The SAVE Technique

A Rare Case of Ruptured Distal Posterior Cerebral Artery Aneurysm Followed by Middle Cerebral Artery Occlusion due to Delayed Diagnosis of Infective Endocarditis

A 31-year-old female presented to our hospital with sudden headache and altered consciousness. Computed tomography showed left acute subdural hematoma, and digital subtraction angiography revealed a small aneurysm on the left distal posterior cerebral artery. Coil embolization was conducted, and the patient was discharged with no neurological deficits. However, two weeks later, she presented with complete left hemiplegia and with the National Institutes of Health Stroke Scale of 20. Magnetic resonance angiography showed the occlusion of right middle cerebral artery, and the Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Score was four. Mechanical thrombectomy was conducted. Complete recanalization was achieved, and the patient recovered favorably. Although she showed no symptoms of infection such as fever throughout the treatment of aneurysm and thrombectomy, her blood culture was positive for streptococcus mitis. Furthermore, the thrombus retrieved by thrombectomy showed bacterial mass, and transesophageal echocardiography (TEE) showed vegetation on the mitral valve that could not be detected by transthoracic echocardiography. Therefore, the patient was diagnosed with infective endocarditis (IE). She was administered penicillin for 6 weeks and was discharged with no neurological deficits. When treating young patients with small aneurysms in rare locations, IE should be suspected, and blood culture and TEE should be conducted, even when there are no obvious symptoms of systemic infection.

In vitro evaluation of how the presence of the stent retriever and microcatheter influences aspiration parameters in thrombectomy according to their position inside the aspiration catheter

BACKGROUND

Several variations of the combined thrombectomy technique for acute ischemic stroke using a stent retriever and aspiration catheter have been described. The aim of our study was to assess how the presence of the microcatheter and stent retriever affect the basic aspiration parameters, namely, flow rate and aspiration force, depending on their position within the aspiration catheter.

METHODS

Two experimental set-ups were designed to assess changes in flow rate and aspiration force according to the position of the stent retriever and microcatheter within the aspiration catheter.

RESULTS

The transition of the stent retriever and microcatheter from the distal to proximal position resulted in a progressive increase in the flow rate, but with no impact on aspiration force. Additionally, the size of the stent retriever had no significant effect on flow rate changes and the reduction in flow rate was related to the microcatheter diameter. Negative pressure generated inside the aspiration catheter impacted on its distal segment located beyond the radiopaque marker, thus leading to its partial collapse. As a consequence, the measured aspiration force was lower than the theoretical aspiration force level for all tested aspiration catheters.

CONCLUSIONS

In our experimental model, the position of the stent retriever and microcatheter within the aspirator catheter affected the flow rate, but not the aspiration force. Negative pressure generated within the aspiration catheter appeared to determine a partial collapse of the distal segment that resulted in a less effective aspiration force than the theoretical aspiration force level.

Current Approaches and Methods to Understand Acute Ischemic Stroke Treatment Using Aspiration Thrombectomy

Acute ischemic stroke occurs when a blood clot occludes a cerebral artery. Mechanical interventions, primarily stent retrievers and aspiration thrombectomy, are used currently for removing the occluding clot and restoring blood flow. Aspiration involves using a long catheter to traverse the cerebral vasculature to reach the blood clot, followed by application of suction through the catheter bore. Aspiration is also used in conjunction with other techniques such as stent retrievers and balloon guide catheters. Despite the wide use of aspiration, our physical understanding of the process and the causes of the failure of aspiration to retrieve cerebral clots in certain scenarios is not well understood. Experimental and computational studies can help develop the capability to provide deeper insights into the procedure and enable development of new devices and more effective treatment methods. We recapitulate the aspiration-based thrombectomy techniques in clinical practice and provide a perspective of existing engineering methods for aspiration. We articulate the current knowledge gap in the understanding of aspiration and highlight possible directions for future engineering studies to bridge this gap, help clinical translation of engineering studies, and develop new patient-specific stroke therapy.

Initial clinical experience with a novel mechanical thrombectomy device-the ThrombX retriever

BACKGROUND AND PURPOSE

The ThrombX Retriever is a novel mechanical thrombectomy device that adjusts the distance between two mesh segments to axially hold thrombus. A post-market study assessed safety and performance in acute ischemic stroke patients with large artery occlusion.

METHODS

A single-arm prospective multi-center study enrolled patients at 5 European Centers. Patients had a symptomatic large-artery occlusion of the intracranial Internal Carotid or the Middle Cerebral Artery, M1 segment. The primary outcome measure was the modified treatment in cerebral infarction (mTICI) score, on the immediate post-procedure angiogram after up to three device passes. Key secondary outcome measures were the mTICI score after a single pass and functional independence, defined as an mRS score ≤ 2 at 90 days.

RESULTS

Thirty patients (16 Females, mean age 72 years), with NIHSS 4-25 (mean 15.5) were treated. Twenty-eight (93%) achieved mTICI 2b-3 within 3 passes, and 24 (80%) were with the first pass (FP). FP mTICI 2c-3 reperfusion was achieved in 19 (63%) cases. Seventeen of 24 (71%) patients treated with a balloon guide and the ThrombX Retriever had a FP mTICI 2c-3 reperfusion. After all interventions, mTICI 2b-3 was seen in 30 (100%) patients. Twenty-one of the 29 (73%) patients with 90-day follow-up were functionally independent (mRS≤2). No device-related serious adverse events were observed.

CONCLUSION

This preliminary study suggests the ThrombX Retriever is safe and has a high rate of substantial reperfusion. A larger prospective trial to assess the device effectiveness is planned.

Mechanical Thrombectomy in Stroke-Retrospective Comparison of Methods: Aspiration vs. Stent Retrievers vs. Combined Method-Is Aspiration the Best Starting Point?

Background: There are three main methods of mechanical thrombectomy (MT): using a stent retriever (SR) only (SO), aspiration catheter (AC) only (AO) and the combined method (CM) using both the SR and AC. This paper describes a real-life, single-center experience using SO, AO and CM during 276 consecutive MTs. Methods: The primary endpoint was the frequency of first-pass complete (FPE TICI3). The secondary endpoints were final mTICI 2b-3, procedure duration, clinical outcome and the total number of device passes. The third aim of this study was to test the association between the clinical outcomes in patients treated with each method and various factors. Results: There was a significant difference (p = 0.016) between the groups' FPE TICI3 rates with 46% mTICI 3 in the AO group, 41% in the CM group and 21% in the SO group. AO resulted in procedure time shortening to a mean duration of 43 min, and the scores were 56 min for CM and 63 min for SO (p < 0.0001). There were no significant differences in clinical outcomes or in-hospital mortality. The analysis showed a correlation between good clinical outcomes and the administration of IVT: OR 1.71 (1.03-2.84) p = 0.039. Patients ≥66 years old had higher odds of a bad outcome compared to younger patients in general (OR, 1.99 95% CI, 1.17-3.38; p = 0.011). FPE TICI3 was associated with good functional outcomes in the whole treated cohort (OR, 1.98; 95% CI, 1.21-3.25; p = 0.006). Conclusions: In our series, AO proved to be the best starting point in most cases. It demonstrates good technical efficacy regarding FPE, it is fast and clinical outcomes seem to be the least age- and FPE TICI3-dependent. It can be easily converted into the combined method, which had the second-best outcomes in our cohort.

Mechanical thrombectomy using the retrograde semi-retrieval technique for patients with underlying intracranial atherosclerotic stenosis

Background

The retrograde semi-retrieval technique (RESET) has been described as a modified technique for endovascular thrombectomy (EVT) whose safety and efficacy for intracranial atherosclerosis stenosis (ICAS) patients remain uncertain. This article presents our single-center experience, comparing RESET vs. non-RESET in ICAS patients.

Materials and methods

We analyzed 327 consecutive ICAS patients who underwent EVT at Tianjin Huanhu Hospital from January 2018 and December 2022. Patients were categorized into two groups: RESET and non-RESET. The primary outcome was the first-pass effect (FPE). Secondary outcomes included successful reperfusion, functional independence at 90 days, mortality, and symptomatic intracranial hemorrhage (sICH).

Results

RESET was significantly associated with FPE [adjusted odds ratio (aOR) 2.00, 95% confidence interval (CI) 1.03-3.87, p = 0.040]. RESET was not significantly associated with successful reperfusion (aOR 1.5, CI 0.55-4.06, p = 0.425), an mRS of 0-2 at 90 days (aOR 1.36, CI 0.83-2.21, p = 0.223), sICH (aOR 0.39, CI 0.12-1.23, p = 0.108), and mortality (aOR 0.49, CI 0.16-1.44, p = 0.193). After propensity score matching, the results were consistent with the primary analysis.

