Institutional and provider variations for mechanical thrombectomy in the treatment of acute ischemic stroke: a survey analysis

Endovascular Thrombectomy for Acute Ischemic Stroke : Current Concept in Management

Endovascular thrombectomy (EVT) has been established as the standard of care in the treatment of acute ischemic stroke (AIS) based on landmark randomized controlled trials. Nevertheless, while the strict eligibility of EVT for AIS patients restrict the wide application of EVT, a considerable population still undergoes off-label EVT. Besides, it is important to acknowledge that recanalization is not achieved in approximately 20% of procedures, and more than 50% of patients who undergo EVT still do not experience a favorable outcome. This article reviews the brief history of EVT trials and recent progressions in the treatment of AIS, with focusing on the expanding eligibility criteria, new target for EVT, and the evolution of EVT techniques.

Flow reversal during stroke thrombectomy

When performing mechanical thrombectomy for stroke patients, some physicians use balloon guide catheters (BGCs) in order to achieve flow reversal and thereby improve reperfusion quality. There is substantial evidence favoring the use of BGCs to improve reperfusion rates and clinical outcomes for thrombectomy patients; however, as we will outline in this review, there is also evidence that BGCs do not achieve reliable flow reversal in many circumstances. Therefore, if we are able to modify our techniques to improve the likelihood of flow reversal during thrombectomy maneuvers, we may be able to further improve reperfusion quality and clinical outcomes. This paper provides an overview of concepts on this topic and outlines some potential techniques to facilitate flow reversal more consistently, including a method to visually confirm it, with the aim of making iterative improvements towards optimal reperfusion for stroke patients.

Intracranial Carotid Occlusions : ADAPT versus SAVE and the role of Balloon Guide Catheters

PURPOSE

Specific decisions made by neurointerventionists are often lost behind the data of large-scale trials, and many of these studies have taken place before the development of new techniques and devices. This study compares the stent-retriever assisted vacuum-locked extraction (SAVE) technique with a direct aspiration first pass (ADAPT), as well as the use of a balloon guide catheter (BGC), in intracranial internal carotid artery (IC-ICA) occlusions.

METHODS

Observational and retrospective study from an Italian hospital, including patients who underwent thrombectomy for IC-ICA occlusion between 1 January 2019 and 31 March 2021.

RESULTS

Out of 91 IC-ICA occlusions, the ADAPT was the first choice in 20 (22%) and the SAVE in 71 (78%). A BGC was used in 32 (35%) cases, always in conjunction with the SAVE technique. The use of SAVE technique without BGC was associated with the least risk of distal embolization (DE) in the territory occluded (44% vs. 75% when ADAPT technique was used; p = 0.03) and achieved first pass effect (FPE) more frequently (51% vs. 25%, p = 0.09). When the SAVE technique was used, BGC (BGC-SAVE) compared to no BGC (NoBGC-SAVE) was associated with a tendency for less DE (31% vs. 44%, p = 0.3), more FPE (63% vs. 51%, p = 0.5), the same median number of passes (1, p = 0.8) and similar groin-to-recanalization times (36.5 vs. 35.5 min, p = 0.5), none of which reached statistical significance.

CONCLUSION

Our findings support the use of SAVE technique for IC-ICA occlusions; the added benefit of BGC compared to long sheaths was not remarkable in this sample.

Effect of Standardized Perioperative Management on EEG Indexes and Nerve and Limb Functions of Patients with Acute Cerebral Infarction Undergoing Mechanical Thrombectomy

Objective

To explore the application value of standardized perioperative management in mechanical thrombectomy for acute cerebral infarction.

Methods

98 patients with acute cerebral infarction admitted to our hospital from January 2019 to January 2022 were selected as the study sample in this study, and all patients were given the standardized perioperative management. According to the interventional methods, they were divided into the thrombolytic treatment group (arteriovenous combined thrombolysis, n = 49) and mechanical thrombectomy group (mechanical thrombectomy, n = 49) to compare the nerve function, limb function, thrombolysis in myocardial infarction (TIMI) flow grade, symptomatic intracranial hemorrhage within 24 hours, acute vascular reocclusion, and the death status within 1 year and incidence of adverse events in 90 days of the two groups after treatment.

