Thrombus composition and distribution patterns by thrombus volume in acute ischemic stroke

Jaeseob Yun¹Jae Wook Jung²Kwang Hyun Kim³HYO SUK NAM^2,4JoonNyung Heo²Hyungwoo Lee²Byung Moon Kim⁵Dong Joon Kim⁵Minyoul Baik⁶Joonsang Yoo⁶Jinkwon Kim⁶Hyungjong Park¹Sung-Il Sohn¹Jeongho Hong¹Tae-Jin Song⁷Yoonkyung Chang⁸Jung Hwa Seo⁹Gyu Sik Kim¹⁰Kwon-Duk Seo¹¹Seong Hwan Ahn¹²Jang-Hyun Baek¹³Han-Jin Cho¹⁴Jin Kyo Choi¹⁵Yo Han Jung¹⁶Bang-Hoon Cho¹⁷Il Kwon⁴Ji Hoe Heo¹⁸Young Dae Kim^2,4*

• ¹Department of Neurology, Keimyung University School of Medicine, Daegu, Republic of Korea
• ²Department of Neurology, Yonsei University College of Medicine, Seoul, Republic of Korea
• ³Kyungpook National University Chilgok Hospital, School of Medicine, Daegu, Republic of Korea
• ⁴Integrative Research Institute for Cerebrovascular and Cardiovascular Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea
• ⁵Department of Radiology, Yonsei University College of Medicine, Seoul, Republic of Korea
• ⁶Department of Neurology, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin, Republic of Korea
• ⁷Department of Neurology, Seoul Hospital, Ewha Woman’s University, College of Medicine, Seoul, Republic of Korea
• ⁸Department of Neurology, Mokdong Hospital, Ewha Womans University College of Medicine, Seoul, Republic of Korea
• ⁹Department of Neurology, Busan Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea
• ¹⁰Department of Neurology, National Health Insurance Service Ilsan Hospital, Goyang, Republic of Korea
• ¹¹Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
• ¹²Department of Neurology, Chosun University School of Medicine, Gwangju, Republic of Korea
• ¹³Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
• ¹⁴Department of Neurology, Pusan National University School of Medicine, Seoul, Republic of Korea
• ¹⁵Department of Neurology, Seoul Medical Center, Seoul, Republic of Korea
• ¹⁶Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
• ¹⁷Department of Neurology, Korea University Anam Hospital and College of Medicine, Seoul, Republic of Korea
• ¹⁸CHA Bundang Medical center, Seongnam, Republic of Korea

Background Thrombus burden considerably impacts ischemic stroke presentation and outcomes. However, the relationship between thrombus histology and volume has not been studied well. We investigated whether ischemic stroke thrombus composition and spatial distribution patterns differed with thrombus volume. Methods We enrolled patients with thrombi undergoing endovascular therapy (EVT) between July 2017 and July 2023. Thrombus volume on thin-section non-contrast computed tomography was measured using three-dimensional software. Immunohistochemistry analysis included fibrin, red blood cells (RBCs), and platelets. Thrombi were classified based on the overall distribution pattern of the components: layered, erythrocytic, mixed, and diffuse platelet. We analyzed the association between thrombus volume, histopathology, distribution patterns, and clinical/radiologic outcomes. Results Among 210 patients, the median (interquartile range) thrombus volume was 43.7 (23.5, 74.5) mm3. Increased thrombus volume correlated with high RBC proportion (r = 0.359, P < 0.001) and low platelet proportion (r = -0.194, P = 0.005). Thrombus volume was independently related to the RBC proportion (β 1.00, standard error [SE] 0.27, P < 0.001), mixed (β 21.04, SE 10.10, P = 0.038), and erythrocytic pattern (β -29.78, SE 11.54, P = 0.011). The number of fragmented thrombi during the procedure was independently related to thrombus volume (ß 0.006, SE 0.002, P = 0.006) and RBC proportions (ß 0.18, SE 0.009, P = 0.049). Conclusion Large thrombi had increased RBC proportions and a mixed pattern. RBC incorporation significantly contributes to the volumetric growth of thrombi and their fragmentation susceptibility. These findings may provide additional clue for tailoring EVT strategies.