Higher Annual Operator Volume Is Associated With Better Reperfusion Rates in Stroke Patients Treated by Mechanical Thrombectomy

The effect of operator's experience on mechanical thrombectomy outcomes: A systematic review

BACKGROUND

Mechanical thrombectomy (MT) has become the standard of care for stroke patients. The majority of the clinical trials and publications analyzing the outcomes related to the procedures report interventional performance by experienced practitioners. However, few of them individualize their preliminary metrics according to the operator's experience.

OBJECTIVE

To summarize the literature and report safety and efficacy outcomes following MT procedures and correlate them with the operator's experience. Primary outcomes were successful recanalization, defined as modified thrombolysis in cerebral infarction greater or equal to 2b or 3, duration of the procedure measured in minutes, and serious adverse event.

METHODS

This systematic review was performed according to the PRISMA guidelines. The PubMed, Embase, and Cochrane databases were utilized.

RESULTS

There were six studies comprising 9348 patients (mean age 69.8 years; 51.2% males), and 9361 MT procedures were included. Each publication used for this review used a different experience definition to report their data. Higher interventionists' experience demonstrated a positive relationship with the possibility of successful recanalization and an inverse relationship with the duration needed for the operation in almost all of the included studies. As for the complications, none of the authors reported a statistically significant risk reduction of an adverse event, except Olthuis et al. correlating increasing training with lower odds of stroke progression.

CONCLUSIONS

A higher experience level is associated with better recanalization rates and shorter procedural duration in MT operations. Further studies are warranted to define the minimum required level of experience for operational autonomy.

Initiation of mechanical thrombectomy in an insular setting with helicopter transfer: a 2-year experience from the first, complete, tertiary stroke center in the Caribbean

BACKGROUND

This is the first cohort study of patients treated with mechanical thrombectomy (MT) for acute ischemic stroke in the French West Indies, with a mothership center and helicopter transfer.

OBJECTIVE

To describe the population and to evaluate imaging, clinical, and time metric outcomes, in order to assess the feasibility and adjust the territorial organization.

METHODS

In this observational study, we retrospectively analyzed our prospectively collected data of a population of consecutive patients treated with MT for anterior and posterior circulation large vessel occlusions. Primary outcome was 3-month functional independence (modified Rankin Scale score ≤2). Secondary outcomes included aerial and terrestrial times of arrival, in-hospital delays, demographics, imaging and clinical data at onset, discharge, and at 3 months. We compared the results of the mothership and drip-and-ship paradigms.

RESULTS

Between January 2020 and December 2021, 223 patients were included (74% mothership, 26% drip-and-ship). Mean National Institutes of Health Stroke Scale (NIHSS) score of the population was 16 before MT, with significant reduction (NIHSS score 6) at discharge (9 mothership, 12 drip-and-ship, P=0.025). There was significant difference in onset-to-operation room times among the two centers (335 min mothership, 500 min drip-and-ship, P=0.004). Successful recanalization (modified Thrombolysis in Cerebral Infarction score 2b-3) was 80.3%. Functional independence at 3 months was 35%, symptomatic intracranial hemorrhage was 11%, and the complication rate was 9.4%, all without statistically significant difference between the two groups.

CONCLUSION

The population has distinct risk factors. MT with helicopter transfer is feasible in the French West Indies. Reduction of prehospital and in-hospital times is mandatory; evaluation of the territorial strategy is underway, to avoid over-selection of transferred patients.

High mechanical thrombectomy procedural volume is not a reliable predictor of improved thrombectomy outcomes in patients with acute ischemic stroke in the United States

BACKGROUND

The volume of mechanical thrombectomy (MT) performed at hospitals is used as one of the criteria for advanced-level designation for stroke care.

OBJECTIVE

Our study sought to determine the relationship between annual MT procedural volume and in-hospital outcomes in acute ischemic stroke patients undergoing MT in the United States.

METHODS

We analyzed the National Inpatient Sample from 2016 to 2020. The hospitals were grouped into quartiles based on the volume of MT procedures performed within the calendar year. We compared the rates of routine discharge/home health care; in-hospital mortality, and post-treatment intracranial hemorrhage (ICH) between the quartiles after adjusting for potential confounders.

RESULTS

Patients undergoing MT ranged from 15,395 in quartile 1 to 78,510 MT in quartile 4. There were lower rates of discharge home/self-care of 22.5%, 20.8%, and 20.8% for quartiles 2, 3, and 4, respectively, compared with 34.9% in quartile 1. The odds of ICH increased to 1.81 (p < 0.001), 1.84 (p < 0.001), and 1.98 (p < 0.001) among the quartiles from lowest to highest procedural volumes. The odds of home discharge/self-care decreased to 0.66 (p < 0.001), 0.60 (p < 0.001), and 0.63 (p < 0.001) among the quartiles from lowest to highest procedural volumes. The odds of in-hospital mortality increased to 1.92 (p < 0.001), 1.99 (p < 0.001), and 1.84 (p < 0.001) among the quartiles from lowest to highest procedural volumes.