Results

After treatment, the values of brain symmetry index (BSI) and power ratio indices (DTABR) in the two groups were obviously lower than those before treatment (P < 0.05), and the values of BSI and DTABR in the mechanical thrombectomy group were lower than those in the thrombolytic treatment group (P < 0.05). According to the statistical data of National Institutes of Health Stroke Scale (NIHSS) score in patients, the NIHSS scores of the two groups after treatment were visibly decreased (P < 0.05), while the NIHSS score in the mechanical thrombectomy group after treatment was lower than that in the thrombolytic treatment group (P < 0.05). The proportion of modified Rankin scale (mRS) score < 3 in the mechanical thrombectomy group was distinctly higher than that in the thrombolytic treatment group (P < 0.05). The proportion of TIMI flow grade ≥ 2 in the mechanical thrombectomy group was significantly higher than that in the thrombolytic treatment group (P < 0.05). The rate of symptomatic intracranial hemorrhage within 24 hours in the mechanical thrombectomy group was lower than that in the thrombolytic treatment group (P < 0.05), with the indistinctive difference between the two groups (P > 0.05). The incidence of acute vascular reocclusion in the mechanical thrombectomy group was markedly lower than that in the thrombolytic treatment group (P < 0.05). There was no significant difference in 1-year mortality between the two groups (P > 0.05). In the mechanical thrombectomy group, there were 1 case of gingiva bleeding, 1 case of hemorrhinia, and 2 cases of recurrent cerebral infarction in 90 days, with a total of 4 cases (8.16%), while in the thrombolytic treatment group, there were 4 cases of gingiva bleeding, 4 cases of hemorrhinia, and 15 cases of recurrent cerebral infarction in 90 days, with a total of 23 cases (46.94%), indicating that the incidence of adverse events in 90 days in the mechanical thrombectomy group was significantly lower than that in the thrombolytic treatment group (P < 0.05).

Conclusion

The standardized perioperative management is effective in patients with acute cerebral infarction who were treated with arteriovenous combined thrombolysis or mechanical thrombectomy, which can improve the neurological function and physical function of patients. However, the mechanical thrombectomy has a better improvement effect on the neurological function and physical function of patients, with the relatively better safety, thrombolytic effect, and long-term prognosis.

Blind exchange technique to facilitate large-bore aspiration catheter navigation during stroke thrombectomy

OBJECTIVES

Optimizing mechanical thrombectomy (MT) techniques is an essential facet of our developing field. Herein, we describe the "Blind exchange" (BE) technique; an alternative fashion of efficiently performing stent-retriever (SR) coupled with contact aspiration thrombectomy (aspiration-retriever technique for stroke-ARTS).

METHODS

A prospectively collected MT database was reviewed from July 2018-February 2020. We included all consecutive patients with anterior circulation large vessel occlusions in whom BE technique was performed. According to the response of the retriever, the decision to add an aspiration catheter (AC) for ARTS was made. The microcatheter was then fully retracted and the AC tracked over the deployed SR wire in a BE fashion. The primary outcome was technical success and safety measures included procedural-related complications.

RESULTS

One hundred nineteen patients were identified, mean age was 66.7 ± 15.8 years and 57(47.9%) were males. Twenty-six patients (21.8%) had intracranial ICA occlusion and 93(78.2%) had MCA-M1 segment occlusion. The median ASPECTS was 7(IQR;8-9), baseline NIHSS score was 18(IQR;14-21), and procedure time was 36(IQR;25-57) minutes. IV-tPA was used in 26(21.8%) of cases. Successful reperfusion (eTICI2b-3) was achieved in 100% of cases including full reperfusion (eTICI3) in 67(56.3%) of cases. The AC was successfully navigated into the target lesion without any complications in all cases. Symptomatic intracranial hemorrhage occurred in 4.2% of patients. The rates of 90-day mRS0-2 and mortality were 44.3% and 12.5%, respectively.

