Late Window Imaging Selection for Endovascular Therapy of Large Vessel Occlusion Stroke: An International Survey
Authors: Nguyen Thanh N. , Klein Piers , Berberich Anne , Nagel Simon , Abdalkader Mohamad , Herning Ana , Chen Yimin , Huo Xiaochuan , Miao Zhongrong , Sheth Sunil A. , Qureshi Muhammad M. , Siegler James E. , Sacco Simona , Strbian Daniel , Fischer Urs , Yamagami Hiroshi , Kristoffersen Espen Saxhaug , Puetz Volker , Schonewille Wouter , Tsivgoulis Georgios , Drumm Brian , Banerjee Soma , Demeestere Jelle , Alemseged Fana , Sandset Else C. , Arsovska Anita Ante , Krishnan Kailash , Dhillon Permesh S. , Corredor Angel , Rivera Rodrigo , Sedova Petra , Mikulik Robert , Masoud Hesham E. , Martins Sheila O. , Nguyen Thang Huy , Ton Mai Duy , Liu Xinfeng , Zhu Yuyou , Li Fengli , Zaidi Wan Asyraf Wan , Zedde Marialuisa , Yaghi Shadi , Miao Jian , Inoa Violiza , Zhang Liqun , Masiliūnas Rytis , Slade Peter , Matuja Sarah Shali , Marto João Pedro , Michel Patrik , Fiehler Jens , Thomalla Götz , Castonguay Alicia C. , Mokin Maxim , Parsons Mark , Campbell Bruce C.V. , Yavagal Dileep R. , Dippel Diederik , Goyal Mayank , Zaidat Osama O. , Jovin Tudor G. , Hu Wei , Nogueira Raul G. , Qiu Zhongming , Raymond Jean , Saposnik Gustavo 
Published: December 2022

Background
Current stroke guidelines recommend advanced imaging (computed tomography [CT] perfusion or magnetic resonance imaging) prior to endovascular therapy (EVT) in patients with late presentation of large vessel occlusion. Adherence to guidelines may be constrained by resources or timely access to imaging. We sought to understand the factors which influence late window imaging selection for EVT candidates with large vessel occlusion.

Methods
We conducted an international survey from January to May 2022. The questions aimed to identify advanced imaging and treatment decisions based on access to imaging, time delays, and simulated patient scenarios.

Results

There were 3000 invited participants and 1506 respondents, the majority (89.6%) from comprehensive stroke centers in high‐income countries. Neurointerventionalists comprised 31.8% and noninterventionalists 68.2% of respondents. Overall, 70.7% reported routine use of advanced imaging for late EVT selection, and 63.6% reported its usage in every case. There was greater availability of advanced imaging in comprehensive stroke centers versus primary stroke centers (67.0% versus 33.7%;
P
<0.0001), and high‐ versus low‐middle income countries (70.5% versus 44.5%;
P
<0.0001). When presented with a late window patient, 41.6% would complete CT perfusion or magnetic resonance imaging prior to EVT, 25.4% would perform CT perfusion or magnetic resonance imaging prior to IVT and EVT, and 25.8% would refer to EVT without advanced imaging. If advanced imaging was not readily available, 70.1% would refer a patient to EVT based on CT in the late window. Additional time delay within 20 minutes to obtain advanced imaging was considered acceptable in 77.7% of respondents.

Conclusion
Current guidelines for imaging late window EVT candidates are inconsistent with imaging decisions by physicians. Most respondents consider an imaging delay of greater than 20 minutes unacceptable. Access to advanced imaging was greater in comprehensive stroke centers and high‐income countries. In the case of limited access most respondents would consider EVT based on CT only.