In-Vitro Clot Modeling for the Preclinical Assessment of Mechanical Thrombectomy in Acute Ischemic Stroke

Author(s):  
Juyu Chueh ◽  
Christine F. Silva ◽  
Ajay K. Wakhloo ◽  
Matthew J. Gounis

Mechanical thrombectomy devices, such as retrievers or aspiration catheters, have recently received approval from the FDA for the treatment of acute ischemic stroke. There is growing interest in endovascular recanalization procedures due to mounting evidence of favorable clinical outcomes. Several attempts have been made to establish dedicated clot models for in-vitro or in-vivo simulation of thromboembolism [1,2]. However, little is known about the mechanical and structural similarities between experimental clots and human sources of emboli that cause stroke. The goal of this study is to compare the structure and compression behavior of the possible sources of the cerebral emboli extracted from patients and model clots produced in-vitro using human, porcine and bovine donors.

2021 ◽  
Vol 11 (4) ◽  
pp. 504
Author(s):  
Dalibor Sila ◽  
Markus Lenski ◽  
Maria Vojtková ◽  
Mustafa Elgharbawy ◽  
František Charvát ◽  
...  

Background: Mechanical thrombectomy is the standard therapy in patients with acute ischemic stroke (AIS). The primary aim of our study was to compare the procedural efficacy of the direct aspiration technique, using Penumbra ACETM aspiration catheter, and the stent retriever technique, with a SolitaireTM FR stent. Secondarily, we investigated treatment-dependent and treatment-independent factors that predict a good clinical outcome. Methods: We analyzed our series of mechanical thrombectomies using a SolitaireTM FR stent and a Penumbra ACETM catheter. The clinical and radiographic data of 76 patients were retrospectively reviewed. Using binary logistic regression, we looked for the predictors of a good clinical outcome. Results: In the Penumbra ACETM group we achieved significantly higher rates of complete vessel recanalization with lower device passage counts, shorter recanalization times, shorter procedure times and shorter fluoroscopy times (p < 0.001) compared to the SolitaireTM FR group. We observed no significant difference in good clinical outcomes (52.4% vs. 56.4%, p = 0.756). Predictors of a good clinical outcome were lower initial NIHSS scores, pial arterial collateralization on admission head CT angiography scan, shorter recanalization times and device passage counts. Conclusions: The aspiration technique using Penumbra ACETM catheter is comparable to the stent retriever technique with SolitaireTM FR regarding clinical outcomes.


Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Ameer E Hassan ◽  
Mahmoud Dibas ◽  
Amr Ehab El-Qushayri ◽  
Sherief Ghozy ◽  
Adam A Dmytriw ◽  
...  

Background: Mechanical thrombectomy (MT) has significantly improved outcomes of acute ischemic stroke (AIS) patients due to large vessel occlusion (LVO). The first-pass effect (FPE), defined as achieving complete reperfusion (mTICI3/2c) with a single pass, was reported to be associated with higher functional independence rates following EVT and has been emphasized as an important procedural target. We compared MT outcomes in patients who achieved FPE to those who did not in a real world large database. Method: A retrospective analysis of LVO pts who underwent MT from a single center prospectively collected database. Patients were stratified into those who achieved FPE and non-FPE. The primary outcome (discharge and 90 day mRS 0-2) and safety (sICH, mortality and neuro-worsening) were compared between the two groups. Results: Of 580 pts, 261 (45%) achieved FPE and 319 (55%) were non-FPE. Mean age was (70 vs 71, p=0.051) and mean initial NIHSS (16 vs 17, p=0.23) and IV tPA rates (37% bs 36%, p=0.9) were similar between the two groups. Other baseline characteristics were similar. Non-FPE pts required more stenting (15% vs 25%, p=0.003), and angioplasty (19% vs 29%, p=0.01). The FPE group had significantly more instances of discharge (33% vs 17%, p<0.001), and 90-day mRS score 0-2 (29% vs 20%, p<0.001), respectively. Additionally, the FPE group had a significant lower mean discharge NIHSS score (12 vs 17, p<0.001). FPE group had better safety outcomes with lower mortality (14.2% vs 21.6%, p=0.03), sICH (5.7% vs 13.5, p=0.004), and neurological worsening (71.3% vs 78.4%, p=0.02), compared to the non-FPE group. Conclusion: Patients with first pass complete or near complete reperfusion with MT had higher functional independence rates, reduced mortality, symptomatic hemorrhage and neurological worsening. Improvement in MT devices and techniques is vital to increase first pass effect and improve clinical outcomes.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Mona N Bahouth ◽  
Rebecca Gottesman