Conclusion

Compared to non-RESET, patients treated with RESET showed increased FPE incidence and significantly decreased puncture-to-reperfusion time. RESET was proven to be safe and effective in enhancing reperfusion for LVO patients receiving EVT with underlying ICAS.

Double stent-retriever as the first-line approach in mechanical thrombectomy: a randomized in vitro evaluation

BACKGROUND

A repeated number of passes during mechanical thrombectomy leads to worse clinical outcomes in acute ischemic stroke. Initial experiences with the simultaneous double stent-retriever (double-SR) technique as the first-line treatment showed promising safety and efficacy results.

OBJECTIVE

To characterize the potential benefits of using the double-SR as first-line technique as compared with the traditional single-SR approach.

METHODS

Three types of clot analogs (soft, moderately stiff, and stiff) were used to create terminal internal carotid artery (T-ICA=44) and middle cerebral artery (MCA=88) occlusions in an in vitro neurovascular model. Sixty-six cases were randomized into each treatment arm: single-SR or double-SR, in combination with a 0.071" distal aspiration catheter. A total of 132 in vitro thrombectomies were performed. Primary endpoints were the rate of first-pass recanalization (%FPR) and procedural-related distal emboli.

RESULTS

FPR was achieved in 42% of the cases. Overall, double-SR achieved a significantly higher %FPR than single-SR (52% vs 33%, P=0.035). Both techniques showed similar %FPR in T-ICA occlusions (single vs double: 23% vs 27%, P=0.728). Double-SR significantly outperformed single-SR in MCA occlusions (63% vs 38%, P=0.019), most notably in saddle occlusions (64% vs 14%, P=0.011), although no significant differences were found in single-branch occlusions (64% vs 50%, P=0.275). Double-SR reduced the maximal size of the clot fragments migrating distally (Feret diameter=1.08±0.65 mm vs 2.05±1.14 mm, P=0.038).

CONCLUSIONS

This randomized in vitro evaluation demonstrates that the front-line double-SR technique is more effective than single-SR in achieving FPR when treating MCA bifurcation occlusions that present saddle thrombus.

Combined technique as first approach in mechanical thrombectomy: Efficacy and safety of REACT catheter combined with stent retriever

INTRODUCTION

Mechanical thrombectomy (MT) with combined treatment including both a stent retriever and distal aspiration catheter may improve recanalization rates in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). Here, we evaluated the effectiveness and safety of the REACT aspiration catheter used with a stent retriever.

METHODS

This prospective study included consecutive adult patients who underwent MT with a combined technique using REACT 68 and/or 71 between June 2020 and July 2021. The primary endpoints were final and first pass mTICI 2b-3 and mTICI 2c-3 recanalization. Analysis was performed after first pass and after each attempt. Secondary safety outcomes included procedural complications, symptomatic intracranial hemorrhage (sICH) at 24 h, in-hospital mortality, and 90-day functional independence (modified Rankin Scale [mRS] 0-2).

RESULTS

A total of 102 patients were included (median age 78; IQR: 73-87; 50.0% female). At baseline, median NIHSS score was 19 (IQR: 11-21), and ASPECTS was 9 (IQR: 8-10). Final mTICI 2b-3 recanalization was achieved in 91 (89.2%) patients and mTICI 2c-3 was achieved in 66 (64.7%). At first pass, mTICI 2b-3 was achieved in 55 (53.9%) patients, and mTICI 2c-3 in 37 (36.3%). The rate of procedural complications was 3.9% (4/102), sICH was 6.8% (7/102), in-hospital mortality was 12.7% (13/102), and 90-day functional independence was 35.6% (36/102).

CONCLUSION

A combined MT technique using a stent retriever and REACT catheter resulted in a high rate of successful recanalization and first pass recanalization in a sample of consecutive patients with AIS due to LVO in clinical use.

Impact on Endovascular Thrombectomy for Acute Ischemic Stroke of Aortic Arch Calcification on Chest X-ray

BACKGROUND

Vascular conditions can affect the recanalization rates after endovascular thrombectomy (EVT) for acute ischemic stroke (AIS). Chest radiography can assess the conditions of the aortic arch based on the presence or absence of aortic arch calcification (AoAC). The aim of this study was to investigate the relationship between AoAC on chest radiography and first-pass successful recanalization (modified thrombolysis in cerebral infarction 2b/3 after the first-pass).

METHODS

We compared the rate of first-pass successful recanalization between patients with and without AoAC. A total of 193 patients with anterior circulation occlusion who underwent EVT between January 2017 and December 2021 were included.

RESULTS

AoAC was observed in 80 (41.5%) patients. Patients with AoAC were older (74.5 ± 7.78 vs. 63.9 ± 12.4 years, p < 0.001), had more EVT attempts (3.04 ± 1.95 vs. 2.01 ± 1.34 times, p < 0.001), and a longer procedural time (71.7 ± 31.2 vs. 48.7 ± 23.1 min, p < 0.001) than those without AoAC. Moreover, Patients with AoAC showed a lower incidence of first-pass successful recanalization (18.8% vs. 47.8%, p < 0.001) and a higher incidence of postprocedural hemorrhage (45.0% vs. 27.7%, p = 0.015) than those without AoAC. On multivariate analysis, AoAC was independently associated with first-pass successful recanalization (odds ratio: 0.239 [0.121-0.475], p < 0.001).

CONCLUSIONS

AoAC on chest radiography can be used as a preoperative predictor of successful first-pass recanalization in patients undergoing EVT for AIS.

Contemporary Methods for Detection and Intervention of Distal Medium and Small Vessel Occlusions

The efficacy of using mechanical thrombectomy for proximal large vessel occlusions has been demonstrated in multiple large-scale trials and has further raised the question of its potential utility for distal medium and small vessel occlusions (DMSVOs). Their longer, more tortuous course and smaller corresponding vascular territories render a significant challenge for detection and intervention. The aim of this study is to provide a comprehensive overview of the current imaging and endovascular intervention options for DMSVOs and review the current works in the literature. Compared with traditional computed tomography angiography (CTA) and CT perfusion, recent advances such as multiphase CTA and maps derived from the time-to-maximum parameter coupled with artificial intelligence have demonstrated increased sensitivity for the detection of DMSVOs. Furthermore, newer generations of mini stent retrievers and thromboaspiration devices have allowed for the access and navigation of smaller and more fragile distal arteries. Preliminary studies have suggested that mechanical thrombectomy using this newer generation of devices is both safe and feasible in distal medium-sized vessels, such as M2. However, endovascular intervention utilizing such contemporary methods and devices must be balanced at the discretion of operator experience and favorable vascular anatomy. Further large-scale multicenter clinical trials are warranted to elucidate the indications for as well as to strengthen the safety and efficacy of this approach.

CT-based thrombus radiomics nomogram for predicting secondary embolization during mechanical thrombectomy for large vessel occlusion

Background and aims

Secondary embolization (SE) during mechanical thrombectomy (MT) for cerebral large vessel occlusion (LVO) could reduce the anterior blood flow and worsen clinical outcomes. The current SE prediction tools have limited accuracy. In this study, we aimed to develop a nomogram to predict SE following MT for LVO based on clinical features and radiomics extracted from computed tomography (CT) images.

Materials and methods

A total of 61 patients with LVO stroke treated by MT at Beijing Hospital were included in this retrospective study, of whom 27 developed SE during the MT procedure. The patients were randomly divided (7:3) into training (n = 42) and testing (n = 19) cohorts. The thrombus radiomics features were extracted from the pre-interventional thin-slice CT images, and the conventional clinical and radiological indicators associated with SE were recorded. A support vector machine (SVM) learning model with 5-fold cross-verification was used to obtain the radiomics and clinical signatures. For both signatures, a prediction nomogram for SE was constructed. The signatures were then combined using the logistic regression analysis to construct a combined clinical radiomics nomogram.

Results

In the training cohort, the area under the receiver operating characteristic curve (AUC) of the nomograms was 0.963 for the combined model, 0.911 for the radiomics, and 0.891 for the clinical model. Following validation, the AUCs were 0.762 for the combined model, 0.714 for the radiomics model, and 0.637 for the clinical model. The combined clinical and radiomics nomogram had the best prediction accuracy in both the training and test cohort.

Conclusion

This nomogram could be used to optimize the surgical MT procedure for LVO based on the risk of developing SE.

Combined balloon guide catheter, aspiration catheter, and stent retriever technique versus balloon guide catheter and stent retriever alone technique: a systematic review and meta-analysis

BACKGROUND

The use of a combination of balloon guide catheter (BGC), aspiration catheter, and stent retriever in acute ischemic stroke thrombectomy has not been shown to be better than a stent retriever and BGC alone, but this may be due to a lack of power in these studies. We therefore performed a meta-analysis on this subject.