CONCLUSION

BE is a safe and feasible alternative technique of navigating large bore AC into the intracranial vasculature while performing ARTS.

Balloon guide catheters: use, reject, or randomize?

Thrombectomy devices played an important role in the success of endovascular treatment trials over the past five years. A balloon guide catheter (BGC) is an adjunctive device used to arrest and reverse flow by inflating the balloon at its tip, which allows for flow reversal in intracranial arteries during retrieval of thrombectomy devices by applying concomitant aspiration through its lumen. Thereby, it can decrease the risk of clot fragmentation and distal embolization. Despite the numerous benchtop and clinical observational studies showing the superiority of BGC to conventional guide catheters in improving reperfusion quality and clinical outcome, its use is still low in clinical practice. The reasons behind this reluctance might be related to technical and cost issues. Therefore, high level evidence data, i.e., a randomized clinical trial, are needed to increase its implementation in thrombectomy procedures. Nonetheless, several obstacles and challenges can prevent the completion of such a trial, and efforts are needed to overcome them. We provide an overview of the current opinions about BGCs in the neurointerventional community and discuss the feasibility and challenges of a possible randomized trial to answer the question "should a BGC be routinely used in endovascular treatment of acute ischemic stroke?"

Access-site complications in ultrasound-guided endovascular thrombectomy: a single-institution retrospective cohort study

OBJECTIVE

Mechanical endovascular thrombectomy (EVT) is an increasingly relied-on treatment for clot retrieval in the context of ischemic strokes, which otherwise are associated with significant morbidity and mortality. Despite several known risks associated with this procedure, there is a high degree of technical heterogeneity across both centers and operators. The most common procedural complications occur at the point of transfemoral access (the common femoral artery), and include access-site hematomas, dissections, and pseudoaneurysms. Other interventional fields have previously popularized the use of ultrasound to enhance the anatomical localization of structures relevant to vascular access and thereby reducing access-site complications. In this study, the authors aimed to describe the ultrasound-guided EVT technique performed at a large, quaternary neurovascular referral center, and to characterize the effects of ultrasound guidance on access-site complications.

METHODS

A retrospective chart review of all patients treated with EVT at a single center between January 2013 and August 2020 was performed. Patients in this cohort were treated using a universal, unique, ultrasound-guided, single-wall puncture technique, which bears several theoretical advantages over the standard technique of arterial puncture via palpation.

RESULTS

There were 479 patients treated with EVT within the study period. Twenty patients in the cohort were identified as having experienced some form of access-site complication. Eight (1.67%) of these patients experienced minor access-site complications, all of which were groin hematomas and none of which were clinically significant, as defined by requiring surgical or interventional management or transfusion. The remaining 12 patients experienced arterial dissection (n = 5), arterial pseudoaneurysm (n = 4), retroperitoneal hematoma (n = 2), or arterial occlusion (n = 1), with only 1.04% (5/479) requiring surgical or interventional management or transfusion.

CONCLUSIONS

The authors found an overall reduction in total access-site complications as well as minor access-site complications in the study cohort compared with previously published randomized controlled trials and observational studies in the recent literature. The findings suggested that there may be a role for routine use of ultrasound-guided puncture techniques in EVT to decrease rates of complications.

Clot composition of embolic strokes of undetermined source: a feasibility study

BACKGROUND

A number of emerging studies have evaluated clot composition in acute ischemic stroke. Studies of clot composition of embolic strokes of undetermined strokes are lacking.

OBJECTIVES

We sought to analyze the RBC to platelet ratios in clots and correlated our findings with stroke etiology.

