Brain imaging prior to thrombectomy in the late window of large vessel occlusion ischemic stroke: a systematic review and meta-analysis

PURPOSE

Optimal imaging modalities to select patients for endovascular thrombectomy (EVT) in the late window of acute ischemic stroke due to large vessel occlusions (AIS-LVO) are not known. We conducted a systematic review comparing outcomes of patients selected by non-contrast computed tomography (NCCT)/CT angiography (CTA) vs. those selected by CT perfusion (CTP) or magnetic resonance imaging (MRI) for EVT in these patients.

METHODS

We searched PUBMED, EMBASE, and the Cochrane Library from January 1, 2000, to July 15, 2023, to identify studies comparing outcomes of patients selected for EVT by NCCT/CTA vs. CTP or MRI in the late time window for AIS-LVO. Primary outcome was independence (mRS 0-2) at 90 days or discharge. Secondary outcomes were symptomatic intracranial hemorrhage (sICH) and mortality. We pooled data across studies based on an inverse variance method.

RESULTS

Six cohort studies with 4208 patients were included. Pooled results showed no significant difference in the rate of independence at 90 days or discharge (RR 0.96, 95% CI 0.88-1.03) and sICH (RR 1.26, 0.85-1.86) between patients selected by NCCT/CTA vs. CTP or MRI for EVT in the late window of AIS-LVO. However, patients selected by NCCT/CTA vs. CTP or MRI for EVT were associated with a higher risk of mortality (RR 1.21, 1.06-1.39).

CONCLUSION

For AIS-LVO in the late window, patients selected by NCCT/CTA compared with those selected by CTP or MRI for EVT might have a comparable rate of functional independence and sICH. Baseline NCCT/CTA may triage AIS-LVO in the late window.

Larger ischemic cores and poor collaterals among large vessel occlusions presenting in the late evening

BACKGROUND

Components critical to cerebral perfusion have been noted to oscillate over a 24-h cycle. We previously reported that ischemic core volume has a diurnal relationship with stroke onset time when examined as dichotomized epochs (i.e. Day, Evening, Night) in a cohort of over 1,500 large vessel occlusion (LVO) patients. In this follow-up analysis, our goal was to explore if there is a sinusoidal relationship between ischemic core, collateral status (as measured by HIR), and stroke onset time.

METHODS

We retrospectively examined collection of LVO patients with baseline perfusion imaging performed within 24 h of stroke onset from four international comprehensive stroke centers. Both ischemic core volume and HIR, were utilized as the primary radiographic parameters. To evaluate for differences in these parameters over a continuous 24-h cycle, we conducted a sinusoidal regression analysis after linearly regressing out the confounders age and time to imaging.

RESULTS

A total of 1506 LVO cases were included, with a median ischemic core volume of 13.0 cc (IQR: 0.0-42.0) and median HIR of 0.4 (IQR: 0.2-0.6). Ischemic core volume varied by stroke onset time in the unadjusted (p = 0.001) and adjusted (p = 0.003) sinusoidal regression analysis with a peak in core volume around 7:45PM. HIR similarly varied by stroke onset time in the unadjusted (p = 0.004) and adjusted (p = 0.002) models with a peak in HIR values at around 8:18PM.

CONCLUSION

The results suggest that critical factors to the development of the ischemic core vary by stroke onset time and peak around 8PM. When placed in the context of prior studies, strongly suggest a diurnal component to the development of the ischemic core.

Neurovascular complications that can be seen in COVID-19 patients

Coronavirus disease 2019 (COVID-19), a clinical manifestation of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), was declared a global pandemic by the World Health Organization on March 11, 2020. Hypercoagulable state has been described as one of the hallmarks of SARS-CoV-2 infection and has been reported to manifest as pulmonary embolisms, deep vein thrombosis, and arterial thrombosis of the abdominal small vessels. Here we present cases of arterial and venous thrombosis pertaining to the head and neck in COVID-19 patients.

Trials in thrombectomy for acute ischemic stroke: Describing the state of clinical research in the field

BACKGROUND

Endovascular thrombectomy has revolutionized treatment of ischemic stroke. Given the clinical and socioeconomic support for thrombectomy, new devices, procedures, and pharmaceuticals have emerged in recent years, and have been subject to a growing number of clinical trials worldwide.

OBJECTIVE

To define the current state of thrombectomy clinical trials, highlight recent trends, and help guide future research in this area.

METHODS

Current and previous clinical trials involving thrombectomy for ischemic stroke were queried from the Clinicaltrials.gov database. Trials were categorized by their current status, study design, funding type, exclusion criteria, study phase, enrollment, start and completion dates, country of origin, item of investigation, outcome metrics, and whether a peer-reviewed publication was linked to the trial.

RESULTS

Querying the ClinicalTrials.gov registry yielded 196 trials, of which 161 (82.1 %) were started within the past 5 years. The average time to completion was 30.6 months. A total of 62 studies (31.6 %) examined the safety or efficacy of a thrombectomy device, 29 (14.8 %) investigated a pharmacological intervention alone or in combination with a device, 59 (30.1 %) examined aspects of the endovascular procedure on patient outcomes, and 14 (7.2 %) examined diagnostic utility during thrombectomy. Most trials were funded by academic centers (53.1 %) or industry (34.7 %). Although the United States contributed the most studies overall (59; 30.1 %), studies from European and Asian countries have been increasing since 2015.

CONCLUSION

These trends indicate an increasing number of trials starting the past few years, with most occurring in Europe and examining devices or aspects of the thrombectomy procedure.