METHODS

A systematic literature search was performed on PubMed, Scopus, Embase/Ovid, and the Cochrane Library from inception to October 20, 2021. Our primary outcomes were the rate of successful final reperfusion (Treatment in Cerebral Ischemia (TICI) 2c-3) and first pass effect (FPE, defined as TICI 2c-3 in a single pass). Secondary outcomes were 3 month functional independence (modified Rankin Scale score of 0-2), mortality, procedural complications, embolic complications, and symptomatic intracranial hemorrhage (SICH). A meta-analysis was performed using RevMan 5,4, and heterogeneity was assessed using the I² test.

RESULTS

Of 1629 studies identified, five articles with 2091 patients were included. For the primary outcomes, FPE (44.9% vs 45.4%, OR 1.04 (95% CI 0.90 to 1.22), I²=57%) or final successful reperfusion (64.5% vs 68.6%, OR 0.98 (95% CI 0.81% to 1.20%), I²=85%) was similar between the combination technique and stent retriever only groups. However, the combination technique had significantly less rescue treatment (18.8% vs 26.9%; OR 0.70 (95% CI 0.54 to 0.91), I²=0%). This did not translate into significant differences in secondary outcomes in functional outcomes, mortality, emboli, complications, or SICH.

CONCLUSION

There was no significant difference in successful reperfusion and FPE between the combined techniques and the stent retriever and BGC alone groups. Neither was there any difference in functional outcomes, complications, or mortality.

Thrombectomy-Capable Stroke Centre-A Key to Acute Stroke Care System Improvement? Retrospective Analysis of Safety and Efficacy of Endovascular Treatment in Cardiac Cathlab

The optimal structure of the acute ischaemic stroke treatment network is unknown and eagerly sought. To make it most effective, different treatment and transportation strategies have been developed and investigated worldwide. Since only a fraction of acute stroke patients with large vessel occlusion are treated, a new entity-thrombectomy-capable stroke centre (TCSC)-was introduced to respond to the growing demand for timely endovascular treatment. The purpose of this study was to present the early experience of the first 70 patients treated by mechanical means in a newly developed cardiac Cathlab-based TCSC. The essential safety and efficacy measures were recorded and compared with those reported in the invasive arm of the HERMES meta-analysis-the largest published dataset on the subject. We found no significant differences in terms of clinical and safety outcomes, such as early neurological recovery, level of functional independence at 90 days, symptomatic intracranial haemorrhage, parenchymal haematoma type 2, and mortality. These encouraging results obtained in the small endovascular centre may be an argument for the introduction of the TCSC into operating stroke networks to increase patient access to timely treatment and to improve clinical outcomes.

Aspiration versus stent retriever for posterior circulation stroke: A meta-analysis

AIMS

New thrombectomy strategies have emerged recently. Differences between posterior circulation stroke management via aspiration and stent retriever remain to be evaluated. We compared the safety and efficacy of aspiration and stent retriever in treating posterior circulation stroke.

METHODS

Three databases (PubMed, Embase, and Cochrane Library) were systematically searched for studies comparing aspiration and stent retriever in patients with posterior circulation stroke. The modified Newcastle-Ottawa scale was used to assess the risk of bias. A random-effects model was used.

RESULTS

Fifteen cohort studies with 1451 patients were included. Pooled results showed a significant difference in total complication (odds ratio [OR] 0.48, 95% confidence interval [CI] [0.30, 0.76], p = 0.002). successful recanalization (1.85, [1.30, 2.64], p = 0.0006), favorable outcome (1.30, [1.02, 1.67], p = 0.04), procedure duration (-22.10, [-43.32, -0.88], p = 0.04), complete recanalization (4.96, [1.06, 23.16], p = 0.009), and first-pass effect (2.59, [1.55, 4.32], p = 0.0003) between the aspiration and stent retriever groups, and in favor of aspiration. There was no significant difference in the outcomes of rescue therapy (1.42, [0.66, 3.05], p = 0.37) between the two groups.

CONCLUSION

Patients with posterior circulation stroke receiving treatment with aspiration achieved better recanalization, first-pass effect, and shorter procedure time. Aspiration may be more secure than a stent retriever.

First-line Double Stentriever Thrombectomy for M1/TICA Occlusions : Initial Experiences

BACKGROUND

Mechanical thrombectomy is the standard of care for acute ischemic stroke due to large-vessel occlusion; however, mechanical thrombectomy fails to achieve adequate recanalization in nearly one third of these cases. Rescue therapy using two stentrievers simultaneously yields good results in clots refractory to single stentriever treatment. We aimed to determine the safety and efficacy of first-line double stentriever thrombectomy for acute occlusion of the M1 segment of the middle cerebral artery and/or terminal internal carotid artery (TICA).

METHODS

This single-center study prospectively enrolled consecutive patients with a single M1/TICA occlusion to undergo double stentriever thrombectomy between May and October 2020. Outcomes included successful recanalization (modified thrombolysis in cerebral infarction, TICI 2b/3), first-pass effect, procedure times, number of device passes, symptomatic intracerebral hemorrhage, National Institutes of Health Stroke Scale Score (NIHSS) at discharge, 90-day functional independence (modified Rankin scale 0-2), and 90-day mortality.

RESULTS

We analyzed 39 patients median age 79 years (range 42-96 years); 23 (58.9%) female; 19 (48.7%) with TICA occlusions; 5 (12.8%) with mRS 3-5 at admission; mean NIHSS at admission, 17 ± 4.39). Mean time from symptom onset to final angiogram was 238.0 ± 94.6 min; mean intervention duration was 36.0 ± 24.2 min. The mean number of device passes was 1.5 ± 1.07. All patients had final TICI 2b/3, and 27 (69%) had TICI 2c/3 after the first pass. We observed 3 (7.9%) cases of intracerebral symptomatic hemorrhages. At 90 days, 16 (41%) patients were functionally independent and 9 (23%) had died. The percentage of patients with good clinical outcome at 90 days was 55.5% in the first-pass subgroup.

CONCLUSION

Our findings suggest that first-line double stentriever thrombectomy is safe and effective for M1/TICA occlusions.

[Neurothrombectomy 2022-Extension of indications and technical innovations]

For advanced territorial ischemia numerous retrospective and prospective studies have shown a positive effect of mechanical thrombectomy (MT) compared to best medicinal treatment alone. For patients with minor stroke (NIHSS < 6) there is currently a lack of evidence for MT. Appropriate study protocols must differentiate between patients with large vessel occlusion with disproportionately mild symptoms and more distal vascular occlusion and therefore correspondingly fewer clinical symptoms. The role of intravenous lysis treatment before MT as bridging lysis also currently retains its general recommendation, as large studies could not show a uniform noninferiority of MT alone. In addition, the use of intra-arterial lysis after successful MT offers a promising approach, which still needs to be evaluated. Novel aspiration catheters and stent-retrievers as well as competing thrombectomy techniques can be compared by the first pass effect, the successful recanalization with only one attempt at thrombectomy. Contact aspiration and stent-retriever thrombectomy under aspiration are equivalent and established thrombectomy procedures. For the latter, several detailed maneuver tactics are described for improvement of thrombectomy success. Also, in retrospective studies the combination with a balloon-guided catheter promises a further improvement of recanalization results. In the case of failure of supra-aortic vessel probing with inguinal access, radial access and direct carotid puncture are alternative access routes. Recent studies on ICA stenting with tandem occlusions showed a benefit of stents without an increased risk for symptomatic intracranial hemorrhage. The retrograde approach, to first treat the intracranial vessel occlusion and then the carotid stenosis, seems to be advantageous.

Mechanical thrombectomy for acute ischemic stroke in COVID-19 patients: multicenter experience in 111 cases

BACKGROUND

Data on the frequency and outcome of mechanical thrombectomy (MT) for large vessel occlusion (LVO) in patients with COVID-19 is limited. Addressing this subject, we report our multicenter experience.

METHODS

A retrospective cohort study was performed of consecutive acute stroke patients with COVID-19 infection treated with MT at 26 tertiary care centers between January 2020 and November 2021. Baseline demographics, angiographic outcome and clinical outcome evaluated by the modified Rankin Scale (mRS) at discharge and 90 days were noted.

RESULTS

We identified 111 out of 11 365 (1%) patients with acute or subsided COVID-19 infection who underwent MT due to LVO. Cardioembolic events were the most common etiology for LVO (38.7%). Median baseline National Institutes of Health Stroke Scale score and Alberta Stroke Program Early CT Score were 16 (IQR 11.5-20) and 9 (IQR 7-10), respectively. Successful reperfusion (mTICI ≥2b) was achieved in 97/111 (87.4%) patients and 46/111 (41.4%) patients were reperfused completely. The procedure-related complication rate was 12.6% (14/111). Functional independence was achieved in 20/108 (18.5%) patients at discharge and 14/66 (21.2%) at 90 days follow-up. The in-hospital mortality rate was 30.6% (33/108). In the subgroup analysis, patients with severe acute COVID-19 infection requiring intubation had a mortality rate twice as high as patients with mild or moderate acute COVID-19 infection. Acute respiratory failure requiring ventilation and time interval from symptom onset to groin puncture were independent predictors for an unfavorable outcome in a logistic regression analysis.

