Active Reperfusion Hemorrhage during Thrombectomy: Angiographic Findings and Real-Time Correlation with the CT "Spot Sign"

Subcortical infarcts on admission CTP predict poor outcome despite excellent reperfusion in delayed time windows

PURPOSE

The effect of pretreatment infarct location on clinical outcome after successful mechanical thrombectomy is not understood. Our aim was to evaluate the association between computed tomography perfusion (CTP)-based ischemic core location and clinical outcome following excellent reperfusion in late time windows.

METHODS

We retrospectively reviewed patients who underwent thrombectomy for acute anterior circulation large vessel occlusion in late time windows from October 2019 to June 2021 and enrolled 65 patients with visible ischemic core on admission CTP who had received excellent reperfusion (modified thrombolysis in cerebral infarction grade 2c/3). Poor outcome was defined as a modified Rankin scale score of 3-6 at 90 days. The ischemic core infarct territories were classified into the cortical and subcortical areas. Multivariate logistic regression and receiver operating characteristic (ROC) curve analyses were used in this study.

RESULTS

Of the 65 patients analyzed, 38 (58.5%) had a poor outcome. Multivariable logistic analysis showed that the subcortical infarcts (OR 11.75; 95% CI 1.79-77.32; P = 0.010) and their volume (OR 1.17; 95% CI 1.04-1.32; P = 0.011) were independently associated with poor outcome. The ROC curve indicated the capacity of the subcortical infarct involvement (areas under the curve (AUC) = 0.65; 95% CI, 0.53-0.77, P < 0.001) and subcortical infarct volume (AUC = 0.72; 95% CI, 0.60-0.83, P < 0.001) in predicting poor outcome accurately.

CONCLUSION

Subcortical infarcts and their volume on admission CTP are associated with poor outcome after excellent reperfusion in late time windows, rather than cortical infarcts.

Association between Infarct Location and Hemorrhagic Transformation of Acute Ischemic Stroke following Successful Recanalization after Mechanical Thrombectomy

BACKGROUND AND PURPOSE

The association between infarct location and hemorrhagic transformation of acute ischemic stroke after mechanical thrombectomy is not understood. We aimed to evaluate the association between CTP-based ischemic core variables at admission and hemorrhagic transformation after a successful thrombectomy.

MATERIALS AND METHODS

We retrospectively analyzed patients who underwent endovascular thrombectomy for acute anterior circulation large-vessel occlusion between October 2019 and June 2021. We enrolled 146 patients with visible ischemic core on pretreatment CTP who had successful reperfusion. The ischemic core infarct territories were classified into the cortical and subcortical areas and then qualitatively and quantitatively analyzed by CTP. Logistic regression and receiver operating characteristic curve analyses were performed to determine the association between ischemic core variables and hemorrhagic transformation.

RESULTS

Of the 146 patients analyzed, 72 (49.3%) had hemorrhagic transformation and 23 (15.8%) had symptomatic intracerebral hemorrhage. Multivariate analysis showed that subcortical infarcts were independently associated with hemorrhagic transformation (OR, 8.06; 95% CI, 2.31-28.10; P = .001) and subcortical infarct volume was independently linked to symptomatic intracerebral hemorrhage (OR, 1.05; 95% CI, 1.01-1.09; P = .039). The receiver operating characteristic curve indicated that subcortical infarcts can predict hemorrhagic transformation accurately (area under the curve = 0.755; 95% CI, 0.68-0.82; P < .001) and subcortical infarct volume can predict symptomatic intracerebral hemorrhage (area under the curve = 0.694; 95% CI, 0.61-0.77; P = .002).

CONCLUSIONS

Subcortical infarcts seen on CTP at admission are associated with hemorrhagic transformation in patients after successful thrombectomy, and subcortical infarct volume may influence the risk of symptomatic intracerebral hemorrhage.

Successful Reperfusion is Associated with Favorable Functional Outcome despite Vessel Perforation during Thrombectomy: A Case Series and Systematic Review

BACKGROUND

Arterial perforation is a potentially serious complication during endovascular thrombectomy.

PURPOSE

Our aim was to describe interventional approaches after arterial perforation during endovascular thrombectomy and to determine whether reperfusion remains associated with favorable outcome despite this complication.

DATA SOURCES

Data from consecutive patients with acute stroke undergoing endovascular thrombectomy were retrospectively collected between 2015 to 2020 from a single-center cohort, and a systematic review was performed using PubMed, EMBASE, and Ovid MEDLINE up to June 2020.

STUDY SELECTION

Articles reporting functional outcome after arterial perforation during endovascular thrombectomy were selected.

DATA ANALYSIS

Functional outcomes of patients achieving successful reperfusion (TICI 2b/3) were compared with outcomes of those with unsuccessful reperfusion in our single-center cohort. We then summarized the literature review to describe interventional approaches and outcomes after arterial perforation during endovascular thrombectomy.

