Haussen, Diogo C

Background and Purpose Mechanical thrombectomy (MT) has become the standard of care for treatment of acute ischemic stroke secondary to large vessel occlusion up to 24 h from the last known normal time. With ADAPT and SOLUMBRA techniques, classically, a large bore aspiration catheter is delivered over a microcatheter and microwire crossing the clot to perform thrombectomy. Recently, a novel macrowire (Colossus 035 in.) has been introduced as a potential alternative to the use of microwire-microcatheter to allow the delivery of the aspiration catheter (ID = 0.070 in. up to 0.088 in.) over a macrowire alone. Objective To test the feasibility of delivering an aspiration catheter to clot interface over a macrowire alone. Materials and Methods A retrospective evaluation of prospectively maintained Macrowire for Intracranial Thrombectomy (MINT) Registry where this novel technique was utilized for thrombectomy. Consecutive patients undergoing MT using the MINT technique were included. We collected baseline demographics, imaging and clinical characteristics, rate of procedural success, conversion to traditional MT, and complications. Results Fifty consecutive patients were recruited during the initial 4 months of the larger study duration. The aspiration catheter was able to be advanced to the clot interface successfully in 46/50 (92%) using the MINT technique. Median time from vascular access to the first pass was 11.30 min (IQR = 7.45–14.30 min) and successful thrombectomy was 14 min (IQR = 10–22.15). The modified first-pass effect with this procedure was 71%. One vasospasm was reported as a procedural complication. Conclusions MINT is safe and feasible for large vessel occlusion recanalization based on our initial clinical experience in this multicenter study.

BACKGROUND: The EXCELLENT registry aimed to evaluate the effectiveness of the EMBOTRAP Revascularization Device in an all-comer population in a real-world setting, with a focus on the composition of retrieved clots. METHODS: EXCELLENT is a prospective, global registry of patients with acute ischemic stroke treated with EMBOTRAP as the first-line mechanical thrombectomy device conducted at 34 sites (25 sites contributing clot) from September 2018 to March 2021, utilizing core imaging and central histology laboratories blinded to clinical data, independent 90-day modified Rankin Scale assessment and Clinical Events Committee. RESULTS: After screening 3799 patients, a total of 997 subjects (mean age, 70.0±14.2 years; 51.8% women; 19.7% non-White) were included. The first-pass modified Treatment in Cerebral Infarction (mTICI) ≥2b rate was 64.5% (623/966), first-pass mTICI ≥2c was 39.1% (378/966), and final mTICI ≥2b was 94.5% (931/985). A total of 427/912 (46.8%) patients achieved a 90-day modified Rankin Scale of 0 to 2 or ≤baseline. Embolization to a new territory occurred in 0.2% (2/984), and symptomatic intracranial hemorrhage at 24 hours in 1.6% (16/997). The 90-day mortality was 19.1% (175/918). Device- and/or procedure-related serious adverse events occurred in 5.9% (54/912) through 90 days. The mean RBC percentage of retrieved clots was 45.62±21.372. Among patients who achieved mTICI ≥2b with the first pass, 15.7% (52/331) and 9.7% (32/331), respectively, had RBC-poor (<25%) and RBC-rich (>75%) clots. Patients with no clot retrieved in any procedural pass had a lower percentage of hyperdense or susceptibility vessel sign on baseline imaging (58.9% versus 74.7%; P <0.001), pointing to a potential preprocedure indicator of challenging clot. CONCLUSIONS: The EXCELLENT registry informs real-world practices in mechanical thrombectomy and sheds light on the range of clots effectively retrieved by current technology. This is the first report of detailed patient characteristics where mechanical thrombectomy maneuvers failed to remove any clot material. Although the composition of nonretrievable clots cannot be assessed histologically, the results support the notion that no retrieval may be correlated with imaging findings suggesting clots lower in RBC. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03685578.