CONCLUSION

Our study showed a poor clinical outcome and high mortality, especially in patients with severe acute COVID-19 infection undergoing MT due to LVO.

A prospective, first-in-human use of the NeVa mechanical thrombectomy device for patients with acute coronary syndromes

BACKGROUND

There is no established technique for managing large thrombus burden (LTB) in patients with acute coronary syndrome (ACS).

AIMS

The aim of this study was to assess the safety and efficacy of the NeVa (Vesalio) mechanical thrombectomy device (MTD) in ACS patients with LTB.

METHODS

Consecutive patients with ACS and LTB were treated with the NeVa MTD as the primary vessel recanalisation and thrombus removal modality, followed by conventional intervention. We further developed a bench model and applied to a subset of patients, a vacuum-assisted aspiration technique, exploiting 6 Fr-compatible conventional guiding catheter extensions, as an adjudicative manoeuvre to the use of stent-based MTD. A core laboratory reviewed the angiographic images for procedural complications, Thrombolysis In Myocardial Infarction (TIMI) flow, myocardial blush grade (MBG) and TIMI thrombus grade (TTG).

RESULTS

Between November 2019 and March 2021, 61 patients underwent thrombectomy with the NeVa device. Non-flow limiting and reversible coronary spasm occurred in 14 (23%) patients. One patient (#10) suffered from side branch embolisation, which was successfully treated with the NeVa, triggering the development of a vacuum-assisted aspiration technique in a bench model, which was then applied to the subsequent 51 patients. No other device-related complications occurred. After NeVa use, TIMI flow <3 decreased from 68.3% at baseline to 10.3% (p<0.001), MBG <2 from 65% to 27.6% (p<0.001), TTG ≥3 from 96.7% to 43.2% (p<0.001), respectively.

CONCLUSIONS

In patients with LTB, the NeVa MTD was safe and associated with high rates of vessel recanalisation and thrombus removal. The concomitant use of vacuum-assisted aspiration has potential to improve the effectiveness and safety of the technique.

Safety and Effectiveness of the New Generation APERIO® Hybrid Stent-retriever Device in Large Vessel Occlusion Stroke

BACKGROUND

It is unknown whether technological advancement of stent-retriever devices influences typical observational indicators of safety or effectiveness.

METHODS

Observational retrospective study of APERIO® (AP) vs. new generation APERIO® Hybrid (APH) (Acandis®, Pforzheim, Germany) stent-retriever device (01/2019-09/2020) for mechanical thrombectomy (MT) in large vessel occlusion (LVO) stroke. Primary effectiveness endpoint was successful recanalization eTICI (expanded Thrombolysis In Cerebral Ischemia) ≥ 2b67, primary safety endpoint was occurrence of hemorrhagic complications after MT. Secondary outcome measures were time from groin puncture to first pass and successful reperfusion, and the total number of passes needed to achieve the final recanalization result.

RESULTS

A total of 298 patients with LVO stroke who were treated by MT matched the inclusion criteria: 148 patients (49.7%) treated with AP vs. 150 patients (50.3%) treated with new generation APH. Successful recanalization was not statistically different between both groups: 75.7% for AP vs. 79.3% for APH; p = 0.450. Postinterventional hemorrhagic complications and particularly subarachnoid hemorrhage as the entity possibly associated with stent-retriever device type was significantly less frequent in the group treated with the APH: 29.7% for AP and 16.0% for APH; p = 0.005; however, rates of symptomatic hemorrhage with clinical deterioration and in domo mortality were not statistically different. Neither the median number of stent-retriever passages needed to achieve final recanalization, time from groin puncture to first pass, time from groin puncture to final recanalization nor the number of cases in which successful recanalization could only be achieved by using a different stent-retriever as bail-out device differed between both groups.

CONCLUSION

In the specific example of the APERIO® stent-retriever device, we observed that further technological developments of the new generation device were not associated with disadvantages with respect to typical observational indicators of safety or effectiveness.

[Border areas of thrombectomy]

Mechanical thrombectomy (MT) has become the standard procedure in the treatment of patients with acute ischemic stroke (AIS) due to occlusion of a large proximal cerebral artery of the anterior circulation. Nevertheless, according to the current guidelines large patient collectives are still excluded from this highly effective treatment method. Therefore, this article gives an overview of possible extensions of the indications for treatment with MT. For example, patients in the extended time window with distal occlusions, with large infarct cores and also for very old (90+ years) or young (0-17 years) patients. Furthermore, we discuss recent developments in the interventional treatment of stroke, such as new triage concepts or the question whether an additional intravenous thrombolysis is necessary in patients with MT. We conclude with our own estimations for the discussed indications for treatment based on our clinical experience and the current literature.

Combined Approach to Stroke Thrombectomy Using a Novel Short Flexible Aspiration Catheter with a Stent Retriever : Preliminary Clinical Experience

BACKGROUND

Large-bore aspiration catheters enabling greater flow rates and suction force for mechanical thrombectomy might improve outcomes in patients with stroke secondary to large-vessel occlusion. Complete or near-complete reperfusion after a single thrombectomy pass (first-pass effect) is associated with improved clinical outcomes. We assessed the efficacy and safety of novel MIVI Q™ aspiration catheters in combination with stent-retriever devices.

METHODS

We retrospectively analyzed demographics, procedure characteristics, and clinical data from consecutive patients with acute anterior large-vessel occlusion treated with a combined approach using MIVI Q™ aspiration catheters and stent retrievers. Reperfusion was defined according to the modified thrombolysis in cerebral infarction (mTICI) score. Clinical outcomes were measured by the National Institute of Health Stroke Scale (NIHSS) and modified Rankin scale (mRS) scores.

RESULTS

We included 52 patients (median age, 75 y IQR: 64-83); 31 (59.6%) women; 14 (26.9%) with terminal internal carotid artery occlusions, 26 (50%) middle cerebral artery (MCA) segment M1 occlusions, and 12 (23.1%) MCA segment M2 occlusions; median NIHSS score at admission was 19 (IQR: 13-22). After the first pass, 25 (48%) patients had mTICI ≥ 2c. At the end of the procedure, 47 (90.4%) had mTICI ≥ 2b and 35 (67.3%) had mTICI ≥ 2c. No serious device-related adverse events were observed. Symptomatic intracranial hemorrhage developed in 1 patient. Mean NIHSS score was 13 at 24 h and 5 at discharge. At 90 days, 24 (46.2%) patients were functionally independent (mRS 0-2).

CONCLUSION

This preliminary study found good efficacy and safety for MIVI Q™ aspiration catheters used in combination with stent-retriever devices.

Initial Experience With the Trevo NXT Stent Retriever

Background: The application of a new coating to the delivery wire of the Trevo retriever has the potential to improve its handling. We therefore report our initial experience with this new stent retriever for mechanical thrombectomy of large and medium vessel occlusions. Methods: We pooled data of four high-volume European stroke centers over the time period from October 2020 to February 2021. Patients were included in our study if the Trevo NXT stent retriever was used as a first-line device. Primary endpoints were first-pass near-complete or complete reperfusion, defined as mTICI score of ≥2c. Secondary endpoints were final reperfusion, National Institutes of Health Stroke Scale (NIHSS) at 24 h and discharge, device malfunctions, complications during the procedure, and subjective ratings of the interventionalists regarding device functionality. Results: Eighty patients (39 women, mean age 74 ± 14 years) were eligible for our study. Median NIHSS at admission was 15 (IQR, 8-19), and median Alberta Stroke Program Early CT Score at baseline was 9 (IQR, 8-10). In 74 (93%) patients a primary combined approach was used as first-line technique. First-pass near-complete reperfusion was achieved in 43 (54%) and first-pass complete reperfusion in 34 (43%) patients. Final near-complete reperfusion was achieved in 66 (83%) patients after a median of 1.5 (1-3) passes, while final successful reperfusion was observed in 96% of our cases. We observed no device malfunctions. Median NIHSS at discharge was 2 (IQR, 0-5), and 3 patients (4%) suffered a symptomatic intracranial hemorrhage. Conclusions: Based on our initial data, we conclude that the Trevo NXT is an effective and safe tool for mechanical thrombectomy especially when used for combined approaches.