CONCLUSIONS

We observed a paradoxical relationship between adverse outcomes and the annual procedural volume of MT at the hospital presumably due to the higher severity of acute ischemic stroke treated at high-volume hospitals.

Comparison of predictors of failure of early neurological improvement after successful endovascular treatment for posterior and anterior circulation large vessel occlusion: Data from ANGEL-ACT registry

PURPOSE

To identify and compare the predictors of failure of early neurological improvement (fENI)after successful EVT for anterior circulation large vessel occlusion (ACLVO) and posterior circulation LVO (PCLVO).

METHODS

Subjects were selected from the ANGEL-ACT registry. fENI was defined as unchanged or worsened in National Institutes of Health Stroke Scale score (NIHSS) between admission and 24 h after EVT. Predictors of fENI after successful EVT (mTICI 2b-3) were determined via center-adjusted analyses. Univariable and multivariable comparisons between ACLVO and PCLVO were performed.

RESULTS

A total of 1447 patients, 1128 were with ACLVO, and 319 were with PCLVO. Among the patients with ACLVO, there were 409 patients (36.3%) with fENI and 719 patients (63.7%) with ENI. We observed that pre-stroke mRS scale score of 2 (odd ratio[OR] 95% confidence interval[CI], 6.93[1.99-24.10], P = 0.002), initial NIHSS score (OR per point[95%CI], 0.97[0.95-0.99], P = 0.012), diabetes (OR[95%CI], 1.56[1.08-2.25], P = 0.017), previous ICH (OR[95%CI] 9.21[1.76-48.15], P = 0.008), local anesthesia (OR[95%CI] 1.63[1.10-2.42], P = 0.014), onset-to-puncture time (OR[95%CI], 1.001[1.000-1.001], P = 0.009), symptomatic ICH (OR[95%CI] 3.90[2.27-6.69], P < 0.001), and continued use of tirofiban within 2 h after EVT (OR[95%CI], 0.69[0.51-0.93], P = 0.014) were independent predictors of fENI of ACLVO after EVT. Among the patients with PCLVO, there were 112 patients (35.1%) with fENI and 207 patients (64.9%) with ENI. In contrast, admission SBP (OR[95%CI], 0.98[0.97-0.99], P = 0.012), and vascular dissection within 2 h after EVT (OR[95%CI], 7.23[1.33-39.13], P = 0.022) were independent predictors of fENI of PCLVO after EVT.

CONCLUSION

In selected patients, successful EVT can lead to similar outcomes in PCLVO and ACLVO. Some predictors of fENI in both anterior circulation and posterior circulation were identified in our study, which should be highly considered in the clinical practice in LVO patients undergoing EVT.

Higher proceduralist stroke thrombectomy volume is associated with reduced inpatient mortality

BACKGROUND

The aim of this study was to determine the impact of endovascular thrombectomy (EVT) proceduralist volume on in-hospital mortality in acute ischemic stroke (AIS) patients.

METHODS

We performed a retrospective cohort study using the 2020 Florida State Inpatient Database, including adult patients who had a diagnosis of AIS and underwent EVT during the same admission. The primary study outcome was in-hospital death. We used Youden's Index to define an optimal threshold for number of EVTs/year/provider. Based on this cut-point, the cohort was dichotomized into low and high proceduralist volume groups. We fit logistic regression models to mortality in the full cohort, both as univariate analyses and after adjusting for covariates.

RESULTS

Among 3143 AIS patients who underwent EVT, 1907 patients across 59 hospitals and 106 providers met our inclusion criteria. Among the providers, the median number of EVTs performed was 13.5 (IQR 7-25). The optimal cut-point was 17 EVTs. Demographics and comorbidities were similar between the cohorts. The high volume strata had a lower rate of in-hospital mortality (low volume 11.0% vs high volume 7.2%, P=0.005). After adjusting for potential confounders, high proceduralist volume remained significantly associated with lower odds of in-hospital death (OR 0.52, 95% CI 0.36 to 0.76, P=0.001). The difference in absolute risk of death was 4.8% (P=0.005).

CONCLUSIONS

We found that high proceduralist volume, defined by ≥18 EVTs/year, was associated with reduced in-hospital morality. Further research is necessary to understand the effects of proceduralist experience and benchmarks for technical proficiency in stroke care.

