to identify the baseline clinical, imaging, and MT factors associated with good clinical outcome (defined as modified Rankin scale score of 0-2) at 3 months. Between January 2018 and January 2021, 61 patients underwent a MT for an AIS with a primary DMVO. Overall, good clinical outcome was achieved in 56% (34 of 61) of our patients. In multivariate analysis, an older age (odds ratio [OR] 0.89 [95% confidence interval 0.83-0.96], P= 0.003), longer puncture to recanalization time (OR 0.97 [0.93-0.99], P= 0.033), and higher baseline core volume (OR 0.84 [0.75-0.94], P= 0.003) decreased the probability of good clinical outcomes, while a final complete (or near-) recanalization (modified Thrombolysis In Cerebral Infarction [mTICI] score 2c-3) increased the probability of good outcome (OR 14.19 [1.99-101.4], P= 0.008). An older age, a longer puncture to recanalization time, and a higher baseline core volume decreased the probability of good clinical outcomes, while successful recanalization (mTICI 2c-3) was associated with better outcomes after MT for DMVO.

Endovascular Thrombectomy for Distal Medium Vessel Occlusions of the Middle Cerebral Artery: A Safe and Effective Procedure

Distal medium vessel occlusions (DMVOs) are increasingly recognized as a next target for endovascular thrombectomy (EVT). Our objective was to investigate safety and clinical outcomes of EVT for DMVO of the middle cerebral artery (MCA). We analyzed data of the Lille Reperfusion Registry from January 2017 to September 2020. Patients with a primary or secondary DMVO of the MCA seen on pretreatment angiogram were included. Only patients with a eTICI score 2b50-2b67 on initial angiogram were considered. Baseline characteristics, angiographic clinical, and safety outcomes were compared between patientstreated with EVT or standard medical treatment (no-EVT). Of the 171 patients included, 96 received EVT (46.9% male, 68.7 ± 15.8 years) and 75 received standard medical treatment (44% male, 73.9 ± 13.1 years). EVT patientshad a better improvement of the NIHSS score atdischarge (adjusted mean difference: 3.71; 95% CI: 1.18-6.24). In the distal M2 occlusions subgroup, EVT was significantly associated with a higher rate of early neurologic improvement (adjusted OR: 3.62 95% CI: 1.31-10.03), NIHSS improvement at discharge (adjusted mean difference: 5.23; 95% CI: 2.18-8.29), and improved modified Rankin Scale score at 3 months (adjusted common OR for 1 point improvement: 3.06; 95% CI: 1.30 to 7.23). Symptomatic intracranial hemorrhage occurred in 3.1% in the EVT group and in 9.5% in the no-EVT group. EVT for DMVO of the MCA appears to be safe and may lead to improved clinical outcomes. This effect was especially pronounced in patients with distal M2 occlusions, warranting randomized trials to validate this result.

Advances in Stroke: Treatments-Interventional.

Advances in Stroke: Treatments-Interventional.

Persistent challenges in endovascular treatment decision-making for acute ischaemic stroke.

Although endovascular treatment (EVT) is the gold standard for treating acute stroke patients with large vessel occlusion (LVO), multiple challenges in decision-making for specific conditions persist. Recent evidence on a selection of patient subgroups will be discussed in this narrative review. Two randomized controlled trials (RCTs) have been published in EVT of basilar artery occlusion (BAO). Large single arm studies showed promising results in Patients with low Alberta stroke program early CT score (ASPECTS) and more distal vessel occlusions. Recent data confirm patients with low National Institutes of Health Stroke Scale (NIHSS) despite LVO to represent a heterogeneous and challenging patient group. The current evidence does not justify withholding EVT from BAO patients as none of the RCTs showed any signal of superiority of BMT alone vs. EVT. Patients with low ASPECTS, more distal vessel occlusions and patients with low NIHSS scores should be included into RCTs if possible. Without participation in a RCT, patients should be selected for EVT based on age, severity and type of neurological impairment, time since symptom onset, location of the ischaemic lesion and perhaps also results of advanced imaging.

Abstract 1122‐000084: Does Intravenous Thrombolysis Promote Delayed Reperfusion After Incomplete Mechanical Thrombectomy?