Background Mechanical thrombectomy has become the standard of care for treatment of acute ischemic stroke secondary to large‐vessel occlusion up to 24 hours from last known normal time. Multiple different techniques for mechanical thrombectomy have been described, including a direct aspiration first‐pass technique and stent retriever thrombectomy. With a direct aspiration first‐pass technique, classically, a large‐bore aspiration catheter is delivered over a microcatheter and microwire to the clot. Recently, a novel macrowire has been introduced as a potential alternative to the use of microwire–microcatheter to allow the delivery of the aspiration catheter. The aim of this study is to develop a multicenter registry comparing delivery of an aspiration catheter for intracranial thrombectomy for acute ischemic stroke secondary to emergent large‐vessel occlusion over a macrowire in comparison with traditional use of microcatheter and microwire. Methods MINT (Macrowire for Intracranial Thrombectomy) is a multicenter, observational study currently enrolling patients with large‐vessel occlusion who underwent mechanical thrombectomy using a macrowire to deliver the aspiration catheter to the intracranial occlusion. All the participating sites will screen and report cases on a monthly basis. The decision to use the macrowire and various aspiration catheters is at the discretion of the interventionalist. Results We will collect patient's clinical, demographic, and radiographic data. In addition, we plan to collect procedure variables and postprocedure clinical and imaging data. Outcomes include successful delivery of the reperfusion catheter to the clot interface, time taken from groin access to first pass, and a bailout strategy for thrombectomy in cases where this is not feasible. Conclusion The MINT registry will add to our understanding of safety and efficacy of this novel macrowire in intracranial thrombectomy. This registry will also highlight and allow for understanding in workflow improvements from simplifying setup and possibly cost effectiveness of this technique.

Introduction EXCELLENT (NCT03685578; Cerenovus) is a large, prospective, international, real‐world registry of endovascular clot removal in acute ischemic stroke (AIS) with EmboTrap as the first line mechanical thrombectomy (MT) device, which included collection and analysis of the retrieved thrombus material. Methods Between September 2018 and March 2021, 1000 “all‐comer” patients were enrolled at 34 global sites (27 US, 5 EU, 1 UK, 1 Israel) and treated according to standard of care at each center (with Embrotrap as first line). The study employed blind endpoint evaluation, including a core imaging lab and an independent 90‐day mRS assessment. Retrieved clot was collected per each MT maneuver from 538 subjects across 26 sites and clot analysis was performed by independent central labs blinded to clinical data. Results mITT population included 998 subjects. Mean age was 69.9±14.18 years (range 18–102), 51.8% (517/998) subjects were female and 9.9% (97/997) had a pre‐stroke mRS 3–5. Baseline NIHSS was 15.6±6.87 (range 0–36); 10.1% (82/815) subjects had a large core (ASPECTS 0–5); 5.8% (57/990) had posterior stroke; 56.3% (523/929) underwent MT ≤ 6hrs of onset and 38.1% (380/998) received IV‐tPA prior to MT. First pass eTICI 2c‐3 was achieved in 38.3% (377/984) and final 2b‐3 in 94.5 % (930/984; median number of passes = 1) of subjects. 90‐day mRS≤2 or ≤pre‐stroke was 46.9% (429/915) and 90‐day all‐cause mortality was 19.0% (175/921). The univariate analysis of clot components showed high red blood cell and low platelet content were significant predictors of good mRS outcome (p < 0.001 and 0.009) and negative predictors of 90‐day mortality (p < 0.001 and 0.017, respectively). Conclusions This large multi‐center, all‐comer cohort reflects the population undergoing thrombectomy today in a real world‐setting. Final angiographic, clinical and thrombus composition results, along with multivariate analysis of predictors of clinical outcomes, will be presented at the time of the conference.