Decompressive craniectomy for internal carotid artery and middle carotid artery infarctions: a long-term comparative outcome study

OBJECTIVE

Malignant internal carotid artery (ICA) infarction is an entirely different disease entity when compared with middle cerebral artery (MCA) infarction. Because of an increased area of infarction, it is assumed to have a poorer prognosis; however, this has never been adequately investigated. Decompressive craniectomy (DC) for malignant MCA infarction has been shown to improve mortality rates in several randomized controlled trials. Conversely, aggressive surgical decompression for ICA infarction has not been recommended. The authors sought to compare the functional outcomes and survival between patients with ICA infarctions and those with MCA infarctions after DC in the largest series to date to investigate this assumption.

METHODS

A multicenter retrospective review of 154 consecutive DCs for large territory cerebral infarctions performed from 2005 to 2020 were analyzed. Patients were divided into ICA and MCA groups depending on the territory of infarction. Variables, including age, sex, medical comorbidities, laterality of the infarction, preoperative neurological status, primary stroke treatment, and the time from stroke onset to DC, were recorded. Univariable and multivariable analyses were performed for the clinical exposures for functional outcomes (modified Rankin Scale [mRS] score) on discharge and at the 1- and 6-month follow-ups, and for mortality, both inpatient and at the 1-year follow-up. A favorable mRS score was defined as 0-2.

RESULTS

There were 67 patients (43.5%) and 87 patients (56.5%) in the ICA and MCA groups, respectively. Univariable analysis showed that the ICA group had a comparably favorable mRS (OR 0.15 [95% CI 0.18-1.21], p = 0.077). Inpatient mortality (OR 1.79 [95% CI 0.79-4.03], p = 0.16) and 1-year mortality (OR 2.07 [95% CI 0.98-4.37], p = 0.054) were comparable between the groups. After adjustment, a favorable mRS score at 6 months (OR 0.17 [95% CI 0.018-1.59], p = 0.12), inpatient mortality (OR 1.02 [95% CI 0.29-3.57], p = 0.97), and 1-year mortality (OR 0.94 [95% CI 0.41-2.69], p = 0.88) were similar in both groups. The overall survival, plotted using the Cox proportional hazard regression, did not show a significant difference between the ICA and MCA groups (HR 0.581).

CONCLUSIONS

Unlike previous smaller studies, this study found that patients with malignant ICA infarction had a functional outcome and survival that was similar to those with MCA infarction after DC. Therefore, DC can be offered for malignant ICA infarction for life-saving purposes with limited functional recovery.

Effect of distal access catheter tip position on angiographic and clinical outcomes following thrombectomy using the combined stent-retriever and aspiration approach

Purpose

Mechanical thrombectomy using the stent-retriever in conjunction with the distal access catheter may improve the rates of successful revascularization and clinical outcomes in patients with acute stroke. We aimed to compare two different thrombectomy techniques, according to the position of the distal access catheter tip in the combined stent-retriever and aspiration approach.

Methods

In this retrospective study, patients with middle cerebral artery occlusion treated with the combined technique were divided into two groups based on the tip position of the distal access catheter: distal group (catheter placed adjacent to the thrombus) and proximal group (catheter placed in the cavernous segment of the internal carotid artery below the ophthalmic artery). Baseline characteristics, angiographic results, and clinical outcomes were compared.

Results

Eighty-three patients (distal group, n = 45; proximal group, n = 38) were included. Higher complete reperfusion was observed in the distal group (unweighted analysis: 66.7% vs. 42.1%, p = 0.025; weighted analysis: 74.0% vs. 28.8%; p = 0.002). In the multivariate analysis, the distal tip position was independently associated with complete reperfusion (unweighted analysis: aOR, 4.10; 95% CI, 1.40–11.98; p = 0.01; weighted analysis: aOR, 5.20; 95% CI, 1.72–15.78; p = 0.004). The distal group also showed more favorable clinical outcomes and early neurological improvement (unweighted analysis: 62.2% vs. 55.3%; p = 0.521, 60% vs. 50%; p = 0.361, respectively; weighted analysis: 62.7% vs. 61.1%; p = 0.877, 66% vs. 45.7%; p = 0.062, respectively). However, more arterial dissections were observed in the distal group (8.9%, n = 4 vs. 2.6%, n = 1; p = 0.36). In the distal group, one patient with vascular injury died due to complications. No cases of emboli in new territory were observed.

Conclusions

Distal tip position of the distal access catheter has a significant impact on reperfusion in patients with acute ischemic stroke. However, there was also a higher rate of vascular injury as the catheter was advanced further. If advancement to the target lesion is too difficult, placing it in the cavernous internal carotid artery may be a viable method without complications.

True first-pass effect in basilar artery occlusions: First-pass complete reperfusion improves clinical outcome in stroke thrombectomy patients

BACKGROUND

Complete reperfusion (mTICI 3) in anterior circulation ischemic stroke patients after a single mechanical thrombectomy (MT) pass has been identified as a predictor of favorable outcome (modified Rankin Score 0-2) and defined as true first-pass effect recently. This effect has not yet been demonstrated in posterior circulation ischemic stroke. We hypothesized a true first-pass effect for the subgroup of acute basilar artery occlusions (BAO).

METHODS

Consecutive patients with acute thromboembolic occlusions in the posterior circulation, treated between 2010 and 2017, were screened and all BAO patients with complete angiographic reperfusion and known symptom onset included for unmatched and matched analysis after adjustment for multiple confounding factors (demographics, time intervals, stroke severity, posterior circulation Alberta Stroke Program early computed tomography Score and comorbidity. The primary objective was outcome at 90 days between matched cohorts of single pass vs. multi pass complete reperfusion patients.

RESULTS

90 MTs in BAO were analyzed, yielding 56 patients with known symptom onset, in whom we achieved complete reperfusion (mTICI 3), depending on whether complete reperfusion was achieved after a single pass (n = 28) or multiple passes (n = 28). Multivariable analysis of 56 non-matched patients revealed a significant association between first-pass complete reperfusion and favorable outcome (p < 0.01). In matched cohorts (n = 7 vs. n = 7), favorable outcome was only seen if complete reperfusion was achieved after a single pass (86% vs. 0%).

CONCLUSION

Single pass complete reperfusion in acute basilar artery occlusion is an independent predictor of favorable outcome. Achieving complete reperfusion after multiple passes might impair favorable patient recovery.

Mechanical Thrombectomy in Stroke. Experience from Switching from Stent Retriever Only to Stent Retriever Combined with Aspiration Catheter

Endovascular treatment is a rapidly evolving technique; therefore, there is a constant need to evaluate this method and its modifications. This paper discusses a single-center experience and the results of switching from the stent retriever only (SO) mechanical thrombectomy (MT) to the combined approach (CA), with a stent retriever and aspiration catheters.

METHODS

The study involved a retrospective analysis of 70 patients undergoing MT with the use of either SO or CA. The primary endpoint was the frequency of perfect reperfusion defined as grade 3 of the modified Thrombolysis in Cerebral Infarction scale (mTICI) after the first pass. The secondary endpoints were the procedure success, defined as mTICI grades 2b-3; time of the procedure; clinical outcome, measured by 90 days' modified Rankin Scale (mRS) score; Δ NIHSS, defined as the difference between National Institutes of Health Stroke Scale (NIHSS) score at patients' admission and discharge; and the total number of device passes.

RESULTS

Out of the 70 patients included, 33 were treated with SO and 37 with CA. In both groups, a total number of 42 patients received intravenous recombined tissue plasminogen activator (iv-rTPA: 20 patients (60.6%) in the SO group and 22 patients (59.5%) in the CA group (p = 1.000). There was a significant difference between the groups regarding first-pass success rate, with 46% in the CA group and 18% in the SO group, (OR 3.83, 95% CI 1.28 to 11.44, p = 0.016). Complete procedure success tended to be more frequent in the CA group than in the SO group-94.6% vs. 84.8% (OR 3.13, 95% CI 0.56 to 17.34, p = 0.193)-and CA tended to require a lower number of passes than SO (mean 1.76 vs. 2.09 passes per procedure, p = 0.114), yet these differences did not reach statistical significance. Mean duration of the procedure was significantly shorter in the CA group than in the SO group (49 min vs. 64 min, p = 0.017). There was a significant difference in clinical outcomes, with higher Δ NIHSS (9.3 in the CA group vs. 6.7 in the SO group, p = 0.025) after the procedure and 90-day mRS (median 2 in the CA group vs. 4 in the SO group, p = 0.031).

CONCLUSIONS

Combining stent retrievers with aspiration catheters may offer a beneficial effect on angiographic results and clinical outcomes in stroke patients undergoing endovascular treatment.

A Patient with a Delayed Diagnosis of Artery of Percheron Occlusion in Whom Thrombectomy Was Effective

Objective

A case of posterior cerebral artery (P1 segment) occlusion with consciousness disturbance and Weber's syndrome treated by mechanical thrombectomy is reported.