METHODS

This was a prospective study analyzing clots retrieved by mechanical thrombectomy in acute ischemic stroke patients at our institution. All clots were stained and scanned at 200x magnification by using a Scanscope XT digital scanner (Apergio, Vista, California). Image-J software (National Institutes of Health, Bethesda, Maryland) was used for semi quantitative analysis of percentage RBC's and platelets. Unpaired t-test was used to compare means of RBC to Platelet ratios. Correlation of RBC to Platelet ratios with stroke etiology was performed.

RESULTS

A total of 33 clots from 33 patients were analyzed. Stroke etiology was undetermined in 6 patients, cardioembolic in 14, large vessel atherosclerosis (LVA) in 9, and carotid dissection in 4. The mean RBC to platelet ratio was 0.78:1 (+/- 0.65) in cardioembolic clots, 1.73:1 (+/- 2.38) in LVA and 1.4:1(+/- 0.70) in carotid dissections. Although patients with undetermined etiology had a similar clot composition to cardioembolic stroke (0.36:1+/- 0.33), (p = 0.19), it differed significantly from LVA and dissections respectively (p = 0.037, p = 0.01).

CONCLUSION

In our study, a low RBC to Platelet ratio was found among patients with embolic strokes of undetermined source, however shared similar characteristics with cardioembolic thrombi. Ongoing collection and analysis is needed to confirm these findings and its significance in evaluating stroke etiology.

Comparison of First-Pass Efficacy Among Four Mechanical Thrombectomy Techniques: A Single-Center Experience

BACKGROUND

First-pass efficacy (FPE) is an established marker of technical and clinical efficacy among mechanical thrombectomy (MT) techniques. It is unclear what the optimal approach is in achieving FPE. We present a single-center experience comparing rates of FPE among 2 MT techniques and evaluate the potential predictors of FPE among other outcomes.

METHODS

A single-center retrospective analysis was carried out of patients with consecutive large-vessel occlusion strokes (LVOS) of anterior circulation from September 2015 to April 2019 who underwent MT and for whom data were available on the status of FPE. Four MT techniques were identified: ADAPT (a direct first-pass aspiration), SrADAPT (stent retriever with aspiration), SRBG (stent retriever with balloon guide catheter), and STRAP (stent retriever-aspiration and proximal flow arrest). The primary outcome was FPE and secondary outcomes included the rate of successful reperfusion.

RESULTS

Among 226 patients with LVOS of the anterior circulation who underwent MT, data were available for 164 on FPE for the 4 MT techniques. SRBG was the most prevalent technique. No significant difference was found in rates of FPE among the 4 MT techniques (P = 0.332). No independent predictors of FPE were identified on multivariable analysis. STRAP had the highest rate of successful reperfusion compared with the other techniques (P = 0.049) and was the only independent predictor of that outcome (P = 0.027).

CONCLUSIONS

Among patients with LVOS of the anterior circulation, the rate of FPE did not differ among the 4 MT techniques. There were no predictors of FPE among the studied variables. STRAP was the only predictor of successful reperfusion.

Impact of the COVID-19 pandemic on the process and outcome of thrombectomy for acute ischemic stroke

BACKGROUND

The novel coronavirus disease 2019 (COVID-19) pandemic is still spreading across the world. Although the pandemic has an all-round impact on medical work, the degree of its impact on endovascular thrombectomy (EVT) for patients with acute ischemic stroke (AIS) is unclear.

METHODS

We continuously included AIS patients with large artery occlusion who underwent EVT in a comprehensive stroke center before and during the Wuhan shutdown. The protected code stroke (PCS) for screening and treating AIS patients was established during the pandemic. The efficacy and safety outcomes including the rate of successful reperfusion (defined as modified Thrombolysis In Cerebral Infarction (mTICI) graded 2b or 3) and time intervals for reperfusion were compared between two groups: pre-pandemic and pandemic.

RESULTS

A total of 55 AIS patients who received EVT were included. The baseline characteristics were comparable between the two groups. The time from hospital arrival to puncture (174 vs 125.5 min; p=0.002) and time from hospital arrival to reperfusion (213 vs 172 min; p=0.047) were significantly prolonged in the pandemic group compared with the pre-pandemic group. The rate of successful reperfusion was not significantly different between the two groups (85.7% (n=18) vs 88.2% (n=30); OR 0.971, 95% CI 0.785 to 1.203; p=1.000).