Despite the proven benefit of stent retrievers, challenges to rapid revascularization of large vessel occlusions (LVO) persist. Current stent retrievers have limited effectiveness for removing organized thrombi. The NeVa device is a novel stent retriever designed with openings in the basket cell structure (“drop zones”) intended to capture organized thrombi within the central scaffold during retrieval. Prospective, multicenter, open label, single arm, FDA-regulated IDE study to evaluate the performance of the NeVa device for recanalizing occluded intracranial vessels including ICA, M1/M2 MCA, and vertebrobasilar arteries, within 8 hours of onset. Primary endpoint was rate of eTICI 2b-3 within 3 NeVa passes, tested for non-inferiority against a performance goal of 72% with a margin of -10%. Additional efficacy endpoints included first pass effect to eTICI 2b-3 (FPE) and 90-day mRS 0-2. Primary safety endpoint was 90-day mortality. (ClinicalTrials.gov NCT04514562) (Site-adjudicated revascularization results are reported here. Final core lab results will be presented at the conference.) From April 1, 2021 to April 28, 2022, 139 subjects were enrolled at 25 centers in the US and Europe. Mean age was 67 ± 13 years; 47% were female. Median NIHSS score was 16 (IQR: 12-20). Occlusions were 14 (10%) ICA, 85 (61%) M1, 38 (27%) M2, 1 (1%) Basilar and 1 (1%) PCA. Mean time to first pass was 19 ± 12 minutes. eTICI 2b-3 within 3 NeVa passes occurred in 87.8% (122/139; CI 81.1%,92.7%; non-inferiority p<0.0001; post hoc superiority p=0.002, tested against performance goal of 72%). FPE (to eTICI 2b-3) was observed in 67.6% (94/139), with first pass to eTICI 2b67-3 in 61.2% (85/139) and to eTICI 2c-3 in 43.9% (61/139). Median number of passes was 1 (IQR 1-2). Final eTICI 2b-3 rate was 94.2% (131/139); final eTICI 2c-3 rate was 65.5% (91/139). Good outcome (90-day mRS 0-2) was seen in 62.6% (87/139) and was 74.4% in patients with FPE (70/94 vs. 17/45 (37.8%) without FPE; p<0.0001). Mortality was 9.4% (13/139) with sICH in 8 (5.8%) subjects. The NeVa device is effective and safe for revascularization of LVO strokes and demonstrates high first pass success in this international multicenter study. First pass reperfusion (eTICI 2b-3) was strongly associated with functional independence.

Background: Understanding clot composition may allow for better technical planning and improved outcomes in mechanical thrombectomy (MT). We sought to correlate clot composition with reperfusion outcomes in MT. Methods: Clinical, imaging, and clot data from patients enrolled in the STRIP Registry from September 2016 to September 2020 were analyzed. Samples were fixed in 10% phosphate-buffered formalin and stained with hematoxylin and eosin and Martius Scarlett Blue. Percent composition, richness, and gross appearance were evaluated. Outcome measures included the rate of First-Pass Effect (mTICI2c/3, FPE) and the number of device passes. Results: A total of 1430 patients (mean age, 68.4±13.5years; median [IQR] baseline NIHSS,17.2 [10.5-23]; IV-tPA use, 36%; Stent-Retrievers [SR], 27%; Contact Aspiration [CA], 27%; Combined SR + CA, 43%) were included. The median [IQR] number of passes was 1 [1-2]. FPE was achieved in 39.3% of the cases. There was no association between percent histological composition or clot richness and FPE in the overall population. However, the combined technique resulted in lower FPE rates for RBC-rich (P<0.0001), platelet-rich (P=0.003), and mixed (P<0.0001) clots. Fibrin-rich and platelet-rich clots required a higher number of passes compared to RBC-rich and mixed clots (median, 2 and 1.5 vs.1, respectively, P=0.02). CA displayed a trend towards a higher number of passes with fibrin-rich clots (2 vs.1, P=0.12). By gross appearance, mixed/heterogeneous clots had lower FPE rates than red and white clots. Conclusion: Despite the lack of correlation between clot histology and FPE in the overall population, our study adds to the growing body of evidence supporting the notion that clot composition influences reperfusion treatment strategy outcomes. Additional studies are needed.