DATA SYNTHESIS

In our single-center cohort, 1419 patients underwent endovascular thrombectomy, among whom 32 (2.3%) had vessel perforation and were included in the analysis. The most common hemostatic strategy was watchful waiting (71% of cases). Patients with successful reperfusion had a higher proportion of favorable 90-day mRS scores (60% versus 12.5%; P = .006) and a lower mortality rate (13.3% versus 56.3%, P = .01) than patients without successful reperfusion. Thirteen articles were included in the systematic review. Successful reperfusion also appeared to be associated with better outcomes.

LIMITATIONS

Given the low number of published reports, we performed only a descriptive analysis.

CONCLUSIONS

Arterial perforation during endovascular thrombectomy is rare but is associated with high mortality rates and poor outcome. However, successful reperfusion remains correlated with favorable outcome in these patients.

How Long Are Reperfusion Therapies Beneficial for Patients after Stroke Onset? Lessons from Lethal Ischemia Following Early Reperfusion in a Mouse Model of Stroke

Ischemic stroke caused by cerebral artery occlusion induces neurological deficits because of cell damage or death in the central nervous system. Given the recent therapeutic advances in reperfusion therapies, some patients can now recover from an ischemic stroke with no sequelae. Currently, reperfusion therapies focus on rescuing neural lineage cells that survive in spite of decreases in cerebral blood flow. However, vascular lineage cells are known to be more resistant to ischemia/hypoxia than neural lineage cells. This indicates that ischemic areas of the brain experience neural cell death but without vascular cell death. Emerging evidence suggests that if a vascular cell-mediated healing system is present within ischemic areas following reperfusion, the therapeutic time window can be extended for patients with stroke. In this review, we present our comments on this subject based upon recent findings from lethal ischemia following reperfusion in a mouse model of stroke.

Early Reperfusion Following Ischemic Stroke Provides Beneficial Effects, Even After Lethal Ischemia with Mature Neural Cell Death

Ischemic stroke is a critical disease caused by cerebral artery occlusion in the central nervous system (CNS). Recent therapeutic advances, such as neuroendovascular intervention and thrombolytic therapy, have allowed recanalization of occluded brain arteries in an increasing number of stroke patients. Although previous studies have focused on rescuing neural cells that still survive despite decreased blood flow, expanding the therapeutic time window may allow more patients to undergo reperfusion in the near future, even after lethal ischemia, which is characterized by death of mature neural cells, such as neurons and glia. However, it remains unclear whether early reperfusion following lethal ischemia results in positive outcomes. The present study used two ischemic mouse models—90-min transient middle cerebral artery occlusion (t-MCAO) paired with reperfusion to induce lethal ischemia and permanent middle cerebral artery occlusion (p-MCAO)—to investigate the effect of early reperfusion up to 8 w following MCAO. Although early reperfusion following 90-min t-MCAO did not rescue mature neural cells, it preserved the vascular cells within the ischemic areas at 1 d following 90-min t-MCAO compared to that following p-MCAO. In addition, early reperfusion facilitated the healing processes, including not only vascular but also neural repair, during acute and chronic periods and improved recovery. Furthermore, compared with p-MCAO, early reperfusion after t-MCAO prevented behavioral symptoms of neurological deficits without increasing negative complications, including hemorrhagic transformation and mortality. These results indicate that early reperfusion provides beneficial effects presumably via cytoprotective and regenerative mechanisms in the CNS, suggesting that it may be useful for stroke patients that experienced lethal ischemia.

Imaging After Thrombolysis and Thrombectomy: Rationale, Modalities and Management Implications

PURPOSE OF REVIEW

Urgent reperfusion treatment with intravenous thrombolysis or mechanical thrombectomy reduces disability after ischaemic stroke. Imaging plays an important role in identifying patients who benefit, particularly in extended time windows. However, the role of post-treatment neuroimaging is less well established. We review recent advances in neuroimaging after reperfusion treatment and provide a practical guide to the options and management implications.

RECENT FINDINGS

Post-treatment imaging is critical to identify patients with reperfusion-related haemorrhage and oedema requiring intervention. It also can guide the timing and intensity of antithrombotic medication. The degree of reperfusion on post-thrombectomy angiography and infarct volume and topography using CT or MRI carry important prognostic significance. Perfusion-weighted MRI and permeability analysis may help detect persistent perfusion abnormalities post-treatment and predict haemorrhagic complications. Post-treatment neuroimaging provides clinically relevant information to identify complications, assess prognosis and perform quality assurance after acute ischaemic stroke. Recent advances in neuroimaging represent a potential avenue to explore post-reperfusion pathophysiology and uncover therapeutic targets for secondary ischaemic and haemorrhagic injury.