CONCLUSION

The results of this study suggest a proper PCS algorithm which combines the COVID-19 screening and protection measures could decrease the impact of the disease on the clinical outcomes of EVT for AIS patients to the lowest extent possible during the pandemic.

Contemporary Management of Acute Ischemic Stroke Across the Continuum: From TeleStroke to Intra-Arterial Management

In this comprehensive contemporary review of acute ischemic stroke management, what is new and different will be highlighted beginning with prehospital stroke systems of care, emergency medical systems, and mobile stroke units, followed by hospital stroke teams, emergency evaluation, telemedicine, and brain and vascular imaging, and finishing with emergency treatments including thrombolysis and mechanical thrombectomy.

Understanding the Radial Force of Stroke Thrombectomy Devices to Minimize Vessel Wall Injury: Mechanical Bench Testing of the Radial Force Generated by a Novel Braided Thrombectomy Assist Device Compared to Laser-Cut Stent Retrievers in Simulated MCA Vessel Diameters

Background

Recent reports have raised various concerns about the risk of vessel wall injury while withdrawing current laser-cut stent retrievers during active strut apposition to the vessel walls. The development of braided thrombectomy assist devices in conjunction with aspiration systems may be gentler on the fragile brain vessels and more optimized with regard to the radial force (RF) for vessel diameters of proximal (M1) and distal (M2) large vessel occlusions (LVOs).

Methods

Mechanical bench testing of the RF was performed using a radial compression station mounted on a tensile testing machine. The total RF in newtons (N) generated in vessels with diameters ranging from 2.25 to 3 mm as seen in proximal LVOs (∼M1), and in vessel diameters ranging from 1.5 to 2.24 mm as seen in distal LVOs (∼M2), was measured. The outer diameter of each stent was recorded, and an RF ≤1 N was grouped as "low," while an RF >1 N was grouped as "high" for this analysis.

Results

The total RFs of all laser-cut stent retrievers were all higher in the simulated M2 vessels (>1 N) than in the M1 vessels (<1 N), whereas the total RFs of the braided thrombectomy assist devices were uniformly low in both the simulated M1 and the simulated M2 vessels.

Conclusions

Novel braided thrombectomy assist devices in conjunction with aspiration systems have lower RFs than existing laser-cut stent retrievers in M1 and M2 vessel diameters. Further in vivo studies are needed to delineate the impact of lowering the RF on vessel wall integrity.

Endovascular treatment decision in acute stroke: does physician gender matter? Insights from UNMASK EVT, an international, multidisciplinary survey

Background and purpose

Differences in the treatment practice of female and male physicians have been shown in several medical subspecialties. It is currently not known whether this also applies to endovascular stroke treatment. The purpose of this study was to explore whether there are differences in endovascular treatment decisions made by female and male stroke physicians and neurointerventionalists.

Methods

In an international survey, stroke physicians and neurointerventionalists were randomly assigned 10 case scenarios and asked how they would treat the patient: (A) assuming there were no external constraints and (B) given their local working conditions. Descriptive statistics were used to describe baseline demographics, and the adjusted OR for physician gender as a predictor of endovascular treatment decision was calculated using logistic regression.

Results

607 physicians (97 women, 508 men, 2 who did not wish to declare) participated in this survey. Physician gender was neither a significant predictor for endovascular treatment decision under assumed ideal conditions (endovascular therapy was favored by 77.0% of female and 79.3% of male physicians, adjusted OR 1.03, P=0.806) nor under current local resources (endovascular therapy was favored by 69.1% of female and 76.9% of male physicians, adjusted OR 1.03, P=0.814).

Conclusion

Endovascular therapy decision making between male and female physicians did not differ under assumed ideal conditions or under current local resources.