Long-Term Effect of Mechanical Thrombectomy in Stroke Patients According to Advanced Imaging Characteristics

PURPOSE

Data on long-term effect of mechanical thrombectomy (MT) in patients with large ischemic cores (≥ 70 ml) are scarce. Our study aimed to assess the long-term outcomes in MT-patients according to baseline advanced imaging parameters.

METHODS

We performed a single-centre retrospective cohort study of stroke patients receiving MT between January 1, 2010 and December 31, 2018. We assessed baseline imaging to determine core and mismatch volumes and hypoperfusion intensity ratio (with low ratio reflecting good collateral status) using RAPID automated post-processing software. Main outcomes were cross-sectional long-term mortality, functional outcome and quality of life by May 2020. Analysis were stratified by the final reperfusion status.

RESULTS

In total 519 patients were included of whom 288 (55.5%) have deceased at follow-up (median follow-up time 28 months, interquartile range 1-55). Successful reperfusion was associated with lower long-term mortality in patients with ischemic core volumes ≥ 70 ml (adjusted hazard ratio (aHR) 0.20; 95% confidence interval (95% CI) 0.10-0.44) and ≥ 100 ml (aHR 0.26; 95% CI 0.08-0.87). The effect of successful reperfusion on long-term mortality was significant only in the presence of relevant mismatch (aHR 0.17; 95% CI 0.01-0.44). Increasing reperfusion grade was associated with a higher rate of favorable outcomes (mRS 0-3) also in patients with ischemic core volume ≥ 70 ml (aOR 3.58, 95% CI 1.64-7.83).

CONCLUSION

Our study demonstrated a sustainable benefit of better reperfusion status in patients with large ischemic core volumes. Our results suggest that patient deselection based on large ischemic cores alone is not advisable.

The Application of Software "Rapid Processing of Perfusion and Diffusion" in Acute Ischemic Stroke

In the event of an acute ischemic stroke, saving the penumbra is the most important aspect of early treatment. The rapid and accurate identification of ischemic penumbra plays a key role in its comprehensive treatment. At present, the identification method and evaluation standard of ischemic penumbra have not been unified. Numerous pieces of software identifying ischemic penumbra have been developed, such as rapid processing of perfusion and diffusion (RAPID), Sphere, Vitrea, and computed tomography perfusion+ (CTP+). The RAPID software, analyzing and integrating multi-mode image data (mainly based on perfusion weighted imaging (PWI) or computed tomography perfusion (CTP) images, shows good performance in identifying ischemic penumbra and has been utilized for the assessment of ischemic penumbra in many ischemic stroke clinical studies, achieving good outcomes and promoting the transition from "time window" to "tissue window" in the treatment of early stage AIS. To obtain a comprehensive understanding of the RAPID software and its accuracy in evaluating ischemic penumbra, this paper reviews the background and development of the RAPID software, summarizes the published acute cerebral infarction trials using the RAPID software, generalizes the threshold parameters in different time windows, and further discusses its application and limitations.

RAPID Software to the Clinical Application Value of Acute Basilar Artery Occlusion with Endovascular Treatment

OBJECTIVE

To investigate the clinical application value of RAPID software based on computed tomography perfusion imaging (CTP) in the endovascular treatment of acute basilar artery occlusion (BAO).

MATERIALS AND METHODS

The data of patients with acute basilar artery occlusion who received endovascular treatment in Taizhou Hospital, Zhejiang Province, between January 2020 and April 2021 were retrospectively analysed. The patients were divided into a perfusion imaging and a no-perfusion imaging group based on whether the image analysis results were obtained by RAPID software. Age, preoperative National Institute of Health stroke scale (NIHSS) score, onset to puncture time (OPT), operation methods, good prognosis at 3 months after surgery (modified Rankin scale (mRS) score ≤3), symptomatic intracranial haemorrhage (sICH) and other clinical data were compared between the two groups. Multivariate logistic regression analysis was used to identify the independent factors affecting the prognosis of BAO patients.

RESULTS

In total, 61 patients with acute BAO were included: 31 patients in the perfusion imaging group and 30 patients in the no-perfusion imaging group. There were no statistically significant differences between the two groups in age, NIHSS score or operation methods (all P >0.05). However, OPT and the good prognosis rate were significantly higher in the perfusion imaging group than in the no-perfusion imaging group (χ²=8.176, 5.003, P < 0.05). SICH was significantly lower in the perfusion imaging group than in the no-perfusion imaging group (χ²=5.628, P < 0.05). Logistic regression analysis showed that the image analysis results of RAPID software influenced the prognosis of EVT in patients with acute BAO (OR=4.048, 95%CI: 1.276-12.840).

CONCLUSIONS

RAPID software based on CTP can be used for preoperative screening of patients with acute basilar artery occlusion to identify those suitable for endovascular treatment, which is worthy of clinical promotion.

Eligibility for intravenous thrombolysis in acute ischemic stroke patients presenting in the 4.5-9 h window

PURPOSE

Recent randomized-controlled clinical trials have provided preliminary evidence for expanding the time window of intravenous thrombolysis (IVT) in acute ischemic stroke (AIS) patients by applying certain neuroimaging criteria. We prospectively assessed the potential eligibility for IVT in the extended time window (4.5-9 h) among consecutive AIS patients treated in a comprehensive stroke center during a nine-month period.

METHODS

Potential eligibility for IVT in the extended time window was evaluated by using inclusion criteria from the EXTEND trial. All patients were underwent baseline emergent neurovascular imaging using either computed tomography angiography/computed tomography perfusion (CTA/CTP) or magnetic resonance angiography/magnetic resonance perfusion (MRA/MRP). Images were post processed by the automated software RAPID.

RESULTS

Our study population consisted of 317 AIS patients, and, among them, 31 (9.8 %) patients were presented in the time window of 4.5-9 h. Seven patients (2.2 %) fulfilled the EXTEND neuroimaging criteria. Four patients (1.3 %) were treated with IVT because they fulfilled both clinical and neuroimaging EXTEND criteria. Patients eligible for EXTEND neuroimaging criteria had no ischemic core lesion, whereas the mean volume of critical hypoperfusion was relatively small (17.0 ± 11.8 ml). There was no hemorrhagic complication in any of the patients treated with IVT. The median mRS score at three months was 0 (range: 0-3) among patients who were eligible for EXTEND neuroimaging criteria.

CONCLUSION

Our everyday clinical practice experience suggests 9.8 % of consecutive AIS patients present in the 4.5-9 h window and 2.2 % adhere to EXTEND neuroimaging eligibility criteria for IVT. Only 1.3% of AIS is eligible for IVT according to EXTEND neuroimaging and clinical eligibility criteria.