Introduction : The value of intravenous thrombolysis (IVT) in patients eligible for mechanical thrombectomy (MT) remains unclear. We hypothesized that pre‐treatment with and/or ongoing IVT may facilitate reperfusion of distal vessel occlusion after incomplete MT. We evaluated this potential association using follow‐up perfusion imaging. Methods : Retrospective observational analysis of our institution`s stroke registry included patients with incomplete reperfusion after MT, admitted between February 1, 2015 and December 8, 2020. Delayed reperfusion (DR) was defined as the absence of a persistent perfusion deficit on contrast‐enhanced perfusion imaging ⁓24h±12h after the intervention. The association between baseline parameters and the occurrence of DR was evaluated using a logistic regression analyses. To account for possible time‐dependent associations of IVT with DR, additional stratification sets were made based on different time windows between IVT start time and final angiography runs. Results : Among the 378 included patients (median age 73.5, 50.8% female), DR occurred in 226 (59.8%). Atrial fibrillation (aOR 2.53 [95% CI 1.34 ‐ 4.90]), eTICI score (aOR 3.79 [95% CI 2.71 ‐ 5.48] per TICI grade increase), and intervention‐to‐follow‐up time (aOR 1.08 [95% CI 1.04 ‐ 1.13] per hour delay) were associated with DR. Dichotomized IVT strata showed no association with DR (aOR 0.75 [95% CI 0.42 ‐ 1.33]), whereas shorter intervals between IVT start and end of the procedure showed a borderline significant association with DR (OR 2.24 [95% CI 0.98 ‐ 5.43, and OR 2.07 [95% 1.06 – 4.31], for 80 and 100 minutes respectively). Patients with DR had higher rates of functional independence (modified Rankin scale 0–2 at 90 days, DR: 63.3% vs PPD: 38.8%; p&lt;0.01) and longer survival time (at 3 years, DR: 69.2% vs PPD: 45.8%; p = 0.001). Conclusions : There is weak evidence that IVT may favor DR after incomplete MT if the time interval between IVT administration and end of the procedure is short. In general, perfusion follow‐up imaging may constitute a suitable surrogate parameter for evaluating medical rescue strategies after incomplete MT, because a considerable proportion of patients do not experience DR, and there seems to be a close correlation with clinical outcomes.

Abstract 1122‐000157: Safety and Effectiveness of MT for Primary Isolated Distal Vessel Occlusions: A Retrospective Comparative Study

This meeting abstract was removed due to the OA licensing requirements of this journal. The full abstract is listed here : https://www.svin.org/files/SVIN_2021_Abstracts_for_Web.pdf

Distribution of Diagnoses and Clinical and Imaging Characteristics in 1,322 Consecutive Suspected Stroke Patients.

Background: Endovascular thrombectomy (EVT) has become the standard of care for large-vessel occlusion strokes, but several barriers for implementing an optimal organization of stroke management remain. Major issues include the lack of reliable data on the percentage of stroke patients potentially eligible for EVT especially in times of expanding indications for EVT. Our aim was therefore to study the frequencies of possible EVT-eligible patients such as patients with medium-vessel occlusions, patients with low Alberta Stroke Program Early Computed Tomography Scores (ASPECTS), patients presenting in an extended time window after onset of symptoms, and patients with mild symptoms at presentation (National Institutes of Health Stroke Scale, NIHSS ≤ 5). We also give detailed imaging and clinical information about the patients presenting with intracranial hemorrhage and other ischemic stroke mimics stratified by symptoms at presentation.Methods: Cohort study of all consecutive patients with suspected acute stroke presenting to a tertiary care center in Germany between September 1, 2016, and August 31, 2017. Baseline and follow-up clinical and imaging characteristics were collected from patients' medical charts.Results: Of 1,322 patients with a suspected acute stroke, 592 (44.8%) had ischemic strokes, 221 (16.7%) had hemorrhagic strokes, 190 (10.9%) had transient ischemic attacks (TIAs), and 319 (24.1%) were classified as stroke mimics. Stroke severity was mild (NIHSS ≤ 5) in 866 (65.5%) patients; 15.7% of the patients with an occlusion of the anterior circulation had an ASPECTS ≤ 5, 17.4% of the patients with an ischemic stroke had distal vessel occlusions, and 49% of the patients presented later than 6 h after onset of symptoms.Conclusion: Our results help to plan resources in thrombectomy-capable centers in times of expanding indications for EVT where resources will have to be adjusted to patients with low-NIHSS, low-ASPECTS, and distal occlusions, and patients presenting in the extended time window, which may altogether account for an additional 20% of all ischemic stroke patients.

The Tigertriever 13 for mechanical thrombectomy in distal and medium intracranial vessel occlusions.

To report our two-center initial experience using the Tigertriever 13 in the treatment of acute stroke of distal, medium vessel occlusions (DMVO). We performed a retrospective analysis of all patients treated by mechanical thrombectomy using the Tigertriever 13 device (a manually expandable low profile stent retriever) due to an acute DMVO. Locations included the anterior, middle, and posterior cerebral artery in the A2 and A3, the M3 and M4, and the P2 or P3 segment and the superior cerebellar artery. Forty-three patients with 45 DMVOs underwent MTE using the Tigertriever 13 with the intention-to-treat approach between May 2019 and December 2020. After a median of two thrombectomy maneuvers, the successful recanalization rate (mTICI 2b-3) was 84.4% (38/45) with a first pass effect of 26.7% (12/45). The rate of symptomatic intracranial hemorrhages (sICH) and subarachnoid hemorrhages (SAH) was 7.0% (3/43) and 14.0% (6/43), respectively. At discharge, 53.5% (23/43) of the patients had a favorable clinical outcome (mRS 0-2). Mechanical thrombectomy in DMVOs using the Tigertriever 13 leads to high recanalization rates. The incidence of mostly asymptomatic hemorrhagic events appears higher compared to MTE procedures in LVOs. Further studies will help to identify anatomic and clinical criteria to define a guideline for MTE in DMVOs.