Case Presentation

The patient was a 69-year-old man with consciousness disturbance, left hemiparesis, and anisocoria. MRI revealed acute cerebral infarction in the midbrain and right thalamus. Angiography demonstrated that the right P1 segment was occluded and mechanical thrombectomy was performed. The right P1 segment and its perforator artery, the artery of Percheron (AOP), were both recanalized after the treatment, and the symptoms of perforator occlusion significantly improved.

Conclusion

Mechanical thrombectomy for P1 segment occlusion may be effective for improving the symptoms caused by occlusion of its perforator, the AOP.

Thrombus Composition and Efficacy of Thrombolysis and Thrombectomy in Acute Ischemic Stroke

Thrombi retrieved from patients with acute ischemic stroke are highly heterogeneous. Recent data suggest that thrombus composition may impact on mechanical thrombectomy, the number of recanalization manoeuvres, resistance to retrieval, and on thrombolytic potential. Our aim was to summarize evidence describing the impact of thrombus composition on efficacy of mechanical thrombectomy and thrombolysis in patients with acute ischemic stroke. The scoping review methodology guided by the Joanna Briggs Institute, an adaption of the Arksey and O'Malley, was followed. Comprehensive searches were conducted in MEDLINE, EMBASE, SCOPUS, and Web of Science. Articles were classified into 4 key themes: (1) composition of stroke thrombi, (2) thrombus composition and mechanical thrombectomy, (3) thrombus composition and thrombolytic therapy, and (4) novel imaging and endovascular approaches. Our search identified 698 articles published from 1987 to June 2020. Additional articles were extracted from reference lists of the selected articles. Overall, 95 topic-specific articles identified for inclusion published in 40 different journals were included. Reports showed that thrombus composition in stroke was highly heterogeneous, containing fibrin, platelets, red blood cells, VWF (von Willebrand Factor), and neutrophil extracellular traps. Thrombi could roughly be divided into fibrin- and red blood cell-rich clots. Fibrin-rich clots were associated with increased recanalization manoeuvres, longer procedure time, and less favorable clinical outcomes compared with red blood cell-rich clots. Advances in detection or treatment of thrombi that take into account clot heterogeneity may be able to improve future endovascular and thrombolytic treatment of stroke.

Experimental evaluation of direct thromboaspiration efficacy according to the angle of interaction between the aspiration catheter and the clot

Background

Successful direct thromboaspiration (DTA) is related to several factors such as clot consistency, size, and location. It has also been demonstrated recently that the angle of interaction (AOI) formed by the aspiration catheter and the clot is related to DTA efficacy. The aims of this study were three-fold: (a) to confirm the clinical finding that the AOI formed by the aspiration catheter and the clot influence DTA efficacy; (b) to evaluate to what extent this influence varies according to differences in clot consistency and size; and (c) to validate stent retriever thrombectomy as an effective rescue treatment after DTA failure in the presence of an unfavorable AOI.

Methods

A rigid vascular phantom designed to reproduce a middle cerebral artery trifurcation anatomy with three M2 segments forming different angles with M1 and thrombus analog of different consistencies and sizes was used.

Results

DTA was highly effective for AOIs >125.5°, irrespective of thrombus analog features. However, its efficacy decreased for acute AOIs. Rescue stent retriever thrombectomy was effective in 92.6% of cases of DTA failure.

Conclusions

This in vitro study confirmed that the AOI formed by the aspiration catheter and the thrombus analog influenced DTA efficacy, with an AOI >125.5° related to an effective DTA. Stent retriever thrombectomy was an effective rescue treatment after DTA failure, even in the presence of an unfavorable AOI.

Mechanical Thrombectomy with the Novel NeVa M1 Stent Retriever: Do the Drop Zones Represent a Risk or a Benefit?

OBJECTIVE

The NeVa M1 thrombectomy device is a novel hybrid-cell stent retriever with multifunctional zones for optimized retrieval of resistant clots located in the M1 segment of the middle cerebral artery. The objective was to evaluate the safety and efficacy of the NeVa in a "real-life" setting.

METHODS

Twenty-nine consecutive patients (median age: 77 years) treated with the NeVa M1 for acute ischemic stroke of the M1 segement were retrospectively reviewed. First-pass and final modified thrombolysis in cerebral infarction (mTICI) scores, device-related complications, symptomatic intracranial hemorrhage, and 90-day modified Rankin scale (mRS) scores are reported. Primary outcome parameters were first-pass mTICI 2b-3 reperfusion and mRS 0-2 at 90 days.

RESULTS

Median National Institutes of Health Stroke Scale scores decreased from 16 to 12 after treatment. mTICI 2b-3 reperfusion rates were 55% after the first pass, 79% after 1-2 passes, and 100% after the final pass. mTICI 2c-3 was obtained in 48% after the first pass, 62% after 1-2 passes, and 72% after the final pass. Rescue treatment was performed in 4 patients (14%). Device-related complications included 1 asymptomatic caroticocavernous fistula, 1 asymptomatic M2 dissection, and 1 symptomatic intracranial hemorrhage. The procedure-related vasospasm rate was 48%. A 90-day mRS of 0-2 was achieved by 31%.

CONCLUSIONS

The NeVa M1 provides a high first-pass complete reperfusion rate with an adequate safety profile. To retrieve resistant clots, the stent design exerts high mechanical traction forces, which may trigger vasospasm and vessel wall damage. Large, comparative studies are warranted to draw a definite conclusion on this device.

Mortality after mechanical thrombectomy in anterior circulation stroke may be higher at nighttime and on weekends

Objectives

The objective of this study was to compare clinical outcome and procedural differences of mechanical thrombectomy (MT) during on-call with regular operating hours. We particularly focused on dosimetric data which may serve as potential surrogates for patient outcome.

Methods

A total of 246 consecutive patients who underwent MT in acute anterior circulation stroke between November 2017 and March 2020 were retrospectively included. Patients treated (1) during standard operational hours (n = 102), (2) daytime on-call duty (n = 38) and (3) nighttime on-call duty (n = 106) were compared with respect to their pre-interventional status, procedural specifics, including dosimetrics (dose area product (DAP), fluoroscopy time and procedural time), and outcome.

Results

The collectives treated outside the regular operational hours showed an increased in-hospital mortality (standard operational hours 7% (7/102), daytime on-call duty 16% (6/38), nighttime on-call duty 20% (21/106), p = 0.02). Neither the dosimetric parameters nor baseline characteristics other procedural specifics and outcome parameters differed significantly between groups (p > 0.05 each). In most cases (> 90%), a successful reperfusion was achieved (TICI ≥ 2b).

Conclusions

We found an increased in-hospital mortality in patients admitted at night and during weekends which was not explained by technical aspects of MT.

Key Points

• There is an increased mortality of stroke patients admitted at night and on weekends.

• This is not explained by technical aspects of mechanical thrombectomy.

• There were no statistical differences in the comparison of parameters linked to the radiation exposure, such as DAP, fluoroscopy time and procedure time.

Risk profile of decompressive hemicraniectomy for malignant stroke after revascularization treatment

OBJECTIVE

Revascularization by pharmacological and/or endovascular treatment is an effective therapy for acute ischemic stroke caused by artery occlusion. In the context of malignant middle cerebral artery infarction (MMI), decompressive hemicraniectomy (DHC) can be life-saving. However, its effectiveness and safety after revascularization have not been thoroughly assessed. This retrospective study aimed to determine the risk profile of pre-surgical revascularization treatment (RT) for subsequent DHC.

METHODS

A total of 152 consecutive patients treated by DHC after MMI were identified between 2012 and 2015. After elimination of cases with previous stroke and cases pre-treated with antiplatelets or anticoagulants (increased postoperative bleeding), twenty-four out of fifty patients (n = 24/50, 48%) received pre-surgical revascularization treatment by intravenous thrombolysis (TL), mechanical thrombectomy (MT) or a combination of both. Demographic data was compared alongside perioperative, postoperative complications (intra-/extracerebral hemorrhage, revision surgery due to hemorrhage or infection, and overall mortality) and economic parameters.

RESULTS

Comparing patients with and without prior RT, there was no statistically significant difference in duration of surgery (RT: 83 [57-116] min vs. no-RT: 96 [69-119] min, p = 0.308), intraoperative blood loss (RT: 300 [225-375] ml vs. no-RT: 300 [250-400] ml, p = 0.763), intraoperative transfusion requirement (RT: 12.5% vs. no-RT: 26.9%, p = 0.294), or need for volume substitution (RT: 1300 [1200-1400] ml vs. no-RT: 1200 [1100-1400] ml, p = 0.359). The rate of postoperative complications was also comparable in both groups, including intra-/extracerebral hemorrhage, revision due to hemorrhage or infections, and mortality (p = 0.814, p = 0.520, p = 0.697, and p = 0.769). Health economic parameters were not affected (ventilation time: RT: 309 [12-527] hrs. vs. no-RT: 444 [171-605] hrs., p = 0.120, length of stay: RT: 23 [13-32] days vs. no-RT: 28 [19-41], p = 0.156, and stay costs: RT: 27768 [13044-60,248] € vs. no-RT: 35422 [21225-49,585] €, p = 0.312).