Introduction: EXCELLENT (NCT03685578) is a global prospective, multicenter, real-world registry of mechanical thrombectomy for stroke with the EmboTrap device as first line treatment which includes clot collection and analysis. Aim of the study: To report the rates of clinical outcomes and clot characteristics associated with first pass reperfusion in EXCELLENT. Methods: Per pass angiographic outcomes assessed by an independent core lab were available in 984 subjects Analysis of clot from 538 cases was performed by independent central labs blinded to clinical data. 90-day mRS assessment was blinded to subject data. Results: First pass reperfusion of mTICI 2b-3 (63.2%) and 2c-3 (38.3%) was significantly predictive of mRS 0-2 or ≤pre-stroke (p=0.011 and p=0.016) but not all-cause mortality at 90 days (p=0.080 and p=0.123, respectively). Further, mTICI 2c-3 in one pass was associated with a higher rate of mRS 0-2 or ≤pre-stroke vs. mTICI 2c-3 reperfusion in >1 pass, (55.5% and 45.1%, respectively, p=0.013) and a rate of all-cause mortality at 90 days of 14.6% vs. 19.8% (p=0.097). Full patient characteristics and clinical outcomes are shown in Table 1. Notable clot composition findings included: RBC (%, mean±SD): mTICI 2c-3, 1 pass 47.69±22.25, mTICI 2c-3, >1 pass 43.86±19.05, (p=0.088); fibrin: mTICI 2c-3, 1 pass 23.20±13.80, mTICI 2c-3 >1 pass 25.40 ± 13.52 (p=0.131); von Willebrand factor (VWF): mTICI2c-3, 1 pass 16.09±14.62, mTICI 2c-3, >1 pass 19.42±17.15 (p=0.038). Conclusions: First pass reperfusion in the EXCELLENT registry was associated with better clinical outcomes at 90 days. Clots retrieved with first pass reperfusion had higher RBC and lower fibrin and VWF content compared to those who achieved reperfusion at greater than one pass.

Background Basal ganglia infarcts are thought to carry worse clinical outcomes compared with other infarct patterns. We aimed to investigate whether pretreatment topographic infarct patterns including complete basal ganglia involvement versus other infarct patterns help predict mechanical thrombectomy outcomes. Methods This was a review of a prospectively collected database of consecutive mechanical thrombectomy patients with anterior circulation large vessel occlusion strokes between January 2014 and November 2018. Patients were categorized into the following 2 groups: (1) total basal ganglia (TBG) strokes defined as infarcts affecting both the caudate and lentiform nuclei regardless of cortical involvement and (2) other infarct patterns. Infarct location was assessed on preprocedure noncontrast computed tomography using an automated software (e‐ASPECTS). Baseline characteristics and outcome measures were compared. Results A total of 1011 patients were analyzed of which 234 (23.12%) had TBG strokes. Patients with TBG strokes were younger ( P =0.01); had higher National Institutes of Health Stroke Scale (NIHSS) ( P =0.006), lower e‐ASPECTS ( P <0.001), and lower systolic blood pressure ( P =0.024); and had diabetes less often ( P =0.01). Baseline characteristics were otherwise comparable between groups. Involvement of the caudate or lentiform nucleus alone was observed in 237 (30.5%) and 21 (2.7%) patients, respectively, in the other infarct patterns group. No internal capsule involvement was detected in either group. There were no differences in terms of 90‐day functional outcomes whether dichotomized (modified Rankin Scale score≤2: TBG=44.6% versus other=50.1%; P =0.14) or looking at the entire spectrum of the scale (shift analysis; P =0.74). However, TBG strokes had significantly higher rates of any parenchymal hematomas (15.4% versus 8.2%; P =0.001), an association that held true in multivariable analysis (adjusted odds ratio, 2.57 [95% CI, 1.41–4.62]; P =0.002). Conclusions Despite increased rates of hemorrhagic transformation, ganglionic infarcts carry similar functional outcomes after mechanical thrombectomy compared with other stroke patterns.