Introduction: Impaired hydration measured by elevated blood urea nitrogen (BUN) to creatinine ratio has been associated with worsened outcome after acute ischemic stroke. Whether hydration status is relevant for patients with acute ischemic stroke treated with mechanical thrombectomy remains unknown. Materials and Methods: We conducted a retrospective review of consecutive acute ischemic stroke patients who underwent endovascular procedures for anterior circulation large artery occlusion at Johns Hopkins Comprehensive Stroke Centers between 2012 and 2017. A volume contracted state (VCS), was determined based on surrogate lab markers and defined as blood urea nitrogen (BUN) to creatinine ratio greater than 15. Endpoints were achievement of successful revascularization (TICI 2b or 3), early re-occlusion, and short term clinical outcomes including development of early neurological worsening and functional outcome at 3 months. Results: Of the 158 patients who underwent an endovascular procedure, 102 patients had a final diagnosis of anterior circulation large vessel occlusion and met the inclusion criteria for analysis. Volume contracted state was present in 62/102 (61%) of patients. Successful revascularization was achieved in 75/102 (74%) of the cohort. There was no relationship between VCS and successful revascularization, but there was a 1.13 increased adjusted odds (95% CI 1.01, 1.27) of re-occlusion within 24 hours for every point higher BUN/creatinine ratio in the subset of patients who underwent radiological testing for pre-procedure planning (n=57). There was no relationship between VCS and clinical outcomes including early neurological worsening and 3 month outcome. Conclusions: Patients with VCS and large vessel anterior circulation stroke may have a higher odds of early re-occlusion after mechanical thrombectomy than their non-VCS counterparts, but no differences in successful revascularization nor clinical outcomes were present in this cohort. These results may suggest an opportunity for the exploration of pre-procedure hydration to improve outcomes.


2020 ◽  
Vol 12 (10) ◽  
pp. 1002-1007
Author(s):  
Sarah Johnson ◽  
Ray McCarthy ◽  
Brian Fahy ◽  
Oana Madalina Mereuta ◽  
Seán Fitzgerald ◽  
...  

​BackgroundCalcified cerebral emboli (CCEs) are a rare cause of acute ischemic stroke (AIS) and are frequently associated with poor outcomes. The presence of dense calcified material enables reliable identification of CCEs using non-contrast CT. However, recanalization rates with the available mechanical thrombectomy (MT) devices remain low.ObjectiveTo recreate a large vessel occlusion involving a CCE using an in vitro silicone model of the intracranial vessels and to demonstrate the feasability of this model to test different endovascular strategies to recanalize an occlusion of the M1 segment of the middle cerebral artery (MCA).​MethodsAn in vitro model was developed to evaluate different endovascular treatment approaches using contemporary devices in the M1 segment of the MCA. The in vitro model consisted of a CCE analog placed in a silicone neurovascular model. Development of an appropriate CCE analog was based on characterization of human calcified tissues that represent likely sources of CCEs. Feasibility of the model was demonstrated in a small number of MT devices using four common procedural techniques.​ResultsCCE analogs were developed with similar mechanical behavior to that of ex vivo calcified material. The in vitro model was evaluated with various MT techniques and devices to show feasibility of the model. In this limited evaluation, the most successful retrieval approach was performed with a stent retriever combined with local aspiration through a distal access catheter, and importantly, with flow arrest and dual aspiration using a balloon guide catheter.​ConclusionCharacterization of calcified tissues, which are likely sources of CCEs, has shown that CCEs are considerably stiffer than thrombus. This highlights the need for a different in vitro AIS model for CCEs than those used for thromboemboli. Consequentially, an in vitro AIS model representative of a CCE occlusion in the M1 segment of the MCA has been developed.


2020 ◽  
pp. neurintsurg-2020-015957 ◽  
Author(s):  
John Benson ◽  
Seyed Mohammad Seyedsaadat ◽  
Ian Mark ◽  
Deena M Nasr ◽  
Alejandro A Rabinstein ◽  
...  

