Optimizing thrombectomy and the patient in acute ischemic stroke

Background: Endovascular stroke treatment offers acute stroke patient a high recanalization rate with a good chance of regaining independent functional outcomes. However up to half of such patients continue to have poor functional outcomes, and the aim of the project was to find ways to improve the rate of good outcomes. We studied new radiological signs, patient subgroups and imaging techniques to stratify patients for treatment, as well as looked at the efficacy of new thrombectomy devices.

Methods: Paper I is a retrospective study on the prognostic capability of asymmetry of the internal cerebral veins (ICV) seen on the multiphasic CT-angiogram before thrombectomy. Paper II is a prospective pilot on extending the window of the Ct-angiogram during acute stroke to include the cardiac chambers to detect cardioembolic sources. Paper III is a meta-analysis comparing stentretriever alone thrombectomy against a combined technique and Paper IV is an animal study looking at MRI perfusion imaging in rats with a stroke induced and then administered different doses of carbon dioxide (CO2).

Results: Paper I showed that ICV asymmetry is associated with poor functional outcomes but progression of ICV asymmetry was associated with reduced mortality. The prognostic ability of this radiological sign was additive when added to the clinical NIHSS to predict functional outcomes. Paper II showed that in 20 pilot patients, it was feasible to pick up 2 cardioembolic sources of strokes and 1 dissection by increasing the length of the z-axis of the CT-angiogram to include the heart, without an increased contrast dose and without gating it to the ECG. Paper III showed that in a meta-analysis of 2091 patients, there was no difference in outcomes between stentretriever alone and a combined technique, although there was less rescue treatments in the combined technique. Paper IV suggested that inhaled CO2 may reduce the size of hypoperfused tissue in an acute stroke in rats and is a potential modality for treatment.

Conclusions: Endovascular thrombectomy outcomes can potentially be improved by a novel acute stroke imaging techniques looking at the heart and the internal cerebral veins, novel treatment modalities with CO2 and streamlining thrombectomy techniques.

List of scientific papers

I. Internal Cerebral Vein Asymmetry on Multiphasic Computed Tomography is an Independent Predictor of Poor Functional Outcome in Acute Ischemic Stroke Patients Undergoing Endovascular Thrombectomy. May Zin Myint, Leonard Leong-Litt Yeo, Benjamin YQ Tan, Ei Zune The, Ching-Hui Sia, Hock luen Teoh, Vijay K Sharma, Bernard Chan, Aftab Ahmad, Prakash Paliwal, Anil Gopinathan, Yang Cunli, Tommy Andersson, Fabian Arnberg, Staffan Holmin. J Neurointerv Surg. 2022 Jul;14(7):683-687.
https://doi.org/10.1136/neurintsurg-2021-017684

II. Nongated Cardiac Computed Tomographic Angiograms for Detection of Embolic Sources in Acute Ischemic Stroke. Yeo LLL, Holmin S, Andersson T, Lundström E, Gopinathan A, Lim EL, Leong BSH, Kuan WS, Ting E, Tan BYQ, Eide SE, Tay ELK. Stroke. 2017 May;48(5):1256-1261.
https://doi.org/10.1161/STROKEAHA.117.016903

III. Combined Balloon guide catheter, Aspiration catheter and Stentretriver technique versus balloon guide catheter and stentretriver alone technique: A Systematic Review and Meta-analysis.Yao Neng Teo, Ching-Hui Sia, Benjamin YQ Tan, Jing Mingxue, Bernard Chan, Vijay Kumar Sharma, Andrew Makmur, Anil Gopinathan, Cunli Yang, Stanley EK Loh, Sheldon NJ Keat, Shao Jin Ong, Teoh Hock Luen, Rahul Rathakrishnan, Tommy Andersson, Fabian Arnberg, Vamsi Gontu, Lee Tsong-Hai, Volker Maus, Lucas Meyer, Pervinder Bhogal, Oliver Spooner, Tony YW Li, Rodney YH Soh, Leonard LL Yeo. J Neurointerv Surg. 2022 Jan 31;neurintsurg-2021-018406.
https://doi.org/10.1136/neurintsurg-2021-018406

IV. The role of carbon dioxide in the rat acute stroke penumbra. A potential new modality for stroke treatment. Leonard LL Yeo, Fabian Arnberg, Arvin Chireh, Vijay K Sharma, Benjamin Tan, Vamsi Gontu, Philip Little, Staffan Holmin. Front. Digit. Health. 2022.
https://doi.org/10.3389/fdgth.2021.824334