Thrombectomy for distal medium vessel occlusion with a new generation of Stentretriever (Tigertriever 13).

PurposeTo evaluate the safety and efficacy of the Tigertriever 13 (Rapid Medical, Yoqneam, Israel) stent retriever in acute ischemic stroke (AIS) patients with primary or secondary distal, medium vessel occlusions (DMVO).MethodsWe performed a retrospective analysis of all consecutive AIS patients who underwent thrombectomy with the Tigertriever13 for DMVO. Patients’ characteristics were reviewed, procedural complications, angiographic (modified thrombolysis in cerebral infarction score [mTICI]) and clinical (modified Rankin Scale [mRS]) outcomes were documented.ResultsBetween November 2019 and November 2020, 16 patients with 17 DMVO were included (40% female, median age 60 [50–65] years). The Tigertriever13 was used in 11/17 (65%, median NIHSS of 8 [6–15]) primary DMVO and in 6/17 (35%, median NIHSS of 20 [13–24]) cases of secondary DMVO after a proximal thrombectomy. The successful reperfusion rate (mTICI 2b, 2c, 3) was 94% (16/17) for the dedicated vessel. At day 1, CT imaging showed a subarachnoid hemorrhage in 29% of the cases and a parenchymal hematoma in 12%. At 3 months, 65% of the patients (11/17) had a favorable outcome (mRS 0–2).ConclusionMechanical thrombectomy using the Tigertriever13 appears to be safe and effective for DMVO. Clinical and anatomical results are in line with those of patients with proximal occlusions.

Evidence-Based Updates to Thrombectomy: Targets, New Techniques, and Devices.

Endovascular thrombectomy (EVT) has been validated in several randomized controlled trials in recent years for its efficacy in the treatment of acute ischemic strokes (AIS) and is now the standard of care according to international guidelines. However, in about 20% of EVT procedures, recanalization is not achieved, and over 50% of patients who undergo EVT still do not have good functional outcome. In this article, we provide an extensive review of the latest evidence and developments in the field of EVT, with particular focus on the factors that improve patient outcomes. These factors include new and adjunctive techniques such as combination of direct aspiration and stent retriever, intra-arterial urokinase or 2b/3a inhibitors, rescue stenting, as well as novel devices including balloon guide catheters and the newer generations of aspiration catheters and stent retrievers. We also examined the latest notion of using first-pass effect (FPE) as the target to achieve during EVT, which has been associated with an improved functional outcome. While the field of EVT has been rapidly evolving, further research is required in specific AIS patient populations such as those with large ischemic core, late presentation beyond 24 h, posterior circulation strokes, and with distal medium vessel occlusion or tandem lesions to better assess its efficacy and safety.

Distinct intra‐arterial clot localization affects tissue‐level collaterals and venous outflow profiles

Arterial clot localization affects collateral flow to ischemic brain in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). We determined the association between vessel occlusion locations, tissue-level collaterals (TLC), and venous outflow (VO) profiles and their impact on good functional outcomes. We conducted a multicenter retrospective cohort study of consecutive AIS-LVO patients who underwent thrombectomy triage. Baseline computed tomographic angiography (CTA) was used to localize vessel occlusion, which was dichotomized into proximal vessel occlusion (PVO; internal carotid artery and proximal first segment of the middle cerebral artery [M1]) and distal vessel occlusion (DVO; distal M1 and M2), and to assess collateral scores. TLC were assessed on computed tomographic perfusion data using the hypoperfusion intensity ratio. VO was determined on baseline CTA by the cortical vein opacification score. Primary outcomes were favorable VO and TLC; secondary outcome was the modified Rankin Scale after 90days. A total of 649 patients met inclusion criteria. Of these, 376 patients (58%) had a PVO and 273 patients (42%) had a DVO. Multivariate ordinal logistic regression showed that DVO predicted favorable TLC (odds ratio [OR] = 1.77, 95% confidence interval [CI] = 1.24-2.52, p = 0.002) and favorable VO (OR = 7.2, 95% CI = 5.2-11.9, p < 0.001). DVO (OR = 3.4, 95% CI = 2.1-5.6, p < 0.001), favorable VO (OR = 6.4, 95% CI = 3.8-10.6, p < 0.001), and favorable TLC (OR = 3.2, 95% CI = 2-5.3, p < 0.001), but not CTA collaterals (OR = 1.07, 95% CI = 0.60-1.91, p = 0.813), were predictors of good functional outcome. DVO in AIS-LVO patients correlates with favorable TLC and VO profiles, which are associated with good functional outcome.

Distal Cerebral Vessel Occlusions and Mechanical Thrombectomy: Straightforward Questions, Generating Evidence, and Gearing Toward Submillimetric Vessels

Distal Cerebral Vessel Occlusions and Mechanical Thrombectomy: Straightforward Questions, Generating Evidence, and Gearing Toward Submillimetric Vessels