BackgroundTo assess if leukoaraiosis severity is associated with outcome in patients with acute ischemic stroke (AIS) following endovascular thrombectomy, and to propose a leukoaraiosis-related modification to the ASPECTS score.MethodsA retrospective review was completed of AIS patients that underwent mechanical thrombectomy for anterior circulation large vessel occlusion. The primary outcome measure was 90-day mRS. A proposed Leukoaraiosis-ASPECTS (“L-ASPECTS”) was calculated by subtracting from the traditional ASPECT based on leukoaraiosis severity (1 point subtracted if mild, 2 if moderate, 3 if severe). L-ASEPCTS score performance was validated using a consecutive cohort of 75 AIS LVO patients.Results174 patients were included in this retrospective analysis: average age: 68.0±9.1. 28 (16.1%) had no leukoaraiosis, 66 (37.9%) had mild, 62 (35.6%) had moderate, and 18 (10.3%) had severe. Leukoaraiosis severity was associated with worse 90-day mRS among all patients (P=0.0005). Both L-ASPECTS and ASPECTS were associated with poor outcomes, but the area under the curve (AUC) was higher with L-ASPECTS (P<0.0001 and AUC=0.7 for L-ASPECTS; P=0.04 and AUC=0.59 for ASPECTS). In the validation cohort, the AUC for L-ASPECTS was 0.79 while the AUC for ASPECTS was 0.70. Of patients that had successful reperfusion (mTICI 2b/3), the AUC for traditional ASPECTS in predicting good functional outcome was 0.80: AUC for L-ASPECTS was 0.89.ConclusionsLeukoaraiosis severity on pre-mechanical thrombectomy NCCT is associated with worse 90-day outcome in patients with AIS following endovascular recanalization, and is an independent risk factor for worse outcomes. A proposed L-ASPECTS score had stronger association with outcome than the traditional ASPECTS score.


2021 ◽  
Vol 12 ◽  
Author(s):  
Gang Luo ◽  
Feng Gao ◽  
Xuelei Zhang ◽  
Baixue Jia ◽  
Xiaochuan Huo ◽  
...  

Background and Purpose: Studies on rescue therapy for acute posterior circulation stroke due to basilar artery occlusion (BAO) are limited in the modern era of mechanical thrombectomy (MT). The aim of this study was to evaluate the safety and efficacy of rescue stenting (RS) following MT failure in patients with BAO.Methods: Data were collected from the Endovascular Treatment Key Technique and Emergency Work Flow Improvement of Acute Ischemic Stroke (ANGEL-ACT) prospective registry in China. Patients who underwent MT for BAO with failure of recanalization were enrolled in this study. The patients were divided into the RS and non-RS groups. Clinical and laboratory findings, procedural details, and clinical outcomes were compared between the two groups.Results: Overall, 93 patients with acute BAO were analyzed. The RS group included 81 (87.1%) patients, and the non-RS group included 12 patients. A modified treatment in cerebral infarction (mTICI) score of 2b/3 was achieved in 75 (92.6%) patients in the RS group. Compared with the non-RS group, the RS group had a significantly higher rate of successful recanalization and favorable clinical outcomes (modified Rankin Scale score at 90 days post-procedure, 0–3: 16.7 vs. 51.9%, respectively; P = 0.023) without an increase in the rate of symptomatic intracranial hemorrhage and a significantly lower mortality rate (58.3 vs. 18.5%, respectively; P = 0.006). Furthermore, the use of a glycoprotein IIb/IIIa inhibitor improved the rate of recanalization of the target artery without increasing the rate of symptomatic intracranial hemorrhage.Conclusions: Permanent stenting appears to be a feasible rescue modality when MT fails and might provide functional benefits in patients with acute ischemic stroke due to BAO.


2021 ◽  
Vol 18 ◽  
Author(s):  
Huiling Sun ◽  
Feng Zhou ◽  
Guoxing Zhang ◽  
Jiankang Hou ◽  
Yukai Liu ◽  
...  

Background: Mounting evidence has shown that mechanical thrombectomy [MT] improves clinical outcomes for large vessel occlusions [LVOs] in patients with acute ischemic stroke [AIS] of the anterior circulation. The present study aimed to provide a comprehensive analysis of risk factors associated with clinical outcomes in AIS patients receiving MT. Methods: A total of 212 consecutive patients who underwent MT for AIS were enrolled in the present study. Clinical characteristics were recorded at admission. Two endpoints were defined according to the 3-month modified Rankin scale [mRS] score after AIS [good outcome, mRS 0-2; and death, mRS 6]. Additionally, we compared the clinical outcomes and safety of MT alone and bridging therapy in AIS patients. Results: Of the 212 patients treated with MT, 114 [53.77%] patients had a good outcome and 31 [14.62%] died. The incidence of a worse outcome after MT was significantly elevated in males and patients with high WBC counts, high admission blood glucose levels, high baseline NIHSS scores and a long interval time from groin puncture to reperfusion in AIS patients treated with MT after adjustment for covariates [P<0.05]; these risk factors were further confirmed by our constructed nomograms. In addition, we observed no significant benefit of bridging therapy compared to MT alone in AIS patients. Conclusion: Our constructed nomogram based on male sex, admission WBC, admission blood glucose, NIHSS, and the interval time from groin puncture to reperfusion predicts prognosis after mechanical thrombectomy in patients with acute ischemic stroke.


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