CONCLUSION

DHC for patients with MMI who previously received revascularization therapy appears to be safe and not associated with a higher complication rate or increased health economic burden.

A short history of thrombectomy - Procedure and success analysis of different endovascular stroke treatment techniques

Background

The historical development of interventional stroke treatment shows a wide variation of different techniques and materials used. Thus, the question of the present work is whether the technical and procedural differences of thrombectomy techniques lead to different technical and clinical results.

Methods and results

Analysis of a mixed retrospective/prospective database of all endovascular treated patients with an occlusion of the Carotid-T or M1 segment of the MCA at a single comprehensive stroke center since 2008. Patients were classified regarding the technical approach used. Six hundred sixty-eight patients were available for the final analysis. Reperfusion rates ranged between 56% and 100% depending on the technical approach. The use of balloon guide catheters and most recently the establishment of combination techniques using balloon guide catheters, aspiration catheters and stent retrievers have shown a further significant increase in the rates of successful recanalization, full recanalization and first-pass recanalization. Additionally, the technical development of interventional techniques has led to a subsequent drop in complications, embolization into previously unaffected territories in particular.

Conclusion

Technical success of MT has improved substantially over the past decade owing to improved materials and procedural innovations. Combination techniques including flow modulation have emerged to be the most effective approach and should be considered as a standard of care.

Level of evidence: Level 3, retrospective study.

Adjustment of Stent Retriever Length to Clot Extent Affects First-Pass Reperfusion in Endovascular Treatment of Acute Ischemic Stroke

BACKGROUND

Stent retriever technology has evolved, and significantly longer devices have become available for mechanical thrombectomy (MT) of large cerebral vessel occlusions in ischemic stroke. We hypothesized that increased stent retriever length may improve the rate of complete angiographic reperfusion and decrease the respective number of attempts, resulting in a better clinical outcome.

METHODS

Retrospective analysis of patients with large vessel occlusion in the anterior and posterior circulation treated with stent retriever MT. The study group was dichotomized into short (20 mm) and long (>20 mm) retrievers using propensity matching. In the anterior circulation, the clot burden score was evaluated. Primary end points were first-pass modified thrombolysis in cerebral infarction (mTICI) 3 reperfusion and first-pass mTICI ≥ 2b reperfusion, and the secondary end point was functional independence (defined as modified Rankin Scale score 0-2) at discharge and 90 days.

RESULTS

Overall, 394 patients were included in the analysis. In the anterior circulation, short stent retrievers had a significantly higher rate of first-pass reperfusion in cases with low clot burden (mTICI 3: 27% vs. 17%; p = 0.009; mTICI ≥ 2b: 42 vs. 30%; p = 0.005) and in middle cerebral artery occlusions (mTICI ≥ 2b: 51 vs. 41%; p = 0.024). Higher rates of favorable outcome at discharge and 90 days were observed for the short stent retriever group (p < 0.001).

CONCLUSION

Stent retriever length should be adjusted to clot burden score and vessel occlusion site.

Mechanical Thrombectomy in Acute Ischemic Stroke Using a Manually Expandable Stent Retriever (Tigertriever) : Preliminary Single Center Experience

OBJECTIVE

The aim of this study was to evaluate the safety and efficacy of a manually expandable stent retriever (Tigertriever, Rapid Medical, Yoqneam, Israel) in the treatment of acute ischemic stroke caused by intracranial large vessel occlusions (LVO).

METHODS

We performed a single center retrospective analysis of all patients treated by mechanical thrombectomy due to LVO using the Tigertriever. The angiographic and clinical success was evaluated by the modified thrombolysis in cerebral infarction score (mTICI) and the modified Rankin score (mRS).

RESULTS

A total of 68 acute intracranial arterial occlusions in 61 patients (42 female, median age 77 years, range 43-92 years) were treated by mechanical thrombectomy using the Tigertriever. The overall successful reperfusion rate (mTICI 2b-3) was 85.3% (58/68 occlusions) with a first pass effect (mTICI 3) of 23.5% (16/68 occlusions). In 57 of the 68 occlusions the Tigertriever was used on an intention to treat approach with a success rate of 86.0% and in the 11 remaining occlusions where the Tigertriever was used as a bail-out device the success rate was 81.9%. In seven patients a mild subarachnoid hemorrhage occurred (11.5%) and one symptomatic intracerebral hemorrhage was observed (1.6%). At discharge 39.3% of the patients (24/61) had a favorable outcome (mRS 0-2).

CONCLUSION

The Tigertriever offers a safe and effective treatment option in ischemic stroke due to LVOs with reperfusion rates and a safety profile similar to alternative devices. The Tigertriever is a promising bail-out tool in complex cases. Its role as a first line device has to be evaluated in further prospective studies.

Evolution of Stroke Thrombectomy Techniques to Optimize First-Pass Complete Reperfusion

Since 2015, endovascular therapy (EVT) has become the standard of care for acute ischemic stroke (AIS) due to large vessel occlusion. It is a safe and highly effective treatment, and its number needed to treat of 2.6 is one of the highest throughout medicine. The ultimate goal when performing EVT is to maximize chances of good outcome through achievement of fast first-pass complete reperfusion, as incomplete and delayed reperfusion increases complication rates and negatively affects outcome. Since EVT has been established as standard of care, new devices have been developed and treatment techniques have been refined. This review provides a brief overview about the rationale for and history of EVT, followed by a detailed step-by-step description of how to perform EVT using the BADDASS (BAlloon guide with large bore Distal access catheter with Dual Aspiration with Stent-retriever as Standard approach), a combined technique, which is in our opinion the safest and most effective way to achieve fast first-pass complete reperfusion. We also discuss treatment strategies for patients with simultaneous high-grade carotid stenosis/pseudoocclusion/occlusion and gaining carotid access in challenging arch anatomy, as these are commonly encountered situations in AIS, and conclude with an outlook on new technologies and future directions of EVT.

Repeated mechanical thrombectomy in short-term large vessel occlusion recurrence: multicenter study and systematic review of the literature

BACKGROUND

Data on the frequency and outcome of repeated mechanical thrombectomy (MT) in patients with short-term re-occlusion of intracranial vessels is limited. Addressing this subject, we report our multicenter experience with a systematic review of the literature.

METHODS

A retrospective analysis was conducted of consecutive acute stroke patients treated with MT repeatedly within 30 days at 10 tertiary care centers between January 2007 and January 2020. Baseline demographics, etiology of stroke, angiographic outcome and clinical outcome evaluated by the modified Rankin Scale (mRS) at 90 days were noted. Additionally, a systematic review of reports with repeated MT due to large vessel occlusion (LVO) recurrence was performed.

RESULTS

We identified 30 out of 7844 (0.4%) patients who received two thrombectomy procedures within 30 days due to recurrent LVO. Through systematic review, three publications of 28 participants met the criteria for inclusion. Combined, a total of 58 participants were analyzed: cardioembolic events were the most common etiology for the first (65.5%) and second LVO (60.3%), respectively. Median baseline NIHSS (National Institutes of Health Stroke Scale) was 13 (IQR 8-16) before the first MT and 15 (IQR 11-19) before the second MT (p=0.031). Successful reperfusion was achieved in 91.4% after the first MT and in 86.2% patients after the second MT (p=0.377). The rate of functional independence (mRS 0-2) was 46% at 90 days after the second procedure.

CONCLUSION

Repeated MT in short-term recurrent LVO is a rarity but appears to be safe and effective. The second thrombectomy should be pursued with the same extensive effort as the first procedure as these patients may achieve similar good outcomes.

Impact of early division of the middle cerebral artery on outcome following mechanical thrombectomy

BACKGROUND

Mechanical thrombectomy has become the standard care for acute ischemic stroke caused by large vessel occlusion. However, complete reperfusion cannot be achieved in all cases, and several factors influencing the results of mechanical thrombectomy have been investigated. Among others, a tortuous anatomy is associated with lower rates of complete reperfusion. We aimed to investigate whether an early division of the middle cerebral artery has an impact on reperfusion results in mechanical thrombectomy.

METHODS

Retrospective review of consecutive patients with M1 occlusion treated endovascularly between January 2016 and December 2019 at three tertiary care centers. The study group was dichotomized based on the length of the M1 segment. Early division of the middle cerebral artery was defined as a maximum length of 10 mm of the M1 segment. Primary endpoints were first-pass mTICI scores of 3, ≥2c, and ≥2b. Secondary endpoints contained final reperfusion, number of device-passes, time interval from groin puncture to reperfusion, rate of postinterventional symptomatic intracranial hemorrhage, and frequency of emboli of new territory.

