Thrombectomy For Acute Stroke Research Articles

Abstract TMP68: Core/perfusion Mismatch In Acute Ischemic Stroke With M2 Occlusion: Prevalence And Associated Factors.

Background: The benefit of mechanical thrombectomy (MT) in acute ischemic stroke (AIS) patients with M2 occlusion is uncertain. Observational studies suggest that perfusion imaging may help select optimal M2 candidates for MT. We aimed to study the prevalence and factors associated with core/perfusion mismatch, as assessed by both CT and MRI, in an unselected population of AIS with M2 occlusion. Methods: Retrospective observational study including AIS patients with M2 occlusion and baseline perfusion imaging (MRI or CT) performed within 24hrs from last seen well. To avoid selection bias, patients were selected from the prospective registries of 3 centers with systematic use of perfusion imaging, including both MT-treated and untreated patients. Core/perfusion mismatch was defined as mismatch ratio (Tmax>6s/ core volume) >1.8 and mismatch volume (Tmax>6s - core volume) >15mL. Results: Overall, 156 and 196 patients were included in the MRI and CT cohorts, respectively. Last-seen-well to imaging time was 5.6hrs (IQR 3.9-9.7) and 3.5hrs (1.5-9.8) in the MRI and CT cohorts, and 103/156 (66%) and 134/196 (68%) had proximal M2 occlusions (the remainder had distal M2 occlusions). Median ASPECT score was 7 (5-8) and 8 (7-9), and core/perfusion mismatch was present in 70/156 (45%) and 167/196 (85%) patients. In both cohorts, mismatch was less frequent in distal M2 occlusions and among patients with lower ASPECTS (Figure). Multivariable analysis showed higher ASPECT scores (OR=3.09, 95%CI=2.11-4.52, P <0.001 and OR=2.41, 95%CI 1.63-3.58, P <0.001 in the MRI and CT cohorts) and proximal M2 occlusion (with distal M2 as a reference: OR=3.94, 95%CI=1.68-9.26, P =0.002 and OR=32.78, 95%CI 8.36-128.47, P <0.001 in the MRI and CT cohorts) were independently associated with core/perfusion mismatch. Conclusion: Perfusion imaging may be useful in triaging M2 patients, particularly for those with ASPECT score <8 and distal M2 occlusions. This has implication for trials.

Abstract TMP87: A Novel Approach For Automated First Pass Effect Prediction On Computed Tomographic Angiography In Acute Ischemic Stroke Patients

Background and Purpose: First pass effect (FPE), or effective reperfusion with a single pass of endovascular thrombectomy (EVT) for acute ischemic stroke (AIS), is strongly associated with good functional outcome (mRS≤2) and can aid in optimal device selection for EVT. We aim to investigate the arterial tortuosity from great vessel origin to the intracranial occlusion location and predict first pass effect, automatically by a novel neural network, on computed tomographic angiography (CTA). Materials and Methods: Patients with thin-slice (≤2.5 mm) neck CTA from the ESCAPE-NA1 trial (Efficacy and safety of nerinetide for the treatment of AIS) were included. Arterial centerlines from the aortic arch to the intracranial occlusion site were manually traced by three experienced readers on CTA. The centerlines were modeled and organized by tortuosity. A model based on graph neural network (GNN) was proposed to predict FPE on the processed data. Model performance was compared to manual annotations and traditional classification algorithms using diagnostic statistics. Results: 539 patients were included, with a 429/110 training/testing-ratio. FPE was observed in 136(31.7%, training set) and 35 (31.8%, testing set). The suggested model showed an overall good performance with an area under the receiver operating characteristic curve (AUC-ROC) of 0.66 (95% CI=0.65-0.67), precision of 0.46(17/37), sensitivity of 0.71(17/35), specificity of 0.61(55/75) and accuracy of 0.65(72/110), whereas the manually annotated features with traditional classification methods had an AUC-ROC of 0.54 (95%CI=0.53, 0.55), precision of 0.42(8/19), sensitivity of 0.23(8/35), specificity of 0.85(64/75) and accuracy of 0.65(72/110). Conclusion: An automated model for FPE prediction on CTA had better performance and higher sensitivity as compared to manual annotations and traditional machine learning algorithms, suggesting that it could be used in routine clinical practice prior to EVT.