Modeling Robotic-Assisted Mechanical Thrombectomy Procedures with the CorPath GRX Robot: The Core-Flow Study

BACKGROUND AND PURPOSE

Endovascular robotic devices may enable experienced neurointerventionalists to remotely perform endovascular thrombectomy. This study aimed to assess the feasibility, safety, and efficacy of robot-assisted endovascular thrombectomy compared with manual procedures by operators with varying levels of experience, using a 3D printed neurovascular model.

MATERIALS AND METHODS

M1 MCA occlusions were simulated in a 3D printed neurovascular model, linked to a CorPath GRX robot in a biplane angiography suite. Four interventionalists performed manual endovascular thrombectomy (n = 45) and robot-assisted endovascular thrombectomy (n = 37) procedures. The outcomes included first-pass recanalization (TICI 2c-3), the number and size of generated distal emboli, and procedural length.

RESULTS

A total of 82 experimental endovascular thrombectomies were conducted. A nonsignificant trend favoring the robot-assisted endovascular thrombectomy was observed in terms of final recanalization (89.2% versus manual endovascular thrombectomy, 71.1%; P = .083). There were no differences in total mean emboli count (16.54 [SD, 15.15] versus 15.16 [SD, 16.43]; P = .303). However, a higher mean count of emboli of > 1 mm was observed in the robot-assisted endovascular thrombectomy group (1.08 [SD, 1.00] versus 0.49 [SD, 0.84]; P = .001) compared with manual endovascular thrombectomy. The mean procedural length was longer in robot-assisted endovascular thrombectomy (6.43 [SD, 1.71] minutes versus 3.98 [SD, 1.84] minutes; P < .001). Among established neurointerventionalists, previous experience with robotic procedures did not influence recanalization (95.8% were considered experienced; 76.9% were considered novices; P = .225).

CONCLUSIONS

In a 3D printed neurovascular model, robot-assisted endovascular thrombectomy has the potential to achieve recanalization rates comparable with those of manual endovascular thrombectomy within competitive procedural times. Optimization of the procedural setup is still required before implementation in clinical practice.

Telestroke network to robotic telestroke network: How to upgrade regional stroke care to include remote robotics?

Objective

Selected patients with large vessel occlusion (LVO) strokes can benefit from endovascular therapy (EVT). However, the effectiveness of EVT is largely dependent on how quickly the patient receives treatment. Recent technological developments have led to the first neurointerventional treatments using robotic assistance, opening up the possibility of performing remote stroke interventions. Existing telestroke networks provide acute stroke care, including remote administration of intravenous thrombolysis (IVT). Therefore, the introduction of remote EVT in distant stroke centers requires an adaptation of the existing telestroke networks. The aim of this work was to propose a framework for centers that are potential candidates for telerobotics according to the resources currently available in these centers.

Methods

In this paper, we highlight the future challenges for including remote robotics in telestroke networks. A literature review provides potential solutions.

Results

Existing telestroke networks need to determine which centers to prioritize for remote robotic technologies based on objective criteria and cost-effectiveness analysis. Organizational challenges include regional coordination and specific protocols. Technological challenges mainly concern telecommunication networks.

Conclusions

Specific adaptations will be necessary if regional telestroke networks are to include remote robotics. Some of these can already be put in place, which could greatly help the future implementation of the technology.

Association Between Intravenous Thrombolysis and Clinical Outcomes Among Patients With Ischemic Stroke and Unsuccessful Mechanical Reperfusion

Importance

Clinical evidence of the potential treatment benefit of intravenous thrombolysis preceding unsuccessful mechanical thrombectomy (MT) is scarce.

Objective

To determine whether intravenous thrombolysis (IVT) prior to unsuccessful MT improves functional outcomes in patients with acute ischemic stroke.

Design, Setting, and Participants

Patients were enrolled in this retrospective cohort study from the prospective, observational, multicenter German Stroke Registry-Endovascular Treatment between May 1, 2015, and December 31, 2021. This study compared IVT plus MT vs MT alone in patients with acute ischemic stroke due to anterior circulation large-vessel occlusion in whom mechanical reperfusion was unsuccessful. Unsuccessful mechanical reperfusion was defined as failed (final modified Thrombolysis in Cerebral Infarction grade of 0 or 1) or partial (grade 2a). Patients meeting the inclusion criteria were matched by treatment group using 1:1 propensity score matching.

Interventions

Mechanical thrombectomy with or without IVT.

Main Outcomes and Measures

Primary outcome was functional independence at 90 days, defined as a modified Rankin Scale score of 0 to 2. Safety outcomes were the occurrence of symptomatic intracranial hemorrhage and death.