Background and Purpose: Field Assessment Stroke Triage for Emergency Destination (FAST-ED) scale is a helpful tool to triage patients with stroke in the field. However, data on its reliability in the prehospital setting are lacking. We aim to test the reliability of FAST-ED scale when used by paramedics in a mobile stroke unit covering a metropolitan area. Methods: As part of standard operating mobile stroke unit procedures, paramedics initially evaluated patients. If the event characterized a stroke alert, the FAST-ED score was determined by the paramedic upon patient contact (in-person) and then independently by a vascular neurologist (VN) immediately after paramedic evaluation (remotely/telemedicine). This allowed testing of the interrater agreement of the FAST-ED scoring performance between on-site prehospital providers and remotely located VN. Results: Of a total of 238 patients transported in the first 15 months of the mobile stroke unit’s activity, 173 were included in this study. Median age was 63 (interquartile range, 55.5–75) years and 52.6% were females. A final diagnosis of ischemic stroke was made in 71 (41%), transient ischemic attack in 26 (15%), intracranial hemorrhage in 15 (9%), whereas 61 (35%) patients were stroke mimics. The FAST-ED scores matched perfectly among paramedics and VN in 97 (56%) instances, while there was 0 to 1-point difference in 158 (91.3%), 0 to 2-point difference in 171 (98.8%), and 3 or more point difference in 2 (1.1%) patients. The intraclass correlation between VN and paramedic FAST-ED scores showed excellent reliability, intraclass correlation coefficient 0.94 (95% CI, 0.92–0.96; P <0.001). When VN recorded FAST-ED score ≥3, paramedics also scored FAST-ED≥3 in majority of instances (63/71 patients; 87.5%). A large vessel occlusion was identified in 16 (9.2%) patients; 13 occlusions were identified with a FAST-ED≥3 while 3 were missed. All of the latter patients had National Institutes of Health Stroke Scale score ≤5. Conclusions: We demonstrate excellent reliability of FAST-ED scale performed by paramedics when compared with VN, indicating that it can be accurately performed by paramedics in the prehospital setting.

Background Several animal studies have demonstrated that mechanical thrombectomy (MT) for acute ischemic stroke (AIS) may cause vessel wall injury (VWI). However, the histological changes in human cerebral arteries following MT are difficult to determine. Objective To investigate the occurrence of VWI during MT by histological and immunohistochemical evaluation of AIS clots. Methods As part of the multicenter STRIP registry, 277 clots from 237 patients were analyzed using Martius Scarlett Blue stain and immunohistochemistry for CD34 (endothelial cells) and smooth muscle actin (smooth muscle cells). Results MT devices used were aspiration catheters (100 cases), stentriever (101 cases), and both (36 cases). VWI was found in 33/277 clots (12%). There was no significant correlation between VWI and MT device. The degree of damage varied from grade I (mild intimal damage, 24 clots), to grade II (relevant intimal and subintimal damage, 3 clots), and III (severe injury, 6 clots). VWI clots contained significantly more erythrocytes (p=0.006*) and less platelets/other (p=0.005*) than non-VWI clots suggesting soft thrombus material. Thrombolysis correlated with a lower rate of VWI (p=0.04*). VWI cases showed a significantly higher number of passes (2 [1–4] vs 1 [1–3], p=0.028*) and poorer recanalization outcome (p=0.01*) than cases without VWI. Conclusions Histological markers of VWI were present in 12% of AIS thrombi, suggesting that VWI might be related to MT. VWI was associated with soft thrombus consistency, higher number of passes and poorer revascularization outcome. There was no significant correlation between VWI and MT device.