Abstract TP15: Rationale And Ongoing Status In A Phase 3 Trial Of Nelonemdaz, A Novel Neuroprotection Drug, For Patients With Acute Ischemic Stroke And Reperfusion

Background: A phase III Rescue On reperfusion Damage in cerebral Infarction by Nelonemdaz (RODIN) trial has been launched since December, 2021 and patients are being enrolled. Rationale: Nelonemdaz (previously, neu2000) targets (1) selectively the 2B subunit of the N-methyl-D-aspartate glutamate receptor, the activation of which causes Na+ and Ca++ influx into neuronal cells and then induces downstream death-signaling pathways, and (2) free radical species, which are released both from the downstream pathways of glutamate receptors and from following reperfusion injury. Phase I and II trials showed its safety and a tendency of clinical outcome improvements. Methods: RODIN is a multicenter, double-blinded clinical trial. A total of 496 patients will be randomly assigned into nelonemdaz and placebo groups. Patients will be included if they have an acute ischemic stroke (National Institutes of Health Stroke Scale score ≥8 scores) caused by intracranial large vessel occlusion in the anterior circulation (Alberta Stroke Program Early CT Score ≥4), and they are expected to undergo endovascular thrombectomy within 12 hours after stroke onset. The primary endpoint is a favorable shift in the modified Rankin Scale (mRS) score at 90 days after the first dose of drug, analyzed by the Cochran-Mantel-Haenszel shift test. Ongoing status: By August 23, 2022, 210 patients have been enrolled. It is expected that enrollment could be finalized until spring season of 2023. Conclusions: This trial will clarify the efficacy and safety of nelonemdaz in patients with acute ischemic stroke and endovascular thrombectomy. This study was registered in ClinicalTrials.gov, number NCT05041010.

The Rescue on Reperfusion Damage in Cerebral Infarction by Nelonemdaz (RODIN) Trial: Protocol for a Double-Blinded Clinical Trial of Nelonemdaz in Patients with Hyperacute Ischemic Stroke and Endovascular Thrombectomy.

Nelonemdaz (Neu2000) has both selective antagonism against 2B subunit of N-methyl-D-aspartate receptor and antioxidant activity. This drug provides sufficient evidence of neuroprotection in acute cerebral ischemia/reperfusion models. This phase III trial aims to determine this effect in patients. The Rescue on Reperfusion Damage in Cerebral Infarction by Nelonemdaz is a multicenter, double-blinded clinical trial. A total of 496 patients will be randomly assigned into the nelonemdaz (a total of 5,250 mg divided by 10 times for 5 days) and placebo groups. Patients will be included if they have an acute ischemic stroke (National Institutes of Health Stroke Scale score ≥8) caused by intracranial large vessel occlusion in the anterior circulation (Alberta Stroke Program Early CT Score ≥4), and if they are expected to undergo endovascular thrombectomy within 12 hours after stroke onset. The primary endpoint is a favorable shift in the modified Rankin Scale (mRS) score at 90 days after the first dose of drug. The data will be analyzed by the Cochran-Mantel-Haenszel shift test. The secondary endpoints include functional independence (mRS 0-2) at 35 and 90 days, the favorable shift of mRS at 35 days, the proportion of mRS 0 at 35 and 90 days, and the occurrence rates of symptomatic intracranial hemorrhage within 7 days. This trial will clarify the efficacy and safety of nelonemdaz in patients with acute ischemic stroke and endovascular thrombectomy. This study has been registered at ClinicalTrials. gov (NCT05041010).

Correlation between Thrombus Perviousness and Distal Embolization during Mechanical Thrombectomy in Acute Stroke.

Thrombus permeability has been related to clot composition and treatment outcomes in stroke patients undergoing reperfusion therapies. The aim of this study was to evaluate whether thrombus perviousness, evaluated by multiphase computed tomography angiography (mCTA), is associated with distal embolization risk. We interrogated our dataset of acute ischemic stroke (AIS) patients involving the M1 segment of the middle cerebral artery (MCA) who had undergone mechanical thrombectomy, and we calculated thrombus average attenuation measurement (dHU) on non-contrast CT (NCCT) and clot perviousness on mCTA. dHU was calculated as the difference between the thrombus HU average value (tHU) and the HU average value on the contralateral side (cHU), while perviousness was calculated as the difference in mean clot density on mCTA and NCCT both in arterial (Perviousness pre-post-1) and delayed (Perviousness pre-post 2) phases. A total of 100 patients (53 females (53%), mean age 72.74 [± 2.31]) with M1 occlusion were available for analysis. Perviousness, calculated between baseline and arterial phase of mCTA (Perviousness pre-post1), was lower in patients with distal embolization (p = 0.05), revealing an association between reduced perviousness and distal embolization risk. Logistic regression showed that thrombus perviousness calculated on the arterial phase of mCTA (OR, 0.66; 95% CI, 0.44-0.99] (p = 0.04)) and the contact aspiration technique (OR, 0.39; 95% CI, 0.15-1.02] (p = 0.05)) were protecting factors against distal embolization. Our study showed an association between reduced perviousness and distal embolization, suggesting that perviousness evaluation may be a useful neuroimaging biomarker in predicting distal embolization risk during mechanical thrombectomy.