Results

After matching, 746 patients were compared by treatment arms (median age, 78 [IQR, 68-84] years; 438 women [58.7%]). The proportion of patients who were functionally independent at 90 days was 68 of 373 (18.2%) in the IVT plus MT and 42 of 373 (11.3%) in the MT alone group (adjusted odds ratio [AOR], 2.63 [95% CI, 1.41-5.11]; P = .003). There was a shift toward better functional outcomes on the modified Rankin Scale favoring IVT plus MT (adjusted common OR, 1.98 [95% CI, 1.35-2.92]; P < .001). The treatment benefit of IVT was greater in patients with partial reperfusion compared with failed reperfusion. There was no difference in symptomatic intracranial hemorrhages between treatment groups (AOR, 0.71 [95% CI, 0.29-1.81]; P = .45), while the death rate was lower after IVT plus MT (AOR, 0.54 [95% CI, 0.34-0.86]; P = .01).

Conclusions and Relevance

These findings suggest that prior IVT was safe and improved functional outcomes at 90 days. Partial reperfusion was associated with a greater treatment benefit of IVT, indicating a positive interaction between IVT and MT. These results support current guidelines that all eligible patients with stroke should receive IVT before MT and add a new perspective to the debate on noninferiority of combined stroke treatment.

Influence of the interventionist's experience on outcomes of endovascular thrombectomy in acute ischemic stroke: results from the MR CLEAN Registry

BACKGROUND

The relationship between the interventionist's experience and outcomes of endovascular thrombectomy (EVT) for acute ischemic stroke of the anterior circulation, is unclear.

OBJECTIVE

To assess the effect of the interventionist's level of experience on clinical, imaging, and workflow outcomes. Secondly, to determine which of the three experience definitions is most strongly associated with these outcome measures.

METHODS

We analysed data from 2700 patients, included in the MR CLEAN Registry. We defined interventionist's experience as the number of procedures performed in the year preceding the intervention (EXPfreq), total number of procedures performed (EXPno), and years of experience (EXPyears). Our outcomes were the baseline-adjusted National Institutes of Health Stroke Scale (NIHSS) score at 24-48 hours post-EVT, recanalization (extended Thrombolysis in Cerebral Infarction (eTICI) score ≥2B), and procedural duration. We used multilevel regression models with interventionists as random intercept. For EXPfreq and EXPno results were expressed per 10 procedures.

RESULTS

Increased EXPfreq was associated with lower 24-48 hour NIHSS scores (adjusted (a)β:-0.46, 95% CI -0.70 to -0.21). EXPno and EXPyears were not associated with short-term neurological outcomes. Increased EXPfreq and EXPno were both associated with recanalization (aOR=1.20, 95% CI 1.11 to 1.31 and aOR=1.08, 95% CI 1.04 to 1.12, respectively), and increased EXPfreq, EXPno, and EXPyears were all associated with shorter procedure times (aβ:-3.08, 95% CI-4.32 to -1.84; aβ:-1.34, 95% CI-1.84 to -0.85; and aβ:-0.79, 95% CI-1.45 to -0.13, respectively).

CONCLUSIONS

Higher levels of interventionist's experience are associated with better outcomes after EVT, in particular when experience is defined as the number of patients treated in the preceding year. Every 20 procedures more per year is associated with approximately one NIHSS score point decrease, an increased probability for recanalization (aOR=1.44), and a 6-minute shorter procedure time.

Association of occlusion time with successful endovascular recanalization in patients with symptomatic chronic intracranial total occlusion

OBJECTIVE

Endovascular treatment is one of the choices for symptomatic chronic intracranial total occlusion (CITO); however, its safety and efficacy remain unclear. The present study was performed to evaluate the safety and long-term outcome of endovascular treatment for CITO at a high-volume stroke center.

METHODS

Data about patients with symptomatic CITO who received endovascular treatment were retrospectively collected. Technique success was regarded as ≤ 30% residual stenosis. Periprocedural complications within 30 days were used to evaluate safety. Baseline characteristics and lesion features were compared between patients with successful recanalization and those with recanalization failure. Stroke recurrence and in-stent restenosis (ISR) of the culprit arteries during follow-up were used to evaluate long-term efficacy.

RESULTS

From June 2012 to September 2019, 117 patients (mean ± SD age 55.8 ± 9.6 years) were included. The successful recanalization rate was 82.9% (97/117 patients). The combined rate of periprocedural stroke, myocardial infarction, and death was 8.5% (10/117). Compared with patients with successful recanalization, patients with recanalization failure had longer occlusion time and longer lesion length (27.0 mm vs 15.4 mm, p = 0.001). In the median 23.0-month clinical follow-up period, recurrent stroke occurred in 12.6% (11/87) of patients with successful recanalization. In the median 5-month imaging follow-up period, ISR was detected in 26.6% (21/79) of patients.

