Endovascular revascularization techniques are increasingly used to treat arterial occlusions in patients with acute ischemic stroke. To monitor and communicate treatment results, a valid, reproducible, and clinically relevant, yet easy to use grading scheme of arterial recanalization and tissue reperfusion for digital subtraction angiography is needed. An ideal scoring system would consider the target arterial lesion, the perfusion deficit, and the collateral status before treatment and measure recanalization, reperfusion, early venous shunting, vasospasm, as well as distal embolization after flow restoration. Currently, a variety of different flow restoration scales are in use, including the Thrombolysis in Myocardial Infarction scoring system, the Thrombolysis in Cerebral Infarction score, and the Arterial Occlusive Lesion score, which describe the local recanalization result. These scores are not used homogeneously throughout the literature, are often modified and not fully documented, which make them inept to compare treatment effects across studies. In addition, none of these scores cover all of the above-mentioned aspects, nor are they able to describe satisfactorily all relevant angiographic findings, and data on their reliability and predictive power regarding clinical outcome are sparse. We aimed to review and illustrate the different revascularization scales, discuss their advantages and limitations as well as the available data regarding standardization, reliability testing, and outcome prediction. In addition, we give examples for the use of the scales and show potential pitfalls.
We declare that all human studies have been approved by our institutional Ethics Committee and have therefore been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. Due to the retrospective nature of this anonymized patient image and data study, patient consent was waived.
Conflict of interest
JG received personal fees and non-financial support from Penumbra Inc., non-financial support from Covidien and MicroVention Deutschland GmbH and personal fees from DePuy Codman and J&J Medical GmbH, all unrelated to the submitted work. YIM received personal fees from Synarc during the study. RVK received personal fees from Synarc, Lundbeck, Penumbra and Covidien, all unrelated to the submitted work.
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