Association between thrombus composition and stroke etiology in the MR CLEAN Registry biobank

PurposeThe composition of thrombi retrieved during endovascular thrombectomy (EVT) in acute ischemic stroke (AIS) due to large vessel occlusion (LVO) may differ depending on their origin. In this study, we investigated the association between thrombus composition and stroke etiology in a large population of patients from the Dutch MR CLEAN Registry treated with EVT in daily clinical practice.MethodsThe thrombi of 332 patients with AIS were histologically analyzed for red blood cells (RBC), fibrin/platelets (F/P), and white blood cells (leukocytes) using a machine learning algorithm. Stroke etiology was assessed using the Trial of Org 10,172 in acute stroke treatment (TOAST) classification.ResultsThe thrombi of cardioembolic origin contained less RBC and more F/P than those of non-cardioembolic origin (25.8% vs 41.2% RBC [p = 0.003] and 67.1% vs 54.5% F/P [p = 0.004]). The likelihood of a non-cardioembolic source of stroke increased with increasing thrombus RBC content (OR 1.02; [95% CI 1.00–1.06] for each percent increase) and decreased with a higher F/P content (OR 1.02; [95% CI 1.00–1.06]). Thrombus composition in patients with a cardioembolic origin and undetermined origin was similar.ConclusionThrombus composition is significantly associated with stroke etiology, with an increase in RBC and a decrease in F/P raising the odds for a non-cardioembolic cause. No difference between composition of cardioembolic thrombi and of undetermined origin was seen. This emphasizes the need for more extensive monitoring for arrhythmias and/or extended cardiac analysis in case of an undetermined origin.

Direct Mechanical Thrombectomy Versus Prior Bridging Intravenous Thrombolysis in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis.

The current guideline recommends using an intravenous tissue-type plasminogen activator (IV tPA) prior to mechanical thrombectomy (MT) in eligible acute ischemic stroke (AIS) with emergent large vessel occlusion (ELVO). Some recent studies found no significant differences in the long-term functional outcomes between bridging therapy (BT, i.e., IV tPA prior to MT) and direct MT (dMT). We conducted a systematic review and meta-analysis to compare the safety and functional outcomes between BT and dMT in AIS patients with ELVO who were eligible for IV tPA administration. Based on the ELVO location, patients were categorized as the anterior group (occlusion of the anterior circulation), or the combined group (occlusion of the anterior and/or posterior circulation). A subgroup analysis was performed based on the study type, i.e., RCT and non-RCT. Thirteen studies (3985 patients) matched the eligibility criteria. Comparing the BT and dMT groups, no significant differences in terms of mortality and good functional outcome were observed at 90 days. Symptomatic intracranial hemorrhagic (sICH) events were more frequent in BT patients in the combined group (OR = 0.73, p = 0.02); this result remained significant only in the non-RCT subgroup (OR = 0.67, p = 0.03). The RCT subgroup had a significantly higher rate of successful revascularization in BT patients (OR = 0.73, p = 0.02). Our meta-analysis uncovered no significant differences in functional outcome and mortality rate at 90 days between dMT and BT in patients with AIS who had ELVO. Although BT performed better in terms of successful recanalization rate, there is a risk of increased sICH rate in this group.

Factors related to white thrombi in acute ischemic stroke in cancer patients.