CONCLUSIONS

Endovascular treatment was relatively safe for patients with symptomatic CITO. Shorter occlusion time and shorter lesion length may be associated with higher recanalization rate. The rates of stroke recurrence and symptomatic ISR were acceptable but need to be confirmed in future studies.

Stent-Based Retrieval Techniques in Acute Ischemic Stroke Patients with and Without Susceptibility Vessel Sign

BACKGROUND AND PURPOSE

Randomized controlled trials have challenged the assumption that reperfusion success after mechanical thrombectomy varies depending on the retrieval techniques applied; however, recent analyses have suggested that acute ischemic stroke (AIS) patients showing susceptibility vessel sign (SVS) may respond differently. We aimed to compare different stent retriever (SR)-based thrombectomy techniques with respect to interventional outcome parameters depending on SVS status.

METHODS

We retrospectively reviewed 497 patients treated with SR-based thrombectomy for anterior circulation AIS. Imaging was conducted using a 1.5 T or 3 T magnetic resonance imaging (MRI) scanner. Logistic regression analyses were performed to test for the interaction of SVS status and first-line retrieval technique. Results are shown as percentages, total values or adjusted odds ratio (aOR) with 95% confidence intervals (CI).

RESULTS

An SVS was present in 87.9% (n = 437) of patients. First-line SR thrombectomy was used to treat 293 patients, whereas 204 patients were treated with a combined approach (COA) of SR and distal aspiration. An additional balloon-guide catheter (BGC) was used in 273 SR-treated (93.2%) and 89 COA-treated (43.6%) patients. On logistic regression analysis, the interaction variable of SVS status and first-line retrieval technique was not associated with first-pass reperfusion (aOR 1.736, 95% CI 0.491-6.136; p = 0.392), overall reperfusion (aOR 3.173, 95% CI 0.752-13.387; p = 0.116), periinterventional complications, embolization into new territories, or symptomatic intracerebral hemorrhage. The use of BGC did not affect the results.

CONCLUSION

While previous analyses indicated that first-line SR thrombectomy may promise higher rates of reperfusion than contact aspiration in AIS patients with SVS, our data show no superiority of any particular SR-based retrieval technique regardless of SVS status.

Cumulative experience improves the procedures of mechanical thrombectomy

Background

Mechanical thrombectomy has been widely performed for large vessel occlusion stroke. The present study aimed to determine whether cumulative experience could improve thrombectomy outcomes.

Methods

In this retrospective single-center analysis, patients who underwent mechanical thrombectomy with the Solitaire stent in 3 years from 25 April 2015 were enrolled in the current study. Patients’ characteristics, durations of admission and treatment, recanalization rates, clinical outcomes, and hemorrhage transformation rates were compared among the 3 years. Logistic analysis was used to analyze the independent correlation of the years and procedural outcomes.

Results

A total of 222 patients underwent mechanical thrombectomy in the 3 years: 50 in the first year, 68 in the second year, and 104 in the third year. Door-to-puncture time (P < 0.001) and puncture-to-recanalization time (P = 0.033) decreased significantly among the 3 years, while successful recanalization rates increased (P = 0.001). Logistic regression analysis showed an independent increase in the successful recanalization rates in the second year and third year (P = 0.020, P = 0.001) as compared to that in the first year.

Conclusions

Cumulative experience might improve the procedures of mechanical thrombectomy. The current findings suggested a potential benefit for centralization in the treatment of large vessel occlusion stroke.

Stroke Center Designations, Neurointerventionalist Demand, and the Finances of Stroke Thrombectomy in the United States

PURPOSE OF THE REVIEW

This article aims to provide an update on the designation of stroke centers, neurointerventionalist demand, and cost-effectiveness of stroke thrombectomy in the United States.

RECENT FINDINGS

There are now more than 1,660 stroke centers certified by national accrediting bodies in the United States, 306 of which are designated as thrombectomy-capable or comprehensive stroke centers. Considering the amount of nationally certified centers and the number of patients with acute stroke eligible for thrombectomy, each center would be responsible for 64 to 104 thrombectomies per year. As a result, there is a growing demand placed on neurointerventionalists, who have the ability to alter the trajectory of large vessel occlusive strokes. Numbers needed to achieve functional independence after stroke thrombectomy at 90 days range from 3.2 to 7.4 patients in the early time window and 2.8 to 3.6 patients in the extended time window in appropriately selected candidates. With the low number needed to treat, in a variety of valued-based calculations and cost-effectiveness analyses, stroke thrombectomy has proved to be both clinically effective and cost-effective.

