Endovascular Therapy for Ischemic Stroke Can Be Successfully Performed by Peripheral Vascular Interventionalists

Clinical outcomes of delayed mechanical thrombectomy: Descriptive analysis and development of a screening tool

BACKGROUND AND PURPOSE

Limited data guide the selection of patients with large vessel occlusion ischaemic stroke who may benefit from referral to a distant tertiary centre for mechanical thrombectomy (MT). We aimed to characterize this population, describe clinical outcomes and develop a screening system to identify patients most likely to benfit from delayed mechanical thrombectomy (MT).

METHODS

We undertook a retrospective cohort analysis enrolling patients transferred from regional sites to one of two MT comprehensive stroke units with a time from non-contrast computed tomography (NCCT) of the brain to reperfusion of 4 h or more. We describe Alberta Stroke Programme Early Computed Tomography Score (ASPECTS), National Institute of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) in our patients and compare these patients to those in extended-time-window trials. Lastly, we developed and validated a scoring model to help clinicians identify appropriate patients based on variables associated with poor outcomes.

RESULTS

We included 563 patients, 46% of whom received thrombolysis; the median (interquartile range [IQR]) ASPECTS was 8 (7-10) and the median (IQR) NIHSS score was 16 (11-20). The median (IQR) symptom to mechanical reperfusion time was 390 (300-580) min. Eight patients (1%) had a symptomatic haemorrhage. We achieved good clinical outcome (defined as mRS score ≤2) in 299 patients (54%). Age, diabetes, NIHSS score and ASPECTS were used to create a weighted scoring system with a validated area under the curve of 0.83 (95% confidence interval 0.74-0.92).

CONCLUSION

Our study shows, in highly selected patients, that delayed MT many hours after baseline NCCT is associated with good clinical outcomes. However, older patients with diabetes, high NIHSS score and low ASPECTS may not benefit from transfer to a hub centre many hours away for MT in this model of care.

Endovascular thrombectomy for acute ischaemic stroke improves and maintains function in the very elderly: A multicentre propensity score matched analysis

Introduction

The very elderly (⩾80 years) are under-represented in randomised endovascular thrombectomy (EVT) clinical trials for acute ischaemic stroke. Rates of independent outcome in this group are generally lower than the less-old patients but the comparisons may be biased by an imbalance of non-age related baseline characteristics, treatment related metrics and medical risk factors.

Patients and methods

We compared outcomes between very elderly (⩾80) and the less-old (<80 years) using retrospective data from consecutive patients receiving EVT from four comprehensive stroke centres in New Zealand and Australia. We used propensity score matching or multivariable logistic regression to account for confounders.

Results

We included 600 patients (300 in each age cohort) after propensity score matching from an initial group of 1270 patients. The median baseline National Institutes of Health Stroke Scale was 16 (11-21), with 455 (75.8%) having symptom free pre-stroke independent function, and 268 (44.7%) receiving intravenous thrombolysis. Good functional outcome (90-day modified Rankin Scale 0-2) was achieved in 282 (46.8%), with very elderly patients having less proportion of good outcome compared to the less-old (118 (39.3%) vs 163 (54.3%), p < 0.01). There was no difference between the very elderly and the less-old in the proportion of patients who returned to baseline function at 90 days (56 (18.7%) vs 62 (20.7%), p = 0.54). All-cause 90-day mortality was higher in the very elderly (75 (25%) vs 49 (16.3%), p < 0.01), without a difference in symptomatic haemorrhage (very elderly 11 (3.7%) vs 6 (2.0%), p = 0.33). In the multivariable logistic regression models, the very elderly were significantly associated with reduced odds of good 90-day outcome (OR 0.49, 95% CI 0.34-0.69, p < 0.01) but not with return to baseline function (OR 0.85, 90% CI 0.54-1.29, p = 0.45) after adjusting for confounders.

Conclusion

Endovascular thrombectomy can be successfully and safely performed in the very elderly. Despite an increase in all-cause 90-day mortality, selected very elderly patients are as likely as younger patients with similar baseline characteristics to return to baseline function following EVT.

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.

Outcomes of Stroke Thrombectomy Performed by Interventional Radiologists vs Neurointerventional Physicians

PURPOSE

To test the hypothesis that interventional radiologists (IR) have outcomes for endovascular stroke thrombectomy (EVT) similar to Neurointerventional (NI) physicians and could be used to improve availability of thrombectomy.

MATERIALS AND METHODS

Eight hospitals providing EVT performed by IR and NI in the same institution submitted sequential retrospective data limited to the era of modern devices. Good clinical outcome (90 day modified Rankin score 0-2) and successful revascularization (modified Thrombolysis in Cerebral Infarction score > 2b) were compared between specialties, adjusted for treating hospital, patient age, stroke severity, Alberta Stroke Program Early CT Score (ASPECTS), time from symptom onset to door, and clot location. Propensity score matching was used to compare outcomes. A total of 1009 patients were entered (622 treated by IR and 387 treated by NI).

RESULTS

Median stroke onset to puncture was 245 vs 253 minutes (p=.49), technically successful revascularization was 81.8% vs 82.4% (p=.81), and good clinical outcome was 45.5% vs 50.1% (p=.16), respectively. After adjusting, physician specialty was not a significant predictor of good clinical outcome (odds ratio 1.028 [95% CI 0.760-1.390]; p=.86). After matching, mRS 0-2 was 47.7% for IR and 51.1% for NI (p=0.366).

CONCLUSION

There was no significant difference in successful revascularization and good clinical outcomes between IR and NI physicians. Outcomes by IR were similar to NI outcomes from previously published trials and registries. This may be useful to address coverage and access to stroke interventions.