Thrombi in cerebral large vessel occlusion associated with active cancer are often fibrin and platelet-rich white thrombi. However, evaluating the thrombus composition in a short time before thrombectomy is often ineffective. We sought to determine factors related to white thrombi in acute ischemic stroke due to large vessel occlusion in cancer patients. Consecutive cancer patients undergoing thrombectomy for acute ischemic stroke due to large vessel occlusion between January 2018 and May 2022 were retrospectively reviewed. The patients were classified into white thrombus and red thrombus groups on the basis of the pathological findings of retrieved thrombi. Patient characteristics and laboratory findings were compared between the two groups. There were 12 patients in the white thrombus group and 11 patients in the red thrombus group. Active cancer was significantly more in the white thrombus group than in the red thrombus group (91.7% vs. 36.3%, p = 0.0094). Internal carotid artery occlusion was significantly less in the white thrombus group than in the red thrombus group (0% vs. 36.4%, p = 0.037). Among laboratory findings, D-dimer levels were an independent factor associated with white thrombi (odds ratio 8.97 [95% confidence interval 1.71-368.99], p < 0.0001). The cutoff value of D-dimer levels for predicting white thrombi was 3.5μg/mL (83.3% sensitivity and 100% specificity). In acute ischemic stroke in cancer patients, active cancer, no internal carotid artery occlusion, and higher D-dimer levels (≥3.5μg/mL) may be associated with occlusion with fibrin and platelet-rich white thrombi.

Outcomes of Patients With Atrial Fibrillation Following Thrombectomy for Stroke

Patients with atrial fibrillation (AF) treated with mechanical thrombectomy (MT) for acute ischemic stroke (AIS) have been reported to experience worse outcomes compared with patients without AF. To assess differences between patients with AF and their counterparts without AF treated with MT for AIS, focusing on safety outcomes, clinical outcomes, and baseline characteristics in both groups. A systematic literature review of the English language literature from inception to July 14, 2022, was conducted using Web of Science, Embase, Scopus, and PubMed databases. Studies that focused on patients with and without AF treated with MT for AIS were included. Multiple reviewers screened studies to identify studies included in analysis. Data were extracted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline to ensure accuracy. Data were pooled using a random-effects model. The primary outcome of interest was rate of modified Rankin Scale (mRS) scores of 0 to 2 at 90 days. Secondary outcomes of interest included rates of successful reperfusion, defined as thrombolysis in cerebral infarction (TICI) scores of 2b to 3, 90-day mortality, symptomatic intracranial hemorrhage (SICH), and baseline patient characteristics. Of 1696 initially retrieved studies, 10 studies were included, with 6543 patients. Patients with AF were a mean of 10.17 (95% CI, 8.11-12.23) years older (P < .001) and had higher rates of hypertension (OR, 1.89 [95% CI, 1.57-2.27]; P < .001) and diabetes (OR, 1.16 [95% CI, 1.02-1.31]; P = .02). Overall, there were comparable rates of mRS scores of 0 to 2 between patients with AF and patients without AF (odds ratio [OR], 0.72 [95% CI, 0.47-1.10]; P = .13), with significant heterogeneity among the included studies. After sensitivity analysis, the rate of mRS scores of 0 to 2 was significantly lower among patients with AF (OR, 0.65 [95% CI, 0.52-0.81]; P < .001). Successful reperfusion rates were similar between the groups (OR, 1.11 [95% CI, 0.78-1.58]; P = .57). The rate of SICH was similar between groups (OR, 1.05 [95% CI, 0.84-1.31]; P = .68). Mortality was significantly higher in the AF group (OR, 1.47 [95% CI, 1.12-1.92]; P = .005). In this systematic review and meta-analysis, patients with AF experienced worse 90-day outcomes, even in the setting of similar rates of successful reperfusion. This was likely associated with greater age and greater rates of comorbidities among patients with AF.

Emergency admission plasma D-dimer: a novel predictor for symptomatic intracranial hemorrhage after thrombectomy in acute ischemic stroke

BackgroundSymptomatic intracranial hemorrhage (sICH) is a common and severe complication in patients with acute ischemic stroke (AIS) after treatment with thrombectomy.ObjectiveTo explore the ability of admission plasma D-dimer levels to...

Mechanical Thrombectomy for Acute Ischemic Stroke in Metastatic Cancer Patients: A Nationwide Cross-Sectional Analysis.

Mechanical thrombectomy (MT) is the standard treatment for large vessel occlusion (LVO) acute ischemic stroke. Patients with active malignancy have an increased risk of stroke but were excluded from MT trials. We searched the National Readmission Database for LVO patients treated with MT between 2016-2018 and compared the characteristics and outcomes of cancer-free patients to those with metastatic cancer (MC). Primary outcomes were all-cause in-hospital mortality and favorable outcome, defined as a routine discharge to home (regardless of whether home services were provided or not). Multivariate regression was used to adjust for confounders. Of 40,537 LVO patients treated with MT, 933 (2.3%) had MC diagnosis. Compared to cancer-free patients, MC patients were similar in age and stroke severity but had greater overall disease severity. Hospital complications that occurred more frequently in MC included pneumonia, sepsis, acute coronary syndrome, deep vein thrombosis, and pulmonary embolism (P<0.001). Patients with MC had similar rates of intracerebral hemorrhage (20% vs. 21%) but were less likely to receive tissue plasminogen activator (13% vs. 23%, P<0.001). In unadjusted analysis, MC patients as compared to cancer-free patients had a higher in-hospital mortality rate and were less likely to be discharged to home (36% vs. 42%, P=0.014). On multivariate regression adjusting for confounders, mortality was the only outcome that was significantly higher in the MC group than in the cancerfree group (P<0.001). LVO patients with MC have higher mortality and more infectious and thrombotic complications than cancer-free patients. MT nonetheless can result in survival with good outcome in slightly over one-third of patients.