SUMMARY

Advancements in the early recognition and treatment of stroke have been paralleled by a remodeling of health care systems to ensure best practices in a timely manner. Stroke center-accrediting bodies provide oversight to safeguard these standards. As successful trial data from high volume centers transform into real-world experience, we must continue to re-evaluate cost-effectiveness, strike a balance between sufficient case volumes to maintain clinical excellence vs the burden and burnout associated with call responsibilities, and improve access to care for all.

Effect of Operator's Experience on Proficiency in Mechanical Thrombectomy: A Multicenter Study

BACKGROUND AND PURPOSE

We aimed to evaluate among trained interventional neuroradiologist, whether increasing individual experience was associated with an improvement in mechanical thrombectomy (MT) procedural performance metrics.

METHODS

Individual MT procedural data from 5 centers of the Endovascular Treatment in Ischemic Stroke registry and 2 additional high-volume stroke centers were pooled. Operator experience was defined for each operator as a continuous variable, cumulating the number of MT procedures performed since January 2015, as MT became standard of care or, if later than this date, since the operator started performing mechanical thrombectomies in autonomy. We tested the associations between operator's experience and procedural metrics.

RESULTS

A total of 4516 procedures were included, performed by 36 operators at 7 distinct centers, with a median of 97.5 endovascular treatment procedures per operator (interquartile range, 57-170.2) over the study period. Higher operator's experience, analyzed as a continuous variable, was associated with a significantly shorter procedural duration (β estimate, -3.98 [95% CI, -5.1 to -2.8]; P<0.001), along with local anesthesia and M1 occlusion location in multivariable models. Increasing experience was associated with better Thrombolysis in Cerebral Infarction scores (estimate, 1.02 [1-1.04]; P=0.013).

CONCLUSIONS

In trained interventional neuroradiologists, increasing experience in MT is associated with significantly shorter procedural duration and better reperfusion rates, with a theoretical ceiling effect observed after around 100 procedures. These results may inform future training and practice guidelines to set minimal experience standards before autonomization, and to set-up operators' recertification processes tailored to individual case volume and prior experience.

A Review of Robotic Interventional Neuroradiology

Robotic interventional neuroradiology is an emerging field with the potential to enhance patient safety, reduce occupational hazards, and expand systems of care. Endovascular robots allow the operator to precisely control guidewires and catheters from a lead-shielded cockpit located several feet (or potentially hundreds of miles) from the patient. This has opened up the possibility of expanding telestroke networks to patients without access to life-saving procedures such as stroke thrombectomy and cerebral aneurysm occlusion by highly-experienced physicians. The prototype machines, first developed in the early 2000s, have evolved into machines capable of a broad range of techniques, while incorporating newly automated maneuvers and safety algorithms. In recent years, preliminary clinical research has been published demonstrating the safety and feasibility of the technology in cerebral angiography and intracranial intervention. The next step is to conduct larger, multisite, prospective studies to assess generalizability and, ultimately, improve patient outcomes in neurovascular disease.

Learning Curve for Endovascular Treatment of Anterior Circulation Large Vessel Occlusion at a Single Center

Background and purpose: Data concerning the learning curve for endovascular treatment (EVT) of anterior circulation large vessel occlusion are scarce. This study aimed to investigate the relationship between operator experience and the outcome of EVT and to further identify the number of cases needed to acquire the ability to perform successful reperfusion.

Materials and methods: Four hundred and thirty-four patients who underwent EVT by seven operators at a single center from January 2016 to September 2019 were enrolled. Procedural experience was defined by the number of cases performed by each operator. Multivariable backward regression analyses were used to investigate the association between procedural experience and functional independence (defined as a modified Rankin Scale score of 0–2), 90-days mortality, successful reperfusion (defined as a modified Thrombolysis in Cerebral Infarction score of 2b-3), and puncture-to-reperfusion time after adjusting for covariates. A risk-adjusted cumulative sum (RA-CUSUM) chart was utilized to identify the number of caseloads needed to overcome the learning curve effect.

Results: Procedural experience was independently associated with functional independence, 90-days mortality, successful reperfusion, and puncture-to-reperfusion time reduction (per 10-case increment: OR 1.219, 95% CI: 1.079–1.383, P < 0.001; OR 0.847, 95% CI: 0.738–0.968, P = 0.016; OR 1.553, 95% CI: 1.332–1.830, P < 0.001 and β 8.087 min, 95% CI: 6.184–9.991, P < 0.001, respectively). The RA-CUSUM chart indicated that at least 29 cases were required to overcome the learning curve effect.

Conclusions: There was a dose-response relationship between operator case volume and clinical outcome, procedure time, and successful reperfusion. The experience needed for successful EVT was at least 29 cases.