RESULTS

Among 284 included patients, 70 presented with an early division of the M1 segment (25%). Reperfusion results did not differ significantly between early and late division of M1. A higher rate of symptomatic intracranial hemorrhage was found in the group with an early M1 division treated with aspiration only (14.3% vs. 0%; p = 0.013). Patients with late M1 division had a significantly higher rate of large artery sclerosis (19.2% vs. 8.6%, p = 0.039).

CONCLUSION

The anatomic variant of an early division of the middle cerebral artery was not a predictor for incomplete reperfusion.

Hybrid mechanical thrombectomy for acute ischemic stroke using an intermediate aspiration catheter and Trevo stent simultaneously

PURPOSE

To overcome the limitations of traditional mechanical thrombectomy (MT), including catheter aspiration and stent retrievers, such as thrombus fragmentation or migration, we designed hybrid MT using an intermediate aspiration catheter and a Trevo stent simultaneously. We retrospectively compared hybrid MT with the traditional MT.

METHODS

From January 2017 to January 2019, we performed MT on 91 occlusions, including internal carotid artery bifurcation (n = 17), M1 segment (n = 53) and M2 segment (n = 21), using hybrid MT (n = 42) and traditional MT (n = 49).

RESULTS

Hybrid MT had a shorter procedure time (52.4 ± 22.0 vs. 73.0 ± 36.2 min, p = 0.002) and fewer attempts (1.50 ± 0.86 vs. 1.92 ± 1.10 times, p = 0.049) than traditional MT did. Hybrid MT achieved more good clinical outcome (3-month modified Rankin Scale score, 2 or less) and better successful recanalization (Thrombolysis In Cerebral Infarction grade, 2b or 3) than traditional MT did, but the difference was not significant (61.9% vs. 55.1%, p = 0.531, 92.9% vs. 87.8%, p = 0.498). Hybrid MT showed a higher first pass successful recanalization rate than traditional MT did (69.0% vs. 40.8%, p = 0.011). Multivariable logistic regression analysis demonstrated that first pass successful recanalization is related to the M1 segment rather than other segments (adjusted odds ratio (OR); 3.277, confidence interval (CI); 1.227-8.749, p = 0.018) and hybrid MT rather than traditional MT (adjusted OR; 4.995, CI; 1.725-14.460, p = 0.003).

CONCLUSIONS

Hybrid MT can be used as a first-line MT modality, particularly in M1 occlusion, based on our high first pass successful recanalization results.

Optimizing Stroke Care for Patients with Large Vessel Occlusions: Current State of the Art and Future Directions

Acute ischemic stroke (AIS) is a severely disabling disease. Endovascular therapy is a powerful and highly effective treatment option for these patients and has recently become standard of care. The benefits of endovascular treatment (EVT) are tremendous both from a patient and from an economic perspective, since it dramatically improves individual patient outcomes while reducing long-term healthcare costs at the same time. The effect of EVT is highly time-dependent. Thus, the overarching goal in AIS is to quickly transport and diagnose the patient to minimize treatment delays. In this review, we provide an overview about the current state of stroke care, propose a fast and simplified imaging protocol and management approach for AIS patients. We also highlight the challenges we are currently facing in endovascular stroke treatment and suggest possible solutions to overcome these.

Public Health and Cost Benefits of Successful Reperfusion After Thrombectomy for Stroke

Background and Purpose—

The benefit that endovascular thrombectomy offers to patients with stroke with large vessel occlusions depends strongly on reperfusion grade as defined by the expanded Thrombolysis in Cerebral Infarction (eTICI) scale. Our aim was to determine the lifetime health and cost consequences of the quality of reperfusion for patients, healthcare systems, and society.

Methods—

A Markov model estimated lifetime quality-adjusted life years (QALY) and lifetime costs of endovascular thrombectomy–treated patients with stroke based on eTICI grades. The analysis was performed over a lifetime horizon in a United States setting, adopting healthcare and societal perspectives. The reference case analysis was conducted for stroke at 65 years of age. National health and cost consequences of improved eTICI 2c/3 reperfusion rates were estimated. Input parameters were based on best available evidence.

Results—

Lifetime QALYs increased for every grade of improved reperfusion (median QALYs for eTICI 0/1: 2.62; eTICI 2a: 3.46; eTICI 2b: 5.42; eTICI 2c: 5.99; eTICI 3: 6.73). Achieving eTICI 3 over eTICI 2b reperfusion resulted on average in 1.31 incremental QALYs as well as healthcare and societal cost savings of $10 327 and $20 224 per patient. A 10% increase in the eTICI 2c/3 reperfusion rate of all annually endovascular thrombectomy–treated patients with stroke in the United States is estimated to yield additional 3656 QALYs and save $21.0 million and $36.8 million for the healthcare system and society, respectively.

Conclusions—

Improved reperfusion grants patients with stroke additional QALYs and leads to long-term cost savings. Procedural strategies to achieve complete reperfusion should be assessed for safety and feasibility, even when initial reperfusion seems to be adequate.

Retrieval of floating clot in the internal carotid artery: extracranial SAVE technique (eSAVE)

Acutely ruptured atherosclerotic plaques with adjacent floating clot within the internal carotid artery in patients suffering from extra-/intracranial tandem lesions are often treated with stent-assisted balloon angioplasty. We present a strategy to retrieve the extracranial thrombus using the "stent retriever assisted vacuum-locked extraction" (SAVE) method, which initially was described for the intracranial vasculature. The extracranial SAVE (eSAVE) method could be an additional tool for the treatment of acute tandem lesions.

Etiology of recurrent large vessel occlusions treated with repeated thrombectomy

BACKGROUND

Repeated mechanical thrombectomy for acute stroke treatment in individual patients has been proven feasible. However, less is known about the etiology of recurrent vessel occlusions after prior thrombectomy. We aimed to understand if the etiology of such recurrent events differs from the first stroke.

METHODS

Retrospectively, we identified all patients at our center who received a repeated mechanical thrombectomy between 2007 and 2019. Clinical data were retrieved from medical records. Etiology of stroke was evaluated retrospectively, and angiographic studies were revisited.

RESULTS

Twenty-three patients (1.5%) were identified. Median age was 68 years (IQR 56-77). Median NIHSS at first admission was 11 points (IQR 5-15). In nine cases (39.1%), the recurrent vessel occlusion was located exactly at the same position as the prior occlusion. Overall, five (21.7%) patients had a remarkable extracranial pathology as likely cause of stroke recurrence. In 16 patients (69.6%), the etiology of the first stroke and its recurrence was considered as likely being the same, mostly of cardioembolic or unknown origin. In the seven remaining patients (30.4%), the cause of stroke possibly differed from the first event, with five patients (21.7%) having a postinterventional intracranial intimal lesion as possible cause of stroke.

CONCLUSION

Incidence of repeated thrombectomy was low. However, the high number of patients with known origin of stroke etiology raises the question how their monitoring may be optimized. The number of patients with remarkable extracranial pathologies or intracranial endothelial lesions supports current clinical practice to pay attention to final angiographic series.

Simultaneous revascularization of the occluded internal carotid artery using the Solitaire as a workhorse wire during acute ischemic stroke intervention

INTRODUCTION

Tandem lesions involving a large vessel occlusion intracranially with concomitant cervical carotid critical stenosis or occlusion are a common presentation of acute ischemic stroke. These lesions are both challenging and time-consuming but can be extremely beneficial for patients when successful. We present a technique utilizing the pusher wire of the stent retriever used for intracranial thrombectomy as the workhorse wire for carotid intervention using a monorail system to perform cervical carotid angioplasty.

METHODS

We reviewed four successive patients who presented with a tandem occlusion and underwent thrombectomy and simultaneous carotid artery intervention using this technique.

RESULTS

All four patients had radiographically successful intracranial thrombectomy and cervical carotid revascularization. Time from groin puncture to intracranial stent retriever deployment was 63 min on average. Then, using the pusher wire as a monorail workhorse, time from stent retriever deployment to carotid angioplasty was on average 6 min.

DISCUSSION

This technique allows for cervical carotid revascularization to begin during the recommended 5-min wait time after stent retriever deployment, allowing for rapid near-simultaneous revascularization across both lesions. This technique has been reported briefly in the past for management of a cervical dissection. There is continued debate regarding the management of tandem occlusions, as to which lesion should be managed first.

CONCLUSION

As the management paradigms of tandem occlusions continue to evolve, this technique may improve outcomes by expediting endovascular intervention. Using the stent retriever wire provides a method of expediting the management of the proximal lesion after addressing the more distal intracranial occlusion first.