Analysis of risk factors for subarachnoid hemorrhage after mechanical thrombectomy in acute ischemic stroke with middle cerebral artery occlusion.

Analysis of risk factors for subarachnoid hemorrhage after mechanical thrombectomy in acute ischemic stroke with middle cerebral artery occlusion.

Takotsubo Cardiomyopathy as an Unusual Complication after Mechanical Thrombectomy for Acute Ischemic Stroke.

Takotsubo Cardiomyopathy as an Unusual Complication after Mechanical Thrombectomy for Acute Ischemic Stroke.

Usefulness of the Preoperative Images Supporting Mechanical Thrombectomy Based on Susceptibility-Weighted Image for Stroke.

This is a report on the usefulness of 3D fusion imaging with susceptibility-weighted imaging (SWI) as preoperative imaging for mechanical thrombectomy (MT) for acute ischemic stroke (AIS). Among 17 cases of patients who underwent MT in AIS between March 2021 and April 2022, 14 patients who underwent MRI with SWI (shortened SWI for stroke) and 3D T2-weighted sampling perfection with application-optimized contrasts using different flip angle evolution were targeted in the study. Three cases with motion artifacts due to body movement were excluded from the images.After imaging, 3D fusion images were constructed to visualize thrombi and occluded vessels. SWI for stroke obtained thrombus information in 11 of the 14 cases (78.5%) and 3D images of the thrombi could be created in all 11 cases. 3D fusion images could be created in nine of the 14 cases (64.2%). 3D fusion images, using SWI for stroke, can visualize thrombi and occluded vessels and may be effectively used as preoperative images for MT.

Mechanical thrombectomy in acute ischemic stroke: Experiences of the Upper-Silesian Medical Center in Katowice based on the treatment of the first 500 patients.

Mechanical thrombectomy in acute ischemic stroke: Experiences of the Upper-Silesian Medical Center in Katowice based on the treatment of the first 500 patients.

Age should not be a contraindication for mechanical thrombectomy in Acute Ischemic Stroke.

Age should not be a contraindication for mechanical thrombectomy in Acute Ischemic Stroke.

Factors relating to good outcomes after mechanical thrombectomy for acute anterior circulation ischemic stroke within 4.5 Hours from the onset

Mechanical thrombectomy (MT) has been accepted as a standard treatment worldwide for patients suffering from acute anterior large vessel occlusion (AC-LVO) who can start early MT within 6 hours. However, in Vietnam, there remains a paucity of information regarding factors that can affect outcomes following this treatment. This study aimed to assess the clinical, imaging, and procedural factors related to good outcomes after MT for patients with AC-LVO within 4.5 hours. We analyzed data from 120 patients at Bach Mai hospital who had acute ischemic stroke (AIS) due to AC-LVO and were treated with MT with and without intravenous thrombolysis (IVT) within 4.5 hours from December 2020 to September 2022. Logistic regression analysis was used to examine the associations of clinical, imaging, and procedural variables with a good outcome. Overall, successful revascularization was achieved in 102/120 cases (85.0%) and 70 patients (58.3%) had a good outcome at 90 days. Successful revascularization (OR, 1.40; 95% CI, 1.24-1.58; p&lt;0.01), initial blood glucose level (OR, 0.86; 95% CI, 0.85-0.87; p=0.046), and hemorrhagic transformation (OR, 0.83; 95% CI, 0.76-0.90; p=0.02) were independent factors associated with good outcome at 90 days.

Non-Neurological Complications after Mechanical Thrombectomy for Acute Ischemic Stroke: A Retrospective Single-Center Study.