Impact of carotid tortuosity on outcome after endovascular thrombectomy

BACKGROUND AND OBJECTIVES

Endovascular thrombectomy (EVT) is efficacious in patients with large vessel occlusion stroke (LVO). We explored whether internal carotid (ICA) tortuosity increases the technical difficulty of EVT thereby lowering the chances of successful recanalization and favorable outcomes.

PATIENTS AND METHODS

Consecutive patients with LVO and patent ICAs who underwent EVT were included. Carotid tortuosity was determined on pre-EVT CTA and classified by raters blinded to outcomes into: type 1-straight ICA trunk and type 2-severe tortuosity potentially impeding adequate catheter placement. Thrombolysis in cerebral infarction (TICI) 2b-3 was considered successful recanalization, and 90-day-modified Rankin Scale ≤ 2 was considered favorable functional outcome.

RESULTS

Among 302 patients (mean age 70 ± 15, median NIHSS 17), 53% had type 1, and 47% type 2 tortuosity. Overall, 85% had successful recanalization. Patients with type 2 tortuosity were significantly older (p < 0.0001) and less frequently achieved successful recanalization (80% vs. 90%; p = 0.019) but had similar outcomes compared with those without tortuosity. On regression analysis, marked tortuosity was associated with lower chances of successful recanalization (OR 0.43 95% CI 0.20-0.92) but had no effect on clinical outcomes.

CONCLUSIONS

Carotid tortuosity does not appear to impact the likelihood of favorable functional outcome but may influence recanalization.

Early epileptic seizures in ischaemic stroke treated by mechanical thrombectomy: influence of rt-PA

BACKGROUND

The epileptogenicity of recombinant tissue-plasminogen activator (rt-PA) has been suggested, but seizures were not evaluated in randomised controlled trials.

OBJECTIVE

To evaluate whether rt-PA was associated with early seizures in a cohort of consecutive patients with cerebral ischaemia.

METHOD

We included consecutive adults with ischaemic stroke due to large-vessel occlusion from the North-of-France stroke network selected for a mechanical thrombectomy (MT). Patients without contraindication received i.v. rt-PA. We evaluated stroke severity with the National Institutes of Health Stroke Scale (NIHSS), and functional status with the modified Rankin scale (mRS), and recorded epileptic seizures occurring between the end of imaging and day 7. We performed statistics using propensity analyses.

RESULTS

We included 1638 patients (783 men, 47.8%; median age 71 years; median NIHSS score 16; 1007 treated by rt-PA, 61.5%), in whom 60 (3.7%) developed early epileptic seizures. After adjustment on propensity scores, early seizures were associated with infections [adjusted odds ratio (_adjOR) 2.86; 95% confidence interval (CI) 1.37-5.95] and delay between stroke recognition and end of MT (_adjOR 1.04 for 10 min more; 95% CI 1.01-1.08), but not with rt-PA (_adjOR 1.35; 95% CI 0.55-3.33). The propensity-matched analysis of 343 pairs of patients found no difference in the occurrence of early seizures between those with and without rt-PA (p = 0.386).

CONCLUSION

We found no significant association between rt-PA and early epileptic seizures. If rt-PA has the potential for epileptogenicity, the magnitude of the effect should be modest compared to its favourable effect on functional outcome.

Mechanical Thrombectomy for Acute Ischemic Stroke Amid the COVID-19 Outbreak: Decreased Activity, and Increased Care Delays

BACKGROUND AND PURPOSE

The efficiency of prehospital care chain response and the adequacy of hospital resources are challenged amid the coronavirus disease 2019 (COVID-19) outbreak, with suspected consequences for patients with ischemic stroke eligible for mechanical thrombectomy (MT).

METHODS

We conducted a prospective national-level data collection of patients treated with MT, ranging 45 days across epidemic containment measures instatement, and of patients treated during the same calendar period in 2019. The primary end point was the variation of patients receiving MT during the epidemic period. Secondary end points included care delays between onset, imaging, and groin puncture. To analyze the primary end point, we used a Poisson regression model. We then analyzed the correlation between the number of MTs and the number of COVID-19 cases hospitalizations, using the Pearson correlation coefficient (compared with the null value).

RESULTS

A total of 1513 patients were included at 32 centers, in all French administrative regions. There was a 21% significant decrease (0.79; [95%CI, 0.76-0.82]; P<0.001) in MT case volumes during the epidemic period, and a significant increase in delays between imaging and groin puncture, overall (mean 144.9±SD 86.8 minutes versus 126.2±70.9; P<0.001 in 2019) and in transferred patients (mean 182.6±SD 82.0 minutes versus 153.25±67; P<0.001). After the instatement of strict epidemic mitigation measures, there was a significant negative correlation between the number of hospitalizations for COVID and the number of MT cases (R² -0.51; P=0.04). Patients treated during the COVID outbreak were less likely to receive intravenous thrombolysis and to have unwitnessed strokes (both P<0.05).

