Cerebral collaterals in acute ischaemia: Implications for acute ischaemic stroke patients receiving reperfusion therapy

Abstract

The cerebral collaterals play an important role in penumbral tissue sustenance after an acute ischaemic stroke. Recent studies have demonstrated the potential role of collaterals in the selection of acute ischaemic stroke patients eligible for reperfusion therapy. However, the understanding of the significance and evidence around the role of collateral status in predicting outcomes in acute ischaemic stroke patients treated with reperfusion therapy is still unclear. Moreover, the use of pre-treatment collaterals in patient selection and prognosis is relatively underappreciated in clinical settings. A focused review of the literature was performed on the various methods of collateral evaluation and the role of collateral status in acute ischaemic stroke patients receiving reperfusion therapy. We discuss the methods of evaluating pre-treatment collaterals in clinical settings. The patient selection based on collateral status as well as the prognostic and therapeutic value of collaterals in acute ischaemic stroke, in settings of intravenous thrombolysis or endovascular therapy alone, and bridge therapy, are summarized. Recommendations for future research and possible pharmacological intervention strategies aimed at collateral enhancement are also discussed. Collaterals may play an important role in identifying acute ischaemic stroke patients who are likely to benefit from endovascular treatment in an extended time window. Future neuroscientific efforts to better improve our understanding of the role of collaterals in | 1239 VISHNI RAVINDRAN et Al.

Prognostic capacity of hyperdense middle cerebral artery sign in anterior circulation acute ischaemic stroke patients receiving reperfusion therapy: a systematic review and meta-analysis

“…Future research should be directed on the combined use of HMCAS with other baseline characteristics or biomarkers. For example, other imaging biomarker considerations, such as arterial collateral status are important in determining the prognosis of AIS patient [ 36 – 39 ]. Although, HMCAS might not be the initial preference in predicting clinical outcome in the tertiary care settings, it may be relatively easy to appreciate in an emergency setting and could reduce the time and complexity of acute stroke workflow [ 5 , 22 ].…”

“…Despite the emerging role of HMCAS, its prognostic role in clinical settings, in settings of reperfusion therapy, needs further consideration. Indeed, the clot composition (such as the degree of clot density, relative composition of red blood cells (RBCs) [ 9 ]) in addition to other factors, such as time to reperfusion [ 10 ], baseline stroke severity [ 11 ], collateral status [ 12 , 13 ], etc., are associated with the efficacy of the EVT [ 14 , 15 ]. This study sought to investigate the association of HMCAS with clinical outcomes and its prognostic capacity in anterior circulation AIS patients receiving reperfusion therapy by performing a systematic review and meta-analysis.…”

CTP‐guided reperfusion therapy in acute ischemic stroke: a meta‐analysis

“…4 NCCT allows clinicians to exclude intracerebral hemorrhage and select patients for intravenous thrombolysis (IVT) with a tissue plasminogen activator (tPA) within 4.5 hours. [4][5][6] Subsequent CTA imaging allows confirmation of large-vessel occlusion, evaluation of the patency of cerebral vasculature, and the assessment of the collateral status, 7 thus is important in guiding patient selection for endovascular thrombectomy (EVT). [8][9][10][11][12] Advanced neuroimaging modalities such as computed tomographic perfusion (CTP) imaging provide additional information regarding baseline tissue perfusion characteristics including the irreversibly infarcted core and the potentially salvageable tissue or ischemic penumbra.…”

“…NCCT allows clinicians to exclude intracerebral hemorrhage and select patients for intravenous thrombolysis (IVT) with a tissue plasminogen activator (tPA) within 4.5 hours 4‐6 . Subsequent CTA imaging allows confirmation of large‐vessel occlusion, evaluation of the patency of cerebral vasculature, and the assessment of the collateral status, 7 thus is important in guiding patient selection for endovascular thrombectomy (EVT) 8‐12 …”

“…CTP derived perfusion parameters, combined with the information on baseline arterial and venous collateral status determined on CTA, [32][33][34] have the potential to improve imaging-based based decision-making. 7 However, special considerations may apply to prevent the risk of infection in the milieu of Coronavirus Disease (COVID-19). [35][36][37] This study has various limitations.…”