The global burden of stroke is high and mechanical thrombectomy is the cornerstone of the treatment. Incidences of acute non-neurological-complications are poorly described. Improve knowledge about these complications may allow to better prevent, detect and/or manage them. The aim is to identify risk markers of death or poor evolution. We conducted a retrospective single-center study to analyzed the incidence of non-neurologicalcomplications after mechanical thrombectomy in acute ischemic stroke. Patients who had experienced a stroke and undergone thrombectomy were identified using a registry in which we prospectively collected data from each patient admitted to our hospital with a diagnosis of stroke. Quantitative and qualitative variables were analyses. The association between studied variables and hospital death was assessed using simple logistic regression models. 361 patients were reviewed but 16 were excluded due to a lack of medical information. Between 2012 and 2019, 345 patients were included. The median admission NIHSS score was 15. Seven percent of the patients died in the ICU. The following independent risk markers of death in the ICU were identified by logistic regression: respiratory complication, hypotension, infectious complication, and hyperglycemia. In this large retrospective study of stroke, respiratory complications and pulmonary infections represented the most important non-neurological adverse events encountered in the ICU and associated with a risk of death.

Impact of leukoaraiosis or blood pressure on clinical outcome, mortality and symptomatic intracerebral hemorrhage after mechanical thrombectomy in acute ischemic stroke

We aimed to study the impact of leukoaraiosis (LA) and blood pressure (BP) on clinical outcome, mortality and symptomatic intracerebral hemorrhage (sICH) in acute ischemic stroke (AIS) patients treated with mechanical thrombectomy (MT). We analyzed data retrospectively from 521 patients with anterior large vessel occlusion treated with MT. LA was dichotomized in 0–2 (absent-to-moderate) versus 3–4 (moderate-to-severe) according to the van Swieten scale. Various systolic (SBP) and diastolic (DBP) BP parameters during the first 24 h were collected. Multivariable logistic regressions were performed to identify predictors of a poor 90-day outcome, mortality and sICH. LA was significantly associated with poor outcome (OR 3.2; p < 0.001) and mortality (OR 3.19; p = 0.008), but not sICH (p = 0.19). Higher maximum SBP was significantly associated with poor outcome (OR per 10 mmHg increase = 1.21; p = 0.009) and lower mean DBP was a predictor of mortality (OR per 10 mmHg increase = 0.53; p < 0.001). In the univariate analysis high SBP variability was associated with poor outcome, mortality and sICH, but not in the multivariate model. There was no association between BP and sICH. Severity of LA, SBP variability, high maximum SBP and low DBP are associated with either poor outcome or mortality in AIS patients undergoing MT. However, neither LA nor BP were associated with sICH in our cohort. Thus, mechanisms of the negative impact on outcome remain unclear. Further studies on impact of BP course and its mechanisms and interventions are needed to improve outcome in patients undergoing MT.

Ischemic post-conditioning in acute ischemic stroke thrombectomy: A phase-I duration escalation study.

Previous experimental studies have found that ischemic post-conditioning exhibits neuroprotective effects by alleviating ischemia-reperfusion injury in an acute ischemic stroke model, and its efficacy is thought to be related to the duration of ischemic post-conditioning. However, ischemic post-conditioning has not been used in patients with acute ischemic stroke. This study aims to determine the safety, tolerability, and maximum tolerable duration of ischemic post-conditioning in patients with acute ischemic stroke receiving mechanical thrombectomy. Patients with acute ischemic stroke with unilateral middle cerebral artery M1 segment occlusion eligible for mechanical thrombectomy will be enrolled. We adopt a 3 + 3 dose-escalation design with a duration escalation schedule of 0, 1, 2, 3, 4, and 5 min × 4 cycles for the ischemic post-conditioning study. After successful reperfusion following mechanical thrombectomy, the balloon for ischemic post-conditioning will be inflated at the site proximal to the culprit lesion four times for 0-5 min with low-pressure (3-4 atmospheres) inflations, each separated by 0-5 min of reflow. We pre-defined the major responses (vessel perforation or rupture, reocclusion of the culprit vessel after ischemic post-conditioning, vessel dissection, severe vasospasm, ischemic post-conditioning related thrombotic events, and rupture of the balloon used for ischemic post-conditioning) as the stopping rules. Each patient will undergo a rigorous evaluation to determine the safety, tolerability, and maximum tolerable duration of ischemic post-conditioning. This will be the first clinical study to ascertain the safety and tolerability of ischemic post-conditioning in patients with acute ischemic stroke receiving mechanical thrombectomy. The maximum tolerable duration obtained in this study will also serve as a starting point for future studies on the efficacy of ischemic post-conditioning. [https://clinicaltrials.gov], identifier [NCT05153655].