CONCLUSIONS

Our study showed a significant decrease in patients treated with MTs during the first stages of the COVID epidemic in France and alarming indicators of lengthened care delays. These findings prompt immediate consideration of local and regional stroke networks preparedness in the varying contexts of COVID-19 pandemic evolution.

Endovascular Treatment Decision Making in Octogenarians and Nonagenarians : Insights from UNMASK EVT an International Multidisciplinary Study

BACKGROUND

Evidence for efficacy and safety in stroke patients ≥80 years is limited, since they were underrepresented in randomized thrombectomy trials. This study sought to explore how physicians approach endovascular therapy (EVT) decision making in octogenarians and nonagenarians under their current local resources under assumed ideal conditions, i.e. without external (monetary or infrastructural) limitations.

METHODS

In an international multidisciplinary survey, 607 physicians involved in acute stroke care were randomly assigned 10 out of a pool of 22 case scenarios with different evidence levels for EVT, 4 of which involved octogenarians and 2 nonagenarians, and asked how they would treat the patient in the given scenario A) under their current local resources and B) under assumed ideal conditions, i.e. with no external restraints. Decision rates were calculated and clustered multivariable regression analysis performed to determine adjusted measures of effect size for patient age.

RESULTS

In octogenarians, physicians decided in favor of EVT in 76.7% (all of which were level 2B evidence scenarios) under current local resources and in 80.2% under assumed ideal conditions. In nonagenarians, 74.0% decided in favor of EVT under current local resources (level 1A scenarios: 87.7%, level 2B scenarios: 60.3%) and 79.2% would offer EVT under assumed ideal conditions (level 1A scenarios: 91.3%, level 2B scenarios: 67.2%). Age was not a significant predictor for treatment decision under current local resources (adjusted odds ratio, OR: 0.99, confidence interval, CI: 0.96-1.02 per decile increase) and under assumed ideal conditions (adjusted OR: 1.00, CI 0.97-1.03 per decile increase).

CONCLUSION

The vast majority of physicians participating in this survey would offer EVT to acute ischemic stroke patients above 80 years.

Influence of Guidelines in Endovascular Therapy Decision Making in Acute Ischemic Stroke: Insights From UNMASK EVT

Background and Purpose- The American Heart Association and the American Stroke Association guidelines for early management of patients with ischemic stroke offer guidance to physicians involved in acute stroke care and clarify endovascular treatment indications. The purpose of this study was to assess concordance of physicians' endovascular treatment decision-making with current American Heart Association and the American Stroke Association stroke treatment guidelines using a survey-approach and to explore how decision-making in the absence of guideline recommendations is approached. Methods- In an international cross-sectional survey (UNMASK-EVT), physicians were randomly assigned 10 of 22 case scenarios (8 constructed with level 1A and 11 with level 2B evidence for endovascular treatment and 3 scenarios without guideline coverage) and asked to declare their treatment approach (1) under their current local resources and (2) assuming there were no external constraints. The proportion of physicians offering endovascular therapy (EVT) was calculated. Subgroup analysis was performed for different specialties, geographic regions, with regard to physicians' age, endovascular, and general stroke treatment experience. Results- When facing level 1A evidence, participants decided in favor of EVT in 86.8% under current local resources and in 90.6% under assumed ideal conditions, that is, 9.4% decided against EVT even under assumed ideal conditions. In case scenarios with level 2B evidence, 66.3% decided to proceed with EVT under current local resources and 69.7% under assumed ideal conditions. Conclusions- There is potential for improving thinking around the decision to offer endovascular treatment, since physicians did not offer EVT even under assumed ideal conditions in 9.4% despite facing level 1A evidence. A majority of physicians would offer EVT even for level 2B evidence cases.

America's Health Care System is Broken: What Went Wrong and How We Can Fix It. Part 3: Hospitals and Doctors

Thirty-two percent of US health care spending goes to hospital care, and 20% goes to physicians' charges. The cost of hospital care in the United States is 2-3 times greater than in most similar countries. A large part of the high cost is due to a very large administrative overhead. Both higher quality and lower cost would be achieved if complex procedures were done in fewer centers. Hospitals with a geographic or prestige monopoly receive higher payments than warranted. As physicians are increasingly employed by hospitals rather than independent, costs go up with no added benefit to patients. The United States has too many specialists and too few primary care physicians. Practice guidelines are slanted to favor expensive treatments, often with little solid evidence behind the recommendations.